Organotin-Substituted [13]-Crown-4 Ethers: Ditopic Receptors for

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Organometallics 2010, 29, 5456–5471 DOI: 10.1021/om100409v

Organotin-Substituted [13]-Crown-4 Ethers: Ditopic Receptors for Lithium and Cesium Halides† Alain C. Tagne Kuate, Ljuba Iovkova, Wolf Hiller, Markus Sch€ urmann, and Klaus Jurkschat* Lehrstuhl f€ ur Anorganische Chemie II, Technische Universit€ at Dortmund, D-44221 Dortmund, Germany. Received May 2, 2010

The synthesis of the organotin- and the bis(organostannyl)methane-substituted crown ethers Ph(3-n)XnSnCH2-[13]-crown-4 (1, n = 0; 2, n = 1, X = I; 3, n = 1, X = Cl; 4, n = 1, X = F; 5, n = 2, X = I; 6, n = 3, X = I; 8, n = 3, X = Cl; 9, n = 2, X = Cl) and Ph(3-n)XnSnCH2Sn(X)nPh(2-n)CH2-[13]-crown-4 (10, n = 0; 11, n = 1, X = I; 12, n = 2, X = I; 13, n = 1, X = F; 14, n=2, X = Cl) as well as of the ditopic complexes 8 3 LiCl 3 H2O and Ph2(SCN)SnCH2-[13]-crown-4 3 LiSCN (15 3 LiSCN) are reported. These compounds were characterized by elemental analyses, by 1H, 13C, 19 F, and 119Sn NMR spectroscopy, electrospray mass spectrometry, and in the case of 2 and 4 also by 119 Sn MAS NMR spectroscopy. Single-crystal X-ray diffraction analyses reveal distorted tetrahedral configurations for the tin atoms in compounds 1, 11 (Sn2), and 12 (Sn2), whereas intramolecular OfSn interactions (Sn-O = 2.416(2) (6) to 2.471(3) (11, Sn1) A˚) characterize the molecular structures of compounds 2, 6, 9, and 11 (Sn1), in which the tin atoms display distorted trigonalbipyramidal configurations. The spatial arrangement of the Sn(1) atom in compound 12 is distorted octahedral (Sn-O = 2.497(3) and 2.649(3) A˚), while the tin atom in compound 8 3 LiCl 3 H2O is also trigonal bipyramidal. In the latter compound there are both intra- and intermolecular O-H 3 3 3 Cl hydrogen bridges. Moreover, the ditopic complexation of cesium fluoride, CsF, lithium iodide, LiI, and lithium chloride, LiCl, by compounds 4 and 6, respectively, as well as of LiCl by compounds 3 and 14, is unambiguously proved by NMR spectroscopy and electrospray mass spectrometry. Introduction Compounds that incorporate in their framework individual anion- and cation-binding sites continue to attract † Part of the Dietmar Seyferth Festschrift. Dedicated in great admiration and gratitude to Prof. Dr. h. c. mult. Dietmar Seyferth for his outstanding and sustainable service he has made to the worldwide community of organometallic chemists and beyond. *To whom correspondence should be addressed. E-mail: klaus. [email protected]. (1) He, X.; Yam, V. W.-W., Inorg. Chem. 2010, in press, DOI: 10.1021/ ic9021068. (2) van der Wijst, T.; Guerra, C. F.; Swart, M.; Bickelhaupt, F. M.; Lippert, B. Angew. Chem., Int. Ed. 2009, 48, 3285. (3) Senthilvelan, A.; Ho, I.-T.; Chang, K.-C.; Lee, G.-H.; Liu, Y.-H.; Chung, W.-S. Chem.;Eur. J. 2009, 15, 6152. (4) Lankshear, M. D.; Dudley, I. M.; Chan, K.-M.; Cowley, A. R.; Santos, S. M.; Felix, V.; Beer, P. D. Chem.;Eur. J. 2008, 14, 2248. (5) Miyaji, H.; Kim, D.-S.; Chang, B.-Y.; Park, S.-M.; Ahn, K. H. Chem. Commun. 2008, 753. (6) Le Gac, S.; Jabin, I. Chem.;Eur. J. 2008, 14, 548. (7) Katayev, E. A.; Melfi, P. J.; Sessler, J. L. In Supramolecular Chemistry: Strategies for Macrocyclic Synthesis; Diedrich, F.; Stang, P. Tykwinski, R. R., Eds.; Wiley-VCH: Weinheim, 2008; p 315. (8) Cametti, M.; Nissinen, M.; Cort, A. D.; Mandolini, L.; Rissanen, K. J. Am. Chem. Soc. 2007, 129, 3641. (9) Lankshear, M. D.; Dudley, I. M.; Chan, K.-M.; Beer, P. D. New J. Chem. 2007, 31, 684. (10) Katsuhiko, A.; Toyoki, K. In Supramolecular ChemistryFundamentals and Applications: The Chemistry of Molecular Recognition-Host Molecules and Guest Molecules; Iwanami, S., Ed.; SpringerVerlag: Berlin, 2006; p 7. (11) Smith, B. D. In Macrycyclic Chemistry: Current Trends and Future Perspectives; Gloe, K., Ed.; Springer: The Netherlands, 2005; p 137.

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considerable attention in the field of supramolecular hostguest chemistry.1-18 The so-called ditopic receptors are multifunctional ligands that complex both an anion and a cation as a contact ion pair or solvent- or spatially-separated ion pair. The growing interest in such compounds is stimulated by the shortcomings of ion-pairing effects involved in the recognition processes of simple anion or cation receptors. Indeed, recent reports showed the strong dependence of the countercation on the complexation affinities of anion receptors.19-22 Furthermore, ditopic receptors are of potential (12) Itsikson, N. A.; Zyranov, G. V.; Chupakhin, O. N.; Matern, A. I. Russ. Chem. Rev. 2005, 74, 747. (13) Amendola, V.; Esteban-G omez, D.; Fabbrizzi, L.; Licchelli, M.; Monzani, E.; Sancen on, F. Inorg. Chem. 2005, 44, 8690. (14) Custelcean, R.; Delmau, L. H.; Moyer, B. A.; Sessler, J. L.; Cho, W.-S.; Gross, D.; Bates, G. W.; Brooks, S. J.; Light, M. E.; Gale, P. A. Angew. Chem., Int. Ed. 2005, 44, 2537. (15) Mahoney, J. M.; Stucker, K. A.; Jiang, H.; Carmichael, I.; Brinkman, N. R.; Beatty, A. M.; Noll, B. C.; Smith, B. D. J. Am. Chem. Soc. 2005, 127, 2922. (16) Tobey, S. L; Anslyn, E. V. J. Am. Chem. Soc. 2003, 125, 14807. (17) Kim, Y.-H.; Hong, J.-I. Chem. Commun. 2002, 512. (18) Kirkovits, G. J.; Shriver, J. A.; Gale, P. A.; Sessler, J. L. J. Inclusion Phenom. Macrocyclic Chem. 2001, 41, 69. (19) Sessler, J. L.; Gross, D. E.; Cho, W.-W.; Lynch, V. M.; Schmidtchen, F. P.; Bates, G. W.; Light, M. E.; Gale, P. A. J. Am. Chem. Soc. 2006, 128, 12281. (20) Pajewski, R.; Ferdani, R.; Pajewska, J.; Li, R.; Gokel, G. W. J. Am. Chem. Soc. 2005, 127, 18281. (21) Shi, X.; Mullaugh, K. M.; Fettinger, J. C.; Jiang, Y.; Hofstadler, S. A.; Davis, J. T. J. Am. Chem. Soc. 2003, 125, 10830. (22) Levitskaia, T. G.; Maya, L.; Van Berkel, G. J.; Moyer, B. A. Inorg. Chem. 2007, 46, 261. r 2010 American Chemical Society

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interest because they can easily solubilize hydrophilic salts in non-polar solvents and, notably, extract salts from an aqueous phase and transport them through an organic membrane, whereas the extraction and transport abilities of simple anion or cation receptors are drastically affected by the counterion.23-26 In spite of these applications, only a limited number of hosts has been reported that incorporate neutral Lewis acidic organometallic/organoelement moieties,8,17,27,28 while several ditopic receptors involving H-bond-donating groups or the electrostatic attraction of metal cations as anion-binding sites are known.1-6,13,15,29,30 For instance, Sessler recently designed ditopic compounds based on a crown ether and calixpyrole that are able to bind cesium fluoride as a solventseparated ion pair.31 On the other hand, Smith reported ditopic receptors containing amide moieties capable of binding and extracting lithium chloride as a water-separated ion pair.32 For ditopic hosts using Lewis acidic metal cations, we are aware of only two closely related examples of CsF and LiCl receptors. Thus, an uranyl-salophen complex containing aromatic pendants33,34 binds CsF as a contact ion pair, whereas an organoaluminum-substituted crown ether35 complexes LiCl as a separated ion pair in the solid state. However, the radioactivity of uranyl-containing compounds and the instability of the latter system under non-inert conditions limit potential applications. Recently, we reported easy-to-synthesize and robust organotin- and bis(organostannyl)methane-substituted crown-5 and crown-6 compounds of types A, B, C, and D (Chart 1) and demonstrated by means of multinuclear NMR spectroscopy, electrospray mass sprectrometry, and X-ray diffraction analysis as well as extraction and transport experiments their ability to ditopically complex sodium and potassium halides as solvent-separated or spatially separated ion pairs.36-40 (23) Wintergerst, M. P.; Levitskaia, T. G.; Moyer, B. A.; Sessler, J. L.; Delmau, L. H. J. Am. Chem. Soc. 2008, 130, 4129. (24) Costero, A. M.; Rodrı´ guez-Mu~ nit, G. M.; Gil, S.; Peransi, S.; Gavi~ na, P. Tetrahedron 2008, 64, 110. (25) Aydogan, A.; Coady, D. J.; Kim, S. K.; Akar, A.; Bielwaski, C. W.; Marquez, M.; Sessler, J. L. Angew. Chem., Int. Ed. 2008, 47, 9648. (26) Mahoney, J. M.; Nawaratna, G. U.; Beatty, A. M.; Duggan, P. J.; Smith, B. D. Inorg. Chem. 2004, 43, 5902. (27) Liu, H.; Shao, X.-B.; Jia, M.-X.; Li, Z.-T.; Chen, G.-J. Tetrahedron 2005, 61, 8095. (28) Reetz, M. T.; Niemeyer, C. M.; Harms, K. Angew. Chem., Int. Ed. Engl. 1991, 30, 1474. (29) Beer, P. D.; Dent, S. W. Chem. Commun. 1998, 825. (30) Rudkevich, D. M.; Mercer-Chalmers, J. D.; Verboom, W.; Ungaro, R.; De Jong, F.; Reinhoudt, D. N. J. Am. Chem. Soc. 1995, 117, 6124. (31) Sessler, J. L.; Kim, S. K.; Gross, D. E.; Lee, C.-H.; Kim, J. S.; Lynch, V. M. J. Am. Chem. Soc. 2008, 130, 13162. (32) Mahoney, J. M.; Beatty, A. M.; Smith, B. C. Inorg. Chem. 2004, 43, 7617. (33) Cametti, M.; Nissinen, M.; Cort, A. D.; Rissanen, K.; Mandolini, L. Inorg. Chem. 2006, 45, 6099. (34) Cametti, M.; Nissenen, M.; Cort, A. D.; Mandolini, L.; Rissanen, K. J. Am. Chem. Soc. 2005, 127, 3831. (35) Reetz, M. T.; Johnson, B. M.; Harms, K. Tetrahedron Lett. 1994, 35, 2525. (36) Reeske, G.; Sch€ urmann, M.; Costisella, B.; Jurkschat, K. Organometallics 2007, 26, 4170. (37) Reeske, G.; Bradtm€ oller, G.; Sch€ urmann, M.; Jurkschat, K. Chem.;Eur. J. 2007, 13, 10239. (38) Reeske, G.; Sch€ urmann, M.; Jurkschat, K. Dalton Trans. 2008, 3398. (39) Tagne Kuate, A. C.; Reeske, G.; Sch€ urmann, M.; Costisella, B.; Jurkschat, K. Organometallics 2008, 27, 5577. (40) Tagne Kuate, A. C. Ph.D. Thesis, Technische Universit€at Dortmund, 2009.

Organometallics, Vol. 29, No. 21, 2010

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Chart 1

In continuation of this work, we have prepared and structurally characterized the corresponding organotin- and bis(organostannyl)methane-substituted [13]-crown-4 compounds of types E and F (Chart 1). We show here that the fluoridotriorganotin-substituted [13]-crown-4 ether (type E) forms a 1:1 ditopic complex with CsF in CD3CN/CDCl3 (2:1). Moreover, the bis(dichloridodiorganostannyl)methane-, the chloridodiphenyltin-, and the trichloridoorganotin-substituted [13]-crown-4 ethers (types F and E), respectively, are capable of ditopically complexing LiCl in CD3CN. The latter complex has been isolated in the solid state and shows the LiCl salt being complexed as a water-separated ion pair.

Results and Discussion Synthetic Aspects and Molecular Structures in the Solid State. The synthesis of the organotin-substituted [13]-crown4 derivatives was carried out according to the procedure reported for the synthesis of the analogous organotin-substituted [16]-crown-536 and [19]-crown-6 ethers.39 Thus, the reaction of 13-methylene-1,4,7,10-tetraoxacyclotridecane41 with triphenyltin hydride provided the tetraorganotin-substituted crown ether 1 in good yield (eq 1).

Treatment of the tetraorganotin compound 1 with one molar equivalent of iodine provided the iodidotriorganotinsubstituted crown ether 2 in almost quantitative yield. Compound 2 was reacted with an excess of silver chloride, AgCl, in acetonitrile over a period of 14 days in the dark to give quantitatively the chloridotriorganotin-substituted crown ether 3. Compound 2 was also converted to its fluorido-substituted derivative 4 by reaction with an excess of sodium fluoride, NaF, in the biphasic mixture CH2Cl2/H2O for two days at room temperature (Scheme 1). The reaction of the tetraorganotin- and the iodidotriorganotin-substituted crown ethers 1 and 2, respectively, with two molar equivalents of iodine afforded the diiodidodiorganotin- and the triiodidomonoorganotin-substituted crown ethers 5 and 6 in almost quantitative yield (Scheme 1). (41) Czech, B. P.; Babb, D. A.; Son, B.; Bartsch, R. A. J. Org. Chem. 1984, 49, 4805.

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Tagne Kuate et al. Scheme 1

Figure 1. Molecular structure of 1 showing 30% probability displacement ellipsoids and the crystallographic numbering scheme.

The treatment of 1 with gaseous HCl in CH2Cl2 at room temperature for six hours provided a mixture of the partially hydrolyzed dichloridohydoxymonorganotin-, the trichloridomonoorganotin-, and the dichloridodiorganotinsubstituted crown ethers 742 (47%), 8 (48%), and 9 (5%). The compounds 8 and 9 were removed from the mixture by recrystallization from ethanol and diethyl ether (Scheme 1). The compounds 1-6, 8, and 9 were isolated as colorless (1-4, 8, 9) or yellow (5, 6) crystalline solids that are soluble in dichloromethane, chloroform, acetone, THF, acetonitrile, and, for 2-4, methanol. The molecular structures of the tetraorganotin compound 1 and the iodidoorganotin-substituted crown ethers 2, 5, and 6 are shown in Figures 1-4. Selected bond distances and bond angles are listed in Tables 1 and 2. The dichloridosubstituted crown ether 9 is isostructural with the diodido (42) Compound 7 is a hydroxido-bridged dimer that shows a 119Sn chemical shift of -450 ppm. It will be presented together with other dihalogenido(di-μ-hydroxy)organostannoxanes in a forthcoming paper.


derivative 5. Its molecular structure is given in the Supporting Information, but the geometric parameters are given in Tables 1 and 2 as well. In compound 1 the Sn(1) atom adopts a monocapped tetrahedral configuration. The O(1) atom approaches the Sn(1) atom via the tetrahedral face defined by C(1), C(13), and C(21). The Sn-O distance of 2.976(16) A˚ is shorter than the sum of the van der Waals radii43 of tin (2.20 A˚) and oxygen (1.50 A˚). The distance is similar to the corresponding distance found in Ph3SnCH2-[19]-crown-6 (2.9820(13) and 2.9963(14) A˚),39 but significantly shorter than the Sn-O distance in Ph3SnCH2-[16]-crown-5 (3.206(1) A˚).36 The Sn(1) atom lies 0.5310(1) A˚ out of the trigonal plane defined by C(1), C(13), and C(21) in the direction of C(7). The crown ether oxygen atoms O(1) and O(2) are above while O(3) and O(4) are below the equatorial plane formed by these atoms. The tin atom in compound 2 is pentacoordinated and exhibits a distorted trigonal-bipyramidal configuration (geoP metrical goodness44 Δ (θ) 62.07°) with C(1), C(7), and (43) Bondi, A. J. Phys. Chem. 1964, 68, 441.

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C(21) occupying the equatorial and O(1) and I(1) occupying the axial positions. The distortion is manifested by the O(1)-Sn(1)-I(1) angle of 171.68(5)°, which deviates by 8.32° from the ideal 180°. The Sn(1) atom is displaced by 0.282(1) A˚ from the trigonal plane in the direction of I(1). The Sn(1)-O(1) distance in compound 2 of 2.467(2) A˚ is the shortest as compared with the intramolecularly coordinated iodidotriorganotin-substituted crown ethers Ph2ISnCH2[16]-crown-5 (2.554(2) A˚)36 and Ph2ISnCH2-[19]-crown-6 (2.610(2) A˚).39 This difference shows that the OfSn interaction becomes stronger when the cavity of the crown ether ring decreases and is very likely the result of the small ring being more rigid than the bigger ones. Moreover, and as observed for the analogous Ph2ISnCH2-[16]-crown-536 and Ph2ISnCH2-[19]-crown-6,39 the OfSn interaction influences the Sn(1)-I(1) (2.8249(12) A˚) bond, which is lengthened in (44) Kolb, U.; Dr€ ager, M.; Jousseaume, B. Organometallics 1991, 10, 2737.


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comparison with the corresponding bond in tetracoordinated triorganotin iodides45,46 and exceeds the sum of the covalent radii of Sn (1.40 A˚) and I (1.33 A˚).47 The tin atoms in compounds 5, 6, and 9 are pentacoordinated, and each exhibits a distorted trigonal-bipyramiP dal configuration (geometrical goodness44 Δ (θ) 61.3° (5), 54.4° (6), 65.0° (9)) with C(1), C(21), and I(1) (5), C(21), I(2), and I(3) (6), and C(1), C(21), and Cl(2) (9) occupying the equatorial and O(1) and I(2) (5), O(1) and I(1) (6), and O(1) and Cl(1) (9) occupying the axial positions. The tin atoms are displaced by 0.308(3) (5), 0.3764(2) (6), and 0.2551(1) A˚ (9) from the corresponding trigonal plane in the direction of I(2), I(1), and Cl(1), respectively. Although they have the same substituent pattern around the tin atom, the configuration adopted by the tin atom in compounds 5, 6, and 9 contrasts well with that observed for the corresponding dichloridodiorganotin- and triiodidomonoorganotinsubstituted crown ethers PhCl2SnCH2-[16]-crown-536 and I3SnCH2-[16]-crown-5.48 Indeed, the tin atoms in the two latters are intramolecularly coordinated by two oxygen atoms of the crown ether ring, and each adopts a distorted octahedral configuration. The coordination of only one oxygen atom from the crown ether ring to the tin atom in 5, 6, and 9 reflects the high rigidity of the [13]crown-4 moiety. The intramolecular Sn(1)-O(1) distances of 2.465(3) (5), 2.416(2) (6), and 2.4177(13) A˚ (9) are almost equal. They are shorter than the corresponding Sn-O distances found in 1 (see above), PhCl2SnCH2-[16]-crown-5 (2.522(1), 2.4793(9) A˚),36 PhX2SnCH2-[19]-crown-6 (2.525(3), 2.554(3) A˚; X = I; 2.516(3), 2.506(3) A˚, X = Br),40 and close to those in I3SnCH2[16]-cronw-5 (2.432(3), 2.470(3) A˚).48 The reaction of the iodidotriorganotin-substituted crown ether 2 with triphenylstannylmethylmagnesium bromide, Ph3SnCH2MgBr, in tetrahydrofuran, at reflux, provided the bis(triorganostannyl)methane-substituted crown ether 10 in good yield as a colorless oil that is soluble in most organic solvents. Its treatment with two and four molar equivalents of iodine in CH2Cl2 at 0 °C gave quantitatively the bis(iodidodiorganostannyl)- and bis(diiodidoorganostannyl)methane-substituted crown ethers 11 and 12, respectively (Scheme 2). The reaction of compound 11 with an excess of potassium fluoride, KF, in CH2Cl2/H2O at room temperature gave the bis(fluoridotriorganostannyl)methane-substituted crown ether 13 in good yield, while the reaction of 12 with an excess of silver chloride, AgCl, in CH3CN for 14 days at room temperature and in the dark afforded the bis(dichlorido-organostannyl)methane-substituted crown ether 14 in moderate yield (Scheme 2). Compounds 11-14 are colorless (13, 14) to yellow (11) and red (12) crystalline solids that are soluble in CH2Cl2, CHCl3, and CH3CN and partially (11, 14) in methanol but insoluble in diethyl ether. The molecular structures of compounds 11 and 12 are shown in Figures 5 and 6; selected bond distances and bond angles are listed in Tables 3 and 4. In both compounds 11 and 12 the Sn(2) atom exhibits a distorted tetrahedral configuration. The tetrahedral angles (45) Kayser, F.; Biesemans, F.; Delmotte, A.; Verbruggen, I.; Gielen, M.; Willem, R.; Tiekink, E. R. T. Organometallics 1994, 13, 4026. (46) Hartson, P.; Howie, A.; McQuillan, G. P.; Wardell, J. L.; Zanetti, E. Polyhedron 1991, 10, 1085. (47) Holleman, A. F.; Wiberg, E., Inorganic Chemistry; , Wiberg N., Ed.; Academic Press: London, 2001. (48) Arens, V. Diploma Thesis, Technische Universit€at Dortmund, 2008.

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Tagne Kuate et al. Scheme 2

Table 1. Selected Bond Distances (A˚) for Compounds 1, 2, 5, 6, and 9 1

2

5

6

9

X(1) = I(1)

X(1) = I(1)

X(1) = Cl(1)

X(2) = I(2)

Sn(1)-C(1) Sn(1)-C(7) Sn(1)-C(21) Sn(1)-O(1) Sn(1)-X(1) Sn(1)-X(2) Sn(1)-X(3)

X(1) = C(13)

X(1) = I(1)

X(2) = I(2)

2.136(2) 2.150(2) 2.1560(2) 2.976(2) 2.128(2)

2.151(3) 2.134(3) 2.145(3) 2.466(2) 2.8248(3)

2.137(4) 2.136(5) 2.465(3) 2.7067(5) 2.7854(5)

X(3) = I(3)

X(2) = Cl(2) 2.119(2)

2.139(3) 2.416(2) 2.7717(3) 2.6953(3) 2.6930(3)

2.123(2) 2.418(1) 2.4190(5) 2.3636(5)

Table 2. Selected Bond Angles (deg) for Compounds 1, 2, 5, 6, and 9 1

2

5

6

9

X(1) = C(13)

X(1) = I(1)

X(1) = I(1)

X(1) = I(1)

X(1) = Cl(1)

X(2) = I(2)

X(2) = I(2)

X(2) = Cl(2)

X(3) = I(3) C(1)-Sn(1)-C(7) C(1)-Sn(1)-C(21) C(1)-Sn(1)-O(1) C(1)-Sn(1)-X(1) C(1)-Sn(1)-X(2) C(7)-Sn(1)-C(21) C(7)-Sn(1)-O(1) C(7)-Sn(1)-X(1) C(21)-Sn(1)-O(1) C(21)-Sn(1)-X(1) C(21)-Sn(1)-X(2) C(21)-Sn(1)-X(3) X(1)-Sn(1)-O(1) X(1)-Sn(1)-X(2) X(1)-Sn(1)-X(3) X(2)-Sn(1)-O(1) X(2)-Sn(1)-X(3) X(3)-Sn(1)-O(1) C(23)-O(1)-Sn(1) C(24)-O(1)-Sn(1) C(22)-C(21)-Sn(1)

105.87(8) 119.71(8) 108.59(8) 102.17(8) 167.134(99) 105.27(8) 113.73(8)

111.9(1) 113.9(1) 86.97(8) 97.95(6) 129.0(1) 85.81(9) 98.46(7) 75.48(9) 96.34(7) 171.68(5)

132.3(2) 86.9(2) 111.6(1) 100.6(1)

75.0(2) 110.5(1) 96.0(1) 85.5(1) 96.52(2) 170.82(7)

120.5(1)

105.6(2) 124.7(2) 115.1(2)

are ranging between 102.29(13)° (C(47)-Sn(2)-I(2)) and 120.25(17)° (C(7)-Sn(2)-C(47)) (11) and between 102.26(10)° (C(7)-Sn(2)-I(4)) and 128.63(15)° (C(7)-Sn(2)-C(41)) (12). The distortion of the tetrahedral configuration is brought

105.2(3) 125.6(3) 114.7(3)

136.41(7) 88.34(6) 98.68(5) 109.19(5)

75.3(1) 98.25(8) 127.65(8) 117.71(8) 172.17(5) 98.30(1) 100.05(1) 82.58(5) 107.61(1) 87.03(5) 108.8(2) 128.6(2) 113.8(2)

76.20(6) 96.75(6) 109.74(5) 172.49(4) 94.95(2) 85.17(3) 106.7(1) 126.1(1) 113.8(1)

about by the I(1) atom intramolecularly approaching the Sn(2) atom at distances of 4.2614(4) (11) and 3.8914(4) A˚ (12), respectively, which are respectively shorter than the sum of the van der Waals radii of tin (2.2 A˚) and iodine (2.1 A˚). The

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Table 3. Selected Bond Distances (A˚) for Compounds 11 and 12

Sn(1)-C(21) Sn(1)-C(7) Sn(1)-C(1) Sn(1)-I(1) Sn(1)-I(2) Sn(1)-O(1) Sn(1)-O(4) Sn(2)-C(7) Sn(2)-C(41) Sn(2)-C(47) Sn(2)-I(2) Sn(2)-I(3) Sn(2)-I(4)

11

12

2.144(5) 2.152(5) 2.172(2) 2.8006(4)

2.137(4) 2.115(4)

2.471(3) 2.118(4) 2.137(5) 2.149(5) 2.7396(4)

2.7878(4) 2.7546(4) 2.497(3) 2.649(3) 2.109(4) 2.128(4) 2.6951(4) 2.7185(4)

Table 4. Selected Bond Angles (deg) for compounds 11 and 12



Sn(2)-I(2) distance of 2.7396(4) A˚ (11) is slightly longer than the Sn(2)-I(3) and Sn(2)-I(4) distances of 2.6951(4) and 2.7185(4) A˚ (12), respectively. They all fall in the range of the Sn-I distances in tetracoordinated organotin iodides.45,46 The Sn(1) atom in compound 11 shows a distorted trigonal-bipyramidal configuration (geometrical goodness44 P Δ θ 62.96°) with O(1) and I(1) occupying the axial and C(1), C(7), and C(21) occupying the equatorial positions. The Sn(1) atom is displaced by 0.2729(3) A˚ from the trigonal plane in the direction of I(1). In compound 12 the Sn(1) atom is hexacoordinated by C(7), C(21), I(1), I(2), O(1), and O(4) and exhibits a configuration that represents a real structure along the path trigonal bipyramid f octahedron. The O(4) atom approaches the Sn(1) atom via the C(7), C(21) edge with the result that the C(7)-Sn(1)-C(21) angle increases to 145.7(2)°. In fact, this O(4)fSn(1) coordination illustrates the enhanced Lewis acidity of the Sn(1) atom in compound 12 as compared with that of compound 11.

C(21)-Sn(1)-C(7) C(21)-Sn(1)-C(1) C(21)-Sn(1)-I(1) C(21)-Sn(1)-I(2) C(21)-Sn(1)-O(1) C(21)-Sn(1)-O(4) C(7)-Sn(1)-C(1) C(7)-Sn(1)-I(1) C(7)-Sn(1)-I(2) C(7)-Sn(1)-O(1) C(7)-Sn(1)-O(4) C(1)-Sn(1)-I(1) C(1)-Sn(1)-O(1) I(1)-Sn(1)-I(2) I(1)-Sn(1)-O(1) I(1)-Sn(1)-O(4) I(2)-Sn(1)-O(1) I(2)-Sn(1)-O(4) O(1)-Sn(1)-O(4) C(41)-Sn(2)-C(7) C(41)-Sn(2)-C(47) C(41)-Sn(2)-I(2) C(41)-Sn(2)-I(3) C(41)-Sn(2)-I(4) C(7)-Sn(2)-C(47) C(7)-Sn(2)-I(2) C(7)-Sn(2)-I(3) C(7)-Sn(2)-I(4) C(47)-Sn(2)-I(2) I(3)-Sn(2)-I(4) Sn(1)-C(7)-Sn(2)

11

12

125.9(2) 118.4(2) 96.4(1)

145.67(15)

74.3(2) 110.9(2) 94.1(1) 85.0(2)

99.9(1) 102.0(1) 72.13(13) 69.71(13) 102.2(1) 99.8(1) 80.8(1) 82.3(1)

101.74(8) 90.2(1) 167.47(8)

116.4(2) 105.3(2) 108.4(1)

99.90(1) 166.69(6) 95.29(7) 92.30(7) 163.82(6) 72.09(9) 128.63(15) 107.9(1) 102.8(1)

120.3(2) 102.8(1) 109.0(1) 102.3(1) 102.3(1) 116.0(2)

103.08(1) 120.8(2)

The distorted octahedral configuration at the Sn(1) atom in compound 12 contrasts well with that exhibited by the tin atom in the diiodidodiorganotin-, triiodidomonoorganotin-, and dichloridodiorganotin-substituted crown ethers 5, 6, and 9 (see above). In compound 12, both oxygen atoms intramolecularly coordinate to the tin atom at distances of 2.497(3) (Sn1-O1) and 2.649(3) A˚ (Sn1-O4). The former is similar to the corresponding one measured for compound 11 but longer than the Sn-O bonds in compounds 2, 5, 6, and 9, whereas the latter distance lies considerably above the Sn-O bond lengths measured for 2, 6, 9, 11, PhX2SnCH2-[16]crown-5 (2.522(1) and 2.4793(9) A˚, X = Cl; 2.482(2), X = I),36 I3SnCH2-[16]-crown-5 (2.432(3) and 2.470(3) A˚),48 and PhX2SnCH2-[19]-crown-6 (2.525(3) and 2.554(3) A˚, X = I; 2.516(3) and 2.506(3) A˚, X = Br).40 Due to the trans influence of the crown ether oxygen atoms, the Sn(1)-I(1) distances of 2.8006(4) (11) and 2.7878(4) A˚ (12) as well as the Sn(1)-I(2) distance of 2.7546(4) A˚ (12) exceed the sum of the covalent radii47 of

5462


Sn (1.40 A˚) and I (1.33 A˚) by 0.071, 0.058, and 0.025 A˚, respectively. Structures in Solution. The 119Sn NMR spectra in CH2Cl2/ D2O or CDCl3 of compounds 1, 10, and 11 (Sn2) show resonances at δ -107 (1), -53 (10; Sn1), -77 (10; Sn2), and -50 (11, Sn2) (according to the numbering scheme shown in Scheme 6), which are comparable to those measured for the analogous Ph3SnCH2-[16]-crown-5 (δ -110),36 Ph3SnCH2[19]-crown-6 (δ -105),39 Ph3SnCH2SnCH2-[16]-crown-5 (δ -56 and -77),37 Ph3SnCH2SnCH2-[16]-crown-5 (δ -55 and -76),39 Ph2ISnCH2Sn(I)PhCH2-[16]-crown-5 (δ -56, Ph2ISnCH2),37 and Ph2ISnCH2Sn(I)PhCH2-[19]-crown-6 (δ -55, Ph2ISnCH2).39 These chemical shifts are close to δ -90, -60, and -68 reported for Ph3SnMe,49 Ph2SnMe2,50 and Ph2MeSnI,51 respectively, and correspond to tetracoordinated tin atoms. Moreover, and as observed for the derivatives Ph2XSnCH2-[16]-crown-5 and Ph2XSnCH2-[19]-crown-6 (X = I, Cl, F),36,39 the tin atoms in the halogenidotriorganotinsubstituted crown ethers 2-4 as well as the Sn(1) tin atom in compound 11 are pentacoordinated, with the intramolecular OfSn interaction found in the solid state for 2 and 11 being retained in solution. This statement is supported by the 119 Sn chemical shifts (CDCl3) of δ -126 (2), - 87 (3), -111 [d, 1J(119Sn-19F) 2208 Hz] (4), and -87 (Sn1, 11) being highfield shifted as compared with the 119Sn chemical shifts of nonsubstituted halogenidotriorganotin compounds (see ref 36 for more details). Furthermore, the 119Sn MAS spectrum of 2 shows a chemical shift at δ -121, which is close to the chemical shift (δ -126) found in solution. However, the 119Sn MAS spectrum of compound 4 displays a triplet resonance at δ -145 [1J(119Sn-19F) 1400 Hz], which is different from the doublet resonance (δ -111) found in solution. This result suggests that the fluoridotriorganotin-substituted crown ether 4 is very likely to exist as a fluoride-bridged dimer or oligomer in the solid state. The tin atoms in compounds 5, 6, 8, 9, and 12 and the Sn(1) atom in 14 are also hypercoordinated, as evidenced by the 119 Sn chemical shifts in CDCl3 of δ -275 (5), -820 (6), -237 (8), -117 (9), -220 (Sn2, 12), -272 (Sn1, 12), and -94 (Sn1, 14) being low-frequency shifted with respect to the 119Sn chemical shifts of non-substituted compounds having similar substituent patterns about the tin atoms such as (PhI2SnCH2)2 (δ -169),52 (PhCl2Sn)2CH2 (δ þ8),53 MeSnX3 [δ -700 (X = I); þ21 (X = Cl)],54 and Me2SnX2 [δ -159 (X = I); 99 (X = Cl)].54,55 The unambiguous assignment of the signals for the tetraiodido-substituted compound 12 was achieved by a 1H-119Sn-HMQC spectrum (see Supporting Information, Figure S2) that shows cross-peaks of the 119Sn signal at δ -220 with the 1H resonances of the o-phenyl and the SnCH2Sn protons, whereas the 119Sn signal at δ -272 shows cross-peaks with both the SnCH2Sn and SnCH2 protons. (49) Davies, A. G.; Harrison, P. G.; Kennedy, J. D.; Mitchell, T. N.; Puddephat, R. J.; McFarlan, W. J. Chem. Soc. 1969, 1136. (50) Hunter, B. K.; Reeves, L. W. Can. J. Chem. 1968, 46, 1399. (51) Gielen, M.; Jurkschat, K. J. Organomet. Chem. 1984, 273, 303. (52) Jurkschat, K.; Hesselbarth, F.; Dargatz, M.; Lehmann, J.; Kleinpeter, E.; Tzschach, A.; Meunier-Piret, J. J. Organomet. Chem. 1990, 388, 259. (53) Dakternieks, D.; Jurkschat, K.; Wu, H. Organometallics 1993, 12, 2788. (54) Kennedy, J. D.; McFarlan, W.; Pyne, G. S.; Clarke, P. L.; Wardell, J. L. J. Chem. Soc., Perkin Trans. 2 1975, 1234. (55) Mitchell, T. N.; Amamria, A.; Fabisch, B.; Kuivila, H. G.; Karol, T. J.; Swami, K. J. Organomet. Chem. 1983, 259, 157.

Tagne Kuate et al.

The 119Sn NMR spectrum in CDCl3 at room temperature of compound 13 showed a broad resonance at δ -27 (ν1/2 = 1217 Hz), indicating exchange in solution that is rapid on the 119 Sn NMR time scale. No measurements at low temperature were carried out. The electrospray ionization mass spectrum, hereafter referred to as ESI-MS, of compound 13 in CH3CN showed in the positive mode a mass cluster centered at m/z 703.1 that is assigned to {Ph2FSnCH2SnPhCH2-[13]-crown4}þ. In the negative mode, a mass cluster centered at m/z 743.0 was observed that is assigned to {Ph2FSnCH2Sn(F)PhCH2-[13]-crown-4 3 F}-. The ESI-MS spectra in the positive mode of compounds 2-4 are characterized by the observation of a mass cluster centered at 477.1 that is assigned to {Ph2SnCH2-[13]-crown4}þ. In addition, for 2 there are mass clusters centered at m/z 627.1 and 668.1 that are assigned to {Ph2ISnCH2-[13]-crown4 3 Na}þ and {Ph2SnCH2-[13]-crown-4 3 Na 3 CH3CN}þ, respectively, while the ESI-MS spectrum (negative mode) of 3 showed a major mass cluster centered at m/z 547.0 that is assigned to {Ph2ClSnCH2-[13]-crown-4 3 Cl}-. The ESI-MS (positive mode) spectrum of compound 5 showed mass clusters centered at m/z 417.0, 527.0, 853.2, 1245, and 1267.4 that are assigned to the species {PhISnCH2-[13]-crown-4}þ, {Ph(OH)SnCH2-[13]-crown-4}þ, {(Ph(μ-O)SnCH2-[13]-crown4)2 3 Na}þ, {(Ph(μ-O)SnCH2-[13]-crown-4)2(Ph(OH)SnCH2[13]-crown-4)}þ, and {(Ph(μ-O)SnCH2-[13]-crown-4)2 3 Na}þ, respectively. For compounds 6 and 8, the ESI-MS spectra in the positive mode showed mass clusters centered at m/z 798.9 and 385.0 that are assigned to {I3SnCH2[13]-crown-4 3 4H2O 3 Na}þ and {(CH3O)2SnCH2-[13]-crown-4}þ, respectively. The ESI-MS spectrum (positive mode) of compound 11 showed mass clusters centered at m/z 813.0 and 862.9 that are assigned to {Ph2SnCH2Sn(I)PhCH2-[13]-crown-4}þ and {Ph2SnCH2Sn(I)PhCH2-[13]-crown-4 3 CH3OH 3 H2O}þ, respectively. The ESI-MS spectra in the positive mode of compounds 12 and 14 showed mass clusters centered at m/z 838.5 and 639.0 that are assigned to {Ph(OH)ISnCH2ICH2-[13]-crown-4 3 2H2O}þ and {PhClSnCH2SnCl2CH2-[13]-crown-4}þ. In the ESI-MS spectrum (negative mode) of 14, there is a mass cluster centered at m/z 708.9 that is assigned to {PhClSnCH2SnCl2CH2-[13]-crown-4 3 Cl}-. Complexation Studies. The complexation behavior of the chloridotriorganotin-substituted crown ether 3 toward lithium rhodanide is similar to that of the halogenidotriorganotin-substituted crown ether derivatives Ph2XSnCH2-[16]-crown-5 and Ph2XSnCH2-[19]-crown-6 (X = Cl, SCN)36,39 toward sodium and potassium rhodanide, respectively. Thus, the reaction in dichloromethane/water of compound 3 with excess LiSCN afforded the ditopic complex [15 3 LiSCN] (15 is here referred to the in situ formed thiocyanatotriorganotin-substituted crown ether Ph2(SCN)SnCH2-[13]-crown-4) in 62% yield as a colorless viscous oil (Scheme 3). The 119Sn NMR spectrum of [15 3 LiSCN] in CDCl3 showed a single resonance at δ -239 that is close to δ -229 and -240 found for the complexes {Ph2(SCN)SnCH2-[16]-crown-5 3 NaSCN}36 and {Ph2(SCN)SnCH2-[19]crown-6 3 KSCN},39 respectively. The 13C NMR spectrum of [15 3 LiSCN] showed that the resonances for the Ci, C20, and C17/C19 (according to the numbering scheme shown in Scheme 6) carbon atoms are respectively 0.9, 6.2, and 3.8 ppm high-frequency shifted with respect to the corresponding chemical shifts of the parent compound 3. The ESI-MS spectrum in the positive mode of [15 3 LiSCN] showed a mass

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Organometallics, Vol. 29, No. 21, 2010 Scheme 3

cluster centered at m/z 542.1 that is assigned to {Ph2(SCN)SnCH2-[13]-crown-4 3 Li}þ. The 119Sn NMR spectra at room temperature of CD3CN or CDCl3 solutions of the fluoridotriorganotin-substituted crown ether 4 and the bis(iodido- and fluoridodiorganostannyl)methane-substituted crown ethers 11 and 13, to which had been added one molar equivalent of lithium fluoride, LiF, showed no formation of the corresponding fluoride complexes. This non-reaction between LiF and compounds 4, 11, or 13 is very likely due to the rather high lattice energy (1033 kJ/mol)56 of lithium fluoride, which cannot be compensated for by complex formation. Moreover, the 119Sn and 19F NMR spectra of a CDCl3 solution containing equimolar amounts of 4 and tetrabutylammonium fluoride, n-Bu4NF, showed no change of the resonances. Apparently, the intramolecular OfSn coordination is rather strong and cannot be broken by attack of the fluoride anion. In contrast, the crown-6 derivative Ph2FSnCH2-[19]-crown-6 reacts with fluoride anion to give the triorganodifluoridostannate complex {Ph2FSnCH2-[19]-crown-6 3 F}-.39 Cesium fluoride, CsF, has a lower lattice energy (748 kJ/ mol)56 than lithium fluoride, and sandwich complexes formed between [12]crown-4 and Csþ are known.57 Moreover, the fluoride anion is able to coordinate to two Lewis acidic tin atoms with formation of a Sn-F-Sn bridge.58 Therefore, for the reaction of compound 4 with CsF one might expect formation of a sandwich-type complex as well that, in addition, should be stabilized by a fluoride bridge. The 19F NMR spectrum at room temperature of a CD3CN/CDCl3 (3:1) solution containing compound 4 and CsF in a molar ratio 2:1 showed two broad resonances at δ -149.1 (ν1/2 = 1011 Hz; integral 1) and -184.8 (ν1/2 = 776 Hz, integral 2). At -45 °C, two major sharp singlet resonances flanked by satellites were observed at δ -152.6 [1J(19F-117/119Sn) 1816/1900 Hz, signal (a)] and -183.4 [1J(19F-117/119Sn) 2098/2183 Hz, signal (b)] of integral ratio 1:2, respectively, as well as two minor intense (total integral approximately 8%) doublet and triplet resonances at δ -164.3 [1J(19F-117/119Sn) 1796 Hz, 2J(19F-19F) 75 Hz, signal (c)] and -136.8 [1J(19F-117/119Sn) 1339 Hz, 2J(19F-19F) 72 Hz, signal (d)], respectively. No resonance was observed in the 119Sn NMR spectrum at room temperature. These results were interpreted in terms of the formation of both a 1:1 and a 2:1 ditopic complex [4 3 CsF] and [42 3 CsF], respectively (Scheme 4). Both compounds are in equilibrium with the free receptor 4, with the equilibrium being slow on the 19F and 119Sn NMR time scales at low temperature. The 19F NMR resonances as well as the magnitudes of the 1 19 J( F-117/119Sn) and 2J(19F-19F) coupling constants are consistent with these interpretations. Indeed, the signal (b) including the 1J(19F-117/119Sn) coupling of 2183 is close to (56) Cubicciotti, D. J. Chem. Phys. 1959, 31, 1646. (57) Ohtsu, K.; Kawashima, T.; Ozutsumi, K. Anal. Sci. 1996, 12, 37. (58) Dakternieks, D.; Jurkschat, K.; Zhu, H. J.; Tiekink, E. R. T. Organometallics 1995, 14, 2512.

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Scheme 4

that measured for a salt-free solution of the fluoridotriorganotin-substituted crown ether 4 (δ -185.8, 1J(19F-117/119Sn) 2112/2211 Hz), whereas signal (a) including the 1J(19F-117/ 119 Sn) coupling of 1892 Hz is close to that obtained for the related KF complex {Ph2FSnCH2 -[19]-crown-6 3 KF} [δ -157.7, 1 J(19F-117/119 Sn) 1912 Hz].39 The doublet and triplet 19F resonances (c) and (d) indicate terminal (Ft) and bridging fluorine (Fb) atoms, respectively. The chemical shifts and the 1J(19F-117/119Sn) and 2J(19F-19F) couplings of 1796/ 1339 Hz and 75/72 Hz are comparable with those measured for the related complex [o-C6H4(SnF3Me2)]-[Et4N]þ [δ -126.8, 1J(19F-117/119Sn) 1172 Hz, 2J(19F-19F) 84 Hz, Fb; δ -155.4, 1J(19F-117/119Sn) 1912 Hz, 2J(19F-19F) 83 Hz, Ft].59 The 119Sn NMR spectrum at room temperature of a solution of 4 in CD3CN/CDCl3 (2:1) to which had been added one molar equivalent of CsF showed a broad triplet resonance at δ -277 [1J(119Sn-19F) 1885 Hz]. The 19F NMR spectrum at room temperature showed a broad signal at δ -149.1 (ν1/2 = 550 Hz). At -45 °C, the triplet resonance observed in the 119Sn NMR spectrum sharpened and shifted slightly to δ -274 [1J(119Sn-19F) 1902 Hz], while the 19F NMR spectrum displayed a single resonance with satellites at δ -151.9 [1J(19F-117Sn) 1818 Hz, 1J(19F-119Sn) 1897 Hz]. These NMR results prove unambiguously the formation of the 1:1 ditopic complex [4 3 CsF] (see Scheme 4) with the latter being kinetically inert at -45 °C on the corresponding NMR time scales. Support for the interaction between the crown ether ring and the cesium cation comes from the 13C NMR spectrum. The resonances for the crown ether carbon atoms C2-C9 and C11/C13 are more broadly distributed as compared with the parent compound 4 and shifted by 1.1 and 4.4 ppm to low and high frequency, respectively. The high preference of compound 4 to form with CsF a 1:1 rather than a 2:1 ditopic complex as expected is very likely the result of a cooperative binding process between Csþ and F-. The 119Sn NMR spectra in CD3CN at room temperature of the mono-, di-, and triiodido-substituted compounds 2, 5, and 6 and of the mono- and trichlorido-substituted compounds 3 and 8 to which had been added three molar (59) Altmann, R.; Jurkschat, K.; Sch€ urmann, M.; Dakternieks, D.; Duthie, A. Organometallics 1998, 17, 5858.

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Organometallics, Vol. 29, No. 21, 2010 Scheme 5

equivalents of lithium iodide, LiI, and lithium chloride, LiCl, respectively, showed single, partially rather broad resonances at δ -150 (ν1/2 = 125 Hz), -331 (ν1/2 = 323 Hz), -1132 (ν1/2 = 166 Hz), -202 (ν1/2 = 2048 Hz), and -362 (ν1/2 =208 Hz), which are displaced by 18, 67, 325, 107, and 72 ppm to low frequency with respect to the chemical shifts of the parent compounds 2 (δ -132), 3 (δ -95), 5 (δ -264), 6 (δ -806), and 8 (δ -286). These results can be interpreted in terms of the equilibrium shown in Scheme 5. The equilibrium is fast on the 119Sn NMR time scale, and the chemical shifts are average ones that are composed of the chemical shifts of the compounds being involved. For each pair of compounds the position of the equilibrium is reflected by the difference between the 119Sn chemical shift actually observed and that of the noncomplexed compound. For the complexes [3 3 LiCl], [6 3 LiI], and [8 3 LiCl] the equilibrium is shifted to the right as their 119Sn chemical shifts are close to the chemical shifts measured for the triorganodichloridostannate complex [Ph2Cl2SnCH2-[16]crown-5]-[(Ph3P)2N]þ (δ -199 in CD3CN)36 and the tetraiodido- and tetrachloridoorganostannate complexes [I4SnCH2-[19]-crown-6]-[n-Bu4N]þ (δ -1032 in CD3CN)40 and [8 3 Cl]-[(Ph3P)2N]þ (δ -402 in CD3CN), respectively. The formation of the ditopic complexes [3 3 LiCl], [6 3 LiI], and [8 3 LiCl] is further supported by 1H and 13C NMR spectroscopy and ESI-MS spectrometry. The 13C NMR spectrum of a solution of 3 þ LiClexcess in CD3CN showed high-frequency shifts for the signals of the Ci, C14, and C11/C13 carbon atoms by 6.3, 9.9, and 6.8 ppm with 1J(13Ci-117/119Sn) = 769/735 Hz and 1J(13C14-117/119Sn) = 656/624 Hz, which are bigger than the corresponding couplings of 662/ 634 Hz and 547/524 Hz measured for pure 3. The resonances of the C2-C9 crown ether carbon atoms moved by 2 ppm to high frequency. Notably, the ditopic complexation of LiCl by compound 3 seems to be favored by cooperative effects of both ions, as the 119Sn NMR spectrum of a solution of 3 in CD3CN, to which had been added one molar equivalent of bis(triphenylphosphoranylidene)ammonium chloride, (Ph3P)2NCl, showed a resonance at δ -91 indicating that no complexation takes place. The formation of the ditopic complex [3 3 LiCl] is in remarkable contrast to the analogous organotin-substituted [16]crown-5 and [19]crown-6 derivatives that are not able to ditopically complex NaCl and KCl, respectively.36,39 The 13C NMR spectrum of an authentic sample containing 6 þ LiIexcess in CD3CN showed, in comparison with the 13 C NMR chemical shifts of pure 6 in CD3CN, a considerable shift (Δδ 31.0) of the C14 signal to low frequency, while the signals of the C12 and C2-C9 crown ether carbon atoms moved by 2.0 and 1.7 ppm to high and low frequency, respectively. In the 1H NMR spectrum of a CD3CN solution containing 6 þ excess LiI, the signals of the HC11/C13 and HC12 protons moved by 0.2 and 0.27 ppm to low frequency,

Tagne Kuate et al.

whereas that of the HC14 hydrogen atoms is high-frequency shifted by 0.67 ppm. The ESI-MS spectrum (positive mode) of this solution showed a mass cluster centered at m/z 787.3 that is assigned to {I3SnCH2-[13]-crown-4 3 Li 3 CH3CN 3 H2O}þ. In the 13C NMR spectrum of a sample of 8 þ LiClexcess in CD3CN, the signals of the C11/C13, C12, and C13 carbon atoms are, with respect to the 13C NMR chemical shifts of pure 8 in CD3CN, high frequency displaced by 1.7, 1.8, and 11.2 ppm, respectively, while those of the C2-C9 crown ether carbon atoms moved by 0.4 ppm to low frequency. Changes were also observed in the 1H NMR spectrum of 8 þ LiClexcess; the signals of the HC11/C13 and HC14 hydrogen atoms are low-frequency shifted by 0.37 and 0.07 ppm, respectively, whereas that of the HC12 hydrogen atom moved by 0.19 ppm to high frequency. From the reactions shown in Scheme 5, the ditopic complex [8 3 LiCl], as its aqua-complex [8 3 LiCl 3 H2O], was isolated as a slightly yellow crystalline solid and characterized by single-crystal X-ray diffraction analysis. The molecular structure of [8 3 LiCl 3 H2O] is shown in Figure 7, and selected bond distances and bond angles are listed in Table 5. The molecular structure of [8 3 LiCl 3 H2O] shows that the LiCl salt is complexed as a solvent-separated ion pair with a water molecule being bridged between the Liþ and Cl-. The Li(1) 3 3 3 Cl(2) distance of 4.504(5) A˚ is almost 2-fold bigger than the Li 3 3 3 Cl distance in crystalline lithium chloride (2.565 A˚).60 The lithium cation adopts a distorted squareplanar pyramidal configuration, with the four crown ether oxygen atoms forming the base of the pyramid and the oxygen atom of the water molecule in axial position. The lithium cation lies slightly out of the crown ether cavity and is placed 0.695(5) A˚ above the pyramid plane in the direction of O(1W). The Li-O(crown) distances range between 1.9179(4) (Li(1)-O(4)) and 2.081(5) (Li(1)-O(3)) A˚, which are slightly shorter than the Li-O distances measured for the lithium chloride aqua complex of {(tert-butyl)(bis(N-phenyl)}benzamide-substituted diazacrown-6 (average Li-O=2.11 A˚)32 and also shorter than the Li-O distances reported for the lithium thiocyanate aqua complex of monoaza-15-crown-5 (Li-O = 2.109(6)-2.449(6) A˚).61 In the latter complexes, the Li-O(water) distances of 1.90 and 1.921(5) A˚, respectively, are however close to the Li(1)-O(1) distance of 1.907(5) A˚ found in [8 3 LiCl 3 H2O]. The latter compound forms by intermolecular O(1W)-H 3 3 3 Cl(1A) hydrogen bonding a one-dimensional polymeric chain structure (Supporting Information, Figure S3). The O(1W)-Cl(1A) and O(1W)-Cl(2) distances of 3.162(2) and 3.245(2) A˚, respectively, are less than the sum of the van der Waals radii43 of O (1.50 A˚) and Cl (1.80 A˚). The tin atom is pentacoordinated and shows a slightly distorted trigonal-bipyramidal configuration (geometrical P goodness44 Δ (θ) 88.1°) with the C(21), Cl(3), and Cl(4) atoms occupying the equatorial and Cl(1) and Cl(2) occupying the axial positions. The Sn(1) atom is displaced by 0.0308(2) A˚ from the trigonal plane in the direction of Cl(1). The Sn(1)-Cl(3) and Sn(1)-Cl(4) distances of 2.3508(7) and 2.3428(6) A˚ are within the range of the Sn(1)-Cl(1) and Sn(1)-Cl(2) distances measured for the compound Cl3SnCH2-[16]-crown-5 (2.3625(5) and 2.3843(5) A˚,48 respectively), (60) Olsher, U.; Izatt, R.; Bradshaw, J. S.; Dalley, N. K. Chem. Rev. 1991, 91, 137. (61) Habata, Y.; Okazaki, C.; Ogura, K.; Akabori, S.; Zhang, X. X.; Bradshaw, J. S. Inorg. Chem. 2007, 46, 8264.

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Figure 7. Molecular structure of [8 3 LiCl 3 H2O] showing 30% probability displacement ellipsoids and the crystallographic numbering scheme. Table 5. Selected Bond Distances (A˚) and Bond Angles (deg) for [8 3 LiCl 3 H2O]a Sn(1)-C(21) Sn(1)-Cl(1) Sn(1)-Cl(2) Sn(1)-Cl(3) Sn(1)-Cl(4) Li(1)-O(1) Li(1)-O(2) Li(1)-O(3) Li(1)-O(4) Li(1)-O(1W) O(1W)-Cl(1A) O(1W)-Cl(2)

a

2.129(2) 2.4731(7) 2.5128(7) 2.3508(7) 2.3428(6) 2.067(5) 2.005(4) 2.081(6) 1.979(4) 1.907(5) 3.161(2) 3.245(2)

C(21)-Sn(1)-Cl(1) C(21)-Sn(1)-Cl(2) C(21)-Sn(1)-Cl(3) C(21)-Sn(1)-Cl(4) Cl(1)-Sn(1)-Cl(2) Cl(1)-Sn(1)-Cl(3) Cl(1)-Sn(1)-Cl(4) Cl(2)-Sn(1)-Cl(3) Cl(2)-Sn(1)-Cl(4) Cl(3)-Sn(1)-Cl(4) O(1)-Li(1)-O(2) O(1)-Li(1)-O(3) O(1)-Li(1)-O(4) O(1)-Li(1)-O(1W) O(2)-Li(1)-O(3) O(2)-Li(1)-O(4) O(2)-Li(1)-O(1W) O(3)-Li(1)-O(4) O(3)-Li(1)-O(1W) O(4)-Li(1)-O(1W) Li(1)-O(1W)-Cl(1A) Li(1)-O(1W)-Cl(2) Cl(1A)-O(1W)-Cl(2) Sn(1)-Cl(2)-O(1W) Sn(1)-Cl(1)-O(1WB) C(22)-C(21)-Sn(1)

94.54(7) 91.14(7) 117.13(7) 130.61(7) 174.22(2) 88.32(2) 88.97(2) 88.16(2) 88.12(3) 112.20(3) 83.25(17) 156.0(2) 90.6(2) 102.8(2) 82.1(2) 121.7(2) 114.7(2) 81.1(2) 100.6(2) 123.1(2) 102.2(2) 119.6(2) 105.35(6) 99.38(4) 114.23(4) 118.3(2)

A = 1þx, y, z; B = -1þx, y, z.

as the latter is analogous to the parent compound 8. On the other hand and as a result of their involvement in hydrogenbonding interactions, the Sn(1)-Cl(1) and Sn(1)-Cl(2) distances of 2.4731(7) and 2.5128(7) A˚ are longer as compared with the sum of the covalent radii47 of Sn (1.40 A˚) and Cl (0.99 A˚). The ditopic complexation of lithium chloride was also achieved with the bis(dichlorido-organostannyl)methanesubstituted crown ether 14, in which the presence of two doubly functionalized tin atoms reflects an improved Lewis acidity with regard to compound 3. The 119Sn NMR spectrum at room temperature of a solution of 14 in CD3CN to which had been added three molar equivalents of LiCl showed two single resonances at δ -207 (ν1/2 = 118 Hz, Sn1) and -279 (ν1/2 = 126 Hz, Sn2), which are 181 and 173 ppm low-frequency shifted in comparison with the 119Sn NMR chemical shifts of free 14 in CD3CN [δ -26 (Sn1) and -106 (Sn2)], but close to the 119Sn NMR chemical shifts

Scheme 6

reported for the diorganotrichlorostannate complexes [PhCl2SnCH2-[19]-crown-6 3 Cl]-[(Ph3P)2N]þ (δ -257, in CDCl3)40 and [(PhCl2SnCH2)2SnCl2 3 Cl]-[(Ph3P)N]þ (δ -188; in CD2Cl2, inner Sn atom),62 respectively. These results are consistent with the equilibrium shown in Scheme 6 being quantitatively shifted toward the ditopic complex [14 3 LiCl], in which the chloride anion is very likely chelated by two tin atoms. Like in [8 3 LiCl], the complexation of the lithium cation in [14 3 LiCl] is confirmed by the change observed in the 1H and 13 C NMR spectra with regard to the 1H and 13C NMR chemical shifts of pure 14. The 1H NMR spectrum of the sample 14 þ LiClexcess showed a closer distribution of the resonances of the HC2-C10 and HC13 hydrogen atoms, whereas they are more broadly distributed in the 1H NMR spectrum of free 14. Moreover, the signals of the HC14 and H12 protons atoms are high-frequency shifted by 0.19 and 0.23 ppm, while that of the HC15 proton atom moved by 0.07 ppm to high field. The 13C NMR spectrum of the same sample showed the signals of the C14, C15, and Ci carbon atoms being considerably low -field shifted by 10.4, 32.3, and 12.2 ppm, respectively. Furthermore, the resonances of the crown ether carbon atoms C2-C9 and C11/C13 moved by 0.5 and 4.6 ppm to high and low field, respectively.

Conclusion Novel ditopic hosts based on organotin- and bis(organostannyl)methane-substituted [13]-crown-4 ethers have been synthesized and completely characterized. Systematic NMR studies reveal that the receptors 3 and 4 bind LiCl and CsF, respectively, in a cooperative fashion, as no affinity of 3 for (Ph3P)NCl and of 4 for n-Bu4NF is observed. We also (62) Altmann, R. Ph.D. Thesis, Technische Universit€at Dortmund, 1999.

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demonstrated that increasing the Lewis acidity at the tin atom is a good way to achieve efficient binding, as evidenced by the ditopic complexation of LiI by compound 6, whereas 2 is not able to bind this salt. The same concept applies for compounds 8 and 14, which quantitatively complex LiCl. The isolation of the ditopic complex [8 3 LiCl 3 H2O] in the solid state shows that the cooperative binding is supported through a water molecule that provides, by a hydrogen bridge, communication between the lithium cation and the chloride anion. This resembles the situation observed for the ditopic complex {Ph2 (I)SnCH 2Sn(Ph)(I)CH 2-[16]crown-5} 3 NaF 3 CH3OH, in which a methanol molecule provides such communication between the sodium cation and the fluoride anion and stabilizes the complex.38 These results inspire us to apply such receptors in extraction and transport processes and, more challenging, to finetune the affinity of these compounds by modification of the substituents at the tin atom in order to allow the ditopic complexation of salts even in pure water.

Experimental Section General Methods. Solvents were dried and distilled from the appropriate desiccants prior to use. All manipulations were performed under an inert atmosphere of nitrogen or argon. Literature procedures were used to prepare 1,4,7,10-tetraoxacyclotridecane41 and triphenyltin hydride.63 The atom numbering of the crown ether fragment is shown in Chart 2. NMR Spectroscopy. The 1H, 13C, 19F, and 119Sn NMR spectra were recorded on Bruker DRX 500, DRX 400, and DPX 300, Varian Nova 600, and Varian Mercury 200 spectrometers with broad band decoupling of 119Sn at 111.92 MHz, 19F at 282.4 MHz, 13C at 100.61 or 125.77 MHz, and 1H at 400.13 or 500.13 MHz. Chemical shifts δ are given in ppm and referenced to tetramethylstannane (119Sn), CFCl3 (19F), and tetramethylsilane (1H, 13C). The solid-state 119Sn NMR spectra of compounds 2 and 4 were recorded on a Bruker AVANCE III 400 spectrometer equipped with a double-bearing CP/MAS probe at room temperature. CP/MAS (cross-polarization/magic angle spinning) experiments were used with a repetition delay of 10 s, and the contact time was set at 2 ms. Two spinning rates (5000 and 7000 Hz) were used to identify the isotropic chemical shift. The number of scans was set at 1000. The 119Sn chemical shifts were calibrated using tetracyclohexyltin (δ = -97.35). The 1H-119Sn correlation was measured with a 500 MHz UnityINOVA NMR spectrometer from Varian, Inc., equipped with a 5 mm gradient triple resonance probe H(C,X). The phasesensitive gradient HMQC sequence was used for the 1H-119Sn correlation without decoupling. It was optimized for a coupling constant of 78 Hz. The gradient strength was 10 G/cm (corresponding to 3.727 G/cm for 119Sn); 10.9 and 46 μs were calibrated for the 1H and 119Sn 90° pulse width, respectively. Two scans per increment and 256 increments were acquired for a 5.5 kHz proton spectral width (4kb data) and a 21 kHz spectral width of 119Sn. The Fourier transformation was performed with 4kb 1kb data. The proton spectrum was carried out with 16 scans, 64 kb data, and a recycle delay of 6 s by using a 45° pulse. Inverse gated decoupling was applied for measuring the 119Sn spectrum; 128 kb data for a 100 kHz window were acquired with a 20° pulse. Complexation Studies. The samples for NMR analyses were prepared by dissolving ca. 50 mg of the corresponding organotin halide and the corresponding amounts of the lithium and cesium salt, respectively, in deuterated solvents. The metal salts used for the complexation studies were dried in vacuo (10-6 mbar) at 100 °C for one day and stored under nitrogen. (63) Kuivila, H. G.; Beumel, O. F. J. Am. Chem. Soc. 1961, 83, 1246.

Tagne Kuate et al. Chart 2

Electrospray mass spectra were recorded on a ThermoquestFinnigan instrument using CH3CN as the mobile phase. The samples were introduced as a solution in CH3CN via a syringe pump operating at 0.5 μL/min. The capillary voltage was 4.5 kV, while the cone skimmer voltage varied between 50 and 250 kV. Identification of the expected ions was assisted by comparison of experimental and calculated isotope distribution patterns. The m/z values reported correspond to those of the most intense peak in the corresponding isotope pattern. Crystallography. Intensity data for the colorless (1, 2, 9), light yellow (11, 8 3 LiCl 3 H2O), yellow (5, 6), and dark yellow (12) crystals were collected on a Nonius KappaCCD (1, 2), Oxford Diffraction Xcalibur S (5, 6, 9, 12, 8 3 LiCl 3 H2O), and Bruker SMART CCD (11) diffractometers with graphite-monochromated Mo KR (0.71073 A˚) radiation at 173(1) K. The data collection covered almost the whole sphere of reciprocal space with 4 (1), 5 (2, 5, 8 3 LiCl 3 H2O), 6 (9), 9 (12), 13 (6), and 4 (11) sets at different κ- (1, 2,5, 6, 9, 12, 8 3 LiCl 3 H2O) and j-angles (11) with 427 (1), 471 (2) 337 (5) 736 (6) 287 (9), 1131 (11), 473 (12), and 194 (8 3 LiCl 3 H2O) frames via ω-rotation (Δ/ω = 0.5° (11) and 1° (1, 2, 5, 6, 9, 12, 8 3 LiCl 3 H2O) at two times 2 s (9), 2.5 s (8 3 LiCl 3 H2O), 3 s (6, 12), 40 s (2), 65 s (5), 100 s (1), and 20 s (11) per frame. The crystal-to-detector distance was 3.4 cm (1, 2), 4 cm (11), and 4.5 cm (5, 6, 9, 12, 8 3 LiCl 3 H2O). Crystal decay was monitored by repeating the initial frames at the end of data collection. On analyzing the duplicate reflections, there was no indication for any decay. The structure was solved by direct methods with SHELXS9764 (1, 2, 5, 6, 9, 12, 8 3 LiCl 3 H2O) and SIR-9765 (11) and successive difference Fourier syntheses. Refinement applied full-matrix least-squares methods with SHELXL97.66 The H atoms were placed in geometrically calculated positions using a riding model with Uiso constrained to 1.2 times Ueq of the carrier atom. Only in 8 3 LiCl 3 H2O have the coordinates of the water molecule (O(1W)) been refined. In 5 three atoms of the crown ether ring are disordered over two positions with occupancies of 0.5 (O(3), O(30 ), C(28), C(280 ),C(29), C(290 )). Atomic scattering factors for neutral atoms and real and imaginary dispersion terms were taken from International Tables for X-ray Crystallography.67 The figures were created by SHELXTL.68 Crystallographic data are given in Table 6; selected bond distances and angles in Tables 1-5. CCDC-769242 (1), -769243 (2), -769244 (5), -769245 (6), -769246 (8 3 LiCl 3 H2O), -769247 (9), -769248 (11), and -769249 (12) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge at www.ccdc. cam.ac.uk/conts/retrieving.html [or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: (internat.) þ44-1223/336-033; e-mail: deposit@ ccdc.cam.ac.uk]. (64) Sheldrick, G. M. Acta Crystallogr. 1990, A46, 467. (65) Altomare, A.; Burla, M. C.; Camalli, M.; Cascarano, G.; Giacovazzo, C.; Guagliardi, A.; Moliterni, A. G. G.; Polidori, G.; Spagna, R. J. Appl. Crystallogr. 1999, 32, 115–119. (66) Sheldrick, G. M. SHELXL97; University of G€ottingen, Germany, 1997. (67) International Tables for Crystallography; Kluwer Academic Publishers: Dortrecht, 1992; Teil C. (68) Sheldrick, G. M. SHELXTL, Release 5.1 Software Reference Manual; Bruker AXS, Inc.: Madison, WI, 1997.

no. of reflns collcd completeness to θmax no. of indep reflns/Rint no. of reflns obsd with (I >2σ(I)) absorpn corr Tmax/Tmin no. of refinedparams GooF (F2) R1 (F) (I >2σ(I)) wR2 (F2) (all data) (Δ/σ)max largest diff peak/hole, e/A˚3

formula fw cryst syst cryst size, mm space group a, A˚ b, A˚ c, A˚ R, deg β, deg γ, deg V, A˚3 Z Fcalcd, Mg/m3 μ, mm-1 F(000) θ range, deg index ranges C22H29IO4Sn 603.04 triclinic 0.2 0.2 0.16 P1 10.4102(8) 11.5682(8) 11.6621(6) 65.213(4) 66.633(4) 73.966(4) 1160.25(13) 2 1.726 2.455 592 2.71 to 27.50 -12 e h e 13 -13 e k e 15 -15 e l e 15 17 051 99.5 5301/0.029 3299 multiscan 0.660/0.616 259 0.830 0.0272 0.0444 0.001 0.642/-1.025

multiscan 0.872/0.758 298 0.787 0.0302 0.0461 0.001 0.450/-0.517

2

C28H34O4Sn 553.24 triclinic 0.28 0.20 0.14 P1 9.4927(6) 11.3246(9) 13.5154(8) 81.561(4) 85.595(3) 65.549(3) 1308.09(15) 2 1.405 1.007 568 2.66 to 27.48 -12 e h e 11 -12 e k e 14 -17 e l e 17 17 615 99.5 5966/0.05 3807

1

multiscan 1.0/0.685 235 0.811 0.028 0.0405 0.001 0.573/-0.530

C16H24I2O4Sn 652.84 monoclinic 0.14 0.04 0.04 P21/n 9.8247(9) 9.9917(9) 21.213(2) 90 97.209(8) 90 2065.9(3) 4 2.099 4.240 1232 2.19 to 25.50 -11 e h e 11 -12 e k e 12 -25 e l e 25 11 685 98.9 3788/0.0471 2323

5

multiscan 1.0/0.7 163 1.027 0.0183 0.0397 0.001 0.676/-0.739

C10H19I3O4Sn 702.64 monoclinic 0.28 0.18 0.11 P21/n 12.2368(4) 12.3283(3) 12.9618(5) 90 109.680(4) 90 1841.18(10) 4 2.535 6.421 1280 2.35 to 25.50 -14 e h e 14 -14 e k e 14 -15 e l e 15 24 148 100.0 3424/0.0364 2977

6

multiscan 1.0/0.857 208 0.958 0.0184 0.0394 0.001 0.362/-0.261

C16H24Cl2O4Sn 469.94 monoclinic 0.40 0.26 0.26 P21/n 9.085(3) 10.1260(4) 20.4107(7) 90 94.777(3) 90 1871.15(12) 4 1.668 1.666 944 2.25 to 26.0 -11 e h e 10 -12 e k e 11 -24 e l e 24 9157 99.8 3469/0.0229 2975

9

multiscan 244 0.954 0.0219 0.0299 0.001 0.840/-0.796

322 1.070 0.0345 0.0418 0.001 3.063/-0.803

C17H26I4O4Sn2 1039.36 monoclinic 0.30 0.22 0.08 P21/n 10.1236(3) 24.3635(8) 10.8838(3) 90 98.687(3) 90 2653.65(14) 4 2.602 6.554 1888 2.07 to 25.50 -12 e h e 12 -29 e k e 29 -13 e l e 13 22 681 100.0 4951/0.0399 4077

12

multiscan

C29H36I2O4Sn2 939.76 monoclinic 0.37 0.19 0.13 P21/c 12.8374(5) 8.9753(3) 28.9525(12) 90 105.6272(13) 90 5746.5(8) 4 1.943 3.507 1792 1.46 to 27.79 -16 e h e 16 -11 e k e 11 -37 e l e 37 37 011 100.0 7576/0.0285 6584

11

Table 6. Crystallographic Data and Structure Refinements for Compounds 1, 2, 5, 6, 9, 11, 12, and [8 3 LiCl 3 H2O]

196 0.962 0.0220 0.0282 0.001 0.375 -0.418

multiscan

C10H21Cl4LiO5Sn 488.70 monoclinic 0.32 0.22 0.22 P21/c 8.3402(4) 12.8298(6) 17.0943(10) 90 90.556(5) 90 1829.06(16) 4 1.775 1.993 968 2.38 to 25.50 -9 e h e 10 -15 e k e 13 -20 e l e 16 6186 94.0 3202/0.0201 2714

[8 3 LiCl 3 H2O]

Article Organometallics, Vol. 29, No. 21, 2010 5467

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Synthesis of (1,4,7,10-Tetraoxacyclotridec-12-ylmethyl)triphenylstannane, Ph3SnCH2-[13]-crown-4 (1). 12-Methylene-1,4,7,10tetraoxacyclotridecane (4.93 g, 24.376 mmol) was mixed with triphenyltin hydride, Ph3SnH (8.56 g, 24.376 mmol). After a small quantity of AIBN (150 mg) had been added, the mixture was stirred at 60-80 °C for 15 h, followed by cooling to room temperature. Addition of CH2Cl2 (100 mL) followed by filtration through Celite and removal of the solvent in vacuo afforded a viscous oil. Purification of the oil by column chromatography with silica gel/CH2Cl2 and elution with ethanol gave 9.18 g (68%) of 1 as a colorless viscous oil, which solidified after it had been kept a few days at room temperature, mp 65-68 °C. Single crystals of 1 suitable for X-ray diffraction analysis were obtained by slow evaporation of a solution of the compound in CH2Cl2/ n-hexane. 1 H NMR (CDCl3, 400.13 MHz, 293 K) δ: 1.54 (d, 3J(1H-1H) = 8.0 Hz, 2J(1H-117Sn) = 48.0 Hz, 2J(1H-119Sn) = 64.0 Hz, 2H, Sn-CH2), 2.37 (m, 1H, CH), 3.41-3.64 (complex pattern, 16H, CH2-O-CH2), 7.35-7.63 (m, 15H, Ph). 13C{1H} NMR (CDCl3, 100.63 MHz, 293 K) δ: 10.8 (1J(13C-117Sn) = 388 Hz, 1J(13C-119Sn) = 407.6 Hz, C14), 37.0 (2J(13C-117/119Sn) = 20 Hz, C12), 69.0-70.0 (C2-C9), 71.4 (3J(13C-117/119Sn) = 45 Hz, C11/C13), 128.3 (3J(13C-117/119Sn) = 48 Hz, Cm), 128.6 (4J(13C-117/119Sn) = 12 Hz, Cp), 136.9 (2J(13C-117/119Sn) = 35 Hz, Co), 140.0 (1J(13C-117Sn) = 471 Hz, 1J(13C-119Sn) = 495 Hz), Ci). 119Sn{1H} NMR (CH2Cl2/D2O capillary, 111.93 MHz, 293 K) δ: -107. Anal. Calcd for C28H34O4Sn (553.28): C 60.8; H 6.2. Found: C 61.1; H 6.4. Synthesis of Iodido(1,4,7,10-tetraoxacyclotridec-12-ylmethyl)diphenylstannane, Ph2ISnCH2-[13]-crown-4 (2). Over a period of three hours, iodine (4.02 g, 15.851 mmol) was added in small portions at 0 °C to a stirred solution of 1 (8.77 g, 15.851 mmol) in CH2Cl2 (150 mL). Stirring was continued and the reaction mixture was warmed to room temperature overnight. Dichloromethane and iodobenzene were removed in vacuo (10-3 mm Hg) to give a viscous and slightly yellow oil. The latter was dissolved in ethanol. Cooling the solution at -5 °C gave 7.18 g (75%) of pure 2 as a white solid of mp 120 °C. Single crystals of 2 suitable for X-ray diffraction analysis were obtained by slow evaporation of a solution of the compound in CH2Cl2/n-hexane. 1 H NMR (CDCl3, 400.13 MHz, 293 K) δ: 1.84 (d, 3J(1H-1H) = 4.0 Hz, 2J(1H-117Sn) = 68.0 Hz, 2J(1H-119Sn) = 76.0 Hz, 2H, Sn-CH2), 2.62 (m, 1H, CH), 3.27-3.73 (complex pattern, 16H, CH2-O-CH2), 7.35-7.82 (m, 10H, Ph). 13C{1H} NMR (CDCl3, 100.63 MHz, 293 K) δ: 20.4 (1J(13C-117Sn) = 478 Hz, 1J(13C-119Sn) = 499 Hz, C14), 37.2 (2J(13C-117/119Sn) = 30 Hz, C12), 69.2-70.0 (C2-C9), 71.2 (3J(13C-117/119Sn) = 38.0 Hz, C11/C13), 128.5 (3J(13C-117/119Sn) = 63 Hz, Cm), 129.3 (4J(13C-117/119Sn)=14 Hz, Cp), 135.9 (2J(13C-117/119Sn) = 47 Hz, Co), 140.3 (1J(13C-117Sn) = 592 Hz, 1J(13C-119Sn) = 620 Hz), Ci). 119Sn{1H} NMR (CDCl3, 111.93 MHz, 293 K) δ: -126. 119Sn MAS NMR (149.20 MHz) δ: -121. Anal. Calcd for C22H29IO4Sn (603.08): C 43.8; H 4.8. Found: C 44.3; H 4.8. Synthesis of Chlorido(1,4,7,10-tetraoxacyclotridec-12-ylmethyl)diphenylstannane, Ph2ClSnCH2-[13]-crown-4 (3). To a solution of 2 (1.0 g, 1.658 mmol) in CH3CN (20 mL) was added excess silver chloride, AgCl (0.71 g, 4.974 mmol). The resulting mixture was stirred at room temperature and in the dark for 14 days. After the AgI formed and the nonreacted AgCl had been removed by filtration the solvent was evaporated in vacuo. The colorless oil thus obtained was dissolved in ethanol and cooled at -5 °C to give 0.60 g (71%) of pure 3 as a white solid, mp 118 °C. 1 H NMR (CDCl3, 400.13 MHz, 293 K) δ: 1.66 (d, 3J(1H-1H) = 4.0 Hz, 2J(1H-117Sn) = 76.0 Hz, 2J(1H-119Sn) = 84.0 Hz, 2H, Sn-CH2), 2.66 (m, 1H, CH), 3.30-3.74 (complex pattern, 16H, CH2-O-CH2), 7.37-7.82 (m, 10H, Ph). 13C{1H} NMR (CDCl3, 100.63 MHz, 293 K) δ: 17.1 (1J(13C-117Sn) = 511 Hz, 1J(13C-119Sn) = 535 Hz, C14), 36.3 (2J(13C-117/119Sn) = 28 Hz, C12), 69.2-70.1 (C2-C9), 71.0 (3J(13C-117/119Sn) = 37 Hz,

Tagne Kuate et al. C11/C13), 128.6 (3J(13C-117/119Sn) = 62 Hz, Cm), 129.4 (4J(13C-117/119Sn) = 14 Hz, Cp), 135.7 (2J(13C-117/119Sn) = 49 Hz, Co), 140.9 (1J(13C-117Sn) = 632 Hz, 1J(13C-119Sn) = 663.2 Hz), Ci). 119Sn{1H} NMR (CDCl3, 111.93 MHz, 293 K) δ: -87. Anal. Calcd for C22H29ClO4Sn (511.63): C 51.6; H 5.7. Found: C 51.8; H 5.6. Synthesis of Fluorido(1,4,7,10-tetraoxacyclotridec-12-ylmethyl)diiphenylstannane, Ph2FSnCH2-[13]-crown-4 (4). A solution of 2 (1.0 g, 1.658 mmol) in CH2Cl2 (25 mL) was mixed with a solution of KF (0.96 g, 16.580 mmol) in water (30 mL). The biphasic mixture was stirred at room temperature for two days. The organic phase was then separated, dried over MgSO4, and filtered. Removing the solvent in vacuo afforded a colorless viscous oil. The oil was dissolved in diethyl ether. Cooling the solution at -5 °C gave 0.42 g (51%) of pure 4 as a colorless solid, mp 115 °C. 1 H NMR (CDCl3, 400.13 MHz, 293 K) δ: 1.51 (d, 3J(1H-1H) = 8.0 Hz, 2J(1H-117Sn) = 72.0 Hz, 2J(1H-119Sn) = 88.0 Hz, 2H, Sn-CH2), 2.66 (m, 1H, CH), 3.33-3.75 (complex pattern, 16H, CH2-O-CH2), 7.37-7.79 (m, 10H, Ph). 13C{1H} NMR (CDCl3, 100.63 MHz, 293 K) δ: 13.2 (d, 2J(13C-19F) = 12 Hz, 1J(13C-117Sn) = 523 Hz, 1J(13C-119Sn) = 549 Hz, C14), 35.9 (2J(13C-117/119Sn) = 27 Hz, C12), 69.2-70.1 (C2-C9), 70.9 (3J(13C-117/119Sn) = 36 Hz, C11/C13), 128.5 (3J(13C-117/119Sn) = 64 Hz, Cm), 129.5 (4J(13C-117/119Sn) = 13 Hz, Cp), 135.8 (2J(13C-117/119Sn) = 47 Hz, Co), 140.9 (d, 2J(13C-19F) = 13 Hz, 1J(13C-117Sn) = 667 Hz, 1J(13C-119Sn) = 669 Hz), Ci). 19 F{1H} NMR (CDCl3, 282.4 MHz, 293 K) δ: -192.1 1 19 ( J( F-117Sn) = 2110 Hz, 1J(19F-119Sn) = 2208 Hz). 119Sn{1H} NMR (CDCl3, 111.93 MHz, 293 K) δ: -111 (d, 1J(119Sn-19F) = 2208 Hz). 119Sn MAS NMR (149.20 MHz) δ: -145 (t, 1J(119Sn-19F) = 2685 Hz). Anal. Calcd for C22H29FO4Sn (495.18): C 53.4; H 5.9. Found: C 52.9; H 5.4. Synthesis of Diiodido(1,4,7,10-tetraoxacyclotridec-12-ylmethyl)phenylstannane, PhI2SnCH2-[13]-crown-4 (5). Over a period of three hours, iodine (0.42 g, 1.658 mmol) was added in small portions at 0 °C to a stirred solution of 2 (1.0 g, 1.658 mmol) in CH2Cl2 (30 mL). Stirring was continued and the reaction mixture was warmed to room temperature overnight. Dichloromethane and iodobenzene were removed in vacuo (10-3 Torr) to afford a yellow solid. Recrystallization from ethanol at -5 °C gave 0.89 g (82%) of pure 5 as yellow crystals, mp 102 °C. 1 H NMR (CDCl3, 400.13 MHz, 293 K) δ: 2.19 (d, 3J(1H-1H) = 4.0 Hz, 2J(1H-117Sn) = 68.0 Hz, 2J(1H-119Sn) = 76.0 Hz, 2H, Sn-CH2), 2.58 (m, 1H, CH), 3.44-3.78 (complex pattern, 16H, CH2-O-CH2), 7.33-7.81 (m, 5H, Ph). 13C{1H} NMR (CDCl3, 100.63 MHz, 293 K) δ: 28.3 (1J(13C-117Sn) = 512 Hz, 1J(13C-119Sn) = 535 Hz, C14), 37.4 (2J(13C-117/119Sn) = 41 Hz, C12), 69.2-69.8 (C2-C9), 70.8 (3J(13C-117/119Sn) = 51 Hz, C11/C13), 128.7 (3J(13C-117/119Sn) = 84 Hz, Cm), 130.3 (4J(13C-117/119Sn) = 12 Hz, Cp), 134.1 (2J(13C-117/119Sn) = 64 Hz, Co), 139.8 (1J(13C-117Sn) = 686 Hz, 1J(13C-119Sn) = 717 Hz), Ci). 119Sn{1H} NMR (CDCl3, 111.93 MHz, 293 K) δ: -275. Anal. Calcd for C16H24I2O4Sn (652.88): C 29.4; H 3.7. Found: C 29.6; H 3.7. Synthesis of Triiodido(1,4,7,10-tetraoxacyclotridec-12-ylmethyl)stannane, I3SnCH2-[13]-crown-4 (6). Over a period of three hours, iodine (0.84 g, 3.316 mmol) was added in small portions at 0 °C to a stirred solution of 2 (1.0 g, 1.658 mmol) in CH2Cl2 (30 mL). Stirring was continued, and the reaction mixture was warmed to room temperature overnight. Dichloromethane and iodobenzene were removed in vacuo (10-3 Torr) to afford a yellow solid. Recrystallization from ethanol at -5 °C gave 0.90 g (77%) of pure 6 as yellow crystals, mp 100 °C. 1 H NMR (CDCl3, 400.13 MHz, 293 K) δ: 2.48 (d, 3J(1H-1H) = 4.0 Hz, 2J(1H-117Sn) = 60.0 Hz, 2J(1H-119Sn) = 68.0 Hz, 2H, Sn-CH2), 2.40 (m, 1H, CH), 3.61-3.80 (complex pattern, 16H, CH2-O-CH2). 13C{1H} NMR (CDCl3, 100.63 MHz, 293 K) δ: 33.0 (1J(13C-117Sn) = 562 Hz, 1J(13C-119Sn) = 588 Hz, C14), 38.4 (2J(13C-117/119Sn) = 60 Hz, C12), 68.7-70.2 (C2C9), 69.6 (3J(13C-117/119Sn) = 70 Hz, C11/C13). 119Sn{1H}

Article NMR (CDCl3, 111.93 MHz, 293 K) δ: -820. Anal. Calcd for C10H19I3O4Sn (702.68): C 17.1; H 2.7. Found: C 17.3; H 2.8. Synthesis of Trichlorido(1,4,7,10-tetraoxacyclotridec-12-ylmethyl)stannane, Cl3SnCH2-[13]-crown-4 (8), and Dichlorido(1,4,7,10-tetraoxacyclotridec-12-ylmethyl)phenylstannane, PhCl2SnCH2-[13]-crown-4 (9). Hydrogen chloride gas, produced by adding dropwise concentrated sulfuric acid to sodium chloride, was bubbled through a solution of 1 (0.92 g, 1.663 mmol) in CH2Cl2 (70 mL) for 3 h at 0 °C and for 6 h at RT. The solvent, the benzene, and the remaining HCl were removed in vacuo to afford a white solid consisting of the dichloridoorganotin hydroxide 7,42 the monoorganotin trichloride 8, and the diorganotin dichloride 9. Compound 8 was separated from the mixture as colorless crystals by recrystallization from ethanol. Yield: 48%, mp 160 °C. 1 H NMR (CDCl3, 400.13 MHz, 293 K) δ: 1.80 (d, 3J(1H-1H) = 4.0 Hz, 2J(1H-117Sn) = 92.0 Hz, 2J(1H-119Sn) = 108.0 Hz, 2H, Sn-CH2), 2.59 (m, 1H, CH), 3.61-4.21 (complex pattern, 16H, CH2-O-CH2). 13C{1H} NMR (CDCl3, 100.63 MHz, 293 K) δ: 30.4 (C14), 34.3 (C12), 68.7-69.3 (C2-C9), 72.8 (3J(13C-117/119Sn) = 66 Hz, C11/C13). 119Sn{1H} NMR (CDCl3, 111.93 MHz, 293 K) δ: -237. Anal. Calcd for C10H20Cl3O4Sn (428.33): C 28.0; H 4.5. Found: C 27.9, H 4.4. Compound 9 was removed from the mixture as colorless crystals by recrystallization from diethyl ether. Yield: 5%, mp 150 °C. 1 H NMR (CDCl3, 500.13 MHz, 293 K) δ: 1.86 (d, 3J(1H-1H) = 4.0 Hz, 2J(1H-117Sn) = 80.0 Hz, 2J(1H-119Sn) = 90.0 Hz, 2H, Sn-CH2), 2.70 (m, 1H, CH), 3.52-3.90 (complex pattern, 16H, CH2-O-CH2), 7.46-7.95 (m, 5H, Ph). 13C{1H} NMR (CDCl3, 125.77 MHz, 293 K) δ: 24.5 (1J(13C-117Sn) = 624 Hz, 1J(13C-119Sn) = 654 Hz, C14), 35.6 (2J(13C-117/119Sn) = 40 Hz, C12), 69.24-69.9 (C2-C9), 71.0 (3J(13C-117/119Sn) = 47 Hz, C11/C13), 129.0 (3J(13C-117/119Sn) = 89 Hz, Cm), 130.7 (4J(13C-117/119Sn)=18 Hz, Cp), 134.9 (2J(13C-117/119Sn) = 65 Hz, Co), 141.5 (Ci). 119Sn{1H} NMR (CDCl3, 111.93 MHz, 293 K) δ: -93. Anal. Calcd for C16H24Cl2O4Sn (469.97): C 40.9; H 5.1. Found: C 40.5; H 4.8. Synthesis of 12-({Diphenyl[(triphenylstannyl)methyl]stannyl}methyl)-1,4,7,10-tetraoxacyclononadecane, Ph3SnCH2Sn(Ph)2CH2-[13]-crown-4 (10). A solution of (bromomagnesiummethyl)triphenylstannane, prepared from (bromomethyl)triphenylstannane (2.21 g, 4.974 mmol) and magnesium (0.13 g, 5.223 mmol) in THF (50 mL), was added dropwise to a stirred solution of 2 (3.0 g, 4.974 mmol) in THF (50 mL) for a period of 2 h. After the addition had been completed, the reaction mixture was heated at reflux overnight and then cooled to room temperature. Cold water (60 mL) was added and the mixture was extracted two times with 50 mL of diethyl ether. The combined organic phases were dried with MgSO4 and filtered, and the solvents evaporated in vacuo to give the crude product. The latter was purified by column chromatography (Al2O3, CH2Cl2, ethyl acetate) to yield 3.34 g (80%) of pure 10 as a colorless viscous oil. 1 H NMR (CDCl3, 400.13 MHz, 293 K) δ: 0.77 (s, 2J(1H117/119 Sn) = 64 Hz, 2H, Sn-CH2-Sn), 1.04 (d, 3J(1H-1H) = 8.0 Hz, 2J(1H-117Sn) = 48.0 Hz, 2J(1H-119Sn) = 64.0 Hz, 2H, SnCH2), 1.63 (m, 1H, CH), 3.29-3.57 (complex pattern, 16H, CH2-O-CH2), 7.19-7.43 (m, 25H, Ph). 13C{1H} NMR (CDCl3, 100.63 MHz, 293 K) δ: -16.0 (1J(13C-117Sn) = 254/268 Hz, 1 13 J( C-119Sn) = 285/298 Hz, C15), 11.6 (1J(13C-117Sn) = 378 Hz, 1J(13C-119Sn) = 396 Hz, C14), 36.9 (2J(13C-117/119Sn) = 20 Hz, C12), 69.0-70.0 (C2-C9), 71.5 (3J(13C-117/119Sn) = 45 Hz, C11/C13), 128.1 (3J(13C-117/119Sn) = 46 Hz, SnPh2, Cm), 128.3 (4J(13C-117/119Sn) = 16 Hz, SnPh2, Cp), 128.3, 3J(13C117/119 Sn) = 50 Hz, SnPh3, Cm), 128.7 (4J(13C-117/119Sn) = 11 Hz, SnPh3, Cp), 136.5 (2J(13C-117/119Sn) = 35 Hz, SnPh2, Co), 136.8 (2J(13C-117/119Sn) = 38 Hz, SnPh3, Co), 139.6 (3J(13C117/119 Sn) = 10 Hz, 1J(13C-117Sn) = 485 Hz, 1J(13C-119Sn) = 507 Hz), SnPh3, Ci), 141.3 (3J(13C-117/119Sn) = 12 Hz,

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J(13C-117Sn) = 455 Hz, 1J(13C-119Sn) = 475 Hz), SnPh2, Ci). 119Sn{1H} NMR (CDCl3, 111.93 MHz, 293 K) δ: -53 (2J(119Sn-117/119Sn) = 238 Hz, SnPh2), -77 (2J(119Sn117/119 Sn) = 241 Hz). Anal. Calcd for C41H46O4Sn2 (840.23): C 58.6; H 5.5. Found: C 58.9; H 5.7. Synthesis of 12-({Iodidophenyl[(iodidodiphenylstannyl)methyl]stannyl}methyl)-1,4,7,10-tetraoxacyclononadecane, Ph2ISnCH2Sn(I)PhCH2-[13]-crown-4 (11). Iodine (1.87 g, 7.378 mmol) was added in small portions and under ice-cooling to a stirred solution of 10 (3.1 g, 3.689 mmol) in CH2Cl2 (80 mL). The reaction mixture was stirred while warming to room temperature overnight. The solvent and the iodobenzene were removed in vacuo (10-3 mm Hg) to afford a yellow oil. The oil was dissolved in diethyl ether (20 mL); cooling the solution at -5 °C gave 2.77 g (80%) of pure 11 as slightly yellow crystals, mp 132 °C. 1 H NMR (CDCl3, 599.83 MHz, 293 K) δ: 1.24/1.60 (br, ABX-type resonance, Sn-CH2), 1.84/2.06 (br, AB-type resonance, 3J(1H-1H) = 12.0 Hz, Sn-CH2-Sn), 2.37 (m, 1H, CH), 3.18-3.59 (complex pattern, 16H, CH2-O-CH2), 7.33-7.91 (m, 15H, Ph). 13C{1H} NMR (CDCl3, 100.63 MHz, 293 K) δ: 4.9 (1J(13C-117Sn) = 291/303 Hz, 1J(13C-119Sn) = 326/341 Hz, C15), 20.0 (1J(13C-117Sn) = 489 Hz, 1J(13C-119Sn) = 517 Hz, C14), 37.0 (2J(13C-117/119Sn) = 31 Hz, C12), 69.0-69.9 (C2-C9), 71.2 (C11/C13), 128.5 (3J(13C-117/119Sn) = 62 Hz, SnIPh, Cm), 128.7 (3J(13C-117/119Sn) = 62 Hz, SnIPh2, Cm), 129.3 (4J(13C-117/119Sn) = 13 Hz, SnIPh, Cp), 129.9 (4J(13C-117/119Sn)=14 Hz, SnIPh2, Cp), 134.9 (2J(13C-117/119Sn) = 49 Hz, SnIPh, Co), 136.6 (br, 2J(13C-117/119Sn) = 50 Hz, SnIPh2, Co), 137.9 (br, SnIPh, Ci), 141.8 (3J(13C-117/119Sn) = 29 Hz, SnIPh2, Ci). 119Sn{1H} NMR (CDCl3, 111.93 MHz, 293 K) δ: -50 (2J(119Sn-117/119Sn) = 251 Hz, SnIPh), -87(2J(119Sn-117/119Sn) = 251 Hz, SnIPh2). Anal. Calcd for C29H36I2O4Sn2 (939.83): C 37.1; H 3.9. Found: C 36.9; H 3.9. Synthesis of 12-({Diiodido[(diiodidophenylstannyl)methyl]stannyl}methyl)-1,4,7,10-tetraoxacyclononadecane, PhI2SnCH2SnI2CH2-[13]-crown-4 (12). Iodine (0.27 g, 1.064 mmol) was added in small portions and under ice-cooling to a stirred solution of 11 (0.5 g, 0.532 mmol) in CH2Cl2 (20 mL). The reaction mixture was stirred while warming to room temperature for three days. The solvent and the iodobenzene were removed in vacuo (10-3 mm Hg) to afford a dark yellow oil. The oil was dissolved in ethanol (10 mL); cooling the solution at -5 °C gave 0.41 g (75%) of pure 12 as dark yellow crystals, mp 145 °C. 1 H NMR (CDCl3, 400.13 MHz, 293 K) δ: 2.18 (d, 3J(1H-1H) = 4.0 Hz, 2J(1H-117Sn) = 80.0 Hz, 1J(1H-119Sn) = 88.0 Hz, 2H, Sn-CH2), 2.43 (m, 1H, CH), 3.09 (s, 1J(1H-117/119Sn) = 68.0 Hz, Sn-CH2-Sn), 3.53-3.86 (complex pattern, 16H, CH2-OCH2), 7.37-7.87 (m, 5H, Ph). 13C{1H} NMR (CDCl3, 100.63 MHz, 293 K) δ: 20.5 (C15), 30.5 (C14), 37.4 (C12), 68.8-69.8 (C2-C9), 70.3 (3J(13C-117/119Sn) = 48 Hz, C11/C13), 128.8 (SnI2Ph, Cm), 131.0 (SnI2Ph, Cp), 135.0 (2J(13C-117/119Sn) = 65 Hz, SnI2Ph, Co), 136.4 (SnI2Ph, Ci). 119Sn{1H} NMR (CDCl3, 111.93 MHz, 293 K) δ: -220 (2J(119Sn-117/119Sn) = 214 Hz, SnI2Ph), -272 (2J(119Sn-117/119Sn) = 218 Hz, SnI2). Anal. Calcd for C17H26I4O4Sn2 (1039.42): C 19.6; H 2.5. Found: C 19.4; H 2.8. Synthesis of 12-({Fluoridophenyl[(fluorodiphenylstannyl)methyl]stannyl}methyl)-1,4,7,10-tetraoxacyclononadecane, Ph2FSnCH2Sn(F)PhCH2-[13]-crown-4 (13). A solution of 11 (0.5 g, 0.532 mmol) in CH2Cl2 (20 mL) was mixed with a solution of KF (0.93 g, 16.008 mmol) in water (25 mL). The biphasic mixture was stirred at room temperature for 10 days. The organic phase was then separated, dried over MgSO4, and filtered. Removing the solvent in vacuo afforded 0.3 g (78%) of pure 13 as a white solid, mp 110 °C. 1H NMR (CDCl3, 599.83 MHz, 293 K) δ: 1.14 (br, Sn-CH2), 1.28 (br, Sn-CH2-Sn), 2.52 (br, 1H, CH), 3.31-3.56 (m, br, complex pattern, 16H, CH2-OCH2), 7.33-7.83 (m, br, 15H, Ph). 13C{1H} NMR (CDCl3,

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100.63 MHz, 293 K) δ: 14.9 (br, C15), 29.6 (br, C12), 35.8 (br, C14), 69.0-69.8 (br, C2-C9), 71.5 (br, C11/C13), 128.2-129.5 (br, SnFPh and SnFPh2, Cm þ Cp), 135.3 (br, SnFPh, Co), 136.1 (br, SnFPh2, Co), 137.1 (br, SnFPh, Ci), 142.9 (br, SnFPh2, Ci). 19 F{1H} NMR (CDCl3, 282.4 MHz, 293 K) δ: -139 (ν1/2 = 358 Hz), -175 (s,1J(19F-117/119Sn) = 2107 Hz), -189 (ν1/2 = 110 Hz), -195 (ν1/2 = 960 Hz). 119Sn{1H} NMR (CDCl3, 111.93 MHz, 293 K) δ: -27 (br, ν1/2 = 1217 Hz). ESI-MS (MeCN, m/ z), positive mode: 703.1 (100%), {Ph2FSnCH2SnPh-[13]-crown4}þ; negative mode: 743.0 (60%), {Ph2FSnCH2Sn(F)Ph-[13]crown-4 3 F}-. Anal. Calcd for C29H36F2O4Sn2 3 2H2O (760.05): C 45.8; H 5.3. Found: C 46.2; H 4.8. Synthesis of 12-({Dichlorido[(dichloridophenylstannyl)methyl]stannyl}methyl)-1,4,7,10-tetraoxacyclononadecane, PhCl2SnCH2SnCl2CH2-[13]-crown-4 (14). To a solution of 12 (0.5 g, 0.481 mmol) in CH3CN (20 mL) was added an excess of silver chloride, AgCl (0.83 g, 5.791 mmol). The resulting mixture was stirred at room temperature and in the dark for 14 days. After the AgI formed and the nonreacted AgCl had been removed by filtration, the solvent was evaporated in vacuo. The slightly yellow oil thus obtained was dissolved in ethanol and cooled at -5 °C to give 0.11 g (34%) of pure 14 as white solid, mp 180 °C. 1 H NMR (CD3CN, 400.13 MHz, 293 K) δ: 1.69 (d, 3J(1H-1H) = 4.0 Hz, 2J(1H-117/119Sn) = 100.0 Hz, 2H, SnCH2), 2.58 (m, 1H, CH), 2.88 (s, 1J(1H-117Sn) = 84.0 Hz, 1 1 J( H-119Sn) = 92.0/100.0 Hz, 2H, Sn-CH2-Sn),, 3.36-3.99 (complex pattern, 16H, CH2-O-CH2), 7.49-7.97 (m, 5H, Ph). 13 C{1H} NMR (CD3CN, 100.63 MHz, 293 K) δ: 29.8 1 13 ( J( C-117Sn)=562 Hz, 1J(13C-119Sn) = 582 Hz, C14), 31.3 (1J(13C-117Sn)=499 Hz, 1J(13C-119Sn) = 521 Hz, C14), 34.3 (2J(13C-117/119Sn)=64 Hz, C12), 65.9-69.6 (C2-C9), 72.3 (3J(13C-117/119Sn) = 34 Hz, C11/C13), 128.9 (3J(13C-117/119Sn) = 92 Hz, SnCl2Ph, Cm), 130.7 (4J(13C-117/119Sn)=18 Hz, SnCl2Ph, Cp), 135.1 (2J(13C-117/119Sn) = 66 Hz, SnCl2Ph, Co), 142.9 (3J(13C-117/119Sn) = 10 Hz, SnCl2Ph, Ci). 119Sn{1H} NMR (CD3CN, 111.93 MHz, 293 K) δ: -11 (ν1/2 = 237 Hz, SnCl2), -94 (ν1/2 = 122 Hz, SnCl2Ph). Anal. Calcd for C17H26Cl4O4Sn2 (673.60): C 30.3, H 3.9. Found: C 29.9; H 4.0. Synthesis of the Ditopic Complex Ph2(SCN)SnCH2-[13]crown-4 3 LiSCN ([15 3 LiSCN]). Lithium thiocyanate (50.7 mg, 0.780 mmol) was added to a solution of 3 (100.0 mg, 0.195 mmol) in CH2Cl2 (10 mL). The mixture was stirred at room temperature for two days. After the excess insoluble salts had been filtered the solvent was removed in vacuo to give 0.07 g (62%) of pure [15 3 LiSCN] as a colorless viscous oil. 1 H NMR (CDCl3, 400.13 MHz, 293 K) δ: 1.48 (d, 3J(1H-1H) = 4.0 Hz, 2J(1H-117Sn) = 68.0 Hz, 2J(1H-119Sn) = 84.0 Hz, 2H, Sn-CH2), 2.54 (m, 1H, CH), 3.30-3.63 (complex pattern, 16H, CH2-O-CH2), 7.30-7.99 (m, 10H, Ph). 13C{1H} NMR (CDCl3, 100.63 MHz, 293 K) δ: 20.8 (1J(13C-117Sn) = 616 Hz, 1 13 J( C-119Sn)=644 Hz, C14), 36.2 (2J(13C-117/119Sn)=24 Hz, C12), 66.9-67.8 (C2-C9), 77.6 (C11/C13), 128.3 (3J(13C117/119 Sn)=70 Hz, Cm), 129.1 (4J(13C-117/119Sn)=14 Hz, Cp), 136.3 (2J(13C-117/119Sn) = 47 Hz, Co), 141.8 (1J(13C-117Sn) = 772 Hz, 1J(13C-119Sn) = 806 Hz, Ci). 119Sn {1H} NMR (CDCl3, 111.93 MHz, 293 K) δ: -239. Anal. Calcd for C24H29N2LiO4S2Sn 3 H2O (617.30): C 46.7; H 5.1; N 4.7. Found: C 46.9; H 4.8; N 4.3. Synthesis of the Aqua Complex of the Ditopic Complex Cl3SnCH2-[13]-crown-4 3 LiCl 3 H2O ([8 3 LiCl 3 H2O]). Lithium chloride (12.5 mg, 0.296 mmol) was added to a solution of 8 (31.7 mg, 0.074 mmol) in CH3CN (10 mL), and the mixture was stirred at room temperature for three days. After filtration of excess salt, slow diffusion of diethyl ether into the clear acetonitrile solution provided 25.0 mg (69%) of pure [8 3 LiCl 3 H2O] as sligthly yellow crystals, mp 233 °C. 1 H NMR (CD3CN, 400.13 MHz, 293 K) δ: 1.64 (d, 3J(1H-1H) = 4.0 Hz, 2J(1H-117Sn) = 116.0 Hz, 2J(1H-119Sn) = 124.0 Hz, 2H, Sn-CH2), 2.80 (m, 1H, CH), 3.64-3.81 (complex

Tagne Kuate et al. pattern, 16H, CH2-O-CH2). 13C{1H} NMR (CD3CN, 100.63 MHz, 293 K) δ: 35.4 (1J(13C-117/119Sn) = 56 Hz, C12), 42.9 (C14), 68.2-68.8 (C2-C9), 74.4 (3J(13C-117/119Sn) = 149 Hz, C11/C13). 119Sn{1H} NMR (CDCl3, 111.93 MHz, 293 K) δ: -360. Anal. Calcd for C10H21Cl4LiO5Sn (488.72): C 24.6; H 4.3. Found: C 24.2; H 4.3. Complexation Studies. In Situ Reaction of 4 with CsF in CD3CN/CDCl3 at Different Molar Ratios. (a) CsF (3.8 mg, 0.025 mmol) was added to a solution of 4 (25.0 mg, 0.050 mmol) in CD3CN/CDCl3 (3:1) (600 μL), and the mixture was studied by NMR spectroscopy. 19 F{1H} NMR (282.4 MHz) 293 K: δ: -149.1 (ν1/2 = 1011 Hz, integral 1), -184.8 (ν1/2 776 Hz, integral 2); 248 K: δ -136.8 [1J(19F-117/119Sn) = 1339 Hz, 2J(19F-19F) = 72 Hz, signal d], -152.6 [1J(19F-117Sn) = 1816 Hz, 1J(19F-119Sn) = 1900 Hz, signal a], -164.3 [1J(19F-117/119Sn) = 1796 Hz, 2J(19F-19F) = 75 Hz, signal c], -183.4 [1J(19F-117Sn) = 2098 Hz, 1J(19F-119Sn) = 2183 Hz, signal b]. 119 Sn{1H} NMR (111.92 MHz, 293 K): No resonance observed. (b) CsF (15.3 mg, 0.101 mmol) was added to a solution of 4 (50.0 mg, 0.101 mmol) in CD3CN/CDCl3 (2:1) (600 μL), and the mixture was studied by NMR spectroscopy. 1 H NMR (400.13 MHz, 293 K) δ: 1.13 (br, 2J(1H-117/119Sn) = 80.0 Hz, 2H, Sn-CH2), 2.44 (m, 1H, CH), 3.26-3.56 (complex pattern, 16H, CH2-O-CH2), 7.25-7.95 (m, 10H, Ph). 13C{1H} NMR (100.63 MHz, 293 K) δ: 19.1 (C14), 35.9 (2J(13C117/119 Sn)=22 Hz, C12), 68.1-68.3 (C2-C9), 74.9 (C11/C13), 127.5 (3J(13C-117/119Sn) = 62 Hz, Cm), 127.8 (Cp), 136.8 (2J(13C-117/119Sn) = 46 Hz, Co). 19 F{1H} NMR (282.4 MHz) 293 K: -149.1 (ν1/2 = 550 Hz); 248 K: δ -151.9 (1J(19F-117Sn) = 1818 Hz, 1J(19F-119Sn) = 1897 Hz). 119Sn{1H} NMR (111.93 MHz, 293 K): δ -277 (t, 1 119 J( Sn-19F)=1885 Hz); 248 K: δ -274 [t, 1J(119Sn-19F) = 1902 Hz. In Situ Reaction of 2 with Three Molar Equivalents of LiI in CD3CN. LiI (33.3 mg, 0.249 mmol) was added to a solution of 2 (50.0 mg, 0.083 mmol) in CD3CN (600 μL), and the mixture was studied by NMR spectroscopy. 119 Sn{1H} NMR (111.92 MHz, 293 K) δ: -150 (ν1/2 = 125 Hz). In Situ Reaction of 5 with Three Molar Equivalents of LiI in CD3CN. LiI (30.9 mg, 0.231 mmol) was added to a solution of 5 (50.0 mg, 0.077 mmol) in CD3CN (600 μL), and the mixture was studied by NMR spectroscopy. 119 Sn{1H} NMR (111.92 MHz, 293 K) δ: -331 (ν1/2 = 254 Hz). In Situ Reaction of 6 with Three Molar Equivalents of LiI in CD3CN. LiI (28.5 mg, 0.213 mmol) was added to a solution of 6 (50.0 mg, 0.071 mmol) in CD3CN (600 μL), and the mixture was studied by NMR spectroscopy. 1 H NMR (400.13 MHz, 293 K) δ: 2.14 (m, 1H, CH), 3.25 (d, 3 1 J( H-1H) = 8.0 Hz, 2H, Sn-CH2), 3.68-3.89 (complex pattern, 16H, CH2-O-CH2). 13C{1H} NMR (100.63 MHz, 293 K) δ: 3.5 (C14), 38.4 (2J(13C-117/119Sn) = 38 Hz, C12), 66.9-68.4 (C2-C9), 74.3 (C11/C13). 119Sn{1H} NMR (111.93 MHz, 293 K) δ: -1132 (ν1/2 = 166 Hz). ESI-MS (MeCN, m/z, positive mode): 787.3, {I3SnCH2-[13]-crown-4 3 Li 3 CH3CN 3 H2O}þ. In Situ Reaction of 3 with Three Molar Equivalents of LiCl in CD3CN. LiCl (12.4 mg, 0.293 mmol) was added to a solution of 3 (50.0 mg, 0.098 mmol) in CD3CN, and the mixture was studied by NMR spectroscopy. 1 H NMR (400.13 MHz, 293 K) δ: 1.59 (d, 3J(1H-1H) = 4.0 Hz, 2H, 2J(1H-117Sn) = 72 Hz, 2J(1H-119Sn) = 88.0 Hz, SnCH2), 2.88 (m, 1H, CH), 3.49-3.81 (complex pattern, 16H, CH2-O-CH2), 7.27-7.34 (m, 8H, Hmþp, Ph), 8.02 (d, 3J(1H-1H) = 8 Hz, 3J(1H-117Sn) = 56 Hz, 3J(1H-119Sn) = 72 Hz, 2H, Ho, Ph). 13 C{1H} NMR (100.63 MHz, 293 K) δ: 26.4 (1J(13C-117Sn) = 624 Hz, 1J(13C-119Sn) = 656 Hz, C14), 35.5 (2J(13C-117/119Sn) = 24 Hz, C12), 66.8-67.8 (C2-C9), 77.4 (3J(13C-117/119Sn) =76 Hz, C11/C13). 127.4 (3J(13C-117/119Sn) = 67 Hz, Cm), 127.9 (4J(13C-117/119Sn) = 15 Hz, Cp), 136.6 (2J(13C-117/119Sn) = 49

Article Hz, Co), 147.6 (1J(13C-117Sn) = 735 Hz, 1J(13C-119Sn) = 769 Hz), Ci). 119 Sn{1H} NMR (111.92 MHz, 293 K) δ: -202 (ν1/2 = 2048 Hz). In Situ Reaction of 8 with One Molar Equivalent of (Ph3P)2NCl in CD3CN. (Ph3P)2NCl (27.0 mg, 0.047 mmom) was added to a solution of 8 (20.0 mg, 0.047 mmol) in CD3CN (600 μL), and the mixture was studied by NMR spectroscopy. 119 Sn{1H} NMR (CD3CN), 111.92 MHz, 293 K) δ: -402 (ν1/2 = 156 Hz). In Situ Reaction of 14 with Excess LiCl in CD3CN. Lithium chloride (3.69 mg, 8.91 10-5 mol) was added to a solution of 14 (20.0 mg, 2.97 10-5 mol) in CD3CN (600 μL), and the mixture was studied by NMR spectroscopy. 1 H NMR (400.13 MHz, 293 K) δ: 1.76 (d, 3J(1H-1H) = 4.0 Hz, 2J(1H-117Sn) = 108.0 Hz, 2J(1H-117Sn) = 116 Hz, 2H, SnCH2), 2.81 (s, 1J(1H-117/119Sn) = 96.0 Hz, 2H, Sn-CH2-Sn), 2.83 (m, 1H, CH), 3.56-3.88 (complex pattern, 16H, CH2-OCH2), 7.23-7.36 (m, 3H, Ph, Hmþp), 8.07 (d, 3J(1H-1H) = 8.0 Hz, 1J(1H-117Sn) = 104 Hz, 1J(1H-119Sn) = 116 Hz, 2H, Ph,


5471

NMR (100.63 MHz, 293 K) δ: 35.3 (2J(13CSn) = 148 Hz, C12), 40.19 (1J(13C-117Sn) = 880 Hz, 1 13 J( C-119Sn) = 922 Hz, C14), 64.0 (1J(13C-117Sn) = 793 Hz, 1 13 J( C-119Sn) = 827 Hz, C14), 66.8-67.8 (C2-C9), 76.9 (3J(13C-117/119Sn) = 101 Hz, C11/C13), 127.0 (3J(13C-117Sn) = 111 Hz, 3J(13C-117Sn) = 116 Hz, SnCl3Ph, Cm), 127.9 (4J(13C117/119 Sn) = 22 Hz, SnCl3Ph, Cp), 134.9 (2J(13C-117/119Sn) = 71 Hz, SnCl3Ph, Co), 155.1 (SnCl3Ph, Ci). 119Sn{1H} NMR (111.93 MHz, 293 K) δ: -207 (ν1/2 = 118 Hz, SnCH2CH), -279 (ν1/2 = 126 Hz, SnPh). Ho). 13C{1H} 117/119

Acknowledgment. A.C.T.K. is grateful to the German Academic Exchange Board (DAAD) for a scholarship. We thank Dr. G. Bradtm€ oller for recording the 119SnMAS NMR and Mrs. S. Marzian for recording the electrospray ionization mass spectra. Supporting Information Available: This material is available free of charge via the Internet at http://pubs.acs.org.

Organotin-Substituted [13]-Crown-4 Ethers: Ditopic Receptors for

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