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Organometallics 2010, 29, 1890–1896 DOI: 10.1021/om1001167
Synthesis of Heavier Group 14 Metal Compounds from 2,6-Lutidylbis(phosphoranosulfide) Wing-Por Leung,* Kwok-Wai Kan, and Thomas C. W. Mak Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People’s Republic of China Received February 12, 2010
The synthesis and characterization of various novel group 14 metal compounds derived from 2,6lutidylbisphosphoranosulfide, [(SdPPri2CH2)2C5H3N-2,6] (1), are reported. The monoanionic bis(thiophosphinoyl) lithium complex [Li{(SdPPri2CH)(SdPPri2CH2)C5H3N-2,6}(Et2O)] (2) has been prepared from the reaction of 1 with an equimolar amount of nBuLi in THF. Treatment of 1 with 1 equiv of M{N(SiMe3)2}2 (M = Sn, Pb) afforded the 1,3-distannacyclobutane [{2-{Sn{C(Pri2Pd S)}}-6-{CH2(Pri2PdS)}}C5H3N]2 (3) and 1,3-diplumbacyclobutane [{2-{Pb{C(Pri2PdS)}}-6-{CH2(Pri2PdS)}}-C5H3N]2 (4), respectively. The metathesis reaction of 2 with GeCl2 3 (dioxane) and SnCl2 gave the unexpected digermylgermylene Ge[GeCl2{(SdPPri2CH)(SdPPri2CH2)C5H3N-2,6}]2 (5) and ionic [2,6-lutidylbis(thiophosphinoyl)methanide]tin(II) trichlorostannate [{C5H3N-2,6(CH2PPri2dS)(CHPPri2dS)}Sn]þ[SnCl3]- (6), respectively. The X-ray structures of 2-6 have been determined by X-ray crystallography.
Introduction The coordination chemistry of thiophosphinoyl transition metal complexes has been studied by several research groups in view of the importance of metal-sulfur interaction and different bonding modes of various metal adducts.1 Phosphoranosulfides can be deprotonated by strong base to give anionic species or novel metal compounds. An unprecedented organoaluminum compound has been prepared by Robinson et al. through in situ double deprotonation of neutral bis(diphenylthiophosphinoyl)methane with AlMe3.2 Using the same ligand, Le Floch and co-workers reported the synthesis of the bis(diphenylthiophosphinoyl)methanediide dianion3 and its coordination chemistry with Pd(II), Ru(II), *To whom correspondence should be addressed. E-mail: kevinleung@ cuhk.edu.hk. (1) Selected examples of thiophosphinoyl metal complexes: (a) Aucott, S. M.; Slawin, A. M. Z.; Woollins, J. D. Eur. J. Inorg. Chem. 2002, 2408. (b) Faller, J. W.; Lloret-Fillol, J.; Parr, J. New J. Chem. 2002, 26, 883. (c) Suranna, G. P.; Mastrorilli, P.; Nobile, C. F.; Keim, W. Inorg. Chim. Acta 2000, 305, 151. (d) Grim, S. O.; Walton, E. D. Inorg. Chem. 1980, 19, 1982. (e) Doux, M.; Bouet, C.; Mezailles, N.; Ricard, L.; Le Floch, P. Organometallics 2002, 21, 2785. (f) Doux, M.; Mezailles, N.; Melaimi, M.; Ricard, L.; Le Floch, P. Chem. Commun. 2002, 1566. (g) Chivers, T.; Fedorchuk, C.; Krahn, M.; Parvez, M.; Schatte, G. Inorg. Chem. 2001, 40, 1936. (h) Rufanov, K. A.; Ziemer, B.; Meisel, M. Dalton Trans. 2004, 3808. (i) Lobana, T. S.; Sandhu, M. K.; Tiekink, E. R. T. J. Chem. Soc., Dalton Trans. 1988, 1401. (j) Baker, P. K.; Clark, A. I.; Drew, M. G. B.; Durrant, M. C.; Richards, R. L. Polyhedron 1998, 17, 1407. (k) Lobana, T. S.; Verma, R.; Singh, A.; Shikha, M.; Castineiras, A Polyhedron 2002, 21, 205. (l) Schumann, H. J. Organomet. Chem. 1987, 320, 145. (m) Arliguie, T.; Blug, M.; Le Floch, P.; Mezailles, N.; Thuery, P.; Ephritikhine, M. Organometallics 2008, 27, 4158. (2) Robinson, G. H.; Self, M. F.; Pennington, W. T.; Sangokoya, S. A. Organometallics 1988, 7, 2424. (3) Cantat, T.; Ricard, L.; Le Floch, P.; Mezailles, N. Organometallics 2006, 25, 4965. (4) Cantat, T.; Mezailles, N.; Ricard, L.; Jean, Y.; Le Floch, P. Angew. Chem., Int. Ed. 2004, 43, 6382. pubs.acs.org/Organometallics
Published on Web 03/29/2010
Zr(IV), Sm(III), and Tm(III) metal centers.4-8 Stable carbenoids and dicarbenoids can also be prepared from oxidation of the dianion.9,10 Nevertheless, thiophosphinoyl ligands have rarely been employed as ancillary ligands in synthesizing group 14 metal compounds. Herein, we report the synthesis of a novel 2,6-lutidylbis(phosphoranosulfide), [(SdPPri2CH2)2C5H3N-2,6] (1), used as a ligand precursor for several group 14 metal complexes.
Results and Discussion Synthesis of 2,6-Lutidylbis(phosphoranosulfide) and a Monoanionic Bis(thiophosphinoyl) Lithium Complex. The diphosphine [(PPri2CH2)2C5H3N-2,6] was prepared according to the modified procedure.11 Treatment of it with 2 equiv of elemental sulfur in toluene at 60 °C afforded the novel 2,6lutidylbis(phosphoranosulfide) [(SdPPri2CH2)2C5H3N-2,6] (1) (Scheme 1). Compound 1 was isolated as a white crystalline solid after recrystallization from toluene or diethyl ether. The reaction of 1 with 1 equiv of nBuLi in THF gave the monoanionic bis(thiophosphinoyl) lithium complex [Li{(SdPPr i 2 CH)(SdPPr i 2 CH 2 )C 5 H 3 N-2,6}(Et 2 O)] (2) (Scheme 1). (5) Cantat, T.; Demange, M.; Mezailles, N.; Ricard, L.; Jean, Y.; Le Floch, P. Organometallics 2005, 24, 4838. (6) Cantat, T.; Jaroschik, F.; Ricard, L.; Le Floch, P; Nief, F.; Mezailles, N. Organometallics 2006, 25, 1329. (7) Cantat, T.; Jaroschik, F.; Nief, F.; Ricard, L.; Mezailles, N.; Le Floch, P. Chem. Commun. 2005, 5178. (8) Cantat, T.; Ricard, L.; Mezailles, N.; Le Floch, P. Organometallics 2006, 25, 6030. (9) Cantat, T.; Jacques, X.; Ricard, L.; Le Goff, X. F.; Mezailles, N.; Le Floch, P. Angew. Chem., Int. Ed. 2007, 46, 5947. (10) Konu, J.; Chivers, T. Chem. Commun. 2008, 4995. (11) Ziessel, R. Tetrahedron Lett. 1989, 30, 463. r 2010 American Chemical Society
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Scheme 1
Scheme 2
Synthesis of 1,3-Distannacyclobutane and 1,3-Diplumbacyclobutane. Reaction of 1 with 1 equiv of M{N(SiMe3)2}2 (M = Sn, Pb) afforded the 1,3-distannacyclobutane [{2-{Sn{C(Pri2PdS)}}-6-{CH2(Pri2PdS)}}C5H3N]2 (3) and 1,3-diplumbacyclobutane [{2-{Pb{C(Pri2PdS)}}-6-{CH2(Pri2Pd S)}}C5H3N]2 (4), respectively (Scheme 2). It is proposed that the reactions proceed through the unstable metallavinylidenes. Elimination of 2 equiv of hexamethyldisilazane formed the intermediate metallavinylidene [{2-{:MdC(Pri2PdS)}-6-{CH2(Pri2PdS)}}-C5H3N] (M = Sn, Pb). Subsequently, this intermediate underwent a head-to-tail cyclodimerization to form the 1,3-dimetallacyclobutane. Our group has reported the synthesis of similar 1,3-dimetallacyclobutanes using phosphoranoimine as the ligand backbone.12-14 Synthesis of Digermylgermylene. Metathesis reaction of 2 with 1.5 equiv of GeCl2 3 (dioxane) afforded the novel digermylgermylene Ge[GeCl2{(SdPPri2CH)(SdPPri2CH2)C5H3N-2,6}]2 (5) (Scheme 3). It is suggested that the intermediate [GeCl{(SdPPri2CH)(SdPPri2CH2)C5H3N-2,6}] (I) formed underwent an insertion reaction into the GeII-Cl bond of GeCl2 3 (dioxane) to give [GeCl(GeCl2){(SdPPri2CH)(Sd PPri2CH2)C5H3N-2,6}] (II). The GeII-Cl bond of II then further reacted with I to form digermylgermylene. A similar insertion reaction of the Ge-Cl bond has been reported by Kira and co-workers.15 Attempts to isolate I by reacting equimolar amounts of 2 and GeCl2 3 (dioxane) were unsuccessful; a mixture of 5 and I was obtained, as shown by 31 P{1H} NMR spectroscopy. (12) Leung, W.-P.; Wong, K.-W.; Wang, Z.-X.; Mak, T. C. W. Organometallics 2006, 25, 2037. (13) Leung, W.-P.; Wang, Z.-X.; Li, H.-W.; Yang, Q.-C.; Mak, T. C. W. J. Am. Chem. Soc. 2001, 123, 8123. (14) Leung, W.-P.; Wang, Z.-X.; Li, H.-W.; Mak, T. C. W. Angew. Chem., Int. Ed. 2001, 40, 2501. (15) Iwamoto, T.; Masuda, H.; Kabuto, C.; Kira, M. Organometallics 2005, 24, 197.
Scheme 3
Synthesis of Ionic [2,6-Lutidylbis(thiophosphinoyl)methanide]tin(II) Trichlorostannate. The reaction of 2 with excess SnCl2 afforded the ionic bis(thiophosphinoyl)methanide tin(II) trichlorostannate [{C5H3N-2,6-(CH2PPri2dS)(CHPPri2dS)}Snþ][SnCl3-] (6) (Scheme 4). The first step probably involved the formation of the chlorostannylene [{C5H3N-2,6-(CH2PPri2dS)(CHPPri2dS)}SnCl] (III) by a metathesis reaction between 2 and SnCl2. The excess SnCl2 is then reacted as a chloride abstracting agent with compound III to yield compound 6. The chloride-abstracting properties of SnCl2 have been reported in the literature.16 Spectroscopic Properties. Compounds 1-6 were isolated as colorless, pale yellow, red, or orange crystalline solids. They are air-sensitive and soluble in THF and CH2Cl2 but sparingly soluble in Et2O. The 1H NMR and 13C{1H} NMR spectra of 1 are consistent with the compounds having the (16) (a) Farkas, E.; Kollar, L.; Moret, M.; Sironi, A. Organometallics 1996, 15, 1345. (b) Tian, X.; Pape, T.; Mitzel, N. W. Z. Naturforsch., B: Chem. Sci. 2004, 59, 1524. (c) Veith, M.; Goedicke, B.; Huch, V. Z. Anorg. Allg. Chem. 1989, 579, 87.
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Scheme 4
Figure 1. Molecular structure of [Li{(SdPPri2CH)(SdPPri2CH2)C5H3N-2,6}(Et2O)] (2) (30% probability ellipsoids).
2,6-lutidyl ligand backbone. The 1H NMR spectrum of 2 displayed two different isopropyl groups, which is consistent with the solid-state structures. The 31P{1H} NMR spectrum of 1 displayed two signals at δ 58.36 and 71.29 ppm. The 1H NMR and 13C{1H} NMR spectra of 3 and 4 are normal. The 31 P{1H} NMR spectrum of 3 displayed two signals at δ 69.70 and 84.29 ppm with tin satellites (2J(31P-119Sn) = 1221 Hz). The 31P{1H} NMR spectrum of 4 displayed two signals at δ 65.16 and 74.57 ppm with lead satellites (2J(31P-207Pb) = 1880 Hz). These are consistent with the solid-state structures of 3 and 4 having two different phosphorus environments. Owing to the low solubility of 3 and 4, we were unable to detect the 119Sn-31P coupling and 207Pb-31P coupling signals from the corresponding 119Sn{1H} and 207Pb{1H} NMR spectra. The 119Sn{1H} NMR signal of 3 and 207Pb{1H} NMR signal of 4 were detected with low intensity at -4.02 and 2193.4 ppm, respectively. The 1H NMR and 13C{1H} NMR spectra of 5 both displayed signals due to the 2,6-lutidylbis(phosphoranosulfide) ligand backbone. The 31P{1H} NMR spectrum of 5 showed two signals at δ 78.92 and 84.28 ppm, which do not correspond to the X-ray structure. In the solid-state structure there are four different phosphorus atoms. However, this is not reflected in solution, where only two 31P resonances are observed. Apparently, the intramolecular PdSfGe coordination is kinetically labile and the dissociation process is fast on the NMR time scale at room temperature. We have carried out the low- temperature 31P NMR study of 5 in d8THF. There was no obvious change in the two signals at -60 °C. The 1H and 13C{1H} NMR spectra of 6 displayed signals assignable to the ligand backbone. The 31P{1H} NMR spectrum of 6 displayed two signals of δ 81.37 and 83.82 ppm which are assignable to two different phosphorus environments and are consistent with the solid-state structure. Due to the low solubility of compound 6 in THF, tin satellites were not observed in the 31P{1H} NMR spectrum. The 119Sn{1H} NMR spectrum of 6 showed two signals at δ -119.94 (2J(119Sn-31P) = 140.3 Hz) and -97.50 ppm, which correspond to the stannyl cation and trichlorostannate anion, respectively. X-ray Structures. The molecular structures of 2-6 are shown in Figures 1-5, respectively. Selected bond distances (A˚) and angles (deg) are given in Tables 1 and 2. Compound 2 is a lithium complex consisting of a lithium center which is bonded to the ligand in S,N,S0 -chelation and coordinated to one Et2O molecule with a tetrahedral geometry. The
Figure 2. Molecular structure of [{2-{Sn{C(Pri2PdS)}}-6{CH2(Pri2PdS)}}C5H3N]2 (3) (30% probability ellipsoids).
Figure 3. Molecular structure of [{2-{Pb{C(Pri2PdS)}}-6{CH2(Pri2PdS)}}C5H3N]2 (4) (30% probability ellipsoids).
P(1)-C(6) bond distance of 1.707(8) A˚ and P(1)-S(1) bond distance of 2.009(3) A˚ in 2 are different from those found in 3 (P-C = 1.835(2) A˚; P-S = 1.941(1) A˚), suggesting the charge delocalization within the C-P-S skeleton. Compound 3 consists of two tin atoms bridged by two methanediide carbon atoms, forming a 1,3-Sn2C2 fourmembered ring. The two pyridyl nitrogen atoms of the ligand coordinate to the trigonal-pyramidal tin centers to form
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Table 1. Selected Bond Distances (A˚) and Angles (deg) for Compounds 2 and 3a [Li{(SdPPri2CH)(SdPPri2CH2)C5H3N-2,6}(Et2O)] (2) Li(1)-O(1) Li(1)-N(1) Li(1)-S(1) Li(1)-S(2) N(1)-C(5)
Figure 4. Molecular structure of Ge[GeCl2{(SdPPri2CH)(Sd PPri2CH2)C5H3N-2,6}]2 (5) (30% probability ellipsoids).
O(1)-Li(1)-N(1) O(1)-Li(1)-S(1) N(1)-Li(1)-S(1) O(1)-Li(1)-S(2) N(1)-Li(1)-S(2)
1.977(2) 2.037(1) 2.393(1) 2.556(2) 1.357(8) 108.6(7) 107.6(7) 113.5(5) 113.2(6) 100.3(6)
N(1)-C(1) P(1)-C(6) P(1)-S(1) P(2)-C(13) P(2)-S(2)
1.386(8) 1.707(8) 2.009(3) 1.819(8) 1.967(3)
S(1)-Li(1)-S(2) C(5)-N(1)-C(1) C(6)-P(1)-S(1) C(13)-P(2)-S(2)
113.5(5) 117.4(6) 118.2(3) 113.6(3)
[{2-{Sn{C(Pri2PdS)}}-6-{CH2(Pri2PdS)}}C5H3N]2 (3) Sn(1)-C(6) Sn(1)-C(6A) Sn(1)-N(1) P(1)-C(6) C(6)-Sn(1)-C(6A) C(6)-Sn(1)-N(1) C(6A)-Sn(1)-N(1) Sn(1)-C(6)-Sn(1A)
2.294(2) 2.322(2) 2.400(2) 1.758(2) 86.7(7) 88.8(6) 59.1(5) 90.7(7)
P(2)-C(13) P(1)-S(1) P(2)-S(2) C(6)-P(1)-S(1) C(13)-P(2)-S(2) P(1)-C(6)-Sn(1) P(1)-C(6)-Sn(1A)
1.835(2) 1.987(8) 1.941(1) 105.8(7) 113.8(9) 104.6(8) 119.4(9)
Figure 5. Molecular structure of [{C5H3N-2,6-(CH2PPri2dS)(CHPPri2dS)}Snþ][SnCl3-] (6) (30% probability ellipsoids).
Sn(1)-C(6)
SnCCN four-membered rings. These SnCCN rings together with the Sn2C2 ring, as the base, form a structure framework similar to an “open box”. The Sn2C2 ring is nonplanar, as indicated by the angle sum of 354.7°. The average Sn-N bond distance of 2.400 A˚ and average Sn-C bond distance of 2.308 A˚ in 3 are comparable to those found in 1,3-[Sn{C(Pri2PdNSiMe3)(2-Py)}]2 (Sn-N = 2.470 A˚; Sn-C = 2.325 A˚)13 and 1,3-[Sn{C(Ph2PdNSiMe3)2}]2 (Sn-N = 2.462 A˚; Sn-C = 2.376 A˚).14 The Sn-Sn distance of 3.283(2) A˚ in 3 is similar to those found in the previous 1,3-distannacyclobutanes (3.28113 and 3.290 A˚14). It is shorter than the sum of the van der Waals radius of 4.4 A˚17 but is in excess of the 2.81 A˚ distance in elemental tin.18 This suggested that a weak Sn-Sn interaction is possible in 3. Compound 4 consists of a 1,3-diplumbacyclobutane ring which is similar to the molecular structure of 3. With the Pb2C2 group as the base, the PbCPS and PbCCN rings form the flaps of an “open box”-like structure framework, which is similar to that of 2. The coordination of the metal centers in 4 is somewhat different from that of 3. The two thio sulfur atoms and two pyridyl nitrogen atoms of the ligand coordinate to the four-coordinated lead center to form PbCPS and PbCCN four-membered rings. The additional coordination from the thio groups is presumably due to the larger atomic size of the Pb(II) atom. The lead centers adopt a distortedsquare-pyramidal geometry. The average Pb-S bond distance of 3.050 A˚ in 4 is similar to that of 2.964 A˚ in [Pb{SO(PPh2)2N}2]19 and 3.093 A˚ in [Pb{S2P-(OC6H11)2}2]n.20 The average Pb-N bond distance of 2.547 A˚ and average Pb-C bond distance of 2.423 A˚ in 4 are comparable to those found in 1,3[Pb{C(Pri2PdNSiMe3)(2-Py)}]2 (Pb-N = 2.594 A˚; Pb-C =
2.411 A˚)13 and 1,3-[Pb{C(Ph2PdNSiMe3)2}]2 (Pb-N = 2.647 A˚; Pb-C = 2.494 A˚).14 Compound 5 is a homoleptic germylene with two germyl substituents, featuring a GeIV-GeII-GeIV linkage. The geometry around the two germanium(IV) centers are distorted tetrahedral, while the germanium(II) center displays a trigonalpyramidal geometry. It is noteworthy that the angles Ge(2)Ge(1)-Ge(3) = 89.4(2)°, Ge(2)-Ge(1)-S(1) = 82.8(3)°, and Ge(3)-Ge(1)-S(1) = 86.4(3)° are close to 90°. This shows that the germanium(II) center is almost nonhybridized. The lone pair occupies an orbital with high s character, and the σ bonds to the germyl substituents are formed by using p orbitals at the germanium(II) center.21 The average GeII-GeIV bond distance of 2.480 A˚ in 5 is comparable to that of 2.544(7) A˚ in C6H32,6-(C6H2-2,4,6-Me3)2GeGe(But)322 and 2.449(1) A˚ in [{μ(Me3Si)C(PMe2)2}2Ge2]2GeCl2.23 The average GeIV-C bond distance of 2.005 A˚ is slightly longer than that of 1.924(7) A˚ in [Ge{μ-C(C5H4N-2)C(Ph)N(SiMe3)}Cl2]2,24 which may be due to the steric repulsion between two ligands. The average GeIV-Cl bond distance of 2.192 A˚ is in good agreement with that of 2.180 A˚ in [{(C5H4N-2)C(H)C(Ph)N}(μ-GeCl2)2].24 The two functionalized pyridines remain uncoordinated, which may result from the steric crowding at the germanium centers. The hydrogen atoms of the pyridine ring are nonequivalent, which may be due to the restricted rotation caused by steric hindrance. Compound 6 is an ionic tin(II) compound consisting of a stannyl cation and a trichlorostannate anion. The geometry around the tin center in the stannyl cation is distorted
(17) Bondi, A. J. Phys. Chem. 1964, 48, 441. (18) Wells, A. F. Structural Inorganic Chemistry, 5th ed.; Clarendon: Oxford, U.K., 1984; p 1279. (19) Garcı´ a-Montalvo, V.; Cea-Olivares, R.; Espinosa-Perez, G. Polyhedron 1996, 15, 829. (20) Larsson, A. C.; Ivanov, A. V; Antzutkin, O. N; Gerasimenko, A. V; Forsling, W. Inorg. Chim. Acta 2004, 357, 2510.
2.294(2)
P(2)-C(13)
1.835(2)
Symmetry transformations used to generate equivalent atoms: -x þ 2, y, -z þ 3/2. a
(21) Jutzi, P.; Keitemeyer, S.; Neumann, B.; Stammler, H.-G. Organometallics 1999, 19, 4778. (22) Setaka, W.; Sakamoto, K.; Kira, M.; Power, P. P. Organometallics 2001, 20, 4460. (23) Karsch, H. H.; Deubelly, B.; Riede, J.; M€ uller, G. Angew. Chem., Int. Ed. 1987, 26, 674. (24) Leung, W.-P.; So, C.-W.; Wu, Y.-S.; Li, H.-W.; Mak, T. C. W. Eur. J. Inorg. Chem. 2005, 513.
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Table 2. Selected Bond Distances (A˚) and Angles (deg) for Compounds 4-6 [{2-{Pb{C(Pri2PdS)}}-6-{CH2(Pri2PdS)}}C5H3N]2 (4) Pb(1)-C(6) Pb(1)-C(25) Pb(1)-N(1) Pb(1)-S(3) Pb(2)-C(6) Pb(2)-C(25) C(25)-Pb(1)-C(6) C(25)-Pb(1)-N(1) C(6)-Pb(1)-N(1) C(25)-Pb(1)-S(3) C(6)-Pb(1)-S(3) C(6)-Pb(2)-C(25)
2.471(7) 2.408(6) 2.538(5) 3.082(2) 2.408(6) 2.415(7) 88.8(2) 89.6(2) 55.5(2) 65.1(2) 111.7(2) 90.1(2)
Pb(2)-N(2) Pb(2)-S(1) P(1)-S(1) P(2)-S(2) P(3)-S(3) P(4)-S(4) C(6)-Pb(2)-N(2) C(25)-Pb(2)-N(2) C(6)-Pb(2)-S(1) C(25)-Pb(2)-S(1) Pb(2)-C(6)-Pb(1) Pb(1)-C(25)-Pb(2)
Conclusion
2.556(5) 3.017(2) 2.002(3) 1.949(3) 1.987(3) 1.946(3) 91.9(2) 55.9(2) 66.5(2) 113.6(2) 88.2(2) 89.5(2)
Ge[GeCl2{(SdPPri2CH)(SdPPri2CH2)C5H3N-2,6}]2 (5) Ge(1)-Ge(2) Ge(1)-Ge(3) Ge(1)-S(1) Ge(2)-C(6) Ge(2)-Cl(1) Ge(2)-Cl(2) Ge(3)-C(25) Ge(2)-Ge(1)-Ge(3) Ge(2)-Ge(1)-S(1) Ge(3)-Ge(1)-S(1) C(6)-Ge(2)-Cl(1) C(6)-Ge(2)-Cl(2) Cl(1)-Ge(2)-Cl(2) C(6)-Ge(2)-Ge(1) Cl(1)-Ge(2)-Ge(1) Cl(2)-Ge(2)-Ge(1)
2.478(6) 2.481(6) 2.675(1) 2.006(4) 2.189(1) 2.192(1) 2.004(4) 89.4(2) 82.8(3) 86.4(3) 108.2(1) 98.7(1) 100.5(5) 115.4(1) 110.9(4) 121.4(3)
Ge(3)-Cl(3) Ge(3)-Cl(4) S(1)-P(1) S(2)-P(2) S(3)-P(3) S(4)-P(4) C(25)-Ge(3)-Cl(3) C(25)-Ge(3)-Cl(4) Cl(3)-Ge(3)-Cl(4) C(25)-Ge(3)-Ge(1) Cl(3)-Ge(3)-Ge(1) Cl(4)-Ge(3)-Ge(1) P(1)-S(1)-Ge(1) P(1)-C(6)-Ge(2) P(3)-C(25)-Ge(3)
2.190(1) 2.193(1) 2.012(2) 1.951(2) 2.000(1) 1.956(1) 107.8(1) 99.8(1) 99.4(5) 119.0(1) 108.8(4) 119.9(4) 109.3(5) 111.4(2) 112.1(2)
[{C5H3N-2,6-(CH2PPri2dS)(CHPPri2dS)}Snþ][SnCl3-] (6) Sn(1)-N(1) Sn(1)-C(6) Sn(1)-S(1) Sn(2)-Cl(1) Sn(2)-Cl(2) N(1)-Sn(1)-C(6) N(1)-Sn(1)-S(1) C(6)-Sn(1)-S(1) Cl(2)-Sn(2)-Cl(1) Cl(2)-Sn(2)-Cl(3)
2.295(5) 2.529(7) 2.662(4) 2.495(4) 2.468(3) 59.6(2) 90.2(1) 72.7(2) 95.5(1) 94.5(9)
Sn(2)-Cl(3) S(1)-P(1) S(2)-P(2) P(1)-C(6) P(2)-C(13) Cl(1)-Sn(2)-Cl(3) P(1)-S(1)-Sn(1) C(6)-P(1)-S(1) C(13)-P(2)-S(2)
distance of 2.478 A˚ in the trichlorostannate anion is similar to that of 2.474(4) A˚ in [Sn9{η-C5Me4(SiMe2But)}6Cl12].28
2.519(4) 2.043(3) 2.003(3) 1.771(6) 1.836(7) 94.9(9) 83.7(1) 107.5(2) 111.6(3)
trigonal pyramidal, while the anionic tin center displays a trigonal-pyramidal structure. Both geometries imply a stereochemically active lone pair at the tin centers. The Sn-C bond distance of 2.529(7) A˚ in 6 is significantly longer than that of 2.329(4) A˚ in Sn[CPh(SiMe3)(C5H4N-2)]225 and 2.281(5) A˚ in Sn[2,4,6-(F3C)3C6H2]2.26 The Sn-S bond distance of 2.662(4) A˚ is shorter than those of 2.838(7) and 2.914(7) A˚ in Sn[OC(CF3)2CH2P(S)tBu2]2.27 The P(1)-C(6) bond distance of 1.771(6) A˚ and P(1)-S(1) bond distance of 2.043(3) A˚ in 6 are different from those found in 3 (P-C = 1.835(2) A˚; P-S = 1.941(1) A˚), suggesting charge delocalization within the C-P-S skeleton. The average Sn-Cl bond (25) Leung, W.-P.; Kwok, W.-H.; Weng, L.-H.; Law, L. T. C.; Zhou, Z.-Y.; Mak, T. C. W. J. Chem. Soc., Dalton Trans. 1997, 4301. (26) Gr€ utzmacher, H.; Pritzkow, H.; Edelmann, F. T. Organometallics 1991, 10, 23. (27) Ionkin, A. S.; Marshall, W. J.; Fish, B. M. Organometallics 2006, 25, 4170. (28) Constantine, S. P.; De Lima, G. M.; Hitchcock, P. B.; Keates, J. M.; Lawless, G. A. Chem. Commun. 1996, 2337.
To summarize, the monolithium salt prepared from [(SdPPri2CH2)2C5H3N-2,6] acts as a ligand transfer reagent in the synthesis of various heavier group 14 metal compounds. Novel compound, including a digermylgermylene and a tin(II) trichlorostannate, were synthesized and structurally characterized by X-ray crystallography and spectroscopic methods.
Experimental Section General Procedures. All manipulations were carried out under an inert atmosphere of dinitrogen gas by standard Schlenk techniques. Solvents were dried over and distilled from CaH2 (hexane) and/or Na (Et2O, toluene, and THF). Sn{N(SiMe3)2}2 and Pb{N(SiMe3)2}2 were prepared according to the literature procedures.29 2,6-Lutidine, diisopropylphosphine, sulfur, n BuLi in 1.6 M hexane, GeCl2 3 (dioxane), and SnCl2 were purchased from Aldrich Chemical Co. and used without further purification. The 1H, 13C{1H}, 31P{1H}, 119Sn{1H}, and 207Pb{1H} NMR spectra were recorded on Bruker WM-300 or Varian 400 spectrometers. The NMR spectra were recorded in THF-d8, and the chemical shifts δ are relative to SiMe4 for 1H and 13 C{1H} and 85% H3PO4, SnMe4, and PbMe4 for 31P{1H}, 19 Sn{1H}, and 207Pb{1H}, respectively. [(SdPPri2CH2)2C5H3N-2,6] (1). A solution of the diphosphine [(PPri2CH2)2C5H3N-2,6] (8.60 g, 25.3 mmol) in toluene (20 mL) was added slowly to a solution of sulfur (1.62 g, 50.6 mmol) in toluene (20 mL) at room temperature. The reaction mixture was stirred at 60 °C for 14 h, and a colorless solution was formed. After filtration and concentration of the filtrate, compound 1 was obtained as colorless crystals. Yield: 9.11 g (89.2%). Mp: 127.8-130.1 °C. Anal. Found: C, 56.66; H, 8.89; N, 3.50. Calcd for C19H35NP2S2: C, 56.55; H, 8.74; N, 3.47. 1H NMR (THF-d8): δ 1.15-1.23 (m, 24H, CHMe2), 2.17-2.35 (m, 4H, CHMe2), 3.36 (d, 4H, JP-H = 13.2 Hz, CH2), 7.26 (d, 1H, JH-H = 6.9 Hz, Py), 7.37 (d, 1H, JH-H = 7.5 Hz, Py), 7.59 (t, 1H, JH-H = 7.8 Hz, Py). 13C{1H} NMR (THF-d8): δ 16.3-18.6 (m, CHMe2), 27.4-30.3 (m, CHMe2), 39.2 (d, JP-C = 150.3 Hz, CH2), 124.0 (d, JP-C = 282.2 Hz, Py), 137.4, 155.0 (Py). 31P{1H} NMR (THF-d8): δ 82.81. [Li{(SdPPri2CH)(SdPPri2CH2)C5H3N-2,6}(Et2O)] (2). To a solution of 1 (0.82 g, 2.03 mmol) in THF (30 mL) was added n BuLi (1.20 mL, 1.92 mmol) slowly at 0 °C. The reaction mixture was stirred at room temperature for 17 h, and a yellow solution was formed. Volatiles in the mixture were removed under reduced pressure, and the residue was extracted with Et2O. After filtration and concentration of the filtrate, compound 2 was obtained as yellow crystals. Yield: 0.40 g (48.7%). Mp: 129.3130.5 °C. Anal. Found: C, 56.98; H, 9.24; N, 3.03. Calcd for C19H34LiNP2S2 3 Et2O: C, 57.12; H, 9.17; N, 2.90. 1H NMR (THF-d8): δ 1.24-1.53 (m, 12H, CHMe2), 1.62-1.86 (m, 12H, CHMe2), 1.92-2.09 (m, 2H, CHMe2), 2.42-2.54 (m, 2H, CHMe2), 2.99 (d, 2H, JP-H = 13.2 Hz, CH2), 3.61 (d, 1H, JP-H = 16.5 Hz, CH), 6.89 (d, 1H, JH-H = 8.7 Hz, Py), 7.12 (t, 1H, JH-H = 8.7 Hz, Py), 7.37 (d, 1H, JH-H = 7.5 Hz, Py). 13 C{1H} NMR (THF-d8): δ 15.7-17.4 (m, CHMe2), 27.4-28.0 (m, CHMe2), 31.3 (d, JP-C = 270.7 Hz, CH2), 65.6 (d, JP-C = 182.0 Hz, CH), 125.2 (d, JP-C = 90.1 Hz, Py), 128.5 (d, JP-C = 150 Hz, Py), 129.1, 133.21, 137.8 (Py). 31P{1H} NMR (THF-d8): δ 58.36, 71.29. (29) Gynane, M. J. S.; Harris, D. H.; Lappert, M. F.; Power, P. P.; Riviere, P.; Riviere-Baudet, M. J. Chem. Soc., Dalton Trans. 1977, 2004.
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Table 3. Crystallographic Data for Compounds 2-4
formula fw color cryst syst space group a (A˚) b (A˚) c (A˚) R (deg) β (deg) γ (deg) V (A˚3) Z dcalcd (g cm-3) μ (mm-1) F(000) cryst size (mm) 2θ range (deg) index ranges no. of rflns collected no. of indep rflns R1, wR2 (I > 2σ(I)) R1, wR2 (all data) goodness of fit, F2 no. of data/restraints/params largest diff peaks, e A˚-3
2
3
4
C23H44LiNOP2S2 483.59 yellow orthorhombic P212121 11.834(2) 14.601(3) 16.589(3) 90 90 90 2866.4(10) 4 1.121 0.311 1048 0.50 0.50 0.30 2.11-25.00 0 e h e 14 0 e k e 17 0 e l e 19 2852 2852 0.0605, 0.1585 0.1310, 0.1942 0.980 2852/4/271 0.298 to -0.284
C38H66Sn2N2P4S4 3 Et2O 1112.53 orange monoclinic C2/c 21.031(2) 15.0474(18) 16.758(2) 90 91.251(2) 90 5302.0(11) 4 1.394 1.252 2288 0.50 0.50 0.40 1.66-28.32 -28 e h e 19 -18 e k e 20 -22 e l e 22 18 286 6568 0.0244, 0.0618 0.0344, 0.0689 1.020 6568/0/249 0.507 to -0.406
C38H66Pb2N2P4S4 3 Et2O 1289.53 red triclinic P1 10.533(3) 15.395(4) 16.602(4) 78.485(5) 85.666(5) 85.908(6) 2626.0(12) 2 1.631 6.715 1272 1.50 0.50 0.30 1.35-25.00 -12 e h e 12 -11 e k e 18 -19 e l e 19 14 225 9222 0.0428, 0.1113 0.0561, 0.1198 1.027 9222/0/496 2.329 to -3.121
[{2-{Sn{C(Pri2PdS)}}-6-{CH2(Pri2PdS)}}C5H3N]2 (3). A solution of Sn{N(SiMe3)2}2 (1.10 g, 2.50 mmol) in toluene (10 mL) was added to a solution of 1 (1.01 g, 2.50 mmol) in toluene (10 mL) at room temperature. The reaction mixture was stirred at room temperature for 2 days, and an orange solution was formed. Volatiles in the mixture were removed under reduced pressure, and the residue was extracted with Et2O. After filtration and concentration of the filtrate, compound 3 was obtained as orange crystals. Yield: 1.57 g (60.4%). Mp: 110.5-112.1 °C. Anal. Found: C, 43.29; H, 6.45; N, 2.65. Calcd for C38H66Sn2N2P4S4: C, 43.86; H, 6.39; N, 2.69. 1H NMR (THF-d8): δ 1.10-1.66 (m, 48H, CHMe2), 2.20-2.43 (m, 8H, CHMe2), 3.39 (d, 4H, JP-H = 21.2 Hz, CH2), 6.68 (d, 2H, JH-H = 1.8 Hz, Py), 7.11 (t, 2H, JH-H = 1.5 Hz, Py), 7.30 (d, 2H, JH-H = 1.5 Hz, Py). 13C{1H} NMR (THF-d8): δ 16.1-17.5 (m, CHMe2), 26.2-29.8 (m, CHMe2), 38.9 (d, JP-C = 129 Hz, CH2), 124.6 (d, JP-C = 142.4 Hz, Py), 130.3 (d, JP-C = 77.8 Hz, Py), 137.2, 157.1, 162.2 (Py). 31P{1H} NMR (THF-d8): δ 69.70, 84.29 with satellites (J = 1221 Hz). 119Sn{1H} NMR (THF-d8): δ -4.02. [{2-{Pb{C(Pri2PdS)}}-6-{CH2(Pri2PdS)}}C5H3N]2 (4). A solution of Pb{N(SiMe3)2}2 (1.75 g, 3.32 mmol) in toluene (10 mL) was added to a solution of 1 (1.33 g, 3.32 mmol) in toluene (10 mL) at room temperature. The reaction mixture was stirred at room temperature for 2 days, and a red solution was formed. Volatiles in the mixture were removed under reduced pressure, and the residue was extracted with Et2O. After filtration and concentration of the filtrate, compound 4 was obtained as red crystals. Yield: 1.44 g (35.7%). Mp: 231.5-234.2 °C. Anal. Found: C, 38.12; H, 5.68; N, 2.05. Calcd for C38H66Pb2N2P4S4 3 1/2THF: C, 38.34; H, 5.59; N, 2.24. 1H NMR (THF-d8): δ 0.88-1.34 (m, 48H, CHMe2), 1.98-2.29 (m, 8H, CHMe2), 3.35 (d, 4H, JP-H = 12.0 Hz, CH2), 6.21 (d, 2H, JH-H = 0.9 Hz, Py), 7.19 (t, 2H, JH-H = 1.2 Hz, Py), 7.34 (d, 2H, JH-H = 0.9 Hz, Py). 13C{1H} NMR (CH2Cl2-d2): δ 16.5-17.4 (m, CHMe2), 26.1-28.5 (m, CHMe2), 38.3 (d, JP-C = 90.3 Hz, CH2), 68.1 (d, JP-C = 113.2 Hz, C-Pb) 115.4 (d, JP-C = 66.8 Hz, Py), 124.3 (d, JP-C = 75.8 Hz, Py), 136.6, 147.8, 162.4 (Py). 31P{1H} NMR (THF-d8): δ 65.16, 73.30 with satellites (J = 1880 Hz). 207Pb{1H} NMR (THF-d8): δ 2193.42.
Table 4. Crystallographic Data for Compounds 5 and 6
formula fw color cryst syst space group a (A˚) b (A˚) c (A˚) R (deg) β (deg) γ (deg) V (A˚3) Z dcalcd (g cm-3) μ (mm-1) F(000) cryst size (mm) 2θ range (deg) index ranges no. of rflns collected no. of indep rflns R1, wR2 (I > 2σ(I)) R1, wR2 (all data) goodness of fit, F2 no. of data/restraints/ params largest diff peaks, e A˚-3
5
6
C38H68Ge3Cl4N2P4S4 1164.63 colorless triclinic P1 9.0484(12) 13.2864(18) 22.754(3) 95.876(3) 92.024(3) 93.584(3) 2713.5(6) 2 1.425 2.148 1196 0.50 0.30 0.20 0.90-28.05 -11 e h e 11 -17 e k e 12 -29 e l e 30 18 630 12 890 0.0460, 0.1062 0.0866, 0.1280 1.023 2852/4/271
C19H34Sn2Cl3NP2S2 746.6 yellow monoclinic P21/c 28.75(4) 7.821(11) 28.33(4) 90 109.53(3) 90 6005(15) 8 1.651 2.184 2944 0.50 0.40 0.30 0.75-25.00 -34 e h e 31 -9 e k e 9 -28 e l e 33 29 245 10 476 0.0434, 0.0992 0.0805, 0.1191 0.992 10 476/0/523
0.298 to -0.284
2.296 to -0.663
Ge[GeCl2{(SdPPri2CH)(SdPPri2CH2)C5H3N-2,6}]2 (5). A solution of 2 (0.93 g, 1.93 mmol) in Et2O (20 mL) was added to a solution of GeCl2 3 (dioxane) (0.67 g, 2.90 mmol) in Et2O (20 mL) at 0 °C. The reaction mixture was stirred at room temperature for 28 h, and a white suspension was formed. Volatiles in the mixture were removed under reduced pressure, and the residue was extracted with CH2Cl2. After filtration and concentration of the filtrate, compound 5 was obtained as colorless crystals. Yield: 0.18 g (18.4%). Mp: 185.3-188.8 °C. Anal. Found: C, 38.88; H, 5.79; N, 2.35. Calcd for C38H68Ge3Cl4N2P4S4: C, 39.18;
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H, 5.88; N, 2.40. 1H NMR (THF-d8): δ 1.05-1.33 (m, 48H, CHMe2), 2.31-2.39 (m, 8H, CHMe2), 3.63 (d, 2H, JP-H = 3.3 Hz, CH), 3.68 (d, 4H, JP-H = 2.4 Hz, CH2), 7.26 (d, 2H, JH-H = 1.2 Hz, Py), 7.36 (d, 2H, JH-H = 1.2 Hz, Py), 7.92 (t, 2H, JH-H = 0.9 Hz, Py). 13C{1H} NMR (THF-d8): δ 16.5-17.4 (m, CHMe2), 26.1-28.5 (m, CHMe2), 37.9 (d, JP-C = 150.5 Hz, CH2), 45.2 (d, JP-C = 90.2 Hz CH-Ge), 123.3 (d, JP-C = 65.8 Hz, Py), 125.3 (d, JP-C = 80.2 Hz, Py), 136.3, 138.4, 155.7 (Py). 31P{1H} NMR (THF-d8): δ 78.92, 84.28. [{C5H3N-2,6-(CH2PPri2dS)(CHPPri2dS)}Snþ][SnCl3-] (6). A solution of 2 (1.32 g, 2.73 mmol) in Et2O (20 mL) was added to a solution of SnCl2 (2.71 g, 14.30 mmol) in Et2O (20 mL) at 0 °C. The reaction mixture was stirred at room temperature for 33 h, and a yellow suspension was formed. Volatiles in the mixture were removed under reduced pressure, and the residue was extracted with CH2Cl2. After filtration and concentration of the filtrate, compound 6 was obtained as yellow crystals. Yield: 1.53 g (75.1%). Mp: 153.5-157.2 °C. Anal. Found: C, 30.39; H, 4.75; N, 1.93. Calcd for C19H34Sn2Cl3NP2S2: C, 30.58; H, 4.59; N, 1.88. 1H NMR (THF-d8): δ 0.88-1.26 (m, 24H, CHMe2), 2.10-2.22 (m, 2H, CHMe2), 2.52-2.69 (m, 2H, CHMe2), 3.13 (d, 1H, JP-H = 3 Hz, CH), 3.45 (d, 2H, JP-H = 12 Hz, CH2), 6.85 (d, 1H, JH-H = 0.9 Hz, Py), 7.01 (d, 1H, JH-H = 0.6 Hz, Py), 7.56 (t, 1H, JH-H = 0.9 Hz, Py). 13C{1H} NMR (THF-d8):
δ 14.8-17.6 (m, CHMe2), 28.5-31.9 (m, CHMe2), 37.7 (d, JP-C = 147.2 Hz, CH2), 63.8 (m, CH-Sn) 123.3 (d, JP-C = 240.8 Hz, Py), 128.0 (d, JP-C = 180.8 Hz, Py), 137.0, 154.9, 161.9 (Py). 31 P{1H} NMR (THF-d8): δ 81.37, 83.82. 119Sn{1H} NMR (THF-d8): δ -119.94 (d, JSn-P = 140.3 Hz), -97.50. X-ray Crystallography. Single crystals were sealed in Lindemann glass capillaries under nitrogen. X-ray data of 2-6 were collected on a Rigaku R-AXIS II imaging plate using graphitemonochromated Mo KR radiation (I = 0.710 73 A˚) from a rotating-anode generator operating at 50 kV and 90 mA. Crystal data are summarized in Tables 3 and 4. The structures were solved by direct phase determination using the computer program SHELXTL-PC30 on a PC 486 and refined by full-matrix least squares with anisotropic thermal parameters for the nonhydrogen atoms. Hydrogen atoms were introduced in their idealized positions and included in structure factor calculations with assigned isotropic temperature factor calculations. Full details of the crystallographic analysis of 2-6 are given in the Supporting Information.
(30) Sheldrick, G. M. In Crystallographic Computing 3: Data Collection, Structure Determination, Proteins, and Databases; Sheldrick, G. M., Kruger, C., Goddard, R., Eds.; Oxford University Press: New York, 1985; p 175.
Supporting Information Available: CIF files giving details about the X-ray crystal structures for 2-6. This material is available free of charge via the Internet at http://pubs.acs.org.
Acknowledgment. This work was supported by The Chinese University of Hong Kong Direct Grant (Project Code 2060379).
