Article pubs.acs.org/Organometallics
Synthesis and Structures of Novel Molecular Ionic Compounds Based on Encapsulation of Anions and Cations Youssef El Aziz,*,† Peter G. Taylor,† Alan R. Bassindale,† Simon J. Coles,‡ and Mateusz B. Pitak‡ †
Department of Life, Health & Chemical Science, Faculty of Science, The Open University, Walton Hall, Milton Keynes MK7 6AA, United Kingdom ‡ U.K. National Crystallography Service, Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom S Supporting Information *
ABSTRACT: The novel coordinate compounds T8[(CH2)n-EWG]8F−-18-crown-6-M+ were prepared by reaction of EWG(CH2)n-Si(OEt)3 (where n = 1−3 and the electron-withdrawing group, EWG, contains an Si−C(sp3) bond) with an 18-crown-6M+F− complex (where M+ is K+, Cs+, and Rb+) in the presence of a limited amount of water. The EWG facilitates the formation and encapsulation of the fluoride anion in a silsesquioxane cage. The reaction takes place by complexing an alkali metal in the crown ether, catalyzing silsesquioxane cage formation, and concomitant encapsulation of a fluoride ion within the final T8 cage. The reaction is simple and takes place in a single step with excellent yields of 81−95%. These novel materials have been studied by 19F and 29Si NMR spectroscopy and X-ray crystallography as well as by MALDI-TOF and ESI mass spectrometry. The T8[(CH2)n-EWG]8F−-18-crown-6-M+ compounds can be also synthesized by a facile reaction of 18-crown-6-M+F− with the corresponding T8[(CH2)n-EWG]8 cage in nearly quantitative yield. Surprisingly, the single-crystal X-ray diffraction analysis has revealed the presence of 1D and 3D polymeric complexes of T8[(CH2)n-EWG]8F−-18-crown-6-M+. To the best of our knowledge, this represents the first dual-encapsulation host−octasilsesquioxane system. The results from thermostability experiments monitored by 19F NMR and 1H NMR and DSC suggest that compound T8[CH2CH2(CF2)3CF3]8F−-18-crown-6-K+ is a potential ionic liquid (IL). the silicon atom via an sp3-hybridized carbon atom.2,3 The product T8[(CH2)n-EWG]8TBAF (Scheme 1) is obtained in near quantitative yield (80−95%), even on a large scale. However, the attempts to encapsulate ions other than fluoride, such as bromide, chloride, and iodide, have been unsuccessful. We have also failed to exchange the tetraalkylammonium cation (TBA+) with different cationic salts such as LiI, NaI, and LiPh4B. Herein, we report a novel class of ionic cage compound which are derived from alkali metal fluorides and in which both the anion and cation are encapsulated/complexed (Scheme 2). A similar complexation of metal fluorides was recently reported by Jurkschat et al. 4−9 using the organotin- and bis(organostannyl)methane-substituted crown-4, crown-5, and
1. INTRODUCTION Polyhedral oligomeric silsesquioxanes (POSS) are a family of inorganic−organic hybrid compounds. The most common POSS cages are the cubic silsesquioxanes, the T8 cages,1 which have the formula (RSiO3/2)8. We have previously synthesized and isolated a wide variety of novel silsesquioxanes with an encapsulated fluoride ion in the middle of the cage, T8[RC(sp2)]8TBAF, by reacting the tetra-n-butylammonium fluoride with RC(sp2)−Si(OEt)3 (Scheme 1). The crystal structures of these compounds have also been reported.2 Until recently, we were unable to synthesize an encapsulated fluoride ion within a silsesquioxane cage in which the pendant groups attached to the silicon atoms of the cage are connected via an sp3-hybridized carbon atom (Si−Csp3). We have now reported a facile, single-step preparation of POSS compounds containing an encapsulated fluoride anion, based on pendant arms with electron-withdrawing groups (EWGs) connected to © XXXX American Chemical Society
Received: July 18, 2016
A
DOI: 10.1021/acs.organomet.6b00565 Organometallics XXXX, XXX, XXX−XXX
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Organometallics Scheme 1. Synthetic Route to T8[EWG-(CH2)n]8TBAF with Si−Csp3
Scheme 2. Synthetic Route to T8[EWG-(CH2)n]8F−-crown ether-M+ with Si−Csp3 Article
Table 1. Yields, Melting Points, and Solvent Systems for Recrystallization of T8[(CH2)n-EWG]8F−-18-crown-6-M+ compound T8[methacryloxymethyl]8F−-18-crown-6-K+ T8[CH2Cl]8F−-18-crown-6-K+ T8[acetoxymethyl]8F−-18-crown-6-K+ T8[2-cyanoethyl]8F−-18-crown-6-K+ T8[CH2CH2P(O) (OEt)2]8F−-18-crown-6-K+ T8[CH2CH2(CF2)3CF3]8F−-18-crown-6-K+ T8[CH2CH2(CF2)5CF3]8F-18-crown-6-K+ T8[CH2CH2(CF2)7CF3]8F−-18-crown-6-K+ T8[2-cyanoethyl]8F−-18-crown-6- Rb+ T8[3-cyanopropyl]8F−-18-crown-6-K+
spacer n 1 1 1 2 2 2 2 2 2 3
compound
yield (%)
T8[(CH2)n-EWG]8F‑-18-crown-6-M+ 1 96 2 81 3 86 4 96 5 89 6 85 7 95 8 95 9 92 10 87
mp (°C) from DSC
solvent system of recrystallization
122 100 169 169 decompose 86 95 101 170 decompose
acetone/xylene chloroform/toluene chloroform/toluene acetone/xylene acetonitrile/toluene ether/ClCH2CH2Cl hexane/chloroform hexane/chloroform chloroform/toluene acetonitrile/toluene
2. RESULTS AND DISCUSSION 2.1. Methods of Preparation and Purification of T8[(CH2)n-EWG]8F−-18-crown-60-M+ Ether with Si−Csp3. The products were prepared from trialkoxysilanes such as EWG-(CH2)n-Si(OEt)3, where n = 1−3 and EWG is an electron-withdrawing group which needs to be inert with respect to nucleophilic substitution by fluoride ion, together with 18-crown-6 and a metal fluoride, M+F− (where M+ is K+ and Rb+). The 18-crown-6 was chosen because of its selectivity toward potassium, cesium, and rubidium ions. The EWG can be cyano, alkanoate, O-methacrylate, O-acrylate, carboxylate, halo, P(O) (OEt)2, and 1H,1H,2H,2H-perfluoroalkyl. All syntheses were carried out in the same fashion: Equimolar amounts of 18-crown-6 ether and metal fluoride (slight excess) were dissolved in equal volumes of acetonitrile−toluene, and the reaction mixture was stirred at room temperature for 15 min under a nitrogen atmosphere. Water (8 equiv) was added to the mixture followed by the trialkoxysilane (8 equiv). The
crown-6 compounds and have demonstrated by means of multinuclear NMR spectroscopy and X-ray diffraction analyze their ability to coordinate metal halides and to transport them through an organic membrane. We are also interested in the properties and coordination in the crystalline state. We report the formation of metal−organic 1D extended structures of silsesquioxane−crown ether complexes for potassium and rubidium complexes and are investigating their ionic liquid properties. Cesium complexation will not be discussed here as it will be the subject of another paper. Future directions for this work include investigation of materials designed for possible use in rechargeable lithiumbased battery technologies.10−13 We are also exploring ion recognition and extraction.14,15 These and other studies will be reported at a later date. B
DOI: 10.1021/acs.organomet.6b00565 Organometallics XXXX, XXX, XXX−XXX
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Organometallics
Figure 1. Molecular structures in the solid state (X-ray diffraction studies) of the fluoride encapsulated octakis(2-cyanoethyl)-octasilsesquioxane fluoride-18-crown-6-potasium (4) and octakis(2-cyanoethyl) octasilsesquioxane fluoride-18-crown-6-rubidium (9).
Table 2. Selected Bond Distances and Angles for Compounds 1, 3, 4, 6, 9, 10, 14, 15, 18, 19, 22, and 23 crystal structure compound 1 T8[methacryloxymethyl]8F−-18-crown-6-K+ 3 T8[acetoxymethyl]8F−-18-crown-6-K+ 4 T8[2-cyanoethyl]8F−-18-crown-6-K+ 6 T8[CH2CH2(CF2)4CF3]8F−-18-crown-6-K+ 9 T8[2-cyanoethyl]8F−-18-crown-6-Rb+ 10 T8[3-cyanopropyl]8F−-18-crown-6-K+ 14 T8[2-carbomethoxy)ethyl]8TBAF 15 T8[3-cyanoethyl]8TBAF 18 T8[3-cyanopropyl]8TBAF 19 T8[2-(carbomethoxy)ethyl]816 22 T8[CH2CH2CH2N(COCH3)2]817 23 T8[2-cyanoethyl]8TEAF
mean Si···F (Ǻ )
mean Si−R(Csp ) (Ǻ )
mean ∑O−Si−O (deg)
mean trans Si−Si (a) (Ǻ )
mean Si−O (Ǻ )
mean Si−O−Si (deg)
2.64 2.65 2.65 2.65 2.64 2.66 2.64 2.65 2.66
1.86 1.86 1.86 1.85 1.85 1.85 1.86 1.86 1.86 1.85 1.85 1.86
338.27 339.02 339.53 338.92 338.20 337.90 338.22 338.04 339.90 329.72 326.70 337.76
5.29 5.29 5.31 5.29 5.29 5.32 5.31 5.30 5.32 5.39 5.40 5.30
1.62 1.62 1.62 1.62 1.62 1.62 1.63 1.62 1.63 1.62 1.62 1.62
140.44 140.54 140.93 140.95 141.99 141.80 141.01 141.05 141.31 148.11 148.10 140.79
2.65
3
reaction was stirred at room temperature for 16 h, under nitrogen, (except for the perfluoro-(CH2)n-Si(OEt)3, where the reaction required gentle reflux). The mixture was filtered to remove excess metal fluoride, and the solvent was removed using a rotary evaporator. The final product was recrystallized to give a pure product in very high yield. Interestingly, this strategy led to only T8 cages (81−96%, Table 1). The yields of these metal/crown ether compounds are similar to those obtained with tetrabutyl ammonium fluoride. We have found that this reaction involving crown ethers fails when R (in R−Si(OEt)3) is not an EWG (R = ethyl, cyclohexyl, and i-butyl) or when R is a phenyl or vinyl group. All of the products were isolated and characterized using NMR (1H, 13C, 19 F, and 29Si) spectroscopy and MALDI TOF and ESI mass spectrometry. A number of them have also been characterized using X-ray crystallography. Attempts to make the lithium encapsulated fluoride ion salt using 2-cynoethlytriethoxysilane with LiF and 12-crown-4 were unsuccessful. 2.2. 19F and 29Si NMR Studies. The new T8[(CH2)nEWG]8F−-18-crown-6-M+ compounds were studied using 19F and 29Si NMR spectroscopy, and their relevant chemical shifts are given in Table S1 together with those of their tetrabutylammonium analogues.2,3 The 19F and 29Si NMR chemical shifts for new T8[CH2−EWG]8F−-18-crown-6-M+
compounds 1−3 and T8[(CH2)n-EWG]8TBAF compounds 11−13 (when the EWG is positioned at n = 1) vary between −24 and −27 ppm (1−3) or −24.9 and −25.1 (11−13) for the 19 F NMR spectra and between −77.5 and −77.9 (1−3) or −77 and −78 ppm (11−13) for the 29Si NMR spectra. For compounds 4−9 of T8[(CH2)2−EWG]8F−-18-crown-6-M+, when the EWG is positioned at n = 2 and for the corresponding T8[(CH2)2−EWG]8TBAF compounds 14−17, the 19F chemical shifts vary between −27 and −28 ppm, but the 29Si NMR chemical shifts are similar to the previous examples. For compounds 10 and 18, when the EWG is positioned at n = 3, the chemical shifts are again similar to those above. In all cases, the encapsulation of fluoride ion within the T8 cage produces a low-frequency 29Si NMR chemical shift of about 3−4 ppm for the cage silicon nuclei (cf. compounds 19−21). 2.3. Single-Crystal X-ray Diffraction-Determined Molecular Structures of T8R8F−-18-crown-6-M+ Complexes. Single crystals were obtained by slow evaporation for compounds 1, 3, 4, 6, 9, and 10. Figures 1−4 show the single-crystal X-ray diffraction determined molecular structures in the solid state of these compounds. Selected bond distances and angles of T8[(CH2)n-EWG]8F−-18-crown-6-M+ are shown in Table 2. C
DOI: 10.1021/acs.organomet.6b00565 Organometallics XXXX, XXX, XXX−XXX
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Organometallics Single-crystal X-ray diffraction data for 1, 3, 6, and 10 reveal the expected structures with triclinic crystal systems with space group P1̅ and a single molecule in the asymmetric unit (Table 4). Compounds 4 and 9 adopted the orthorhombic crystal systems with space group Pbcn and with four molecules in the asymmetric unit (Table 2). A comparison of the crystal structure data of 1, 3, 4, 6, 9, and 10 with those previously reported revealed only very small differences in the bond distances and angles and shows that fluoride ion encapsulated inside the T8 cage causes the Si8O12 cage framework to contract slightly in a consistent fashion (Table 2).2,3 The crown ether complexed cation acts as a link between cages forming extended structures of 1D and 3D polymeric networks. The molecular structures in the unit cells are shown in Figures 1−4. The extended structures are illustrated in Figures 5 and 6.
Figure 4. Molecular structure in the solid state (X-ray diffraction studies) of the fluoride encapsulated octakis(1H, 1H,2H,2H-nonafluorohexyl)-octasilsesquioxane fluoride-18-crown-6-rubidium (6).
The crystal structure of 7 could only be obtained as a ClCH2CH2Cl solvate. In the absence of ClCH2CH2Cl, the crystals rapidly became amorphous, indicating that this solvent is necessary for lattice stabilization. To the best of our knowledge, these examples represent the first dual-encapsulated metal fluoride salts. The packing patterns from the single-crystal X-ray diffraction-determined structures have demonstrated the presence of a 1D polymeric assembly of T 8 [(CH 2 ) nEWG]8F−-18-crown-6-M+ (where M is K or Rb) (Figure 5). Two types of coordination have been observed. The first type has coordination via two diagonally opposite corners of the
Figure 2. Molecular structure in the solid state (X-ray diffraction studies) of the fluoride encapsulated octakis(3-cyanopropyl)-octasilsesquioxane fluoride-18-crown-6-potasium (10).
Figure 3. Molecular structures in the solid state (X-ray diffraction studies) of the fluoride encapsulated octakis(methacryloxymethyl)octasilsesquioxane fluoride-18-crown-6-potasium (1) and octakis(acetoxymethyl) octasilsesquioxane fluoride-18-crown-6-potassium (3). D
DOI: 10.1021/acs.organomet.6b00565 Organometallics XXXX, XXX, XXX−XXX
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Organometallics
Figure 5. Integrated 1D polymeric structure of T8[methacryloxymethyl]8F−-18-crown-6-K+ (1) with linkages through diagonally opposite corners.
Figure 6. Integrated 1D polymeric of T8[2-cyanoethyl]8F−-18-crown-6-Rb+ (9) with linkages through opposite corners on the same face of the cube.
Table 3. Selected Interatomic Distances for Compounds 1, 3, 4, 6, 9, and 10 distances (Å) compound
K+···F−
1 3 4 6 9 10
8.39 7.91 10.31 8.42
Rb+···F−
K+···O 2.81 2.80 2.78 2.78
10.40 8.67
Rb···O
K+···K+ 16.78 15.82 18.81 16.84
Rb+···Rb+
diagonal diagonal horizontal diagonal
2.82 2.81
CN···Rb+
CN···K+
CF···K+
CO···K+ 2.66 2.71
2.99 2.85 10.92 horizontal
16.84 diagonal
3.11 2.80
Scheme 3. New Approach for the Preparation of T8(CH2CH2EWG)8F−-18-crown-6-M+
nitrogen atoms with a Rb+--NC distance of 3.11 Å which is slightly longer than that in the previous examples. The geometric relationship between the potassium ion and the two donor atoms, each from the arms of different T8 cages, for compounds 1, 3, 6, and 10 is linear (180°). However, for compounds 4 and 9 this angle varies between 156 and 160°.
cubic cage (compounds 1, 3, 6, and 10). The second type has coordination via two opposite corners on one of the faces of the cubic cage (compounds 4 and 9) (Figure 6). In metal−organic polymeric complexes 1, 3, 4, 6, and 10, the potassium atom is coordinated to all six oxygen atoms of the 18-crown-6 with K+--O distances varying between 2.78 and 2.81 Å. There is further coordination of the metal ion with two nitrogen atoms (Table 3), oxygen atoms, or fluorine atoms from the corresponding cyano, carbonyl groups, or perfluoalkyl arms. For the coordination bonds K+--OC and K+--NC the distances are 2.66 Å for 1, 2.71 Å for 3, 2.99 Å for 4, and 2.80 Å for 10. The K+--F−CF distance is 2.8 Å for 7. In the case of compound 9, the rubidium is bound to all six oxygen atoms of the 18-crown-6 with a Rb+--O distance of 2.82 Å and to two
3. INCORPORATION OF THE F− ION INTO A FREE T8[(CH2)N-EWG]8 CAGE WITH F−K+-18-CROWN-6 Haddad and co-workers18 have synthesized F− ion encapsulated cages, F‑@R8T8, by reaction of tetramethylammonium fluoride (TMAF) with the corresponding R8T8 cage. While they reported that the synthesis works well for sp2 substituents E
DOI: 10.1021/acs.organomet.6b00565 Organometallics XXXX, XXX, XXX−XXX
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Organometallics and electron-withdrawing substituents, they found that it fails when R is not an EWG (R = ethyl, cyclohexyl, and i-butyl). We have carried out similar preparations using a F−K+-18-crown-6 complex as the source of fluoride ion, together with the free T8(CH2CH2EWG)8 cage. Equimolar amounts of 18-crown-6 ether and M+F− (slight excess) were dissolved in equal volumes of acetonitrile−toluene and the reaction stirred at room temperature for 15 min under a nitrogen atmosphere; then, 1 molar equiv of the T8(CH2CH2EWG)8 was immediately added to the mixture (Scheme 3). The reaction was stirred at room temperature for 16 h under nitrogen, which led to a nearly quantitative yield (95%) of T8(CH2CH2EWG)8F−-18-crown-6-K+.
Figure 8. TGA plot of 6 under a nitrogen atmosphere.
CH2CH2(CF2)3CF3 followed by subsequent polymerization and cross-linking reactions that lead to the formation of a SiOxCy network. The total weight loss (65% at 1000 °C) is thus lower than the organic fraction of the materials (82%), indicating the incorporation of a small fraction of organic matter in the larger siloxane network. The residue following thermal analysis was completely black. The relatively low melting temperature of the T8(CH2CH2EWG)8F−-18-crown-6M+ complexes and their apparent stability up to 250 °C suggests these molecular ionic materials may find uses as ionic liquids, an area we are actively pursuing.
4. THERMAL PROPERTIES OF T8(CH2CH2EWG)8F−M+-18-CROWN-6 COMPLEXES We have studied the thermal properties of T8(CH2CH2EWG)8F−-18-crown-6-M+ complexes using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). DSC was performed under nitrogen at a heating rate of 10 °C/min with two successive heat−cool cycles from 0 to 110 °C (Figure 7). The DSC measurement of
5. CONCLUSIONS Novel molecular ionic materials T8[(CH2)n-EWG]8F−-18crown-6-M+ (where M+ is K+ or Rb+) were synthesized in a facile one-step reaction in near-quantitative yield, even on a large scale (81−96%). Analyses by X-ray crystallography and solution 19F/29Si NMR spectroscopy reveal very similar environments for the encapsulated fluoride octasilsesquioxane cages to the corresponding TBAF compounds. The singlecrystal X-ray diffraction-determined structures have demonstrated the presence of a 1D and a 2 D polymeric assembly of T8[(CH2)n-EWG]8F−-18-crown-6-M+ (where M+ is K+ or Rb+). We have also developed a facile synthesis of these molecular ionic materials by reacting T8[(CH2)n-EWG]8F−-18crown-6-M+. The thermometric studies have demonstrated that such compounds are potential ionic liquids (ILs).
Figure 7. DSC of T8[CH2CH2(CF2)4]8F−-18-crown-6-K+ (6).
T8[CH2CH2(CF2)4]8F−K+-18-crown-6 (6) (Figure 7, heating cycle 1) shows the loss of water at about 61 °C (the water molecules being absorbed from the atmosphere during grinding). A second phase transition occurs at 86.9 °C (onset temperature) which exhibits one endothermic peak assigned to the melting process observed at 88 °C (Figure 7, heating cycle 2). We have examined the thermal stability of 6 by heating 1 g of the compound in an NMR tube at 100 °C for more than an hour in an oil bath. The 19F NMR and 1H NMR spectra of sample 6 before heating and after heating were identical confirming that no decomposition occurs after 1 h of heating at 100 °C. TGA was also employed to study the thermal stability of 6 under a nitrogen atmosphere, as shown in Figure 8. The TGA plot shows three weight loss processes. The initial weight loss between 20 and 255 °C can be assigned to the loss of adventitious water. The second process between 260 and 300 °C represents a weight loss of 12% and may be due to the loss of the18-crown-6 (MW = 322.41 g/mol, which represents 12% of the total weight of the 6 cage, MW = 2715.69 g/mol). The weight loss between 310 and 1000 °C (30%) can be ascribed to the decomposition and loss of the fluorinated organic groups
6. EXPERIMENTAL SECTION 6.1. Measurements. Melting points were determined on an Electrothermal Digital melting point apparatus or on a Mettler Toledo DSC 822. Infrared spectra were obtained as Nujol mulls or thin films using sodium chloride plates or as KBr discs on a Nicolet 205 FT-IR spectrometer. NMR spectra were recorded as solutions in deuteriochloroform with tetramethylsilane as internal standard on a JEOL Lamda 300 NMR spectrometer or a JEOL EX 400 NMR spectrometer (J values are given in Hz). MALDI TOF mass spectra were carried out by the University of Southampton using 2,5-dihydroxybenzoic acid as a matrix and dichloromethane as the solvent. 6.2. Preparation of T8[methacryloxymethyl]8F−-18-crown-6K+ (1). The 18-crown-6 (125.96 mg, 0.48 mmol, 1 equiv) and KF (27.69 mg, 0.48 mmol, 1 equiv, excess) were dissolved in equal volumes of acetonitrile−toluene (10 mL) and the reaction stirred at room temperature for 15 min under a nitrogen atmosphere. Water (69 μL, 3.81 mmol, 8 equiv) was added to the mixture; then, methacryloxymethyltriethoxysilane (1000 mg, 3.81 mmol, 8 equiv) was immediately added. The reaction was stirred at room temperature for 16 h. The reaction mixture was filtered through a sintered glass Buchner funnel. The solvent was removed on a rotary evaporator. The product was obtained as a white solid. Recrystallization from acetone− xylene gave 0.7 g, 96%. Mp: 122.4 °C from DSC. 1H NMR (400 MHz, CDCl3, ppm, δ) 6.20−6.00 (m, 8H, CCH2), 5.40−5.65 (m, 8H, F
DOI: 10.1021/acs.organomet.6b00565 Organometallics XXXX, XXX, XXX−XXX
Article
Organometallics CCH2), 3.69−3.77 (m, 16H, SiCH2), 3.63 (s, 24H, CH2 of 18crown-6), 1.89 (s, 24H, CH3). 13C NMR (75.5 MHz, CDCl3, ppm, δ) 168.53 (s, CO), 136.60 (CH2Cq), 124.88 (CH2), 70.20 (OCH2 of crown), 54.11 (Si−CH2−O), 18.40 (s, CH3). 29Si NMR (79.3 MHz, CDCl3, ppm, δ) −77.56. 19F NMR (376 MHz, CDCl3, ppm, δ) −24.75. IR (Nujol) ν, cm−1: 2889 (νC−H), 2845 (νC−H), 1716 (νCO), 1630 (νCCH2 str), 1414, 1376, 1340, 1312, 1254, 1266, 1180, 1116 (νas(Si−O−Si)), 1015, 940, 811 (νs(Si−O−Si)), 652. Anal. Calcd for C52H80FKO34Si8: C, 44.77; H, 5.26. Found: C, 44.78; H, 5.29. MS (ESI-MS negative mode) C40H56FO28Si8−, exact mass required: 1227.11. m/z (%) Found: 1227.11 (100%) [M − (18-crown-6K+)]−. MS (ESI-MS positive mode) C12H24KO6+, exact mass required: 303.12. m/z (%): Found 303.12 [18-crown-6-K]+. This compound has been fully characterized. 6.3. Preparation of T8[chloromethyl]8F−-18-crown-6- K+ (2). The 18-crown-6 (155.29 mg, 0.59 mmol, 1 equiv) and KF (34.13 mg, 0.59 mmol, 1 equiv, excess) were dissolved in equal volumes of acetonitrile−toluene (10 mL) and the reaction stirred at room temperature for 15 min under a nitrogen atmosphere. Water (85 μL, 4.70 mmol, 8 equiv) was added to the mixture; then, chloromethyltriethoxysilane (1000 mg, 4.70 mmol, 8 equiv) was immediately added. The reaction was stirred at room temperature for 16 h. The reaction mixture was filtered through a sintered glass Buchner funnel. Hexane was added to the mixture. The product was obtained as white crystals 0.54 g, 81%. Mp: 100.1 °C from DSC. 1H NMR (400 MHz, CDCl3, ppm, δ) 3.68 (s, 24H, CH2 of 18-crown-6), 2.17 (s, 16H, Cl−CH2Si). 13 C NMR (75.5 MHz, CDCl3, ppm, δ) 70.38 (O−CH2−CH2−O), 24.30 (Cl−CH2Si). 29Si NMR (79.3 MHz, CDCl3, ppm, δ) −77.98. 19 F NMR (376 MHz, CDCl3, ppm, δ) −25.67. IR (Nujol) ν, cm−1: 2921 (νC−H), 2862 (νC−H), 2303, 1650, 1470, 1351, 1265, 1108 (νas(Si−O−Si)), 961, 748 (ν(C−Cl)), 667 (νs(Si−O−Si)). Anal. Calcd for C20H40Cl8FKO18Si8: C, 21.17; H, 3.55. Found: C, 21.18; H, 3.56. MS (MALDI-TOF negative mode) for C8H16C18FO12Si8−, exact mass required: 826.63. m/z (%): Found 826.62 [M − (18-crown-6-K+)]−. MS (MALDI-TOF positive mode) C12H24KO6+, exact mass required: 303.12. Found m/z (%): 303.12 [18-crown-6-K]+. 6.4. Preparation of T8[acetoxymethyl]8F−-18-crown-6-K+ (3). The 18-crown-6 (139.79 mg, 0.53 mmol, 1 equiv) and KF (30.70 mg, 0.53 mmol, 1 equiv, excess) were dissolved in equal volumes of acetonitrile−toluene (10 mL) and the reaction stirred at room temperature for 15 min under a nitrogen atmosphere. Water (77 μL, 4.23 mmol, 8 equiv) was added to the mixture; then, acetoxymethyltriethoxysilane (1000 mg, 4.23 mmol, 8 equiv) was immediately added. The reaction was stirred at room temperature for 16 h. The reaction mixture was filtered through a sintered glass Buchner funnel. The solvent was removed on a rotary evaporator. The product was obtained as a white solid. Recrystallization from chloroform−toluene gave 0.6 g, 86%. Mp: 169.1 °C from DSC. 1H NMR (400 MHz, CDCl3, ppm, δ) 3.63(s, 16H, SiCH2−O), 3.62 (s, 24H, CH2 of 18crown-6), 2.03 (s, 24H, CH3).13C NMR (75.5 MHz, CDCl3, ppm, δ) 172.08 (CO), 70.33 (O−CH2−CH2−O), 54.28 (O−CH2), 21.24 (CH3). 29Si NMR (79.3 MHz, CDCl3, ppm, δ) −77.78. 19F NMR (376 MHz, CDCl3, ppm, δ) −27.96. IR (Nujol) ν, cm−1: 2918 (νC−H), 2897 (νC−H), 2851, 2467, 1742 (νCO), 1475, 1400, 1351, 1297, 1109 (νas(Si−O−Si)), 1033, 962, 768, 607 (νs(Si−O−Si)). Anal. Calcd for C36H64FKO34Si8: C, 32.67; H, 4.87 Found: C, 32.67; H, 4.88. MS (MALDI-TOF negative mode) C24H40FO28Si8−, exact mass required: 1018.98. m/z (%) Found: 1018.98 (100%) [M − (18-crown-6-K+)]−. MS (MALDI-TOF positive mode) C12H24KO6+, exact mass required: 303.12. m/z (%) Found: 303.12 [18-crown-6-K]+. This compound has been fully characterized. 6.5. Preparation of T8[2-cyanoethyl]8F−-18-crown-6-K+ (4). The 18-crown-6 (152.02 mg, 0.57 mmol, 1 equiv) and KF (33.46 mg, 0.57 mmol, 1 equiv, excess) were dissolved in equal volumes of acetonitrile−toluene (10 mL) and the reaction stirred at room temperature for 15 min under a nitrogen atmosphere. Water (83 μL, 4.60 mmol, 8 equiv) was added to the mixture; then, 2cyanethyltriethoxysilane (1000 mg, 4.60 mmol, 8 equiv) was immediately added. The reaction was stirred at room temperature for 16 h. The reaction mixture was filtered through a sintered glass
Buchner funnel. The solvent was removed on a rotary evaporator. The product was obtained as a white solid. Recrystallization from acetone− xylene gave 0.65 g, 96%. Mp: 170−172 °C. Mp: 169.5 °C from DSC. 1 H NMR (400 MHz, CDCl3, ppm, δ) 3.65 (s, 24H, CH2 of 18-crown6), 2.40 (t, 3JHH = 7.52 Hz, 16H, CN−CH2), 0.85 (t, 3JHH = 7.88 Hz, 16H, SiCH2).13C NMR(75.5 MHz, CDCl3, ppm, δ) 121.81 (s, CN), 70.14 (O−CH2), 11.70 (−CH2−CN), 10.02 (CH2−Si). 29Si NMR (79.3 MHz, CDCl3, ppm, δ) −71.76. 19F NMR (376 MHz, CDCl3, ppm, δ) −27.92. IR (Nujol) ν, cm−1: 2905 (νC−H), 2862 (νC−H), 2247 (νCN), 1422, 1353, 1265, 1197, 1086 (νas(Si−O−Si)), 1007, 959, 904, 837, 737, 697 (νs(Si−O−Si)). Anal. Calcd for C36H56FKN8O18Si8: C, 36.90; H, 4.82. Found: C, 36.91; H, 4.83. MS (MALDI-TOF negative mode) C24H32FN8O12Si8−, exact mass required: 867.03. m/z (%) Found: 867.03 (100%) [M − (18-crown-6-K+)]−. MS (MALDI-TOF positive mode) C12H24KO6+, exact mass required: 303.12. m/z (%) Found: 303.12 [18-crown-6-K]+. This compound has been fully characterized. 6.6. Preparation of T8[diethylphosphatoethyl]8F−-18-crown6-K+ (5). The 18-crown-6 (100.60 mg, 0.38 mmol, 1 equiv) and KF (22.10 mg, 0.38 mmol, 1 equiv, excess) were dissolved in equal volumes of acetonitrile−toluene (10 mL) and the reaction stirred at room temperature for 15 min under a nitrogen atmosphere. Water (55 μL, 3.04 mmol, 8 equiv) was added to the mixture; then, diethylphosphatoethyl)triethoxysilane (2-(Me)2P(O)CH2CH2Si(OEt)3) (1000 mg, 3.04 mmol, 8 equiv) was immediately added. The reaction was stirred at room temperature for 16 h. The reaction mixture was filtered through a sintered glass Buchner funnel. The solvent was removed on a rotary evaporator. The product was obtained as a white solid. Recrystallization from acetonitrile−toluene gave 0.7 g, 89%. 1H NMR (400 MHz, CDCl3, ppm, δ) 4.11 (m, 32H, 2 × [CH3CH2OPO]), 3.67 (s, 24H, CH2 of 18-crown-6), 1.80−1.60 (m, 16H, −CH2PO), 1.45−1.15 (2 × 24H, CH3CH2OPO), 0.95−0.80 (m, 16H, Si−CH2CH2PO), 13C NMR (75.5 MHz, CDCl3, ppm, δ) 70.05 (O−CH2−CH2−O), 61.79 (CH2PO), 19.82 (CH3), 16.57 (P(O)CH2), 4.51 (P(O)CH2CH2Si). 29Si NMR (79.3 MHz, CDCl3, ppm, δ) −72.23. 19F NMR (376 MHz, CDCl3, ppm, δ) −27.80. 31P NMR (161.83 MHz, CDCl3, ppm, δ) 35.8, 34.8, 35.6 (F−@T8). IR (Nujol) ν, cm−1: 3442, 2983, 2909, 2357, 1674, 1476, 1445, 1413, 1392, 1368, 1352, 1273, 1228, 1169 (νPO str), 1109 (νas(Si−O−Si)), 1054 (νP−O), 1028, 962, 880,783, 679 (νs(Si−O−Si)). MS (MALDI-TOF negative mode) C48H112FO36P8Si8−, exact mass required: 1755.3. m/z (%) Found: 1755.3 (100%) [M − (18-crown6-K+)]−. MS (MALDI-TOF positive mode) C12H24KO6+, exact mass required: 303.12. m/z (%) Found: 303.12 [18-crown-6-K]+. 6.7. Preparation of T8[perfluorohexyl]8F−-18-crown-6-K+ (6). The 18-crown-6 (80.50 mg, 0.30 mmol, 1 equiv) and KF (17.70 mg, 0.30 mmol, 1 equiv, excess) were dissolved in equal volumes of acetonitrile−toluene (10 mL) and the reaction stirred at room temperature for 15 min under a nitrogen atmosphere. Water (44 μL, 2.43 mmol, 8 equiv) was added to the mixture; then, 1H,1H,2H,2Hnonafluorohexyltriethoxysilane (1000 mg, 2.43 mmol, 8 equiv) was immediately added. The reaction was stirred at reflux for 16 h. The reaction mixture was filtered through a sintered glass Buchner funnel. The solvent was removed on a rotary evaporator. The product was obtained as a white solid. Recrystallization from ether−1,2-dichlroethane gave 0.7 g, 85%. Mp: 86.9 °C from DSC. 1H NMR (400 MHz, CDCl3, ppm, δ) 3.64 (s, 24H, CH2 of 18-crown-6), 2.34−2.06 (m, 16H, CH2−CF2), 0.72−0.67 (m, 16H, Si−CH2). 13C NMR (75.5 MHz, CDCl3, ppm, δ) 124.63 (CF2), 121.70 (CF2), 115.33 (CF2), 111.96 (CF2), 66.51 (O−CH2), 25.73 (CF2CH2), 3.59 (CH2Si). 29Si NMR (79.3 MHz, CDCl3, ppm, δ) −70.27. 19F NMR (376 MHz, CDCl3, ppm, δ) −126.01, −124.45, −115.93, −81.32, −27.25. IR (Nujol) ν, cm−1: 2889 (νC−H), 2845 (νC−H), 1975, 1470, 1376, 1211, 1103 (ν as(Si−O−Si) ), 878, 667 (ν s(Si−O−Si) ). Anal. Calcd for C59H56F70KO18Si8: C, 26.77; H, 2.13. Found: C, 26.78; H, 2.15. MS (MALDI-TOF negative mode) C48H32F73O12Si8−, exact mass required: 2410.89. m/z (%) Found: 2410 (100%) [M − (18-crown-6-K+)]−. MS (MALDI-TOF positive mode C12H24KO6+, exact mass required: 303.12. m/z (%) Found: 303.01 [18-crown-6-K]+. This compound has been fully characterized. G
DOI: 10.1021/acs.organomet.6b00565 Organometallics XXXX, XXX, XXX−XXX
Article
Organometallics
Table 4. Crystallographic Data for the 1, 3, 4, 6, 9, and 10 Crystalline Systems Investigated by X-ray Diffraction Analysis compound reference
1
3
4
6
9
10
chemical formula formula mass crystal system a (Å) b (Å) c (Å) α (deg) β (deg) γ (deg) unit cell volume (Å3) temperature (K) space group no. of formula units per unit cell, Z absorption coefficient, μ (mm−1) no. of reflections measured no. of unique reflections Rint final R1 values (I > 2σ(I)) final wR2 values (I > 2σ(I)) final R1 values (all data) final wR2 values (all data) goodness of fit on F2
C52H80FKO34Si8 1531.98 triclinic 8.445(3) 14.704(5) 16.727(5) 73.882(13) 79.293(13) 88.688(14) 1959.8(11) 100(2) P1̅ 1
C36H64FKO34Si8 1323.69 triclinic 10.687(4) 11.839(4) 12.269(4) 82.019(13) 78.529(11) 84.780(14) 1503.4(9) 100(2) P1̅ 1
C36H56FKN8O18Si8 1171.71 orthorhombic 15.1770(18) 19.121(2) 18.807(2) 90 90 90 5457.8(10) 100(2) Pbcn 4
C60H56Cl2F72KO18Si8 2814.82 triclinic 13.8521(5) 14.5848(5) 14.9006(10) 69.641(5) 83.129(6) 61.922(4) 2486.6(2) 100(2) P1̅ 1
C36H56FN8O18RbSi8 1218.08 orthorhombic 15.1086(5) 19.1296(6) 18.9252(13) 90 90 90 5469.8(5) 100(2) Pbcn 4
C44H72FKN8O18Si8 1283.92 triclinic 10.8410(5) 10.8627(4) 14.0694(9) 92.776(7) 90.134(6) 104.358(7) 1603.04(14) 100(2) P1̅ 1
0.272
0.342
0.350
0.401
1.157
0.304
29209
19054
30766
33301
41196
21694
8934 0.0432 0.0729 0.1979
6838 0.0405 0.0467 0.1197
6253 0.0239 0.0347 0.0861
11333 0.0327 0.0478 0.1319
6267 0.0397 0.0317 0.0768
7350 0.0272 0.0366 0.0914
0.0837 0.2067 1.009
0.0603 0.1276 1.031
0.0383 0.0881 1.177
0.0534 0.1351 1.034
0.0417 0.0810 1.054
0.0466 0.0962 1.051
6.8. Preparation of T8[Pperfluorooctyl]8F−-18-crown-6-K+ (7). The 18-crown-6 (64.70 mg, 0.24 mmol, 1 equiv) and KF (14.17 mg, 0.24 mmol, 1 equiv, excess) were dissolved in equal volumes of acetonitrile−toluene (10 mL) and the reaction stirred at room temperature for 15 min under nitrogen atmosphere. Water (35.1 μL, 1.95 mmol, 8 equiv) was added to the mixture; then, (1H,1H,2H,2Htridecafluorooctyl)triethoxysilane (1000 mg, 1.95 mmol, 8 equiv) was immediately added. The reaction was stirred at reflux for 16 h. The reaction mixture was filtered through a sintered glass Buchner funnel. The solvent was removed on a rotary evaporator. The product was obtained as a white solid. Recrystallization from hexane−chloroform gave 0.82 g, 95%. Mp: 95.5 °C from DSC. 1H NMR (400 MHz, CDCl3, ppm, δ) 3.66 (s, 24H, CH2 of 18-crown-6), 2.35−2.10 (m, 16H, −CH2CF2), 0.81−0.70 (m, 16H, Si−CH2). 13C NMR (75.5 MHz, CDCl3, ppm, δ) 70.13 (O−CH2−CH2−O), 25.56 (CH2−CH2− CF2), 3.50 (CH2−Si). 29Si NMR (79.3 MHz, CDCl3, ppm, δ) −70.51. 19 F NMR (376 MHz, CDCl3, ppm, δ) −125.88 (16F), −122.55 (16F), −121.85 (16F), −120.93 (16F), −115.15 (t, 16F), −79.79 (24F), −27.04 (1F, F−@T8). IR (Nujol) ν, cm−1: 2922 (νC−H), 2853 (νC−H), 1461, 1374, 1236, 1145, 1109 (νas(Si−O−Si)), 971, 895, 707, 664 (νs(Si−O−Si)). MS (MALDI-TOF negative mode) C64H32F105O12Si8, exact mass required: 3210.84. m/z (%) Found: 3210.8 (100%) [M − (18-crown-6-K+)]−. MS (MALDI-TOF positive mode) C12H24KO6+, exact mass required: 303.12. m/z (%) Found: 303.12 [18-crown-6-K]+. 6.9. Preparation of T8[perfluorodecafluorodecyl]8F−-18crown-6-K+ (8). The 18-crown-6 (54.13 mg, 0.20 mmol, 1 equiv) and KF (11.89 mg, 0.20 mmol, 1 equiv, excess) were dissolved in equal volumes of acetonitrile−toluene (10 mL) and the reaction stirred at room temperature for 15 min under nitrogen atmosphere. Water (30 μL, 1.63 mmol, 8 equiv) was added to the mixture; then, (1H,1H,2H,2H-heptadecafluorodecyl)triethoxysilane (1000 mg, 1.63 mmol, 8 equiv) was immediately added. The reaction was stirred at reflux for 16 h. The reaction mixture was filtered through a sintered glass Buchner funnel. The solvent was removed on a rotary evaporator. The product was obtained as a white solid. Recrystallization from hexane−chloroform gave 0.68 g, 95%. Mp: 101.1 °C from DSC. 1H NMR (400 MHz, CDCl3, ppm, δ) 3.66 (s, 24H, CH2 of 18-crown-6), 2.17−2.05 (m, 16H, −CH2CF2), 0.73−0.60 (m, 16H, Si−CH2). 13C
NMR (75.5 MHz, CDCl3, ppm, δ) 70.13 (O−CH2−CH2−O), 25.56 (CH2−CH2−CF2), 3.53 (CH2−Si). 29Si NMR (79.3 MHz, CDCl3, ppm, δ) −70.65. 19F NMR (376 MHz, CDCl3, ppm, δ) −125.99, −123.45, −122.58, −121.87, −121.64, −121.62, −115.84, −115.80, −27.06 (T8@F−). IR (Nujol) ν, cm−1: 2920 (νC−H), 2862 (νC−H), 1462, 1375, 1202, 1146, −1110 (νas(Si−O−Si)), 970,896, 709, 665 (νs(Si−O−Si)). MS (MALDI-TOF negative mode) C80H32F137O12Si8+ exact mass required: 4010.79. m/z (%) Found: 4011.8 (100%) [M − (18-crown-6-K+)]−. MS (MALDI-TOF positive mode) C12H24KO6+, exact mass required: 303.12. m/z (%) Found: 303.12 [18-crown-6-K]+. 6.10. Preparation of T8[2-cyanethyl]8F−-18-crown-6-Rb+ (9). The 18-crown-6 (152.02 mg, 0.57 mmol, 1 equiv) and RbF (60.08 mg, 0.57 mmol, 1 equiv, excess) were dissolved in equal volumes of acetonitrile−toluene (10 mL) and the reaction stirred at room temperature for 15 min under a nitrogen atmosphere. Water (83 μL, 4.60 mmol, 8 equiv) was added to the mixture; then, 2cyanethyltriethoxysilane (1000 mg, 4.60 mmol, 8 equiv) was immediately added. The reaction was stirred at room temperature for 16 h. The reaction mixture was filtered through a sintered glass Buchner funnel. The solvent was removed on a rotary evaporator. The product was obtained as a white solid. Recrystallization from chloroform−toluene gave 0.65 g, 92%. Mp: 170.5 °C from DSC. 1H NMR (400 MHz, CDCl3, ppm, δ) 3.64 (s, 24H, CH2 of 18-crown-6), 2.41 (t, 3JHH = 7.52 Hz, 16H, CN−CH2), 0.85 (t, 3JHH = 7.68 Hz, 16H, Si−CH2). 13C NMR (75.5 MHz, CDCl3, ppm, δ) 121.85 (s, CN), 70.06 (O−CH2−CH2−O), 11.70 (CH2−CH2−CN), 9.97 (−CH2− Si). 29Si NMR (79.3 MHz, CDCl3, ppm, δ) −72.23. 19F NMR (376 MHz, CDCl3, ppm, δ) −27.98. IR (Nujol) ν, cm 2922 (νC−H), 2872 (νC−H), 2247 (νCN), 1474, 1424, 1356, 1197, 1101 (νas(Si−O−Si)), 955, 796, 750, 696 (νs(Si−O−Si)). Anal. Calcd for C36H56FN8O18RbSi8: C, 35.50; H, 4.63. Found: C, 35.50; H, 4.63. MS (MALDI-TOF negative mode) C24H32FN8O12Si8−, exact mass required: 867.03. m/z (%) Found: 867.03 (100%) [M − (18-crown-6-K+)]−. MS (MALDI-TOF positive mode) C12H24O6Rb+, exact mass required: 349.07. m/z (%) Found: 349.07 [18-crown-6-Rb]+. This compound has been fully characterized and crystallographic data are given in the supporting materials. H
DOI: 10.1021/acs.organomet.6b00565 Organometallics XXXX, XXX, XXX−XXX
Article
Organometallics 6.11. Preparation of T8[3-cyanopropyl]8F−-18-crown-6-K+ (10). The 18-crown-6 (142.81 mg, 0.54 mmol, 1 equiv) and KF (31.39 mg, 0.54 mmol, 1 equiv, excess) were dissolved in equal volumes of acetonitrile−toluene (10 mL) and the reaction stirred at room temperature for 15 min under a nitrogen atmosphere. Water (78 μL, 4.32 mmol, 8 equiv) was added to the mixture; then, 3cyanopropyltriethoxysilane (1000 mg, 4.32 mmol, 8 equiv) was immediately added. The reaction was stirred at room temperature for 16 h. The reaction mixture was filtered through a sintered glass Buchner funnel. The solvent was removed on a rotary evaporator. The product was obtained as a white solid. Recrystallization from acetonitrile/hexane−toluene gave 0.6 g, 87%. 1H NMR (400 MHz, CDCl3, ppm, δ) 3.54 (s, 24H, CH2 of 18-crown-6), 2.41 (t, 3JHH = 7.50 Hz, 16H, CN−CH2), 1.7 (m, 16H, CH2), 0.58 (t, 3JHH = 7.52 Hz, 16H, Si−CH2). 13C NMR (75.5 MHz, CDCl3, ppm, δ) 119.36 (CN), 70.53 (O−CH2−CH2−O), 20.22 (CH2 CH2CH2CN), 19.33 (Si− CH2), 11.62 (−CH2−CN). 29Si NMR (79.3 MHz, CDCl3, ppm, δ) −72.04. 19F NMR (376 MHz, CDCl3, ppm, δ) −27.95. IR (Nujol) ν, cm−1: 2920 (νC−H), 2862 (νC−H), 2245 (νCN), 1652, 1395, 1380, 1310, 1280, 1191, 1109 (νas(Si−O−Si)), 995, 911, 784, 750, 720, 680 (νs(Si−O−Si)). Anal. Calcd for C44H72FKO18Si8: C, 41.16; H, 5.65. Found: C, 41.15; H, 5.64. MS (MALDI-TOF negative mode) C32H48FN8O12Si8−, exact mass required: 979.15. m/z (%) Found: 979.15 (100%) [M − (18-crown-6-K+)]−. MS (MALDI-TOF positive mode) C12H24KO6+, exact mass required: 303.12. m/z (%) Found: 303.12 [18-crown-6-K]+. Crystallographic data are given in the supporting materials. 6.12. Preparation of T8[perfluorohexyl]8F−-18-crown-6-K+ (7) by Incorporation of the F− Ion into a Free T8[Perfluorohexyl]8 Cage With F−-18-crown-6-K+. All syntheses were carried out in the same manner; 718 mg of the R8POSS cage along with 1 molar equiv of 18-crown-6 and KF (with slight excess) were dissolved into equal volumes of acetonitrile−toluene (10 mL) and stirred for 8 h. A sample synthesis is as follows: The 18-crown-6 (80.50 mg, 0.30 mmol, 1 equiv) and KF (17.70 mg, 0.30 mmol, 1 equiv, excess) were dissolved in equal volumes of acetonitrile−toluene (10 mL) and the reaction stirred at room temperature for 15 min under nitrogen atmosphere. T8[perfluorohexyl]8 (718 mg, 0.30 mmol, 1 equiv) was added to the mixture; then, the reaction was stirred at reflux for 8 h. The reaction mixture was filtered through a sintered glass Buchner funnel. The solvent was removed on a rotary evaporator. The product 7 was obtained as a white solid 0.76 g, 93%. 6.13. X-ray Crystallography. The X-ray data of compounds 1, 3, 4, 6, 9, and 10 were collected on Rigaku AFC12 diffractometer equipped with enhanced sensitivity (HG) Saturn724+ CCD detector mounted at the window of an FR-E+ SuperBright rotating anode generator (Mo Kα, λ = 0.71075 Å) with VHF Varimax optics (70 μm focus)19 using Rigaku CrystalClear20 software for data collection and reduction. Crystallographic data are shown in Table 4. The structures were solved by direct methods and refined by full-matrix least-squares procedures on F 2 using SHELXS-9721 and SHELXL-2014, 22 respectively. All hydrogen atoms were added at calculated positions and refined using a riding model with isotropic displacement parameters based on the equivalent isotropic displacement parameter (Ueq) of the parent atom. The crystal structure of compound 1 contains two methyl acrylate groups exhibiting positional disorder, which have been modeled over two sites with approximately 58/42 and 63/37 ratios, respectively. Remaining diffused electron density was masked out using SMTBX toolbox within Olex 2 suite.23 This improved model and led to satisfactory convergence. The crystal structure of compound 6, three disordered −CH2CH2CF2)3CF3 groups, which have been modeled over two sites with 57/43, 66/34, and 68/32 ratios each. Atomic displacement parameters on atoms C9 and C9a atoms were constrained using EADP. It contains also accessible voids, filled with solvent molecules (water). Three of them were found directly from the Fourier map; however, reaming diffused electron density contribution was accounted for by the SMTBX solvent masking routine as implemented
in OLEX2 software.23 For disordered structures (1 and 6), geometrical restraints DFIX/DANG have been applied to maintain reasonable geometry. Additionally, global SIMU, DELU, and RIGU restraints were used to model appropriately atomic displacement parameters. CCDC 1478511−1478513 and 1478515−1478517 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif. The atom connectivity of 5 has been determined by a X-ray diffraction study. However, due to weak and poor data quality, the resulting crystal structure was not suitable for publication. Therefore, it has been deposited in The Cambridge Crystallographic Data Centre as a “Personal Communication” (Mateusz B. Pitak, 2016, CCDC deposition number 1478514).
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ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.organomet.6b00565. 19 F NMR and 29Si NMR chemical shifts for 1−21, ESI MS results, and NMR spectra (PDF)
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AUTHOR INFORMATION
Corresponding Author
*Fax: +441908 858327. E-mail:
[email protected]. ORCID
Peter G. Taylor: 0000-0003-3169-4466 Notes
The authors declare no competing financial interest.
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ACKNOWLEDGMENTS We thank the EPSRC National Mass Spectrometry Service Centre (NMSSC) at Swansea and MEDAC Ltd. of Brunel University for elemental analysis. We thank the EPSRC UK National Crystallography Service at the University of Southampton for the collection of the crystallographic data.
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REFERENCES
(1) Lickiss, P. D.; Rataboul, F. Fully Condensed Polyhedral Oligosilsesquioxanes (POSS): From Synthesis to Application. Adv. Organomet. Chem. 2008, 57, 1−116. (2) Taylor, P. G.; Bassindale, A. R.; El Aziz, Y.; Pourny, M.; Stevenson, R.; Hursthouse, M. B.; Coles, S. J. Dalton. Trans 2012, 41, 2048−2059. (3) El Aziz, Y.; Bassindale, A. R.; Taylor, P. G.; Horton, P. N.; Stephenson, R. A.; Hursthouse, M. B. Organometallics 2012, 31, 6032− 6040. (4) Reeske, G.; Bradtmöller, G.; Schürmann, M.; Jurkschat, K. Chem. - Eur. J. 2007, 13, 10239−10245. (5) Reeske, G.; Schurmann, M.; Jurkschat, K. Dalton Transactions 2008, 3398−3400. (6) Tagne Kuate, A. C.; Reeske, G.; Schürmann, M.; Costisella, B.; Jurkschat, K. Organometallics 2008, 27, 5577−5587. (7) Tagne Kuate, A. C.; Iovkova, L.; Hiller, W.; Schürmann, M.; Jurkschat, K. Organometallics 2010, 29, 5456−5471. (8) Arens, V.; Dietz, C.; Schollmeyer, D.; Jurkschat, K. Organometallics 2013, 32, 2775−2786. (9) Wendji, A. S.; Lutter, M.; Dietz, C.; Jouikov, V.; Jurkschat, K. Organometallics 2013, 32, 5720−5730. (10) Chinnam, P. R.; Wunder, S. L. Chem. Mater. 2011, 23, 5111− 5121. (11) Soo Lee, A. S.; Lee, J. H.; Lee, J.-C.; Hong, S. M.; Hwang, S. S.; Koo, C. M. J. Mater. Chem. A 2014, 2, 1277−1283.
I
DOI: 10.1021/acs.organomet.6b00565 Organometallics XXXX, XXX, XXX−XXX
Article
Organometallics (12) Li, M.; Ren, W.; Zhang, Y.; Zhang, Y. J. Appl. Polym. Sci. 2012, 126, 273−279. (13) Lee, J. Y.; Lee, Y. M.; Bhattacharya, B.; Nho, Y.-C.; Park, J.-K. J. Solid State Electrochem. 2010, 14, 1445−1449. (14) Ravikumar, I.; Saha, S.; Ghosh, P. Chem. Commun. 2011, 47, 4721−4723. (15) Kavallieratos, K.; Sachleben, R. A.; Van Berkel, G. J.; Moyer, B. A. Chem. Commun. 2000, 187−188. (16) Drylie, E. A.; Andrews, C. D.; Hearshaw, M. A.; JimenezRodriguez, C.; Slawin, A.; Cole-Hamilton, D. J.; Morris, R. E. Polyhedron 2006, 25, 853−858. (17) Goodgame, D. M. L.; Kealey, S.; Lickiss, P. D.; White, A. J. P. J. Mol. Struct. 2008, 890, 232−239. (18) Anderson, S. E.; Bodzin, D. J.; Haddad, T. S.; Boatz, J. A.; Mabry, J. M.; Mitchell, C.; Bowers, M. T. Chem. Mater. 2008, 20, 4299−4309. (19) Coles, S. J.; Gale, P. A. Chem. Sci. 2012, 3, 683. (20) CrystalClear-SM Expert 3.1 b27 (Rigaku, 2012). (21) Sheldrick, G. M. SHELXL97 (2008), Acta Cryst. A64, 112−122. (22) Sheldrick, G. M. Acta Crystallogr., Sect. C: Struct. Chem. 2015, 71, 3. (23) Dolomanov, O. V.; Bourhis, L. J.; Gildea, R. J.; Howard, J. A. K.; Puschmann, H. J. Appl. Crystallogr. 2009, 42, 339.
J
DOI: 10.1021/acs.organomet.6b00565 Organometallics XXXX, XXX, XXX−XXX
