C. Strohmann – E. Wack · Bis-, Tris- and Tetrakis(lithiomethyl)germanes
1577
1
1,1-Diethyl-3,3-diphenyl-1-germa-3-silacyclobutane (44)
GeC6H5). – 13C{ H} NMR (50.32 MHz, CDCl3): δ = 7.7
(GeCH2Ge), 128.3 (C-2/C-6 or C-3/C-5 of GeC6H5), 129.0
(C-4 of GeC6H5), 133.7 (C-2/C-6 or C-3/C-5 of GeC6H5),
139.6 (C-1 of GeC6H5). Elemental analysis for C26H24Ge2
(481.7 g mol−1): calcd. C 64.84, H 5.02; found C 65.0,
H 4.9.
B. p. 135 ◦C/10−3 mm (oven temperature); yield 30%.
1H NMR (200.13 MHz, CDCl3): δ = 0.73 (s, 2J(H, Si) =
5.4 Hz, 4 H, GeCH2Si), 0.85 – 1.15 (m, 10 H, GeC2H5),
1
7.25 – 7.7 (m, 10 H, SiC6H5). – 13C{ H} NMR (50.32 MHz,
CDCl3): δ = −0.4 (GeCH2Si), 8.8 (GeCH2CH3), 9.2
(GeCH2CH3), 127.8 (C-2/C-6 or C-3/C-5 of SiC6H5), 129.1
(C-4 of SiC6H5), 134.0 (C-2/C-6 or C-3/C-5 of SiC6H5),
139.0 (C-1 of SiC6H5). – 29Si NMR (39.76 MHz, CDCl3):
Crystal structure determination
Single crystals of compounds 31 and 40 were obtained by
δ = −2.7. – EI-MS (70 eV): m/z (%) = 342 (10, M+), cooling of a saturated solution in hexane to −35 C. Data
313 (100, M+ - C2H5), 285 (38, M+ - 2 C2H5 + H), 197 collections were performed on a STOE IPDS diffractome-
(44, (C6H5SiCH3+). Elemental analysis for C18H24GeSi ter employing graphite-monochromated Mo-Kα radiation.
(341.1 g mol−1): calcd. C 63.39, H 7.09; found C 63.5, The structures were solved by direct methods and refined by
◦
H 7.0%.
full-matrix least-squares methods on F2 [14]. The hydrogen
atoms were calculated on ideal positions and refined by the
riding model. Some phenylthiomethyl groups of 40 are dis-
ordered; corresponding sulfur and carbon atoms were refined
on split positions. Crystal data, data collection parameters
and details of the structure refinement are given in Table 1.
The crystallographic data of 31 and 40 (excluding structure
factors) were deposited with the Cambridge Crystallographic
Data Centre, CCDC-247123 (40) and CCDC-247124 (31).
Copies of the data can be obtained free of charge on appli-
cation to The Director, CCDC, 12 Union Road, Cambridge
CB21EZ, UK (Fax: int.code+(1223)336-033; e-mail for in-
quiry: fileserv@ccdc.cam.ac.uk).
1,1,3,3-Tetraphenyl-1-german-3-silacyclobutane (45) [12]
M.p. 98 ◦C (hexane); yield 32%. 1H NMR (200.13 MHz,
2
CDCl3): δ = 1.30 (s, J(H, Si) = 5.7 Hz, 4 H, SiCH2Ge),
7.2 – 7.60 (m, 20 H, SiC6H5 and GeC6H5). – 13C{ H}
1
NMR (50.32 MHz, CDCl3): δ = 3.8 (SiCH2Ge), 127.9,
128.3 (C-2/C-6 or C-3/C-5 of SiC6H5 or GeC6H5), 129.0,
129.4 (C-4 of SiC6H5 or GeC6H5), 133.8, 134.2 (C-2/C-6
or C-3/C-5 of SiC6H5 or GeC6H5), 137.8, 139.0 (C-1 of
SiC6H5 or GeC6H5). – 29Si NMR (39.76 MHz, CDCl3):
δ = −2.6. – EI-MS (70 eV): m/z (%) = 438 (3, M+), 423
(2, M+ - CH3), 269 (18, M+ - 2 C6H5 - CH3), 197 (18,
(C6H5)2SiCH3+), 128 (100, M+ - 4 C6H5 - 2 H). Elemental
analysis for C26H24GeSi (437.2 g mol−1): calcd. C 71.44,
H 5.53; found C 71.5, H 5.6%.
Acknowledgements
We gratefully acknowledge the generous financial support
of the Deutsche Forschungsgemeinschaft and the Fonds der
Chemischen Industrie. We thank Prof. M. Veith (University
Saarbru¨cken) for supporting this work.
1,1,3,3-Tetraphenyl-1,3-digermacyclobutane (46) [12]
M. p. 50 ◦C (hexane); yield 28%. 1H NMR (200.13 MHz,
CDCl3): δ = 1.58 (s, 4 H, GeCH2Ge), 7.20 – 7.6 (m, 20 H,
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