Tetramethylgermanium

Structural formula
General
Surname	Tetramethylgermanium
other names	Germanium tetramethyl Tetramethylgerman
Molecular formula	C 4 H 12 Ge
Brief description	colorless liquid
External identifiers / databases
CAS number 865-52-1 EC number 212-745-0 ECHA InfoCard 100,011,587 PubChem 70079 ChemSpider 63268 Wikidata Q1354657
properties
Molar mass	132.78 g mol −1
Physical state	liquid
density	0.978 g cm −3 (25 ° C)
Melting point	−88 ° C
boiling point	43.4 ° C
Vapor pressure	326.4 mmHg (19.7 ° C) 139.3 mmHg (0.0 ° C)
Refractive index	1.389 (20 ° C)
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 225-302-312-319-332 P: 210-280-305 + 351 + 338
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Tetramethylgermanium , with the constitutional formula Ge (CH ₃ ) ₄ , is one of the simplest organometallic germanium compounds. It consists of a central germanium atom (Ge) with four methyl groups  (–CH ₃ ) attached to it and is a colorless liquid at room temperature.

presentation

Tetramethylgermanium can be synthesized from germanium tetrachloride and methylmagnesium chloride by the Grignard reaction .

${\displaystyle \mathrm {GeCl_{4}\ +4\ (CH_{3})MgCl+\ {\xrightarrow[{Et_{2}O}]{}}\ Ge(CH_{3})_{4}+\ 4\ MgCl_{2}} }$

It is also possible to convert germanium tetrachloride with dimethyl zinc or dimethyl cadmium, the latter being easier to separate from the resulting product due to its higher boiling point. The conversion takes place almost quantitatively at room temperature.

properties

Tetramethylgermanium is an oily, colorless liquid with a sweetish odor, similar to chloroform . It dissolves without decomposition in ethanol , diethyl ether and gasoline. It reacts slowly with nitric acid at 0 ° C.

use

Tetrametylgermanium can be used as a methylating agent in transmetalation reactions :

${\displaystyle \mathrm {(CH_{3})_{4}Ge+GaCl_{3}{\xrightarrow {<20\,{}^{\circ }C}}(CH_{3})_{3}GeCl+GaCl_{2}(CH_{3})} }$

Individual evidence

1. ↑ EH Brooks and F. Glock Ling: tetramethyl germane . In: Robert W. Parry (Ed.): Inorganic Syntheses . tape 12 . McGraw-Hill Book Company, Inc., 1970, ISBN   07-048517-8  ( defective ) , p. 58-59 (English).
2. ↑ ^{a b c d} data sheet Tetramethylgermanium 98% from Sigma-Aldrich , accessed on November 22, 2011 ( PDF ).
3. ↑ ^{a b c d e} L. M. Dennis: Germanium. Summary of studies in the Department of Chemistry, Cornell University, 1921-1927 . In: Journal of Inorganic and General Chemistry . tape 174 , no. 1 , August 2, 1928, p. 97 , doi : 10.1002 / zaac.19281740114 .
4. ↑ ^{a b} L.H. Long, CI Pulford +: The preparation and physical properties of highly pure tetramethylgermane . In: Journal of Inorganic and Nuclear Chemistry . 30, No. 8, August 1968, ISSN  0022-1902 , pp. 2071-2075. doi : 10.1016 / 0022-1902 (68) 80199-X .
5. ↑ H. Schmidbaur, W. Findeiss: A Simple Route to Organogallium Compounds . In: Angewandte Chemie International Edition in English . tape 3 , no. October 10 , 1964, p. 696 , doi : 10.1002 / anie.196406961 .

Web links

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