CHEMISTRY

V. F. MIRONOV, A. L. KRAVCHENKO, Corresponding Member of the Academy of Sciences of the USSR A. D. PETROV

SYNTHESIS OF 1,1- AND 1,2-BIS(TRIMETHYLGERMYL)ETHYLENES

The isomeric silicoolefins ((\mathrm{CH_3})_3\mathrm{SiCH}=\mathrm{CHSi}(\mathrm{CH_3})_3) (I) and ([(\mathrm{CH_3})_3\mathrm{Si}]_2\mathrm{C}=\mathrm{CH_2}) (II) possess interesting physical and chemical properties. For example, compound I, in contrast to compound II, shows a greater exaltation of molecular refraction, an increased reactivity in ionic addition reactions, and a decreased reactivity in radical reactions ((^1,^2)). In the Raman and infrared spectra of compounds I and II, various kinds of anomalies also appear in the positions of the characteristic frequencies and in their intensities ((^3)).

The exceptional features noted for these compounds are probably due to (d_\pi—p_\pi) overlap of the (\pi)-electron shells of the multiple bond with the (d)-vacant orbitals of the silicon atom.

In order to study this effect in a series of analogous compounds of other group IVB elements, in the present work we obtained 1,1- and 1,2-bis(trimethylgermyl)ethylenes. The synthesis of these compounds was carried out according to the following schemes:

[
(\mathrm{CH_3})_3\mathrm{GeCH}=\mathrm{CHCl}+\mathrm{ClGe}(\mathrm{CH_3})_3
\xrightarrow{\mathrm{Na}}
(\mathrm{CH_3})_3\mathrm{GeCH}=\mathrm{CHGe}(\mathrm{CH_3})_3,
]

[
(\mathrm{CH_3})_3\mathrm{GeCCl}=\mathrm{CH_2}+\mathrm{ClGe}(\mathrm{CH_3})_3
\xrightarrow{\mathrm{Na}}
(\mathrm{CH_3})_3\mathrm{GeCGe}(\mathrm{CH_3})_3.
]

[
\phantom{(\mathrm{CH_3})_3\mathrm{GeCGe}(\mathrm{CH_3})_3}
\begin{matrix}
|\
\mathrm{CH_2}
\end{matrix}
]

In addition, we attempted to obtain 1,2-bis(trimethylgermyl)ethylene by another route as well. However, it turned out that the addition of trichlorogermane to ((\mathrm{CH_3})_3\mathrm{GeC}\equiv\mathrm{CH}), despite the precautions taken, proceeds mainly in the amount of two molecules, as a result of which, after methylation, tris(trimethylgermyl)ethane is formed preferentially.

[
(\mathrm{CH_3})_3\mathrm{GeC}\equiv\mathrm{CH}
\xrightarrow{\mathrm{HGeCl_3}}
(\mathrm{CH_3})_3\mathrm{GeCH}=\mathrm{CHGeCl_3}(\sim 3\%) +
]

[
+\,(\mathrm{CH_3})_3\mathrm{GeCH_2CH}(\mathrm{GeCl_3})_2(\sim 15\%)
\xrightarrow{\mathrm{CH_3MgCl}}
(\mathrm{CH_3})_3\mathrm{GeCH}=\mathrm{CHGe}(\mathrm{CH_3})_3+
]

[
+\,(\mathrm{CH_3})_3\mathrm{GeCH_2CH}[\mathrm{Ge}(\mathrm{CH_3})_3]_2.
]

1,2-Bis(trimethylgermyl)ethylene, just like its silicon analogue, in contrast to 1,1-bis(trimethylgermyl)ethylene possesses a large ((+0.8)) exaltation of molecular refraction.

Experimental Part

α-Chlorovinyltrichlorogermane
[
\mathrm{CH_2}=\mathrm{C}—\mathrm{GeCl_3}
]
[
\phantom{\mathrm{CH_2}=}\left|\begin{matrix}\[-1.0em]\mathrm{Cl}\end{matrix}\right.
]

In a 150-ml flask with a reflux condenser were placed 140 g of (\mathrm{ClCH_2ClCHGeCl_3}) ((^4)) and 7 g of piperidine (pyridine may also be used). The contents of the flask were slowly ((\sim 2) hr) distilled at such a rate that the temperature of the escaping vapors did not rise above 150–160°. Distillation of the condensate on a column gave 30 g of (\mathrm{GeCl_4}), b.p. 83–85°, and 75 g of (\mathrm{Cl_3GeCCl}=\mathrm{CH_2}), b.p. 152.5° (760); (n_D^{20}) 1.4990; (d_4^{20}) 1.7396; found (MR_D) 40.58; calculated (MR_D) 40.90; yield 61.5%. Literature data ((^4)): b.p. 151°, (n_D^{20}) 1.5002.

α-Chlorovinyltrimethylgermane
[
\mathrm{CH_2}=\mathrm{C}—\mathrm{Ge}(\mathrm{CH_3})_3
]
[
\phantom{\mathrm{CH_2}=}\left|\begin{matrix}\[-1.0em]\mathrm{Cl}\end{matrix}\right.
]

To (\mathrm{CH_3MgCl}), prepared from 30.1 g of magnesium in 200 ml of ether, 75 g of (\alpha)-chlorovinyltrichlorogermane was added. The contents of the flask were boiled for 4 hours and then treated with water. Distillation on a column of the dried (\mathrm{CaCl_2}) ether layer gave 45 g of

[
\mathrm{CH_2=C(Cl)-Ge(CH_3)_3}
]

with b.p. (120.5^\circ) (755), (n_D^{20}) 1.4517; (d_4^{20}) 1.1749; found (MR_D) 41.12, calculated (MR_D) 41.31; yield 80.5%. IR spectrum, see Fig. 1.

[
\begin{array}{ll}
\mathrm{C_5H_{11}GeCl}. & \text{Found, \%: C 33.27, 33.37; H 6.31, 6.57; Ge 40.43, 40.27} \
& \text{Calculated, \%: C 33.51; H 6.18; Ge 40.51}
\end{array}
]

Raman spectrum ((\Delta\nu,\ \mathrm{cm}^{-1})) of ((\mathrm{CH_3})_3\mathrm{GeCCl=CH_2}). 147 (1); 190 (3 broad); 232 (2); 302 (2); 473 (1); 493 (7); 577 (10); 611 (6 broad); 740 (0); 1113 (0); 1153 (0); 1253 (2 broad); 1361 (2); 1409 (1 broad); 1601 (3); 2869 (0); 2912 (10); 2981 (3); 3005 (1); 3080 (1).

1,1-Bis(trimethylgermyl)ethylene

[
\mathrm{CH_2=C\bigl(Ge(CH_3)_3\bigr)_2}.
]

To 8 g of finely divided sodium were added 150 ml of ether, 23 g of ((\mathrm{CH_3})_3\mathrm{GeCl}), 1 ml of (\mathrm{CH_2=C(Cl)Ge(CH_3)_3}), and (\sim 0.5) ml of ethyl acetate. After the reaction had begun, the remaining 26 g of (\mathrm{CH_2=C(Cl)Ge(CH_3)_3}) was added dropwise.

Fig. 1

After 5 hours’ boiling, the contents of the flask were filtered from salts and distilled. There were obtained 8 g of ((\mathrm{CH_3})_3\mathrm{Ge—Ge(CH_3)_3}) with b.p. (136^\circ) and 26 g of

[
\mathrm{CH_2=C\bigl(Ge(CH_3)_3\bigr)_2}
]

with b.p. (72\text{–}73^\circ) (28); (n_D^{20}) 1.4655; (d_4^{20}) 1.1646; found (MR_D) 62.12; calculated (MR_D) 62.09; yield 68%.

[
\begin{array}{ll}
\mathrm{C_8H_{20}Ge_2}. & \text{Found, \%: C 37.12, 37.04; H 7.89, 7.93; Ge 54.63, 54.65} \
& \text{Calculated, \%: C 36.75; H 7.71; Ge 55.54}
\end{array}
]

Raman spectrum ((\Delta\nu,\ \mathrm{cm}^{-1})) of (\mathrm{CH_2=C[Ge(CH_3)_3]_2}). 150 (1); 173 (1); 195 (2 broad); 413 (6); 573 (10); 600 (8 broad); 1114 (0); 1147 (0); 1235 (2); 1250 (2); 1399 (1 broad); 1426 (1 broad); 1584 (1); 2906 (8); 2973 (4 broad); 3001 (1).

1,2-Bis(trimethylgermyl)ethylene

[
\mathrm{(CH_3)_3GeCH=CHGe(CH_3)_3}.
]

Under the conditions of the preceding experiment, from 0.85 g of Na, 2.8 g of (\mathrm{ClGe(CH_3)_3}), and 2.5 g of ((\mathrm{CH_3})_3\mathrm{GeCH=CHCl}^{(5)}), 2.5 g of ((\mathrm{CH_3})_3\mathrm{GeCH=CHGe(CH_3)_3}) was obtained (yield 65.7%), b.p. (73^\circ) (29), (n_D^{20}) 1.4628; (d_4^{20}) 1.1444; found (MR_D) 62.90, calculated (MR_D) 62.09.

[
\begin{array}{ll}
\mathrm{C_8H_{20}Ge_2}. & \text{Found, \%: C 36.74, 36.49; H 7.81, 7.68; Ge 55.28, 55.25} \
& \text{Calculated, \%: C 36.75; H 7.71; Ge 55.54}
\end{array}
]

Raman spectrum ((\Delta\nu,\ \mathrm{cm}^{-1})) of ((\mathrm{CH_3})_3\mathrm{GeCH=CHGe(CH_3)_3}). 148 (1); 165 (1); 194 (1 broad); 230 (1); 273 (0); 572 (10); 602 (6); 1032 (0); 1150 (0); 1244 (2 broad); 1284 (2); 1329 (0); 1400 (0 broad); 1558 (1 broad); 2099 (0 broad); 2871 (1); 2907 (10); 2973 (7 broad).

The line 2099 belongs to an impurity of the compound ((\mathrm{CH_3})_3\mathrm{GeC{\equiv}CGe(CH_3)_3}), which, moreover, was identified in an amount of (\sim 1\%) by gas–liquid chromatography, using an authentic sample of ((\mathrm{CH_3})_3\mathrm{GeC{\equiv}CGe(CH_3)_3}).

1-(Trimethylgermyl)-2,2-bis-(trichlorogermyl)ethane
((\mathrm{CH}_3)_3\mathrm{GeCH}_2\mathrm{CH}(\mathrm{GeCl}_3)_2). To 30 g of ((\mathrm{CH}_3)_3\mathrm{GeC}\equiv\mathrm{CH}), 37 g of (\mathrm{HGeCl}_3) was added dropwise with vigorous stirring. Distillation gave 15 g of ((\mathrm{CH}_3)_3\mathrm{GeCl}), b.p. (94\text{--}95^\circ) (750); (n_D^{21}) 1.4340, 2 g of ((\mathrm{CH}_3)_3\mathrm{GeCH}=\mathrm{CHGeCl}_3), b.p. (100\text{--}103^\circ) (12 mm), and 16 g of ((\mathrm{CH}_3)_3\mathrm{GeCH}_2\mathrm{CH}(\mathrm{GeCl}_3)_2), b.p. (138\text{--}139^\circ) (7); (n_D^{20}) 1.5570; (d_4^{20}) 1.8441. Found (MR_D) 88.41; calculated (MR_D) 87.35; yield 11%, m.p. (30\text{--}50^\circ). The substance is prone to strong supercooling.

Raman spectrum ((\Delta\nu,\ \mathrm{cm}^{-1})) of ((\mathrm{CH}_3)_3\mathrm{GeCH}_2\mathrm{CH}(\mathrm{GeCl}_3)_2). 148 (1 sh); 195 (0 sh); 240 (1); 267 (0 sh); 370 (0); 395 (1); 407 (10); 434 (2 sh); 487 (1); 574 (7); 611 (3 sh); 809 (2); 1193 (1); 257 (2 sh); 1292 (0); 1415 (1); 1519 (1 sh); 2873 (0 sh); 2913 (8 sh); 2981 (0 sh).

Tris-(trimethylgermyl)ethane
((\mathrm{CH}_3)_3\mathrm{GeCH}_2\mathrm{CH}[\mathrm{Ge}(\mathrm{CH}_3)_3]_2). To (\mathrm{CH}_3\mathrm{MgCl}), prepared from 12 g of Mg in 100 ml of ether, 14 g of ((\mathrm{CH}_3)_3\mathrm{GeCH}_2\mathrm{CH}(\mathrm{GeCl}_3)_2) was added. After the usual work-up, 8.5 g of ((\mathrm{CH}_3)_3\mathrm{GeCH}_2\mathrm{CH}[\mathrm{Ge}(\mathrm{CH}_3)_3]_2) was isolated, b.p. (110^\circ) (12 mm); (n_D^{20}) 1.5018; (d_4^{20}) 1.2691; found (MR_D) 88.36; calculated (MR_D) 88.17; yield 65%.

Found, %: C 35.02, 34.91; H 7.83, 7.37; Ge 57.14, 57.47.
(\mathrm{C}{11}\mathrm{H}_3). Calculated, %: C 34.74; H 7.95; Ge 57.28.}\mathrm{Ge

Raman spectrum ((\Delta\nu,\ \mathrm{cm}^{-1})) of ((\mathrm{CH}_3)_3\mathrm{GeCH}_2\mathrm{CH}[\mathrm{Ge}(\mathrm{CH}_3)_3]_2). 153 (1 sh); 175 (1); 201 (1 0sh); 227 (1); 275 (1); 407 (0); 441 (1); 462 (3); 575 (10); 597 (9 sh); 826 (1 sh); 1114 (0); 1146 (1 sh); 1238 (3); 1253 (3); 1299 (3); 1334 (0); 1412 (1 sh); 1513 (1); 2910 (10 sh); 2974 (7 sh).

1,2-Bis-(trimethylgermyl)ethylene
((\mathrm{CH}_3)_3\mathrm{GeCH}=\mathrm{CHGe}(\mathrm{CH}_3)_3). To (\mathrm{CH}_3\mathrm{MgCl}), prepared from 2 g of Mg in 30 ml of ether, 2 g of ((\mathrm{CH}_3)_3\mathrm{GeCH}=\mathrm{CHGeCl}_3), b.p. (100\text{--}103^\circ) (12 mm), was added. After the usual work-up, 1 g of ((\mathrm{CH}_3)_3\mathrm{GeCH}=\mathrm{CHGe}(\mathrm{CH}_3)_3) was obtained, b.p. (173^\circ) (760); (n_D^{20}) 1.4655; (d_4^{20}) 1.1756; (MR_D) 61.53; calculated (MR_D) 62.09; yield 61%.

Found, %: C 36.23, 36.44; H 7.67, 7.70; Ge 56.10, 55.70.
(\mathrm{C}8\mathrm{H}_2). Calculated, %: C 36.75; H 7.71; Ge 55.54.}\mathrm{Ge

The Raman spectrum of this compound coincides with the preceding one. The spectral analysis was carried out by L. A. Leites.

Institute of Organic Chemistry
Academy of Sciences of the USSR

Received
4 XI 1963

REFERENCES CITED

1. V. F. Mironov, Bull. Soc. chim. Belgrade, 23—24, No. 1—2, 23 (1958—1959).
2. V. F. Mironov, Chemistry and Practical Application of Organo-Silicon Compounds, vol. 1, 1958, p. 129.
3. Yu. P. Egorov, L. A. Leites, V. F. Mironov, Izv. AN SSSR, OKhN, 1958, 510.
4. V. F. Mironov, N. G. Dzhurinskaya, A. D. Petrov, DAN, 131, 98 (1960).
5. V. F. Mironov, N. G. Dzhurinskaya, Izv. AN SSSR, OKhN, 1963, 75.