Patent ID: 12195486

EXAMPLES 1 TO 14 AND COMPARATIVE EXPERIMENTS 1 TO 5

Reaction of tetramethylsilane with dimethyldichlorosilane

Examples 1 to 14 and comparative experiments 1 to 5 were carried out under inert conditions in a three-neck flask with stirrer, reflux condenser (operated with a cryostat), dropping funnel and reaction temperature measurement. Dimethyldichlorosilane was initially charged and to this was added the catalyst and cocatalyst (examples 1-14). For comparative experiments 1 and 5 only the catalyst was added, and for comparative experiments 2 to 4 only the cocatalysts were added.

Technical-grade tetramethylsilane (approx. 85% by weight, determined by gas chromatography (GC), containing approx. 3-5% by weight of dimethylchlorosilane) was subsequently metered in.

The mixture was heated to reflux and samples were taken at regular intervals. The samples were distilled to remove the solids contents and the distillate was analyzed by means of gas chromatography (GC, column: Agilent DB 210, length: 60 m, diameter: 0.32 mm).

Example 1

150 g of dimethyldichlorosilane

115 g of technical-grade tetramethylsilane

8 g of AlCl3

1.5 g of trifluoromethanesulfonic acid

After a reaction time of 105 min, the remaining tetramethylsilane content was less than 1% by weight and the content of trimethylchlorosilane was 86% by weight.

Example 2

150 g of dimethyldichlorosilane

115 g of technical-grade tetramethylsilane

8 g of AlCl3

1.5 g of trimethylsilyl trifluoromethanesulfonate

After a reaction time of 120 min, the remaining tetramethylsilane content was approx. 1% by weight and the content of trimethylchlorosilane was 86% by weight.

Example 3

150 g of dimethyldichlorosilane

115 g of technical-grade tetramethylsilane

8 g of AlCl3

1.5 g of aluminum tris(trifluoromethanesulfonate)

After a reaction time of 120 min, the remaining tetramethylsilane content was approx. 1% by weight and the content of trimethylchlorosilane was 86% by weight.

Example 4

150 g of dimethyldichlorosilane

115 g of technical-grade tetramethylsilane

8 g of AlCl3

1.5 g of cerium trichloride

After a reaction time of 95 min, the remaining tetramethylsilane content was approx. 1% by weight and the content of trimethylchlorosilane was 86% by weight.

Example 5

150 g of dimethyldichlorosilane

115 g of technical-grade tetramethylsilane

8 g of AlCl3

1.5 g of gadolinium trichloride

After a reaction time of 60 min, the remaining tetramethylsilane content was approx. 1% by weight and the content of trimethylchlorosilane was 86% by weight.

Example 6

1.45 t of dimethyldichlorosilane

1 t of technical-grade tetramethylsilane

18 kg of AlCl3(produced in situ from 16.7 kg of ethylaluminum sesquichloride and hydrogen chloride)

2.5 kg of trifluoromethanesulfonic acid

After a reaction time of 4 h under reflux conditions, the remaining tetramethylsilane content was approx. 2% by weight and the content of trimethylchlorosilane was 85% by weight.

Example 7

The final reaction mixture from example 6 was worked up by distillation and to the remaining distillation bottoms of approx. 0.15 t were added 1.45 t of dimethyldichlorosilane and 1 t of technical-grade tetramethylsilane, and the mixture was reacted analogously to example 6. After a reaction time of 4 h, the remaining tetramethylsilane content was approx. 2% by weight and the content of trimethylchlorosilane was 85% by weight.

Example 8

1.45 t of dimethyldichlorosilane

1 t of technical-grade tetramethylsilane

18 kg of AlCl3(produced in situ from 16.7 kg of ethylaluminum sesquichloride and hydrogen chloride)

1.0 kg of cerium trichloride

After a reaction time of 1 h, the remaining tetramethylsilane content was approx. 1% by weight and the content of trimethylchlorosilane was 86% by weight.

Example 9

The final reaction mixture from example 8 was worked up by distillation and to the remaining distillation bottoms of approx. 0.15 t were added 1.45 t of dimethyldichlorosilane and 1 t of technical-grade tetramethylsilane, and the mixture was reacted analogously to example 8. After a reaction time of 1 h, the remaining tetramethylsilane content was approx. 1% by weight and the content of trimethylchlorosilane was 86% by weight.

Example 10

150 g of dimethyldichlorosilane

115 g of technical-grade tetramethylsilane

6 g of AlCl3

1 g of terbium trichloride

After a reaction time of 60 min at 40° C., the remaining tetramethylsilane content was approx. 1% by weight and the content of trimethylchlorosilane was 86% by weight.

Example 11

150 g of dimethyldichlorosilane

115 g of technical-grade tetramethylsilane

6 g of AlCl3

1 g of gadolinium trifluoride

After a reaction time of 60 min at 40° C., the remaining tetramethylsilane content was approx. 1% by weight and the content of trimethylchlorosilane was 86% by weight.

Example 12

150 g of dimethyldichlorosilane

115 g of technical-grade tetramethylsilane

6 g of AlCl3

1 g of gadolinium tribromide

After a reaction time of 60 min at 40° C., the remaining tetramethylsilane content was approx. 1% by weight and the content of trimethylchlorosilane was 86% by weight.

Example 13

150 g of dimethyldichlorosilane

115 g of technical-grade tetramethylsilane

6 g of AlCl3

0.1 g of gadolinium trichloride

After a reaction time of 60 min at 40° C., the remaining tetramethylsilane content was approx. 1% by weight and the content of trimethylchlorosilane was 86% by weight.

Example 14

150 g of dimethyldichlorosilane

115 g of technical-grade tetramethylsilane

6 g of AlBr3

0.3 g of gadolinium trichloride

After a reaction time of 60 min at 40° C., the remaining tetramethylsilane content was approx. 1% by weight and the content of trimethylchlorosilane was 86% by weight.

Comparative Experiment 1

150 g of dimethyldichlorosilane

115 g of technical-grade tetramethylsilane

8 g of AlCl3

After a reaction time of 120 min, the remaining tetramethylsilane content was approx. 23% by weight; the content of trimethylchlorosilane was 34% by weight. Only after a reaction time of 360 min under reflux conditions was the remaining tetramethylsilane content approx. 1% by weight and the content of trimethylchlorosilane 86% by weight.

Comparative Experiment 2

150 g of dimethyldichlorosilane

115 g of technical-grade tetramethylsilane

8 g of trifluoromethanesulfonic acid

After a reaction time of 120 min it was not possible to detect any conversion, that is to say any change in the composition of the silane mixture.

Comparative Experiment 3

150 g of dimethyldichlorosilane

115 g of technical-grade tetramethylsilane

8 g of aluminum tris(trifluoromethanesulfonate)

After a reaction time of 120 min it was not possible to detect any conversion, that is to say any change in the composition of the silane mixture.

Comparative Experiment 4

150 g of dimethyldichlorosilane

115 g of technical-grade tetramethylsilane

9.5 g of reaction product of aluminum trichloride and trifluoromethanesulfonic acid

After a reaction time of 120 min it was not possible to detect any conversion, that is to say any change in the composition of the silane mixture.

Comparative Experiment 5

Example 6 was repeated with the modification that no trifluoromethanesulfonic acid was added. After a reaction time of 12 h under reflux conditions, the remaining tetramethylsilane content was approx. 2% by weight and the content of trimethylchlorosilane was 85% by weight.

Examples 15 to 30 and comparative experiments 6 to 8:

Reaction of tetramethylsilane with tetrachlorosilane

A mixture of tetrachlorosilane and technical-grade tetramethylsilane (TMS, approx. 85% by weight determined by gas chromatography (GC)) with a content of tetramethylsilane of 46 mol % and tetrachlorosilane of 47 mol % (the remainder consists inter alia of methylchlorohydrogensilanes and chlorohydrogensilanes) is heated to 100° C. under inert conditions with 2 mol %

(mol % based on the silanes) of aluminum trichloride and 0.5 mol % (mol % based on the silanes) of cocatalyst as per table 1 in an autoclave for 4 h with stirring. After cooling, the sedimented catalyst is removed and the reaction product is analyzed using29Si NMR. The results are summarized in table 1.

TABLE 1Starting materials remainingTarget products in theComp.in the reaction mixturereaction mixtureexperiments/Co-% TMSSi(CH3)4SiCl4CH3SiCl3(CH3)2SiCl2(CH3)3SiClExamplescatalystconvertedmol %mol %mol %mol %mol %C 6—14.639.643.614.6C 7*—19.037.74316C 8**GdCl3348.550.7——0.7E 15HfCl43629.742.2——24.1E 16LaCl332.231.443.3——21.9E 17SmCl357.919.540.1——36.7E 18YCl378.410.037.8——48.9E 19Dy(CF3SO3)326.734.044.3——18.6E 20TbCl397.01.434.6—1.658.8E 21Gd(CH3COO)373.112.539.1——46E 22NdCl375.511.438.1—0.147E 23GdCl398.50.544.6—3.858E 24CeCl350.418.239.6——38.1E 25PrCl364.616.339—0.141E 26TmCl340.827.343.5——25.8E 27Gd2O3***49.223.441.5——32.0E 28LuCl377.210.537.3—0.248.8E 29ErCl359.718.540.2——37E 30HoCl384.77.036.2——53.9*2.5 mol % aluminum trichloride**mixture of 50 mol % pure tetramethylsilane and 50 mol % silicon tetrachloride (the mixture does not contain any H-Si compound). No catalyst (AlCl3) is used.***0.5 mol % of cocatalyst, based on gadolinium

Examples 31 and 32

Reaction of Tetramethylsilane with Methyltrichlorosilane

A mixture of tetrachlorosilane and technical-grade tetramethylsilane (TMS, approx. 85% by weight determined by gas chromatography (GC)) with a content of tetramethylsilane of 48 mol % and methyltrichlorosilane of 48 mol % (the remainder consists inter alia of methylchlorohydrogensilanes and chlorohydrogensilanes) is heated to 80° C. under inert conditions with 2 mol % (mol % based on the silanes) of aluminum trichloride and 0.5 mol % (mol % based on the silanes) of cocatalyst as per table 2 in an autoclave for 4 h with stirring. After cooling, the sedimented catalyst is removed and the reaction product is analyzed using29Si NMR. The results are summarized in table 2.

TABLE 2Starting materialsTarget productsremainingin thein the reaction mixturereaction mixtureCo-% TMSSi(CH3)4CH3SiCl3(CH3)2SiCl2(CH3)3SiClExamplescatalystconvertedmol %mol %mol %mol %E 31GdCl310002.154.342.6E 32CeCl399.80.112.135.151.1

Example 33

Reaction of Trimethylchlorosilane with Methyltrichlorosilane

A mixture of 47.5 mol % trimethylchlorosilane and 47.5 mol % methyltrichlorosilane, containing 2.5 mol % of dimethylchlorosilane and 2.5 mol % methyldichlorosilane, is heated to 80° C. under inert conditions with 2 mol % (mol % based on the silanes) of aluminum trichloride and 0.5 mol % (mol % based on the silanes) of cocatalyst as per table 3 in an autoclave for 4 h with stirring. After cooling, the sedimented catalyst is removed and the reaction product is analyzed using29Si NMR. The results are summarized in table 3.

TABLE 3StartingTarget productmaterials remainingin the reactionin the reaction mixturemixtureCo-(CH3)3SiClCH3SiCl3(CH3)2SiCl2Examplescatalystmol %mol %mol %E 33GdCl317.315.663

Example 34

Disproportionation of Dimethyldichlorosilane

A mixture of 95 mol % dimethyldichlorosilane, 2.5 mol % dimethylchlorosilane and 2.5 mol % methyldichlorosilane is heated to 100° C. under inert conditions with 2 mol % (mol % based on the silanes) of aluminum trichloride and 0.5 mol % (mol % based on the silanes) of cocatalyst as per table 4 in an autoclave for 4 h with stirring. After cooling, the sedimented catalyst is removed and the reaction product is analyzed using29Si NMR. The results are summarized in table 4.

TABLE 4Starting materialremainingin the reactionTarget products inmixturethe reaction mixture(CH3)2SiCl2(CH3)3SiClCH3SiCl3ExampleCocatalystmol %mol %mol %E 34GdCl3884.44.1

Example 35

Disproportionation of Phenyltrichlorosilane

A mixture of 95 mol % phenyltrichlorosilane, 2.5 mol % dimethylchlorosilane and 2.5 mol % methyldichlorosilane is heated to 100° C. under inert conditions with 2 mol % (mol % based on the silanes) of aluminum trichloride and 0.5 mol % (mol % based on the silanes) of cocatalyst as per table 5 in an autoclave for 2 h with stirring. After cooling, the sedimented catalyst is removed and the reaction product is analyzed using29Si NMR. The results are summarized in table 5.

TABLE 5Starting materialTarget productsremaining in thein the reactionreaction mixturemixturePhSiCl3Ph2SiCl2ExampleCocatalystmol %mol %E 35GdCl39010