Patent GB-823483-A (GB)
Title: Method of preparing hydrides and organically substituted hydrides of silicon, germanium, tin and phosphorus
IPC: C07F9/50
Filed: 1957-10-31
Abstract: Hydrides (as defined) of silicon, germanium, tin, or phosphorus are produced by reacting in an inert liquid medium halides (as defined) of these elements with sodium hydride in the presence of an organic compound of boron aluminium or gallium (as defined) adapted to render the alkali metal hydride soluble in the liquid. The halides are defined as a compound in which at least one halogen atom is bonded directly to an atom of silicon, germanium, tin or phosphorus, including chlorinated di-silanes, e.g. Si2Cl6, ElHalxRyR1z compounds, where x is 1, 2, 3, or 4, x + y + z = 3 or 4, depending on the valency of El, and R and R1 are H, alkyl, aryl, chloroalkyl, chloroaryl, vinyl, alkoxy, isoalkyl, cycloalkyl, or benzyl, chlorosiloxanes, e.g. Cl6Si2O, chloropolysiloxanes, chlorosilicarbanes Cl3Si(CH2)xSiCl3 and (SiCl)6 and corresponding germanium or tin compounds or similar compounds of trivalent phosphorus where such exist.  The hydrides produced will be the corresponding compounds with halogen replaced with hydrogen and reaction is effected at -40 DEG  to 170 DEG  C., preferably 70-120 DEG  C.  Liquids may be hexane, octane, dodecane, benzene, toluene or halogenated hydrocarbons, triethyl-, tetraethyl-, tetrapropyl- or dipropylsilanes, methyl naphthalene, mineral oil, tetrahydrofuran, or the hydride required.  The solubilizing compounds are MeRxR1y, where x + y = 3, Me is B, Ga, or Al, and R, R1 are methyl, ethyl, propyl, isopropyl, butyl, hexyl, methoxy, ethoxy, propoxy or phenoxy, and R1 may also be H, organic addition products, e.g. etherates, of such compounds, or complexes of such compounds with NaH, e.g. NaH.BR3, NaH.  Al(OR)3, NaH.AlR2H or NaH.AlR3.  Such compounds are present in amount 1-100 molar per cent of the NaH.  The reaction may be carried out in a number of vessels through which the halide is passed in series with agitation.  The last vessel has no solubilizing compound to absorb such compound entrained.  After reaction the first vessel is removed, and the alkali metal halide is removed by filter or centrifuge, or the liquid is distilled off to recover the hydride. The vessel is recharged with alkali metal hydride and liquid and becomes the last vessel of the series.  The reaction may be effected under vacuum or pressure, or in an inert atmosphere of A, N2, He or H2.  In the examples, NaH is used in mineral oil, tetrahydrofuran or benzene/tetrahydrofuran mixture, in the presence of boron or aluminium triethyl, or boron tributyl to prepare SiH4 from SiCl4 (3,9,11); Si2H6 from Si2Cl6 (14); GeH4 from GeCl4 (15); PH3 from PCl3 (18); C2H5SiH3 from C2H5SiCl3 or C2H5SiF3 (2,5,8,12); (C2H5)2 SiH2 from (C2H5)2SiCl2 or (C2H5)2SiF2 (1,4,13); (C2H5)3SiH from (C2H5)3SiF (4); vinyl silane from vinyl trichlorosilane (16); (C6H5)3SiH from (C6H5)3SiF (4) (C6H5)2SiH2 from (C6H5)2SiCl2; (C2H5)2SnH2 from (C2H5)2SnCl2 (10); and (C2H5)3SnCl (7,10).ALSO:Hydrides of silicon are produced by reacting in an inert liquid medium silicon halides (as defined) with sodium hydride in the presence of an organic compound of boron, aluminium or gallium (as defined) adapted to render the alkali metal hydride soluble in the liquid.  The halides are defined as a compound in which at least one halogen atom is bonded directly to an atom of silicon and they include chlorinated di-silanes, e.g. Si2Cl6; Si Halx Ry R1z compounds, where x is 1, 2, 3 or 4, x+y=4, and R and R1 are H, alkyl, aryl, chloroalkyl chloroaryl, vinyl, alkoxy, isoalkyl, cycloalkyl, or benzyl; chlorosiloxanes such as Cl6Si2O; chloropolysiloxanes; chlorosilicarbanes Cl3Si(CH2)x SiCl3 and (SiCl)6.  The hydrides produced will be the corresponding compounds with halogen replaced with hydrogen and reaction is effected at - 40 DEG  to 170 DEG  C., preferably 70-120 DEG  C.  The liquid medium may be hexane, octane, dodecane, benzene, toluene or halogenated hydrocarbons, triethyl-, tetraethyl-, tetrapropyl-, or dipropyl-silanes, methyl naphthalene, mineral oil, tetrahydrofuran or the hydride required. The solubilizing compounds are Me Rx R1y, where x + y = 3, Me is B, Ga, or Al, and R, R1 are methyl, ethyl, propyl, isopropyl, butyl, hexyl, methoxy, ethoxy, propoxy, or phenoxy, and R1 may also be H, organic addition products, e.g. etherates, of such compounds, or complexes of such compounds with NaH, e.g. NaH. BR3, NaH. Al(OR)3, NaH. AlR2H, or NaH. AlR3.  Such compounds are present in amount 1-100 molar % of the NaH.  The reaction may be carried out in a number of vessels through which the halide is passed in series with agitation.  The last vessel has no solubilizing compound to absorb such compound entrained.  After reaction the first vessel is removed, and the alkali metal halide is removed by filter or centrifuge, or the liquid is distilled off to recover the hydride. The vessel is recharged with alkali metal hydride and liquid and becomes the last vessel of the series.  The reaction may be effected under vacuum or pressure, or in an inert atmosphere of A, N2, He or H2.  In the examples, NaH is used in mineral oil, tetrahydrofuran or benzene/tetrahydrofuran mixture, in the presence or boron or aluminium triethyl, or boron tributyl to prepare C2H5SiH3 from C2H5SiCl3 or C2H5SiF3 (2,5,8,12); (C2H5)2SiH2 from (C2H5)2SiCl2 or (C2H5)2SiF2 (1, 4, 13); (C2H5)3SiH from (C2H5)3SiF(4); vinyl silane from vinyl trichlorosilane (16); (C6H5)3SiH from (C6H5)3SiF (4); (C6H5)2 SiH2 from (C6H5)2SiCl2 (17).ALSO:Hydrides (as defined) of silicon, germanium, tin, or phosphorus are produced by reacting in an inert liquid medium halides (as defined) of these elements with sodium hydride in the presence of an organic compound of boron, aluminium or gallium (as defined) adapted to render the alkali metal hydride soluble in the liquid. The halides are defined as a compound in which at least one halogen atom is bonded directly to an atom of silicon, germanium, tin or phosphorus, including chlorinated di-silanes, e.g. Si2Cl6, ElHalxRyR1z compounds, where x is 1, 2, 3 or 4, x + y + z = 3 or 4, depending on the valency of El, and R and R1 and H, alkyl, aryl, chloroalkyl, chloroaryl, vinyl, alkoxy, isoalkyl, cycloalkyl, or benzyl, chlorosiloxanes, e.g. Cl6Si2O, chloropolysiloxanes, chlorosilicarbanes Cl3Si(CH2)xSiCl3 and (SiCl)6, and corresponding germanium or tin compounds, or similar compounds of trivalent phosphorus where such exist.  The hydrides produced will be the corresponding compounds with halogen replaced with hydrogen and reaction is effected at - 40 DEG  to 170 DEG  C., preferably 70-120 DEG  C. Liquids may be hexane, octane, dodecane, benzene, toluene or halogenated hydrocarbons, triethyl-, tetraethyl-, tetrapropyl- or dipropyl-silanes, methyl naphthalene, mineral oil, tetrahydrofuran or the hydride required.  The solubilizing compounds are MeRxR1y, where x + y = 3, Me is B, Ge, or Al, and R, R1 are methyl, ethyl, propyl, isopropyl, butyl, hexyl, methoxy, ethoxy, propoxy, or phenoxy, and R1 may also be H, organic addition products, e.g. etherates, of such compounds, or complexes of such compounds with NaH, e.g. NaH.  BR3, NaH. Al(OR)3, NaH. AlR2H, or NaH. AlR3.  Such compounds are present in amount 1-100 molar per cent of the NaH.  The reaction may be carried out in a number of vessels through which the halide is passed in series with agitation.  The last vessel has no solubilizing compound to absorb such compound entrained.  After reaction the first vessel is removed, and the alkali metal halide is removed by filter or centrifuge, or the liquid is distilled off to recover the hydride. The vessel is recharged with alkali metal hydride and liquid and becomes the last vessel of the series.  The reaction may be effected under vacuum or pressure, or in an inert atmosphere of A, N2, He or H2.  In the examples, NaH is used in mineral oil, tetrahydrofuran or benzene/tetrahydrofuran mixture, in the presence of boron or aluminium triethyl, or boron tributyl to prepare SiH4 from SiCl4 (3,9, 11); Si2H6 from Si2Cl6 (14); GeH4 from GeCl4 (15); PH3 from PCl3 (18); C2H5SiH3 from C2H5SiCl3, or C2H5SiF3 (2, 5, 8, 12); (C2H5)2SiH2 from (C2H5)2SiCl2, or (C2H5)2SiF2 (1, 4, 13); (C2H5)3 SiH from (C2H5)3SiF (4); vinyl silane from vinyl trichlorosilane (16; (C6H5)3SiH from (C6H5)3SiF (4); (C6H5)2SiH2 from (C6H5)2SiCl2; (C2H5)2SnH2 from (C2H5)2SnCl2 (10); and (C2H5)3SnCl (7, 10).