Method for producing higher silanes

A process for preparing dimeric and/or trimeric silicon compounds of the general formula (Ia) or the germanium compounds of the general formula (Ib)

• where R1 to R8 are each hydrogen and/or halogen, where the halogen is selected from chlorine, bromine and/or iodine, where R1 to R8 denote identical or different radicals in the formula (Ia) or (Ib), with the proviso that at least one of the R1 to R8 radicals is a halogen, and n=0 or 1,
• a) wherein a silicon compound of the general formula (IIa)
• or a germanium compound of the general formula (IIb)
• where R9 to R12 are each hydrogen, organyl, where the organyl comprises a linear, branched and/or cyclic alkyl having 1 to 18 carbon atoms, linear, branched and/or cyclic alkenyl having 2 to 8 carbon atoms, unsubstituted or substituted aryl and/or corresponding benzyl, and/or halogen, and the halogen is selected from chlorine, bromine and/or iodine, where R9 to R12 denote identical or different radicals in the formula (IIa) or (IIb) and n=1 or 2,
• the silicon compound of the formula (IIa) in the presence of one or more compounds of the general formula (IIIa)
• or the germanium compound of the formula (IIb) in the presence of one or more compounds of the general formula (IIIb)
• where R13 to R16 are each hydrogen, organyl, where the organyl comprises a linear, branched and/or cyclic alkyl having 1 to 18 carbon atoms, linear, branched and/or cyclic alkenyl having 2 to 8 carbon atoms, unsubstituted or substituted aryl and/or corresponding benzyl, and/or halogen, and the halogen is selected from chlorine, bromine and/or iodine, where R13 to R16 denote identical or different radicals of the formula (IIIa) or (IIIb) and n=1 or 2, especially with the proviso that it is a hydrogen-containing compound, is exposed to a nonthermal plasma and
• b) one or more pure silicon compounds of the general formula (Ia) or germanium compounds of the general formula (Ib) are obtained from the resulting phase.