Preparation of hydrogenosilanes by catalytic hydrogenolysis of polysilanes

A process for the preparation of hydrosilanes from polysilanes, comprising contacting gaseous hydrogen under pressure with polysilanes of formula (I):

• RaHbSinX2n+2−a−b (I)
• in which:
• the R radicals are identical or different and are selected from the group comprising:
• linear or branched C1-C6 alkyls, aryls, linear or branched C1-C6 alkoxyls, a trifluoropropyl radical or a trimethylsiloxyl radical
• the X radicals are halogens which are identical to or different from one another
• n=2 to 20
• a=0 to 2n+2
• b=0 to 2n+2
• a+b=0 to 2n+2
• in order to obtain monosilanes of formula (II):
• RcHdSiX4−c−d (II):
• in which:
• R and X are as defined above
• c=1, 2, 3 or 4
• d=0, 1 or 2
• c+d=2, 3 or 4
• wherein polysilane (I) and hydrogen are brought into contact in the presence of a catalytic system comprising
• —A— on the one hand, at least one precursor of at least one hydrogenation catalyst, this precursor A being selected from salts of at least one transition metal, the anionic or neutral ligands of which are devoid of 7-acceptor orbitals;
• —B— and, on the other hand, at least one aid for dissolution of the precursor A in the reaction medium, this aid B being selected from nucleophiles which are soluble in an aprotic medium;
• with the exclusion of a reducing agent.