Polymethylhydrosiloxane
Polymethylhydrosiloxane is a polymer with the general structure --. It is used in organic chemistry as a mild and stable reducing agent easily transferring hydrides to metal centers and a number of other reducible functional groups. A variety of related materials are available under the following CAS registry numbers 9004-73-3, 16066-09-4, 63148-57-2, 178873-19-3. These include the tetramer, copolymers of dimethylsiloxane and methylhydrosiloxane, and trimethylsilyl terminated materials.
This material is prepared by the hydrolysis of methyldichlorosilane:
The related polymer polydimethylsiloxane is made similarly, but lacking Si-H bonds, it exhibits no reducing properties.
Illustrative of its use, PMHS is used for in situ conversion of tributyltin oxide to tributyltin hydride:
