Description

Polymethylhydrosiloxane (PMHS) is a polymer with the general structure -(CH3(H)Si-O)-. It is used in organic chemistry as a mild and stable reducing agent easily transferring hydrides to metal centers.[1] A variety of related materials are available under the following CAS registry numbers ********3, *********4, *********2, **********3. These include the tetramer ((MeSiHO)4), copolymers of dimethysiloxane and methylhydrosiloxane, and trimethylsilyl terminated materials.
 

This material is prepared by the hydrolysis of methyldichlorosilane:

The related polymer polydimethylsiloxane (PDMS) 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:[2]