Polymethylhydrosiloxane (PMHS) is a

polymer A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...

with the general structure -(CH₃(H)Si-O)-. It is used in

organic chemistry Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; ...

as a mild and stable reducing agent easily transferring

hydride In chemistry, a hydride is formally the anion of hydrogen( H−). The term is applied loosely. At one extreme, all compounds containing covalently bound H atoms are called hydrides: water (H2O) is a hydride of oxygen, ammonia is a hydride of ...

s to metal centers and a number of other reducible functional groups. A variety of related materials are available under the following

CAS registry numbers A CAS Registry Number (also referred to as CAS RN or informally CAS Number) is a unique identification number assigned by the Chemical Abstracts Service (CAS), US to every chemical substance described in the open scientific literature. It inclu ...

9004-73-3, 16066-09-4, 63148-57-2, 178873-19-3. These include the tetramer ((MeSiHO)₄), copolymers of dimethylsiloxane and methylhydrosiloxane, and trimethylsilyl terminated materials. This material is prepared by the hydrolysis of monomethyldichlorosilane CAS#: 75-54-7: :n MeSiHCl₂ + n H₂O → (MeSiHO)_n + 2n HCl The related polymer

polydimethylsiloxane Polydimethylsiloxane (PDMS), also known as dimethylpolysiloxane or dimethicone, belongs to a group of polymeric organosilicon compounds that are commonly referred to as silicones. PDMS is the most widely used silicon-based organic polymer, as its ...

(PDMS) is made similarly, but lacking Si-H bonds, it exhibits no reducing properties. Dimethyldichlorosilane CAS#: 75-78-5 is then used instead of monomethyldichlorosilane CAS#: 75-54-7. Illustrative of its use, PMHS is used for in situ conversion of

tributyltin oxide Tributyltin oxide (TBTO) is an organotin compound chiefly used as a biocide (fungicide and molluscicide), especially a wood preservative. Its chemical formula is C4H9)3Snsub>2O. It is a colorless viscous liquid. It is poorly soluble in water (20 ...

tributyltin hydride Tributyltin hydride is an organotin compound with the formula (C4H9)3SnH. It is a colorless liquid that is soluble in organic solvents. The compound is used as a source of hydrogen atoms in organic synthesis. Synthesis and characterization The ...

: : 2"(MeSiH)" + (Bu₃Sn)₂O → "Me₂Si₂O" + 2 Bu₃SnH

References

Further reading