Diphenylsilanediol, Ph2Si(OH)2, is a silanol.

The tetrahedral molecule forms hydrogen-bonded columns in the solid state.

[4] It can be prepared by hydrolysis of diphenyldichlorosilane Ph2SiCl2.

Diphenylsilanediol can act as an anticonvulsant, in a similar way to phenytoin.

[4] Although the compound is stable in normal conditions, the presence of basic impurities can accelerate the condensation of the silanol groups.