Diphenylsilanediol, Ph<sub>2</sub>Si(OH)<sub>2</sub>, is a silanol. The tetrahedral molecule forms hydrogen-bonded columns in the solid state. It can be prepared by hydrolysis of diphenyldichlorosilane Ph<sub>2</sub>SiCl<sub>2</sub>. Diphenylsilanediol can act as an anticonvulsant, in a similar way to phenytoin. Although the compound is stable in normal conditions, the presence of basic impurities can accelerate the condensation of the silanol groups.