Silanol

An Si–OH group or a compound containing it. Condensation of two silanol groups can form an Si–O–Si bond and water.

A coordination ligand containing deprotonated silanol oxygen, $\mathrm{Si}-{\mathrm{O}}^{-}$, which binds a metal through oxygen. Three silanol groups on a corner-deficient silsesquioxane can give a facial tridentate trianionic donor set.