Tin(II) hydroxide, Sn(OH)<sub>2</sub>, also known as stannous hydroxide, is an inorganic compound tin(II). The only related material for which definitive information is available is the oxy hydroxide Sn<sub>6</sub>O<sub>4</sub>(OH)<sub>4</sub>, but other related materials are claimed. They are all white solids that are insoluble in water.
Crystals of Sn<sub>6</sub>O<sub>4</sub>(OH)<sub>4</sub> has been characterized by X-ray diffraction. This cluster is obtained from solution of basic solutions of tin(II). The compound consists of an octahedron of Sn centers, each face of which is capped by an oxide or a hydroxide. The structure is reminiscent of the Mo<sub>6</sub>S<sub>8</sub> subunit of the Chevrel phases. The structure of pure Sn(OH)<sub>2</sub> is not known.
Sn(OH)<sub>2</sub> has been claimed to arise from the reaction of (CH<sub>3</sub>)<sub>3</sub>SnOH with SnCl<sub>2</sub> in an aprotic solvent:
No crystallographic characterization is available on this material.
Stannous hydroxide adds additional hydroxide ligands to form stannites. Air easily oxidizes stannous hydroxide to stannic oxide (SnO<sub>2</sub>).