Na2SnOH6

Na2SnOH6, commonly called disodium hexahydroxostannate(IV), is an inorganic salt that comprises the hexahydroxo tin(IV) anion [Sn(OH)6]2− and two sodium cations. In the solid state it appears as a white crystalline material and is readily soluble in water, where it exists as the hexahydroxostannate(IV) complex.

Structural details show tin in the +4 oxidation state coordinated by six hydroxide ligands in an octahedral geometry. The overall anion carries a 2− charge, balanced in the salt by two Na+ ions to form Na2[Sn(OH)6], though the empirical formula is often written as Na2SnOH6.

Preparation typically involves forming the hexahydroxo tin(IV) complex under strongly basic conditions and pairing it with sodium ions. Routes include hydrolyzing tin(IV) sources with sodium hydroxide followed by crystallization of the disodium salt; variations exist using sodium stannate routes or stannic hydroxide precursors in aqueous alkali.

In solution, the [Sn(OH)6]2− species is the predominant tin(IV) hydroxy complex at high pH. Under acidic or dehydrating conditions, it can transform to tin oxide or hydroxide species. The salt serves as a convenient source of the hexahydroxo tin(IV) anion for synthesis of tin oxide materials and related tin(IV) compounds.

Safety considerations for Na2SnOH6 are typical of inorganic salts: avoid inhalation or ingestion, and use standard laboratory precautions such as gloves and eye protection.