Tin triphosphide is a binary inorganic compound of tin metal and phosphorus with the chemical formula .
X-ray crystallography reveals that tin triphosphide is not a triphosphide. It is a hexaphosphide, with P<sub>6</sub><sup>6-</sup> rings. These ruffled P<sub>6</sub> rings form three short (2.66 ÃÂ ) and three long (2.95 ÃÂ ) Sn-P bonds. The result is that Sn(II) adopts highly distorted octahedral geometry. The structure of tin triphosphide resembles that of gray arsenic, which also features corrugated, linked six-membered (As<sub>6</sub>) rings, wherein each arsenic atom has a highly distorted octahedral geometry. Germanium triphosphide and tin triphosphide are similar structurally as well.
Tin triphosphide forms triclinic crystals, spatial group R3m with six formula units in a unit cell of dimensions a = 7.378 ÃÂ and c = 10.512 ÃÂ .
Tin triphosphide can be formed from the fusion of stoichiometric amounts of both elements at 580 ðC:
has been evaluated for use in energy storage devices.