Triphenylphosphine selenide

Triphenylphosphine selenide is a organophosphorus compound with the formula (C₆H₅)₃PSe. It is a white solid which is soluble in most organic solvents. The compound is used in the preparation of other selenium compounds and is itself prepared by the reaction of triphenylphosphine with potassium selenocyanate. Single crystals have been isolated with both monoclinic and triclinic structures (space groups: P2₁/c and P1 respectively); in both cases the geometry at phosphorus is tetrahedral.