Structural dependence of the reagent Ph3PCl2 on the nature of the solvent, both in the solid state and in solution; X-ray crystal structure of trigonal bipyramidal Ph3PCl2, the first structurally characterised five-coordinate R3PCl2 compound

The very delicate structural balance of Ph3PCl2 when prepared in diethyl ether solution is illustrated by its X-ray crystallographic study; unlike the ionic species, [Ph3PCl+···Cl–···+ClPPh3]Cl, which prevails in dichloromethane solution, the non-solvated molecular species Ph3PCl2 is formed in diethyl ether which is the first example of a trigonal bipyramidal R3PCl2 compound to be structurally characterised, and this may have an effect on the chlorinating ability of the reagent.