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 CHARACTERIZED 5-COORDINATE R3PCL2 COMPOUND

The very delicate structural balance of Ph3PCl2 when prepared in dieth yl 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 Ph3PC l2 is formed in diethyl ether which is the first example of a trigonal bipyramidal R3PCl2 compound to be structurally characterised, and thi s may have an effect on the chlorinating ability of the reagent.