Three Independent Molecules in the Unit Cell of a Phosphorus Ylide; Changes in the Molecular Geometry on Rotation about the Phosphorus–Carbon Ylide Bond

Abstract

Molecules with different PCl distances and torsion angles about the PC(ylide) bond are revealed in the crystals of the chlorinated phosphorus ylide 1. These “frozen” conformers correspond to rotamers about the ylide bond on the energy surface. Ylide 1 reacts with SnCl2 to give the methylene phosphonium ion 2, which decomposes in solution affording the phosphane 3.