Hydrogen bond formation in the crystals of phosphinic, phosphonic and phosphoric acids, and their cocrystals with phosphine oxides was investigated by single crystal X-ray and ³¹P NMR. There are two decisive factors: 1., the high proton-accepting ability of the PO moiety in the acids; 2., the inclination of the PO group of both the acids and the oxides to form two H-bonds at once.¹  A comparative study on dative vs. electron sharing bonding in Y₃PO and Y₃N→O in comparison to Y₂POY and Y₂N–OY was performed on a theoretical basis.² 

An unexpected, Wurtz-like, coupling of a perfluoroalkyl iodide took place in the presence of triphenylphosphine without the use of any metal to afford the corresponding bis(perfluoroalkyl) derivative (Scheme 1). Subsequent in situ hydrolysis of the iodophosphonium salt gave the related phosphine oxide³