Properties of phosphorus halides and derived compounds

The possibility of using diphosphorus tetraiodide as a convenient starting point for the synthesis of diphosphorus compounds has been investigated, as well as the methods of preparation of both known phosphorus iodides. Interaction between the phosphorus iodides, PI3 and P2I4, and boron fluoride, chloride and bromide has been studied and evidence given for the existence of the solid addition compounds P2I4.2BBr3 and PI3.BBr3. Far infrared investigation of diphosphorus tetraiodide and phosphorus tri-iodide in several media is reported in the region of 300 cm. Ultraviolet spectra of diphosphorus tetraiodide (P2I4) and other Group V element tri-iodides are shown, and some quantitative aspects of these are reported. Reactions of phenyl phosphorus dichloride with boron tribromide and phosphorus tribromide as well as the attempted preparation of phenyl phosphorus difluoride and dibromide are described. The enthalpy of formation of phosphorus tri-iodide has been measured by a synthetic reaction and by aqeuous hydrolysis, and that of diphosphorus tetraiodide by the synthetic reaction only. The solution enthalpies ofphosphorus tri-iodide and diphosphorus tetraiodide in carbon disulphide are also reported. The enthalpies of aqueous hydrolysis of phosphorus pentabromide and its solution in carbon disulphide have been measured.