A spectroscopic investigation of some mixed halide compounds of phosphorus (V) and antimony (V)

Abstract

The fundamental vibrational frequencies of the mixed chlorobromophosphonium ions, PCl3Br+, PCi2Br2+, have been assigned from solid-state Raman and infrared (PCl3Br+ only) measurements. The Raman spectra of the following have been compared: [diagram] From the above, two sets of fundamental vibrational frequencies may be assigned to the tetrahalogenophosphonium ions, depending upon whether they are in the presence of: (a) A polyatomic anion only, or (b) Single halide ions (Cl, Br) The addition of excess chlorine to PC2F yields initially a greenliquid, probably molecular PCl4F, and some white solid, probably. On standing at room temperature for 3-4 days, the whole solidified to give a compound of stoichiometry PClF, which it is suggested (from Raman and infrared spectra and fluoride analyses) may be formulated as containing, and ions. Raman and infrared spectra indicate a trans structure. The fundamental vibrational frequencies of the mixed chlorobromo-phosphonium ions, have been assignedfrom solid-state Raman and infrared (PClBr only) measurements. The Raman spectra of the following have been compared:-Comparison of X-Ray data for and the compound ofstoichiometry indicate a unit cell for, comprising 6 PC1, 2 PClBr+, 4 pCl and 4 Br ions. Solid-31state Raman and P n.m.r. spectra strongly support the aboveformulation for P Cl Br. Solid-state Raman spectra of and P do not confirm the expected formulations. The two compounds [diagram] formulated, according to Ratuan and infrared data, as and respectively. The existence of as a discrete chemical compound and not a 5:1 mixture of and has been demonstrated by: (i) Raman spectroscopy, (ii) X-Ray powder photography, and (iii) Differential scanning calorimetry.Raman and 31P n.m.r. spectra of indicate the formulation PCl4+ SbCl5Br.