The 31P N.M.R. bandshapes and spin-lattice relaxation times for solid PCl5 have been studied under conditions of magic-angle rotation, for both the phase II and phase III forms. Temperature and magnetic field were both varied. The influence of molecular motion on both bandshapes and T 1 is discussed. Second-order effects resulting from the dipolar coupling of 31P to the quadrupolar chlorine nuclei are found to cause splittings in the spectra under certain conditions. It is postulated that Zeeman/quadrupolar cross-relaxation influences T 1 for [PCl4]+ in phase II.

High-resolution phosphorus-31 N.M.R. studies of solid phosphorus pentachloride

The characterisation of the ions [PClnBr4−n]+ (0 ≤ n ≤ 4) in HCl solution

Vibrational assignments for the skeletal modes of some complexes containing CH 3 SX 2 + and (CH 3 ) 2 SX + (X=Cl, Br) havge been made on the basis of their solid-state Raman spectra and compared with any previous data. The stabilities of the parent CH 3 SX 3 and (CH 3 ) 2 SX 2 compounds are discussed; two isomers of (CH 3 ) 2 SBr 2 were obtained under varying reaction conditions and assigned as ionic [(CH 3 ) 2 SBr + Br − ] and charge-transfer [(CH 3 ) 2 S→Br 2 ] forms. The transition of the ionic (metastable) form to the more stable charge-transfer form was monitored by differential scanning calorimetry. High-frequency shifts occur in some fundamental modes of (CH 3 ) 2 SBr + Br − when Br − is replaced with a polyatomic anion, analogous to those seen in halophosphonium complexes; this is rationalized in terms of anion-cation interaction

Raman spectra of some complexes containing methyldihalo- and dimethylhalo-sulphonium cations : isomerism in the dimethyl sulphide-bromine complex

Mixed chlorohalogeno- and chloropseudohalogeno diphenylantimonates

Single-halide anions in phosphorus(V) halide complexes: a Raman investigation

The structure of P2Cl9Br

Existence of chlorobromoantimonates

The existence of the trichlorobromophosphonium ion [PCl3Br]+ has been confirmed in the solid complexes PBCl7Br and P2F6Cl3Br and a vibrational assignment is given.

The existence and vibrational characterisation of the trichlorobromophosphonium ion

The preparation of some complexes and mixtures containing the PCl3Br+, PCl2Br2+ and PClBr3+ ions is described. A vibrational assignment for each species has been made based on data from Raman spectra of the complexes in the solid state. Some characteristic shifts occur in the fundamental frequencies of the phosphonium ions where single halide or polyhalide anions are present in the crystal lattice. It is suggested that such vibrational frequencies can be used to infer (a) the structures of complexes involving phosphonium ions and (b) the presence or absence of single halide or trihalide ions in the lattice.

F. F. Bentley

Papers

The structure of P2Cl9Br

Existence of chlorobromoantimonates

The existence and vibrational characterisation of the trichlorobromophosphonium ion

Mixed halogen complexes of phosphorus. Part I. Preparation and Raman spectra of the chlorobromophosphonium ions, [PClnBr4–n]+(0 ⩽n⩽ 4)

Existenz von chlorobromoantimonaten