Peter N. Gates

Can microorganisms convert antimony trioxide or potassium antimonyl tartrate to methylated stibines

No evidence could be found for the production, in culture, of methylated antimony compounds from water-insoluble or soluble antimony derivatives by the aerobes, Scopulariopsis brevicaulis or Bacillus sp. or by anaerobes associated with cot mattress materials. The study does not support the hypothesis that volatile organoantimony compounds are a cause of cot deaths. Anaerobic cultures from a polluted pond generated trimethylstibine from potassium antimonyl tartrate.

The vibrational spectra of mono and para disubstituted halogenobenzenes

Abstract The infrared and Raman spectra of p -dibromo- and p -difluorotetradeuterobenzene have been measured and sets of assignments for the vibrational fundamentals are proposed. These are shown to be consistent with accepted assignments of related molecules by application of the product and inequality rules. Application of the product rule to the A g , species of p -dibromobenzene indicates that the assignment of Stojiljkovic and Whiffen is to be preferred to that of Shurvell, Dulaurens and Pesteil. The vapour phase band contour of the band at 816 cm −1 in para C 6 D 4 Br 2 has been measured in a high temperature cell and shown to necessitate an assignment revision for para C 6 D 4 Cl 2 .

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

Abstract Phosphorus(V) chloride and bromide complexes containing single-halide anions are surveyed in terms of characteristic phosphonium ion Raman shift patterns. Methods of preparation of Phase III phosphorus pentachloride are reviewed and some modes of formation proposed. The nature of the phosphonium cation-single-halide anion interaction is discussed on the basis of observed Raman shifts. With trihalide anions, similar shifts are observed but are strongly dependent on anion symmetry.

Ionic-molecular isomerism in chlorophenylphosphoranes PhnPCl5−n (1≤n≤3)

Both ionic and molecular modifications of the three Chlorophenylphosphoranes PhnPCl5 –n(1 ⩽n⩽ 3) have been isolated for the first time as solids and all have been characterised by elemental analysis, Raman spectroscopy and 31P magic angle spinning (MAS) NMR spectroscopy.

Solids containing tetrahalophosphonium cations: An investigation using 31P and 11B magic-angle spinning NMR and Raman spectroscopy

Abstract A variety of solid complexes containing PCl+4 or PBr−4 has been studied by magic-angle spinning (MAS) 31P and 11B NMR (the la

Solids containing methylhalophosphonium cations [(CH3)n PX+4−n] (n = 1–3 XCl,Br): an investigation using magic-angle spinning NMR spectroscopy

Abstract A selection of complexes containing [(CH3)nPX+4−n] cations (XCl, Br) have been investigated by magic-angle spinning (MAS) 31P and 11B NMR spectroscopy. Qualitative information about ionic motion in these systems is derived from the observed linewidths, which are dependent upon the nature of the anions present in the lattices. Isomers of [(CH3)PCl+3Cl−] and [(CH3)2PCl+2Cl−] are detected, confirming previous Raman spectroscopic observations. The mixed-halogen cations [(CH3)PCl2Br+], [(CH3)PClBr+2] and [(CH3)2PClBr+] are also observed, complexed with both single-halide and polyatomic anions. Differences in NMR linewidths are again noted. These results are compared with Raman studies on the same complexes and contrasted with a similar investigation of the [PClnBr+4−n] (O⩽n⩽4) system.

Thermochemistry of polyhalides. II. Caesium and rubidium dibromoiodides

Abstract Using a solution-reaction calorimeter the standard enthalpies of formation of crystalline caesium and rubidium dibromoiodides have been determined as −445.5±4.1 and −428.3±4.2 kJ mol −1 , respectively. Thermodynamic parameters, including lattice energies, are calculated and the thermal stability of polyhalides discussed. Thermometric titrations have been used to investigate the mechanism of reaction of caesium dibromoiodide with aqueous silver nitrate.

Vibrational and chlorine-35 nuclear quadrupole resonance spectra of some complexes of ICl4– and AuCl4–. Part 1. Two crystal modifications of trichlorosulphonium tetrachloroiodate, [SCl3][ICl4]

Two crystal modifications of [SCl3][ICl4] have been characterised by elemental analysis, and Raman and n.q.r. spectroscopy. Analysis of the spectra indicates that both form I (stable) and form II (metastable) involve dis-tortion from square planarity (D4h) of the ICl4– ions, a conclusion independently confirmed recently by an X-ray diffraction study of form I. On the basis of the Raman and n.q.r. spectra, the distortion in form II is similar to that observed in Na[ICl4]·2H2O. The origins of these distortions are discussed in terms of secondary bonding interactions in the solid state.

Energetics of the tetrachlorophosphonium cation, PCl4+,g, the hexachlorophosphate anion, PCl6−,g and metastable phosphorus (V) chloride [PCl4+]2[PCl6−][Cl−,c

Abstract Lattice potential energy calculations made on [PCl 4 + ] 2 [PCl 6 − ][Cl − ] lead to an estimate of the lattice energy of this metastable phase of phosphorus (V) chloride to be 956 kJ mol − (corresponding to 319 kJ mol − per PCl 5 formula unit). The known stability characteristics of alkali metal hexachlorophosphates enable the estimation of the enthalpy of formation of PCl 6 − ,g to be in the range: −908 ⩽ Δ f H 0 (PCl 6 P − ,g) ⩽ −896 kJ mol −1 ; similarly, +397 kJ mol −1 ⩾ Δ f H 0 (PCl 4 + ,g) ⩾ +391 kJ mol −1 .

Raman spectra and isomerism of some bromophenylphosphoranes PhnPBr5–n(1 ⩽n⩽ 3) and their salts

A synthetic and Raman investigation of isomerism in the bromophenylphosphoranes has shown no evidence for ionic–covalent isomerism analogous to that in the chlorophenylphosphoranes. Two ionic modifications of PhPBr4 have been identified by Raman spectroscopy, whereas Ph2PBr3 was found to exist in only one ionic form, Ph2PBr2+Br–. A recent proposal that Ph3PBr2 is a molecular four-co-ordinate species is disputed and evidence supporting an ionic formulation Ph3PBr+Br– is presented. Vibrational Raman assignments for the bromophenylphosphoranes and some of their tetrabromoborate and tetrabromoaluminate salts are given.