A decomposition procedure for the determination of arsenic in marine samples

The use of wet and dry ashing procedures to decompose marine biological tissues and to degrade organoarsenic compounds to inorganic arsenic for analysis by zinc-column arsine generation and atomic-absorption spectrophotometry was investigated. Wet ashing with nitric, sulphuric and perchloric acids (10:2:3 v/v) released the largest percentage of arsenic from fish tissue and quantitatively degraded methylated and other organoarsenic compounds to inorganic arsenic. The arsenic concentrations found when standard reference materials were ashed with this acid mixture were in agreement with the certified values.     

Metall-π-komplexe von benzolderivaten : III. Bis(diphenylphosphino-h6-benzol)-chrom(0)

Rhodium complexes containing poly(pyrazolyl)borate ligands are described, and the fluxional nature of some of them considered.     

Cyclometallation reactions XII. On the effect of various leaving groups on internal metallation reactions with alkylmanganese complexes

The interaction of azobenzene and MnR(CO)₅ (R  Me, Et, CH₂Ph, CH₂-C₆Me₅, COCF₃, COCH₂C₆F₅, COCH₂OPh, Ph or C₆F₅) affords M$\text{n(C}{}_6\text{H}{}_4\text{NN}$Ph)-(CO)₄, together with a binuclear complex Mn₂(CO)₆(C₁₂H₁₀N₂) in some cases. The metallation reaction is shown to proceed most readily with Mn-(CH₂Ph)(CO)₅; with this reagent, the metallated complexes M$\text{n(C}{}_6\text{H}{}_4\text{CH}{}_2\text{P}$Me₂)-(CO)₃[PMe₂(CH₂Ph)] (two isomers) and M$\text{n(C}{}_6\text{H}{}_4\text{CH}{}_2\text{A}$sMe₂(CO)₄ have been obtained on treatment with EMe₂(CH₂Ph) (E  P and As, respectively).     

Cluster chemistry. partial hydrogenation of coordinated isocyanide on a ruthenium cluster carbonyl.

Addition of dihydrogen to Ru₃(CO)₁₁(CNBu^t) affords HRu₃(CO)₉(HC:NB as the major product; this complex and four other minor products were identified from their IR, NMR and mass spectra.     

Group IB metal chemistry : V. Some fluxional complexes containing copper or silver

Fluxional poly(pyrazolyl)borate complexes of copper and silver, including the carbonyl Cu(CO)B(pz)₄, contain coordinated and free pyrazolyl groups, which interchange rapidly on the NMR time scale at room temperature; low temperature limiting spectra can be obtained for some copper complexes at ?100°.     

On stabilization of Ek chains

We study special subgroups of infinite groups that generalize double centralizers. We analyze sufficient conditions for descending chains of such subgroups to stop after finitely many steps. We discuss whether this phenomenon can happen in the class of groups satisfying chain condition on centralizers.     

Protonation of metal carbonyl complexes : VI. Protonation of manganese π-cyclopentadienylphosphine complexes studied by 13C and 31P NMR techniques

¹³C and ³¹P NMR techniques have been applied to the complexes CpMn(CO)L₂ and CpMn(CO)₂ L (where L₂ is a bidentate tertiary phosphine, L is a monodentate tertiary phosphine, and Cp is cyclopentadienyl). It is shown that the complexes are protonated reversibly, when dissolved in CH₂Cl₂ in the presence of CF₃COOH, with the proton attacking the manganese atom.