The role of metallic palladium in the reductive decomposition of π-allyl palladium chloride in aqueous alkaline solutions

Russian Chemical Bulletin -     

Divinyl Sulfoxide: XI. Selective Addition of Carbonodithioate Anions to Divinyl Sulfoxide in the Water-Benzene System

Selective monoaddition of carbonodithioate anions to divinyl sulfoxide gives rise to O-alkyl S-[2-(vinylsulfinyl)ethyl] carbonodithioates [ROC(S)SK, R = Et, Bu; 42–50°C, 6 h, NaHCO₃, aqueous benzene].     

Synthesis and electrochemical applications of fluorinated vinylazole copolymers for monitoring NO in model and biological systems

Copolymers of 1-vinyl-1,2,4-triazole and 5-vinyltetrazole with 1,1,5-trihydrooctafluoropentyl methacrylate and 1,1,7-trihydrododecafluoroheptyl methacrylate were prepared under the conditions of radical initiation. These copolymers were used for modification of the surface of a glassy carbon electrode, and the effect of the modification on the electrochemical behavior of the electrode in anodic oxidation of dopamine and NO was studied. The possibility of enhancing the selectivity of the electrochemical sensor for monitoring NO in biological media was demonstrated.     

Organoinorganic composites based on tetraethoxysilane and nitrogen polybases

Hybrid organoinorganic composites insoluble in water and organic solvents were prepared by the hydrolysis of tetraethoxysilane in the presence of poly-1-vinylpyrazole, poly-1-vinylimidazole, and poly-4-vinylpyridine. The composition of the composites was determined by the nature of the polymeric nitrogen base and hydrolysis conditions. The composites synthesized showed high sorption activity in the extraction of the [PdCl₄]^2?, [PtCl₆]^2?, and [AuCl₄]^? ions from hydrochloric acid solutions.     

Application of solid-phase microextraction-gas chromatography-mass spectrometry to characterize intermediates in a joint solar-microbial process for total mineralization of Aroclor 1254

A combined solid-phase microextraction-GC-MS analytical technique was used to monitor the formation of metabolites in the biodegradation of biphenyl, which were originally obtained from the solar photodechlorination of Aroclor 1254 by Pseudomonas pseudoalcaligenes KF707 and Burkholderia sp LB400. In both cases, the following metabolites were detected: 2-hydroxybiphenyl (2-OH-BP), 2,3-dihydroxybiphenyl (2,3-di-OH-BP), and benzoic acid, which was detected as its benzoate derivative 1-methylethylbenzoate. A time course study for the formation and disappearance of these metabolites was used to construct a degradation pathway, which in both cases, involved the formation of 2-OH-BP and 2,3-di-OH-BP.     

Dehydrogenation of 1-(diphenylphosphinoyl)-2-(N′-phenylhydrazino)ethane and N-butyl-N′-phenylhydrazine

Dehydrogenation of 1-(diphenylphosphinoyl)-2-hydrazino-substituted ethanes and N-butyl-N′-phenylhydrazine to the corresponding hydrazone derivatives is performed. Both reactions were established to involve predominantly, if not exclusively, an azo intermediate.     

Influence Exerted by Pyrite Impurity in the Initial Graphite on Properties of Residual Graphite Hydrosulfates

The influence exerted by the particle size and the distribution of sol impurities in the initial graphite, and also by pyrite additives, on the properties of residual graphite hydrosulfates synthesized by oxidation in the CrO₃-H₂SO₄ system was studied.     

Photolysis of hexamethyldisilane at 206 nm

The photolysis of Me₆Si₂ at 206 nm results in two main decomposition processes: simple Si---Si bond breaking with a quantum yield of Φ = 0.21 ± 0.03, and Me₃SiH elimination with the concomitant formation of Me₂SiCH₂ with Φ = 0.18 ± 0.01. There is also a minor decomposition channel with a very small quantum yield, Φ = (5.6 ± 0.2) × 10⁻³, which results in the formation of Me₄Si and Me₂Si. The main fate of the excited Me₆Si₂ molecule produced during photolysis is stabilization by collisional deactivation. The end products observed indicate that the reaction pathways followed by the main intermediates, Me₃Si and Me₂SiCH₂, are the same as those found in the photolysis of Me₄Si (Ahmed et al., J. Photochem. Photobiol. A: Chem. 86 (1995) 33).     

Catalytic Properties of Acid Solutions and the Structure of Acid–Base Complexes with Strong Hydrogen Bonds

The catalytic action of acid solutions involves an equilibrium step in the formation of a reactive complex of reactant molecules with catalyst entities. The relative concentrations of these complexes are determined by using thermodynamic parameters (acidity functions and activities of catalyst components). Data on the structure of complexes with strong H-bonds can be obtained from the vibrational spectra of these species. These data are required for establishing the mechanisms of catalytic reactions and for predicting the catalytic properties of acid solutions containing these complexes.