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The effects of mono- and disubstituted phosphates on the photolysis reaction of reduced nicotinamide adenine dinucleotide (NADH) in a frozen (77 K) aqueous solution were studied by EPR. The dependence of the yield of the paramagnetic intermediates of the reaction, that is, the NADH+ cation radical and atomic hydrogen, on the concentration of phosphates was determined. The results were interpreted from the point of view of the basicity and electron acceptor properties of phosphates. Electron spectroscopy data revealed a significant acceleration of auto-oxidation and photoinduced oxidation of NADH under normal conditions (20°C, aqueous medium, phosphate buffer, pH 6.3). The rate of the dark reaction was directly proportional to the total concentration of orthophosphates and hydrophosphates and was insensitive to oxygen. On the basis of experiments with a nitroxyl trap, the conclusion was made that the reaction is not of a radical nature.

An oxovanadium(IV) complex with dimethyl sulfoxide exhibits a substantial catalytic activity for the reaction of polymerization of 2-hydroxyethyl methacrylate (HEMA) with high selectivity for monomer. The complex does not catalyze polymerization of other monomers, including other methacrylates. A carbo-chain structure of polymeric HEMA is established by 13 C NMR. The resulting poly-HEMA has a narrow unimodal molecular mass distribution. It is found that the polymerization is catalytic in nature. A coordination mechanism for this polymerization is proposed.

An organo-mineral composite bone-grafting material was developed and tested. The composite material is based on synthetic hydroxyapatite (HAP) (30-60 wt%) integrated into the matrix of poly(2-hydroxyethyl methacrylate) (pHEMA) hydrogel. The composite was shown to have a homogeneous and isotropic microstructure, mechanical strength of ~11 MPa, high degree of water absorption reaching 34%, and elastomeric properties under physio-logical conditions (strain at failure is 57%).

The vanadyl ion complex VO(DMSO)5(ClO4)2 (I) exhibits high catalytic activity in the polymerization of 2-hydroxyethyl methacrylate (HEMA) in both aerobic and anaerobic conditions. A feature of I is the formation of a network structure capable of swelling in aqueous medium. On the grounds of studying the elastic properties of hydrogels, the concentrations of elastically active chains nc in a network of bulk poly(HEMA) is determined. An increase in the cross-link density is observed with increasing concentration of I. The topological structure and morphology of poly(HEMA) are investigated; structural manifestations of the bifunctional nature of the catalyst and two directions of polymerization initiation are found.

The vanadyl ionic complex VO(DMSO)5(ClO4)2 (I) exhibits high catalytic activity in the polymerization of 2-hydroxyethyl methacrylate (HEMA). The changes in the vanadium oxidation state during polymerization under argon and in the presence of oxygen were studied by EPR. Under aerobic conditions, the HEMA chain propagation radical was detected; this indicates the presence of a radical chain polymerization pathway caused by the ability of I to perform one-electron reduction of molecular O2. The radical generation rate is controlled by the initial concentration of I: its increase results in the formation of inactive species, presumably, μ-peroxo complexes Vv-O-O-Vv. It was shown by kinetic methods that the radical-chain pathway initiated by the reaction of I with O2 is not crucial in the HEMA polymerization.

The reaction of catalytic hydroxylation of olefins by organic hydroperoxides in the presence of osmium carbonyl clusters supported on polymer matrices is studied. The process occurs with the predominant formation of unsaturated alcohols. The oxidative coupling of olefins with the formation of nonconjugated dienes and in which the double bonds remain intact occurs in parallel. In the course of the reaction, changes in the chemical structures of the initial osmium clusters are not observed.

Oxidation of cyclohexenyl hydroperoxide by molecular oxygen in the presence of penta(dimethylsulfoxido)vanadyl hexathiocyanatoplatinate proceeds at a high rate at low temperatures with the formation of bifunctional, oxygen-containing products. The main route of the reaction is the molecular oxidation of the hydroperoxide with ring opening in a complex [Catm...HOORn]; oxidation of cyclohexenyl hydroperoxide to a dihydroperoxide takes place simultaneously by a chain mechanism.

1. The complex studied — penta (dimethylsulfoxido) vanadyl hexathiocyanatoplatinate (I) is an effective catalyst for the low-temperature oxidation of cyclohexene in alcoholic media, ensuring a high reaction rate up to a high degree of conversion. 2. It has been established that there is a synergism between the component parts of the catalyst, the maximum rate of oxidation of cyclohexene being observed with V/Pt=2. 3. In the initial stages of the oxidation of cyclohexene in the presence of (I), the reaction rate is described by the kinetics of a chain growth-chain breaking process.