I. P. Gozman

High molecular poly-α-alkenylphosphonates and phosphonamides☆

Abstract Polymerization of esters and amides of vinyl- and isopropenylphosphonic acids under the action of Grignard reagents leads to polymers with high intrinsic viscosities. The effect of the monomer structure, temperature and nature of the solvent on the stages of chain propagation, transfer and reinitiation is discussed. The formation of intermolecular P-O-P bonds has an important effect on the thermomechanical properties and the behaviour, during thermooxidative degradation, of the polymers formed.

Structure andmechanism of formation of oligophosphonates from dialkyl chlorophosphites and aldehydes

1. Oligophosphonates are formed upon reaction of dialkyl phosphites with aldehydes. 2. A mechanism is proposed for this process.

Homolytic reactions of organophosphorus compounds 5. The kinetics of 2,2′ diphosphon-2,2′-azopropane Homolysis and stabilization of the radical center of the adjacent phosphoryl group

1. The 2,2′-diethyl- and 2,2′-diphenylphosphon-2,2′-azopropanes undergo thermal homolysis with simultaneous rupture of both of the C-N bonds. 2. Study of the kinetics of the thermal homolysis of the substituted 2,2′-azopropanes gives a basis for determination of the energy of radical stabilization by the substituent. 3. The energy of isopropyl radical stabilization by a P(0) (OR)2 type substituent adjacent to the radical center is some 5 kcal/mole. 4. The ability of the substrate to enter into homolytic addition, displacement, and dissociation depends, in the first instance, on the energy of substituent stabilization of the product radical center, the sensitivity of the substrate to this substituent effect in any one series of reactions increasing with an increase in the activation enthalpy and entropy and the displacement of the transition state along the reaction coordinate.

Reaction mechanism and chemical polarization of phosphorus nuclei when diethyl phenylazophosphonate is reacted with sodium ethylate

The action of ethoxide anion on diethyl phenylazophosphonate leads to nucleophilic substitution of the phenyldiazenyl anion, the cleavage of nitrogen from it, and subsequent electron transfer from the formed phenyl anion to the starting phosphonate molecule. Singlet-triplet evolution in the singlet radical pair that is formed here and its recombination give diethyl diphenylhydrazophosphates, which exhibit the31P CPN effect.

Electrochemical reduction of azophosphonates and the ESR spectra of the ion radicals

1. Reduction of the azophosphonates proceeds in successive one-electron steps, the first of which is reversible. 2. ESR methods have been used to show that azophosphonate anion-radical formation occurs in the first reduction step; an estimate of the spin density in these ions was obtained by these same methods. It has been shown that deuteration has an anomalous effect in delocalizing the unpaired electron in the diethylarylphosphonate anion radicals.

Penta- and tetracoordinated phosphorous in reactions of biacetyl with diethylacetylphosphite and diethyl chlorophosphite

Diethylacetyl phosphite and diethyl chlorophosphite react with biacetyl, intermediately forming, as do other derivatives of phosphorous acid, 1,3,2-dioxaphospholenes with a pentacoordinated phosphorous atom; the latter are rapidly transformed to noncyclic or cyclic derivatives of tetracoordinated phosphorous.