2,6-di-tert-butyl-4-perimidylphenols and their oxidation

1,8-Naphthylenediamine was reacted with 2,6-di-tert-butyl-4-formyl-phenol to produce 2,6-di-tert-butyl-4-(1,3-dihydro-perimidyl) phenol (I). The latter was coverted into 2,6-di-tert-butyl-4-(1H-perimidyl)phenol (II) by oxidizing I with sodium pyrosulfate. When phenol II was oxidized by lead dioxide in toluene and THF, the EPR spectra revealed a 12-component multiplet with perimidyl splitting constants a¹ _N=a³ _N=a_H ^NH=0.2 mT; a_H ^6.7=0.6 mT.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 28, No. 1, pp. 64–67, January, 1992.     

Electrochemical Reduction of Trichlorobiphenyls: Mechanism and Regioselectivity

The regioselectivity of electrochemical reduction of four trichlorobiphenyls (PCB 28–30 and PCB 37) was studied by cyclic voltammetry and bulk electrolysis. The number of stages and mechanism of electrochemical reduction of each of the examined substrate were inferred on the basis of the experimental electron transfer coefficients and calculated (DFT) bond lengths and potential energy surface sections. GC/MS analysis of the controlled potential electrolysis products showed that chlorine atom in the disubstituted ring of trichlorobiphenyls is reduced more readily than in the monosubstituted ring and that the rate of chlorine reduction changes in the series o-Cl > p-Cl > m-Cl.     

Synthesis of new organosilicon and organogermanium derivatives of diallylisocyanurate and cyanuric acid

Conclusion The reactions of the silver, cesium or rubidium salts of diallylisocyanurate and of trimethylsilyldiallylisocyanurate with pentamethylchlorodisilane, 1,2-dichlorotetramethyldisilane, 1,3-dichlorotetramethyldisiloxane and -(trialkylgermyl)propionyl chlorides leads to the corresponding organosilicon and organogermanium triazine derivatives. The reaction of pentamethylchlorodisilane with the trisilver salt of cyanuric acid or tris(trimethyl-silyl) cyanurate leads to the formation of tris(pentamethyldisilanyl)cyanurate.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 941–943, April, 1987.     

Molecular structure of polymeric materials and sorption of water vapor

Methods for calculating the coefficients of the thermal equation of water vapor sorption by polymeric materials were developed. These methods enable calculation of the equilibrium amounts of sorption in a wide temperature range from the cohesion energy of a polymer.     

Kinetics of Polycondensation of Betulin with Adipic Acid

The influence of various factors on the kinetics of polycondensation of betulin (a triterpene alcohol of the lupane series) with adipic acid was studied.     

Rate Constants of Halogen Abstraction from Halogenating Agents by Alkyl Radicals

A procedure has been developed for determination of the relative rate constants for halogen transfer from a number of halogenating agents to alkyl radicals by the competing reactions technique. In combination with the known data, the developed procedure allows estimation of absolute rate constants of the halogen transfer stage.     

A 2D Network in Co-Crystal (1:1) Based on <Emphasis Type="Italic">trans</Emphasis>-[PtBr<Subscript>2</Subscript>(Acetoxime)<Subscript>2</Subscript>] and 18-Crown-6

Abstract  

A 1:1 co-crystal of trans-[PtBr₂(acetoxime)₂] and 18-crown-6 has been obtained by a slow-evaporation of the equimolar mixture of trans-[PtBr₂(acetoxime)₂] and the crown ether. The compound crystallizes in the triclinic space group P [`1] P\,\bar{1} , with unit cell parameters a = 7.4765(2) Å, b = 9.5044(2) Å, c = 10.1591(3) Å, α = 83.687(1)°, β = 70.847(1)°, γ = 79.773(1)°, Z = 1. trans-[PtBr₂(acetoxime)₂] is assembled with 18-crown-6 into a 2D network structure by interactions between the oxygen atoms of 18-crown-6 and the hydroxylic and methyl hydrogen atoms of the oxime ligands.     

Structural and Kinetic Relations Holding in the Halogen Abstraction from Organohalogen Compounds by Alkyl Radicals

The relative rate constants were determined, and the absolute rate constants were estimated, for halogen transfer from N,N-dihaloarenesulfonamides, (dichloroiodo)arenes, benzyl bromides, and arenesulfonyl chlorides to cyclohexyl radical and from N,N-dihaloarenesulfonamides to benzyl radical. Polar effect of the substituent was found to be the main factor determining the rate of halogen transfer from benzyl bromides and arenesulfonyl chlorides; it increases with rise in the electrophilicity of the organohalogen substrate due mainly to charge distribution in the transition state.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 1, 2005, pp. 33–39.Original Russian Text Copyright © 2005 by Dneprovskii, Eliseenkov, Chulkova.