Stereochemistry of 2-substituted 5,6-benzo-1,3,2-dioxarsepines

Russian Chemical Bulletin -     

Synthesis and characterization of polymerizable bisphthalonitrile monomers

The reactions of 4-aminophthalonitrile (APN) with 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BPTDA), and with 1,2,3,4-benzenetetracarboxylic dianhydride (PMDA) have been studied to optimize the conditions for the synthesis of monomeric thermosetting bisphthalonitrile compound. Suitable procedures for the synthesis of the two monomers are presented. Elemental analyses, IR spectra, dynamic thermogravimetric analyses, differential scanning calorimetry, ¹H-NMR, and mass spectral studies have been used to characterize these compounds. Preliminary observations show that these materials can be polymerized to give high-temperature-resistant materials.     

EPR spectra and structure of 1,2-dihydroxy- and 1,2,4-trihydroxy-anthrasemiquinones

Conclusions Radicals of hydroxyanthrasemiquinones were generated by chemical and electrochemical reduction and their probable structures established by EPR.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 822–827, April, 1986.     

Azo initiators for the preparation of hydroxyl-terminated polybutadienes

Azo compounds such as di(4-hydroxybutyl)-2,2′-azobisisobutyrate, di(3-hydroxybutyl)-2,2′-azobisisobutyrate, di(2-hydroxypropyl)-2,2′-azobisisobutyrate, and di(2-hydroxyethyl)-2,2′-azobisisobutyrate were prepared and used as initiators for the preparation of hydroxyl-terminated polybutadienes (HTPBs) of molecular weight (M?_n) ranging from 2000 to 7500 and functionality between 1.90 and 3.0. The polymers were prepared by free-radical solution polymerization in dioxane and toluene. The polymers obtained were characterized for their molecular weight, hydroxyl number, functionality, and instrinsic viscosity.     

Mixed complex combinations of Pd(II) with α-amino acids

Journal of Thermal Analysis and Calorimetry - The present work deals with the synthesis of eight mixed complex combinations of Pd(II) with different α-amino acids. In order to prove the...     

Error analysis of surface area determinations by the chromatographic technique

The systematic and random errors in the determination of the surface area of adsorbents and catalysts by argon thermodesorption chromatography are analyzed.

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Catalytic activity of palladium-containing zeolites in the complete oxidation of benzene

The dependence of palladium distribution in zeolites on the temperature of thermal treatment has been established from the data on oxygen chemisorption and the statistical processing of electron micrographs. The influence of palladium distribution in zeolites on their catalytic activity towards the complete oxidation of benzene has been shown.

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