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.     

Radical intermediates in the electrochemical reduction of alizarin

Conclusions In the electroreduction of alizarin in an aprotic medium the stepwise formation of the anion-radical and subsequently of the dianion has been observed; under conditions of the prolonged process the anion-radical disproportionates and through intermediate stages of deprotonation and reduction is converted into the stable dianion-radical.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 983–988, May, 1985.     

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.     

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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