A. V. Lado

Free radical fixation by tin(IV) diphenylcatecholate complexes

The reactions of sodium and thallium catecholates CatM2 (Cat is the 3,6-di-tert-butylpyrocatechol dianion; M = Na, T1) with tin diphenyl dichloride afford new tin catecholate complexes Ph2SnCat · THF (I) and Ph2SnCat (II). The molecular structure of pentacoordinated complex I is determined by X-ray diffraction analysis. The synthesized complexes are capable of fixating both short-lived (PhC(O)O., (CH3)2NC(S)S., and NC(CH3)2C.) and stable free radicals (aroxyl, nitroxyl, triphenylmethyl, and phenoxazinyl) to form stable o-semiquinone tin derivatives.

Novel germanium(IV) catecholate complexes

The interaction of germanium(II) chloride dioxanate with 3,6-di-tert-butyl-o-benzoquinone or with its mono-and dianion derivatives is attended by the redox transformations. The novel germanium bis-catecholate complexes were synthesized that contained coordinated ether molecules (THF (I), Et2O (II)) irrespective of the initial redox form of o-quinone. The germanium complex was also synthesized by the exchange reaction between GeCl4 and sodium catecholate. Complexes (I), (II) were characterized by NMR and IR spectroscopies, elemental and X-ray diffraction analyses.

Radical polymerization of styrene in the presence of Tin(IV) catecholate complexes

The synthesis of PS in the presence of diethyl(3,6-di-tert-butylcatecholato)tin(IV) tetrahydrofuranate and diphenyl(3,6-di-tert-butylcatecholato)tin(IV) tetrahydrofuranate has been studied. It has been found that such tin catecholates can act as chain length regulators in the polymerization of styrene and ensure a linear increase in molecular mass with conversion. Using the macroinitiators obtained in the presence of diphenyl(3,6-di-tert-butylcatecholato)tin(IV) tetrahydrofuranate, the postpolymerization of styrene has been carried out.

Tin oxidation with 3,6-di-tert-butyl-o-benzoquinone

The kinetics of tin oxidation with 3,6-di-tert-butyl-o-benzoquinone (3,6-Q) in toluene was studied. The scheme of formation of tin o-quinone complexes during metal oxidation with 3,6-Q in different aprotic solvents was suggested on the basis of the kinetic, EPR, and IR data.