Free radical fixation by tin(IV) diphenylcatecholate complexes

Abstract

The reactions of sodium and thallium catecholates CatM 2 (Cat is the 3,6-di- tert -butylpyrocatechol dianion; M = Na, T1) with tin diphenyl dichloride afford new tin catecholate complexes Ph 2 SnCat · THF ( I ) and Ph 2 SnCat ( 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 . , (CH 3 ) 2 NC(S)S . , and NC(CH 3 ) 2 C . ) and stable free radicals (aroxyl, nitroxyl, triphenylmethyl, and phenoxazinyl) to form stable o -semiquinone tin derivatives.