Reactive intermediates of metal alkoxides. Pt. 2: An EPR investigation on irradiated titanium alkoxides

The solid state gamma radiolysis and UV photolysis of Ti alkoxides have been investigated by EPR spectroscopy. The major paramagnetic products were found to be monomeric and dimeric Ti(III) species and alkyl radicals. The dimers yielded a different type of triplet state signals which were consistent with interatomic distances ranging from 3 to 9 A. Such distances correspond to couples of vicinal Ti atoms connected by an oxygen bridge and to Ti atoms at the end of the oligomers chains. The EPR changes observed on warming above 170 K have been tentatively interpreted with the conversion of the short distance into long distance dimers favoured by the fluxionality of the alkoxy groups. (author)