Substituted 1,4-diaza-1,3-butadiene monocyclopentadienyl titanium complexes.: Crystal structure of Ti(η5-C5Me5)(η4-iPrNCH=CHNiPr)Me

We report the synthesis of 1,4-diaza-1,3-butadiene (dad) complexes Ti(eta (5)-C5R5)(eta (4)-R'(2)-dad)-Cl (R = H, Me; R' = Pr-i, Bu-t) by reaction of Ti(eta (5)-C5R5)Cl-3 (R = H, Me) with the dilithium salts of diisopropyl- and di-tert-butyl-substituted 1,4-diaza-1,3-butadienes (Li-2[R'(2)-dad]). Alkylation of the pentamethylcyclopentadienyl diisopropyl and di-tert-butyl derivatives with methylmagnesium chloride and methyllithium gave complexes Ti(eta (5)-C5Me5)(eta (4)-'Pr-2-dad)Me and Ti(eta (5)-C5Me5)(eta (4)-Bu-t(2)-dad)Me, respectively. Addition of excess water to di-tert-butyl chloro complexes gave the ore-bridged complexes [{Ti(eta (5)-C5R5)(eta (4)-Bu-t(2)-dad)}(2)(mu -O)] (R = H, Me). The temperature-dependent spectroscopic behavior of Ti(eta (5)-C5H5)(eta (4)-Bu-t(2)-dad)Cl and [{Ti(eta (5)-C5H5)(eta (4)-Bu-t(2)-dad)}(2)(mu -O)] complexes was studied. The crystal structure of Ti(eta (5)-CsMe5)(eta (4)-Pr-i(2)-dad)Me was determined by X-ray crystal diffraction on a single crystal and shows a distorted trigonal bipyramidal structure.