Cationic metal carbonyls titanium

Zeotype materials containing metal cations, for example ions of titanium, vanadium, chromium, iron, or tin, in the tetrahedral positions of their frameworks have been explored as solid Lewis acid catalysts (Ig). Such materials have been shown to be active in the Meerwein—Pormdorfr-Verley reduction of carbonyl compounds (151,233), and the BV oxidation (also called BV rearrangement) (234). 

The coordination and organometallic chemistry of zirconium and hafnium are surveyed for the year 1991.107,108 There is useful material in a review of homogeneous Group 4 metallocene Ziegler-Natta catalysts, a review of the coordination chemistry of cyclopentadienyl titanium carboxylate and related complexes O and a review of bis(cycIopentadienyl)zirconium(IV) or hafnium(IV) complexes with Si-, Ge-, Sn-, N-, P-, As-, Sb-, 0-, S-, Se-, Te- or transition metal-centred anionic ligands. Cationic zirconocene or hafiiocene complexes serve as Lewis acids with unique reactivities, they are active for C-F bond activation, coordinative activation of ether linkages, carbonyl activation and C-O bond cleavage. New synthetic methods based on the... 

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