Chromium carbonyl hydride anion

The anionic hydrido carbonyls have been much studied because of their intermediacy in catalytic processes like the water gas shift reaction, reduction of organic substances, and other reactions. Thus chromium group hydrides [HM(CO)4PR3] are highly efficient H-transfer agents and for reactions with alkyl halides a reactivity order was established cii-[HW(CO)4PR3] > m-[HCr(CO)4PR3] > [HW(CO)5]... 

Preparation by Reduction of Carbonyl Compounds.- Reductions of carbonyl compounds have been reported using diphenylstibine, anionic Group 6 transition-metal carbonyl hydrides (chromium and... 

Hubaut et has studied the liquid phase hydrogenation of polyunsaturated hydrocarbons and carbonyl compounds over mixed copper-chromium oxides. The selectivity of monohydrogenation was almost 100 % for conjugated dienes but much lower for a,p-unsaturated carbonyls. This was due to the adsorption competition between the unsaturated carbonyls and alcohols as primary products. It was suggested that the hydrogenation site was an octahed-rally coordinated Cu ion with two anionic vacancies, and an attached hydride ion. The Cr ion in the same environment was probably the active site for side reactions (hydrodehydroxylation, nucleophilic substitution, bimolecular elimination). 

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