Transition metal polyhydride

Perhaps the most exciting recent development in the chemistry of hydrogen is the discovery that, in transition metal polyhydrides, the molecule Hj can act as a dihapto ligand, (see below). 

Bayse, C.A. and Hall, M.B. (1999) Prediction of the Geometries of Simple Transition Metal Polyhydride Complexes hy Symmetry Analysis. Journal of the American Chemical Society, 121, 1348-1358. 

Polynuclear complexes associated with transition metal polyhydrides and silver cations have been described those which present silver—metal bonds are more numerous and they will be... 

Generation of Reactive Intermediates via Photolysis of Transition-Metal Polyhydride Complexes... 

The photochemical properties of several transition metal polyhydride complexes are described. Irradiation of [MoH Cdppe) ] (dppe =... 

Transition metal polyhydride complexes attracted our attention for their easiness to liberate H2 giving coordinatively unsaturated species under mild conditions.3 The resulting intermediates are highly reactive and interact with various substrates to produce new complexes. In many cases, polyhydride complexes are fluxional, where the hydrogen atoms in the coordination sphere rapidly exchange their positions. 

Transition metal polyhydrides have several features that are currently attracting considerable interest. For example, some examples have been found to have hydrides bound in a nonclassical t/ -H2 fashion, e.g.. 

Heterobimetallic complexes have recently attracted considerable attention in light of the promise of enhanced reactivity as a result of the cooperativity between adjacent, but electronically different, metal centers. A large number of these bimetallic compounds have been synthesized by the reactions of organometallic halides with anionic metal carbonyls. Here, we describe an extension of this route to the synthesis of hydride rich. Os—Zr and Os—Rh complexes by the reaction of organometallic halides with a metal poly hydride anion. These preparations demonstrate the synthetic utility of transition metal polyhydride anions. 

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