Subject polyhydride

The subject of polyhydride complexes was included as part of a larger, comprehensive review of metal hydride complexes by Kaesz and Saillant (19), and their interesting NMR behavior has been summarized by Jesson (20). The... 

In the late 1950s certain transition metal complexes were recognized to be basic and subject to protonation with acids. This method is an offshoot whereby protonation occurs at the basic hydride ligand and has been widely applicable because it does not require an unsaturated precursor that often either does not exist or is difficult to synthesize. Neutral polyhydride complexes L MHX are often easy targets for protonation to cationic hydrido-H2 complexes, [L M(H2)HX 1]+, which are frequently more robust than complexes prepared from H2 gas. 

Taking into account the usual dynamic behavior in solution of mononuclear polyhydrides, the occurrence of these intermetallic hydride exchanges is not surprising, although its importance can not be underestimated. In fact, hydride transfer among metals has been found to be crucial in order to observe intermetallic cooperation in polynuclear catalysts. This subject will be analyzed in the... 

Since the discovery of the t7 H2 ligand, it has been the subject of intense interest due to the numerous catalytic processes which involve dihydrogen activation. We are exploring the technique of electrosynthesis of dihydrogen complexes from the abundantly available metal polyhydrides. It is our hope that this technique will prove to be generally applicable and allow the synthesis and study of complexes previously unobserved. 

Another example of the nine-coordinate polyhydride is WHg PPh(i-Pr)2 3 which was prepared by subjecting a hexane solution of hexamethyltungsten and PPh(i-Pr)2 to hydrogen at 300 atm for five days. The molecular structure was also confirmed by neutron diffraction... 

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