Cluster chemistry dinuclear/trinuclear complexes

Given the well documented role of homolytic M-M bond cleavage in photoreactions of dinuclear carbonyls, a logical hypothesis for the photofragmentations of trinuclear complexes would be to follow a similar path to give a diradical. Indeed such an intermediate is attractive in the context that the lower quantum yields could be attributed to rapid recombination of the radicals held together by the rest of the cluster. However, experiments with added chlorocarbons in Ru3(CO)i2 photolysis solutions have shown that a trappable diradical is not an intermediate in the photoreaction chemistry, but instead the intermediate formed is susceptible to trapping by two electron donors (i.e., Lewis base nucleophiles) (eq. 13) [17,20,48-50]. 

As mentioned previously, one of the more interesting developments in the chemistry of Wn has been the synthesis and the characterization of dinuclear complexes containing W—W double bonds and trinuclear clusters containing W—W single bonds. 

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