Cluster compounds Metallaboranes

Many novel cluster compounds have now been prepared in this way, including mixed metal clusters. Further routes involve the oxidative fusion of dicarbon metallacarhorane anions to give dimetal tetracarbon clusters such as (103) and (104) O the insertion of isonitriles into metallaborane clusters to give monocarbon meiallacarboranes such as and the... 

Serendipitous insertion of CsHs- into the metallaborane Cp 2Cr2B4Fl8 gave the triple-decker sandwich 122 in low yield.140 This compound can be described as an eight-vertex Cr2C2B4 c/ara-metallacarborane cluster, and its preparation is notable as one of the few examples of metallacarborane synthesis from a metallaborane precursor (rather than by the usual metal insertion into a carborane), an approach first demonstrated by Grimes and co-workers in the 1970s.34,141,141a... 

Photochemical transformations are widely employed in both organic and organoinetallic chemistry and have been extensively used as synthetic strategies for the formation of a variety of new compounds.1 Part of our recent research has focused upon an exploration of the photochemical reactions of borane and metallaborane clusters. As a contextual setting for these photochemical studies, we have also explored several aspects of the thermal and redox chemistry of these clusters. In this paper, we present a summary of our recent work on the thermal, photochemical, and redox reactions of borane and metallaborane clusters. In addition, recent work directed toward the application of these clusters to several aspects of molecular electronics will be presented. 

The existence of mixed metal-boron clusters constitutes one example of the validity of the isolobal principles when applied to a class of compounds. The stoichiometric and structural diversity of metallaboranes is truly striking, and the idea of isolobal fragments combined with the electron counting rules is sufficient to rationalize this diversity—this fact is impressive (67,68,69, 70, 71, 72, 73, 74). We have explored the mixing of boron and metal characters in cluster MOs in the Bs nHg-nlFeCCOla) ] nido cluster series (Fig. 5). Examples of the first four members of this series (a, b, c, and d) have been well characterized (75, 76, 77), and suggestive evidence has been published for a B2H6RU3-... 

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