Complexes, transition metal oligonuclear

It should be clear from the preceding examples that theoretical studies of this type serve not simply to validate computational predictions by detecting potential sources of error, but also to identify the origins of particular spectroscopic characteristics, establish trends, and uncover correlations between structural or electronic features and spectroscopic observables. It remains to be seen in future applications how far this approach can take us in establishing reliable connections between structural parameters and spectroscopic properties for larger and more complex oligonuclear transition metal systems. 

As oligonuclear species, metal clusters can be placed between mononuclear metal complexes on the one hand and polynuclear metal surfaces on the other (Scheme 1). Because of this intermediary position between typical homogeneous and typical heterogeneous catalysts, transition metal clusters may not only provide models for heterogeneous catalysts, but they... 

As a radical, the 1,3-diborolyl ring system cannot exist independently but only in combination with one or two transition metal atoms. It can olfer three electrons to metal atoms by the C n-electrons, whereas the two B atoms act as acceptor centers towards the metals. In formulas (18)-(20) a mononuclear and several oligonuclear 1,3-diborolyl complexes are shown representatively. The ideal number of valence electrons (VE) in such a complex is 12n 6, where n is the number of stacks <88PAC1345>. 

Frosch, W. Back, S. del Rio, I. van Koten, G., and Lang, H. (1999). An Easy Entry to Novel Early-Late Oligonuclear Transition Metal Complexes Containing r-Conjugated Systems. Inorg. Chem. Commun., 2, 584-586. 

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