Copper complexes hexanuclear cluster

It is possible that a heteronuclear molecular cluster can offer a suitable explanation of these latter results a greater variety of heteronuclear molecular clusters with different transition metals are known. However most of them possess three or four metal atoms and do not represent the best models for very small particles of alloys. Examples of heteronuclear clusters with more than four metal atoms are rare. An interesting example is given by the hexanuclear iridium-copper complex syn-thetized by Bruce et al [135] of formula Cu4lr2(PPh3)2 ( C = C-Ph)g. In this cluster the six metal atoms form a distorted octahedron in which two PhaP-Ir moieties are mutually trans four — C = C-Ph units are only a bonded to each Ir atom and four — C = C-Ph units (one from each Ir) form tt linkages to each of the four equatorial copper atoms (Figure 25). 

Ford and Vogler reported the photophysical properties of a hexanuclear copper(I) thiolate cluster [Cu (mtc) ] (13) and the related silver(I) complexes [86]. The copper complex shows an intense emission band at 706 nm (Xo = 0.99 ps) and 767 nm (Xq = 14.0 ps) in the solid state at 294 and 77 K, respectively. The emissive state has been suggested to derive from an admixture of LMCT [thiolate Cu ] and metal-centered d-s character. 

Endicott, J. F. Ramasami, T Tamilarasan, R. Lessard, R. B. Brubaker, G. R. Structuie and Reactivity of the Metal-Centered Transition Metal Excited States, Coord. Chem. Revs. 1987,77,1. Ferraudi, G. Thotochemical Properties of Copper Complexes, Coord. Chem. Revs. 1981,36,45. Ford, P. C. Vogler, A. Photochemical and Photophysical Properties of Tetranuclear and Hexanuclear Clusters of Metals with and Electronic Configurations, Acc. Chem. Res. 1993,26,220. 

The reaction of copper or gold complexes such as (245) with copper or silver trifluoromethanesulphonates gives hexanuclear cluster compounds such as (246). 

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