Nonanuclear Rh-containing clusters

The preparation of both clusters [Rh9 cPc(CO)i9]( (x = 0,1) has been reported and shown to result from similar routes (Eq. 7). Although these redox reactions are complicated, both products have been isolated and shown to be isostructural (see Fig. 

One of the few substituted higher nuclearity clusters results from the reaction of [Rh9(CO)i9] with [Cu(NCMe)4]+, viz. [Rh9(CO)i9(NCMe) /i-Cu(NCMe)2 ]. X-ray analysis shows that the Rh9 unit consists of two condensed, face-sharing octahedra, as found in the starting material, with one of the outer faces containing both the terminal NCMe and the bridging Cu(NCMe)2 units. No NMR data have yet been reported. 

Clusters containing a more close-packed metal framework, viz. mono-capped square antiprismatic, are exemplified by [Rh9E(CO)2i] (E = P, As). The structure is schematically shown in Fig. 16 and it is strictly related to the trans- 

The determination of the formula of [Ru6Rh3 82(00)23] relies heavily upon the isotopic sphtting pattern found in the mass spectrum, because it was difficult to distinguish between Rh and Ru by X-ray analysis and, although there was a low field B resonance, it was broad and so the number of Rhs could not be ascer-tained. The structure (Fig. 18) nevertheless provides an interesting addition to the differently condensed trigonal prismatic metallic cores found in the analogous mono- and di-carbide series of clusters. 

E = S ) is shown in Fig. 17, vide supra. As found for the Rh9 analogs, NMR measurements show that, at low temperature, the solid-state structure (including the distortions) is retained in solution but at higher temperatures there is complete randomization of both the Rhs and COs about the central interstitial atom.  

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