Metal atom reactions with dppm

Full spectroscopic and preparative details for clusters 141 and 142 are given, and the syntheses of positional isomers of MoCoPdPtCp(CO)6(dppm)2 are described. These noninterconverting isomers, which differ in the nature of the exoligated metal atom, are made either by reaction of cluster 138 with [Co-(CO)4] or by reaction of cluster 140 with [CpMo(CO)3] . [P. Braunstein, C. de Meric de Bellefon and M. Ries lnorg. Chem. 29,1181 (1990)]. 

The structure of the pentanuclear gold-cluster [Au5(dppm)3 (dppm-H)] + is related to that of the Au4 clusters, with the fifth gold atom appended (20). This Aus cluster can be synthesized by reduction of [Au2(dppm)](N03)2 with NaBH4 by the evaporation of metallic gold into ethanohc solution of dppm and NH4NO3 or by reaction of [Au9(PPh3)g] + with dppm hgand. 

The M(II) reagents [M CH(PPh2)2 2], (M = Sn or Pb), introduced by Karsch, ° have three coordinate metal atoms, and again are expected to retain their composition when bonded to clusters. In this case though, reactions afford no isolable heterometallic clusters, but after work-up, give cluster adducts of the parent / (phosphine), Ph2PCH2PPh2. The hydrogen in the product must be an artifact of the experimental procedures employed, For example, in reaction with [Ru3(CO)i2], the adduct [Ru3(CO)io(dppm)] was obtained rapidly and quantita-... 

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