Cluster syntheses. 2. The role of heteroatoms in the formation of high nuclearity transition-metal carbonyl cluster compounds. The condensation of small clusters

Abstract

The compounds HOs/sub 3/(..mu../sub 3/-S)(..mu..-HC double bond NR)(CO)/sub 9/, Ia, R = C/sub 6/H/sub 5/, and Ia', R = C/sub 6/H/sub 4/-p-F, lose CO and/or H/sub 2/ when heated to form the hexanuclear osmium complexes Os/sub 6/(..mu../sub 4/-S)(..mu..-HC double bond NR)/sub 2/(CO)/sub 18/, IIa, R = C/sub 6/H/sub 5/, and IIa', R = C/sub 6/H/sub 4/-p-F, H/sub 2/Os/sub 6/(..mu../sub 4/-S)(..mu../sub 3/-S)(..mu..-HC double bond NR)/sub 2/(CO)/sub 17/, IIIa,b, R = C/sub 6/H/sub 5/, and IIIa',b', R = C/sub 6/H/sub 4/-p-F, which exist as two isomers, H/sub 2/Os/sub 6/(..mu../sub 4/-S)(..mu../sub 3/-S)(..mu..-HC double bond NR)/sub 2/(CO)/sub 16/, IVa-c, R = C/sub 6/H/sub 5/, and IVa'-c', R = C/sub 6/H/sub 4/-p-F, which exist as three isomers, and Os/sub 6/(..mu../sub 4/-S)/sub 2/(..mu..-HC double bond NR)/sub 2/(CO)/sub 15/, Va, R = C/sub 6/H/sub 5/, and Va', R = C/sub 6/H/sub 4/-p-F. All compounds have been analyzed by ir and /sub 1/H NMR spectroscopy. Compounds IIIa', IVa and Va have also been characterized by single-crystal x-ray diffraction analyses. Compounds III can be converted to IV, and IV into V. III, IV, and V are believed to be part of a sequence of cluster growth processes in which the sulfido ligands mediate the initial linking of the clustersmore » and the subsequent formation of metal-metal bonds between them. IIIa' contains two open triangular groups of three metal atoms linked by a tetrahedrally coordinated sulfido ligand. In IVa the six metal atoms are arranged in groups of four and two, with the two groups linked by a tetrahedrally coordinated sulfido ligand. In Va the six metal atoms have condensed into a central cluster of four which has the form of a butterfly tetrahedron with sulfido ligands bridging the two open triangular faces. The two remaining metal atoms are bonded to the hinge metal atoms of the central cluster, one to each.« less