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Holmgren, Jennifer Salem 2014-12-15T23:18:36Z 2014-12-15T23:18:36Z 10000-01-01 1986 1986 The triruthenium methylidyne cluster, HRu(,3)(CO)(,10)((mu)(,3)-CH), was prepared by a hydride addition/protonation sequence from HRu(,3)(CO)(,10)((mu)-COCH(,3)). Variable temperature ('1)H and ('13)C NMR experiments suggest the intermediacy of a formyl complex, presumably HRu(,3)(CO)(,9)(C(H)O)((mu)-COCH(,3))('-) , in the preparation of HRu(,3)(CO)(,10)((mu)(,3)-CH). The methylidyne cluster, HRu(,3)(CO)(,10)((mu)(,3)-CH), rearranges rapidly (-10(DEGREES)C) to the isomeric carbonylmethylidyne cluster, H(,2)Ru(,3)(CO)(,9)((mu)(,3)-CCO), via intramolecular coupling of the carbyne ligand and a cluster-bound carbonyl. Hydrogenation of H(,2)Ru(,3)(CO)(,9)((mu)(,3)-CCO) yields H(,3)Ru(,3)(CO)(,9)((mu)(,3)-CH), demonstrating that this C-C coupling process is reversible. The carbonylmethylidyne cluster, H(,2)Ru(,3)(CO)(,9)((mu)(,3)-CCO), is reduced to the vinylidene cluster, H(,2)Ru(,3)(CO)(,9)((mu)-CCH(,2)), with BH(,3)(.)THF. The carbonylmethylidyne cluster, H(,2)Ru(,3)(CO)(,9)((mu)(,3)-CCO), reacts with nucleophiles at the apical carbon atom. Reaction with MeOH or H(,2)O provides H(,3)Ru(,3)(CO)(,9)((mu)(,3)-CC(O)OMe) and H(,3)Ru(,3)(CO)(,9)((mu)(,3)-CC(O)OH), respectively. A hydride addition/protonation sequence from the carbonylmethylidyne, H(,2)Ru(,3)(CO)(,9)((mu)(,3)-CCO), gives the formylmethylidyne complex, H(,3)Ru(,3)(CO)(,9)((mu)(,3)-CC(O)H). The latter reacts with H(,2) to give the ethylidyne cluster, H(,3)Ru(,3)(CO)(,9)((mu)(,3)-CCH(,3)). The triruthenium methylene cluster, Ru(,3)(CO)(,10)((mu)-CO)((mu)-CH(,2)), is prepared by the reaction of diazomethane and Ru(,3)(CO)(,12). Reactivity studies point to facile C-C bond formation involving the cluster bound methylene and added diazomethane or added CO. Reaction with added methylene provides the H(,2)Ru(,3)(CO)(,9)((mu)-CCH(,2)) while reaction with CO provides Ru(,3)(CO)(,12) and ketene. The methylene cluster, Ru(,3)(CO)(,10)((mu)-CO)((mu)-CH(,2)), thermally rearranges to the carbonylmethylidyne cluster, H(,2)Ru(,3)(CO)(,9)((mu)(,3)-CCO). This rearrangement probably involves the previously discussed methylidyne cluster, HRu(,3)(CO)(,10)((mu)(,3)-CH). The trimethylsilyl substituted alkylidene cluster, Ru(,3)(CO)(,10)((mu)-CO)((mu)-CH(,2)), has also been prepared and its reactivity investigated. Spin saturation transfer experiments on Ru(,3)(CO)(,10)((mu)-CO)((mu)-CH(,2)) suggest that the methylene unit can move over the cluster face, presumably via a bridge-to-terminal isomerization process. Reaction of diazomethane with the phosphine substituted triruthenium cluster, Ru(,3)(CO)(,10)(dppm), yields the novel cluster, Ru(,3)(CO)(,7)((eta)('3)-(C,C,O),(mu)(,3)-COCH(,2))((mu)-CH(,2))(dppm). This cluster was characterized spectroscopically as well as by a single crystal X-ray diffraction study. The cluster contains a ketene ligand and a bridging methylene ligand. Surprisingly, each of the three atoms in the C-C-O unit, the ketene ligand, is bound to a different metal atom in the cluster. On addition of CO, the ketene and methylene ligands in Ru(,3)(CO)(,7)((eta)('3)-(C,C,O),(mu)(,3)-COCH(,2))((mu)-CH(,2))(dppm) couple to form an oxaallyl unit, while the triruthenium cluster degrades to a ruthenium dimer, Ru(,2)(CO)(,5)((eta)('4)-(C,C,C,O),(mu)-CH(,2)C(O)CH(,2))(dppm), which was characterized by single crystal X-ray diffraction. Made available in DSpace on 2014-12-15T23:18:36Z (GMT). No. of bitstreams: 1 8610940.pdf: 6909590 bytes, checksum: 921f69b3fb0f069a39bf018d29092be0 (MD5) Previous issue date: 1986 Embargo set by: Seth Robbins for item 70483 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 211 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1986. http://hdl.handle.net/2142/70317 (UMI)AAI8610940 Chemistry, Inorganic The Chemistry of Triruthenium Hydrocarbyls (Metal Clusters) text Chemistry Chemistry University of Illinois at Urbana-Champaign Dissertation Ph.D.