Date of Award

1-1-2013

Document Type

Open Access Dissertation

Department

Chemistry and Biochemistry

Sub-Department

Chemistry

First Advisor

Richard D Adams

Abstract

The reaction of IrRu3(CO)13(µ-H), 2.1 with HSnPh3 in hexane solvent at reflux has provided the new mixed metal cluster compounds Ir2Ru2(CO)11(SnPh3)(µ-H)3, 2.2 and IrRu3(CO)11(SnPh3)3(µ-H)¬4, 2.3 containing SnPh3 ligands. Compound 2.2 which was obtained in low yield (3%) contains a closed cluster having two iridium and two ruthenium atoms, one SnPh3 ligand and three bridging hydride ligands. Compound 2.3 has a butterfly structure for the four metal atoms with three SnPh3 ligands and four bridging hydride ligands around the periphery of the cluster. When compound 2.3 was heated to 97 oC for 30min, IrRu3(CO)9(μ-η2-C6H5)(μ4-SnPh)2(μ-SnPh2), 2.4 was formed by cleavage of phenyl rings from the SnPh3 ligands in low yield. Compound 2.4 contain square IrRu3 clusters of the metal atoms with quadruply bridging SnPh ligands on opposite sides of the cluster, one bridging SnPh2 ligand on one of the Ir-Ru bonds and also a rare η2-bridging phenyl ligand.

The new compound IrRu3(CO)11(GePh3)3(µ-H)¬4, 3.1 was obtained in 64% yield from the reaction of IrRu3(CO)13(μ-H) with HGePh3 at room temperature. Compound 3.1 is the Ge analog of compound 2.3, which contains an open cluster of one iridium and three ruthenium atoms with three GePh3 ligands and four hydride ligands. When the reaction was performed at hexane reflux for 10 min a second minor Ir2Ru2(CO)11(GePh3)(μ-H)3, 3.2 was formed. Compound 3.2 is two iridium atoms and two ruthenium atoms in a tetrahedral structure which must have formed by some metal-metal exchange process. When compound 3.1 was heated to 68 oC for 6h, two new

compounds: IrRu3(CO)10(μ-η2-C6H5)(μ4-GePh)2, 3.3 and IrRu3(CO)9(μ-η2-C6H5)(μ4-GePh)2(μ-GePh2), 3.4 were formed by cleavage of phenyl rings from the GePh3 ligands. Compound 3.3 and 3.4 contain square IrRu3 clusters of the metal atoms with quadruply bridging GePh germylyne ligands on opposite sides of the cluster. Both compounds also contain a rare η2-bridging phenyl ligand. Compound 3.4 was found to react with dimethylacetylenedicarboxylate DMAD to yield new compound IrRu3(CO)9([μ4-Ge(Ph)C(CO2Me)C(CO2Me)](μ-GePh2)2, 3.5 by addition of DMAD to one of the bridging germylyne ligands. In the process the bridging phenyl ligand was transferred to the other bridging germylyne ligand to form a bridging germylene ligand.

The compounds Ru4(CO)12(GePh3)2(μ-H)¬4, 4.1 and Ru4(CO)12(SnPh3)2(μ-H)¬4, 4.2 were obtained from the reactions of Ru4(CO)13(μ-H)2 with HGePh3 and HSnPh3, respectively. Both compounds contain a nearly planar butterfly structure for the four metal atoms with two GePh3 / SnPh3 ligands and four bridging hydride ligands around the periphery of the cluster. When heated, 4.1 and 4.2 were converted into the complexes Ru4(CO)12(μ4-EPh)2, 4.3, E = Ge, and 4.4, E = Sn, by cleavage of two phenyl groups from each of the GePh3 ligands. Compounds 4.3 and 4.4 contain square planar arrangements of the four ruthenium atoms with quadruply bridging germylyne and stannylyne ligands on opposite sides of the square plane. The bonding and electronic transitions of 4.3 were analyzed by DFT computational analyses.

The electronically unsaturated complex [Ru3(CO)8(μ3-CMe)¬(μ-H)¬2(μ3-H)]2¬, 5.1 was obtained by silica gel induced reaction of Ru3(CO)8(μ3-CMe)¬(μ-H)¬3, 5.2. Compound 5.1 can be viewed as a dimer of the 46 electron fragment Ru3(CO)8(μ3-CMe)¬(μ-H)¬3, is held together by a delocalized bonding involving two triply-bridging hydride ligands. Compound 5.1 exhibits a dynamical activity in solution that equilibrates two of the three types of hydride ligands. Compound 5.1 reacts with 1,1-bis(diphenyphosphino)methane to form the macrocyclic complex [Ru3(CO)7(μ3-CMe)¬(μ-H)¬3]2(μ-dppm)¬2, 5.3. Compound 5.3 is a centrosymmetrical dimer linked by two bridging dppm ligands, each phosphorus atom of the dppm is coordinated to a different Ru3 cluster. However, Ru3(CO)7(μ3-CMe)(μ-H)3(μ-dppm), 5.4, was obtained from the reaction of Compound 5.2 with dppm. Reactions of Os3(CO)10(NCMe)2 with HGePh3 have yielded the compounds Os3(CO)10(NCMe)(GePh3)(μ-H)¬, 6.1 and Os3(CO)10(GePh3)2(μ-H)2¬, 6.2 by the sequential replacement of the NCMe ligands and the oxidative addition of the GeH bonds of one and two HGePh3 molecules, respectively, to the osmium atoms of the cluster. Compound 6.2 exists as two isomers in solution at low temperatures which interconvert rapidly on the 1H NMR time scale at room temperature. When heated, 6.1 was transformed into the pentaosmium complex Os5(CO)17(μ-GePh2), 6.3 which exhibits a planar raft structure with one bridging GePh2 ligand. Compound 6.1 reacts with the compound PhAu(PPh3) to yield the compound Os3(CO)8(μ-CO)(μ-O=CPh)(μ-GePh2)(μ-AuPPh3), 6.4 which contains a bridging O=CPh ligand and a Au(PPh3) group that bridges an Os-Ge bond, and compound PhOs4(CO)13(µ-GePh2)(µ-AuPPh3), 6.6 which contains four osmium atoms in a butterfly arrangement with one bridging GePh2 ligand, one bridging AuPPh3 ligand and one σ-bonded phenyl ligand to one of the osmium atoms. A minor product, Os(CO)4(GePh3)(AuPPh3), 6.5 was also obtained in this reaction. Compound 6.4 was also obtained from the reaction of 6.1 with CH3Au(PPh3). Compound 6.4 reacted with PhC2Ph to yield the complex Os3(CO)7(μ-GePh2)(μ-AuPPh3)[μ-(O)CPhCPhCPh)], 6.7 which contains a novel bridging oxa-metallacycle formed by the coupling of PhC2Ph to the bridging O=CPh ligand 6.4 and another example of a Au(PPh3) group that bridges an Os-Ge bond. The bonding of the bridging Au(PPh3) group to the Os - Ge bonds in 6.4 and 6.7 was investigated by DFT computational analyses.

Three new compounds were obtained from the reaction of Os3(CO)10(NCMe)2, 7.1 with BiPh3 in a methylenechloride solution at reflux. These have been identified as Os3(CO)10(μ3-C6H4)¬, 7.2, Os3(CO)10Ph(μ-η2-O=CPh), 7.3, and HOs6(CO)20(μ-η2-C6H4)(μ4-Bi), 7.5. A fourth product HOs5(CO)18(μ-η2-C6H4)(μ4-Bi), 7.4 was also obtained from the reaction of Os3(CO)11(NCMe) with BiPh3. Cleavage of the phenyl groups from the BiPh3 was the dominant reaction pathway and two of the products 7.2 and 7.3 contain rings but no bismuth. Each of the new compounds was characterized structurally by single-crystal X-ray diffraction methods. Compound 7.2 contains a triply bridging benzyne (C6H4) ligand that exhibits a pattern of alternating long and short C - C bonds that can be attributed to partial localization of the π-bonding in the C6 ring. The localization in the π-bonding was supported by DFT calculations. Compound 7.3 contains a triangular cluster of three osmium atoms with a bridging benzoyl ligand and a terminally coordinated phenyl ligand. Compound 7.5 contains six osmium atoms divided into two groups of four and two and the two groups are linked by a spiro-bridging bismuth atom. The group of two osmium atoms contains a bridging C6H4 ligand. When heated, compound 7.3 was converted into 7.2 and the compound Os3(CO)10(μ-η2-O=CPh)2, 7. 6. Compound 7.6 contains two bridging benzoyl ligands.

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