Synthesis and Reactivity of Ruthenium and Platinum Amido and Carbene Complexes: Application Toward Carbon-Nitrogen Bond Forming Reactions

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dc.contributor.advisor Martin, James D., Committee Member en_US
dc.contributor.advisor Bowden, Edmond F., Committee Member en_US
dc.contributor.advisor Melander, Christian, Committee Member en_US
dc.contributor.advisor Gunnoe, T. Brent, Committee Chair en_US Zhang, Jubo en_US 2010-04-02T18:54:13Z 2010-04-02T18:54:13Z 2005-08-02 en_US
dc.identifier.other etd-07312005-154449 en_US
dc.description.abstract Ru carbene complexes have been investigated for potential application toward carbon-nitrogen bond forming and breaking reactions. The reactivity of Grubbs-type olefin metathesis catalysts (Cl)2(L)(L')Ru=CHPh (L = L' = PCy3 or PPh3; L = PCy3 and L' = H2MesNHC) has been studied with cyclic and acyclic imines. The Ru benzylidene complex (Cl)2(PCy3)2Ru=CHPh undergoes a ligand exchange reaction with 1-pyrroline at room temperature, and oligomerizes 1-pyrroline at 90 oC. The low molecular weight poly(1-pyrroline) has been isolated and characterized. The Ru benzylidene complex has no reactivity toward acyclic imine C=N bonds, but reacts with enamine C=C bonds that form through tautomerization of imines. The Ru amido complexes, (PCP)Ru(CO)(NHPh) and (PCP)Ru(CO)(NHPh)(PMe3) (PCP = 2,6-(CH2P-t-Bu2)C6H3), have been synthesized and characterized. Reaction of (PCP)Ru(CO)(NHPh)(PMe3) with acetonitrile produces the amidinate complex (PCP)Ru(CO)(NHC(Me)NPh). Kinetic studies have demonstrated the formation of the amidinate complex occurs through dissociation of the PMe3 ligand, coordination of MeCN, and intramolecular nucleophilic attack of the amido ligand toward MeCN. The intramolecular nucleophilic attack reaction has been extensively studied with aromatic nitriles, carbodiimides, isocyanates, carboxamides and aldehydes. Reaction of (PCP)Ru(CO)(NHC(Me)NPh) with pentafluorobenzonitrile results in formation of a new amidinate complex (PCP)Ru(CO)(NHC(C6F5)NPh). The complex (PCP)Ru(CO)(NHC(C6F5)NPh) can initiate a C-F bond cleavage reaction of C6F5CN with ortho regioselectivity in the presence of ROH (R = H or Me). Reaction of five-coordinate complex (PCP)Ru(CO)(OTf) (OTf = OSO2CF3) with NaBAr'4 (Ar' = 3,5-(CF3)2C6H3) under different conditions results in formation of [(PCP)Ru(CO)(ClCH2Cl)][BAr'4], [(PCP)Ru(CO)(N2)][BAr'4] or [(PCP)Ru(CO)(FC6H5)][BAr'4]. Calculations have confirmed that the possible four-coordinate Ru complex with double agostic interactions has a higher ground state energy than these five-coordinate complexes with labile ligands. The coupling reaction of the carbene or vinylidene ligand with the aryl ipso carbon of the PCP ligand has been observed upon reaction of [(PCP)Ru(CO)(ClCH2Cl)][BAr'4] with PhCHN2 or PhCCH. Calculations have supported that the Ru carbene or vinylidene intermediate is formed, and that the coupling reaction is thermodynamically favored. The Pt(IV) amido systems are studied with potential application toward C-H activation and polymerization sequences. Preliminary studies include isolation of a Pt(IV) amido complex (NCN)Pt(Me)2(NHPh) (NCN = 2,6-(pyrazol-1-yl-CH2)C6H3). en_US
dc.rights I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. en_US
dc.subject Amidinate Complex en_US
dc.subject PCP Ligand en_US
dc.subject Ruthenium Amido en_US
dc.subject Imine Metathesis en_US
dc.subject Ruthenium Carbene en_US
dc.subject Platinum Amido en_US
dc.title Synthesis and Reactivity of Ruthenium and Platinum Amido and Carbene Complexes: Application Toward Carbon-Nitrogen Bond Forming Reactions en_US PhD en_US dissertation en_US Chemistry en_US

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