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theses

Understanding the fundamental processes underlying the activation of small molecules by metal complexes is a continuing goal of organometallic chemistry. This thesis aims to better understand the processes and interactions of small molecules with organometallic complexes. DFT calculations were performed on an extensive series of (PH3)2IrX complexes to investigate the thermodynamics of C-H and N-H oxidative addition. Electronic substituent effects were decomposed into their σ and π effects and individually parameterized; the resulting σX and πX parameters were used to fit the energies of oxidative addition of methane to a series of 3- and 4-coordinate Ir(I) complexes. Regression analysis indicates that oxidative addition of methane to 3-coordinate Ir(I) complexes generally is favored by a less σ-donating ligand trans to the vacant coordination site. DFT calculation was used to investigate the oxidative addition of chlorobenzene and fluorobenzene to pincer iridium complexes. Activation of the aryl C-H bonds proximal to the electron-withdrawing atom is favored. The kinetic barriers were calculated and correlate with the relative steric interactions in the transition state leading to the oxidative addition product. CO stretching frequencies for a series of Ni(CO)3L complexes were calculated using DFT calculations. NBO analysis of these complexes yielded parameters that reflect the extent of backbonding in the π* orbitals of the CO ligands and polarization of the πb orbitals of the CO ligands. The effects of a point charge on free CO were calculated. Experimentally, reactions of small molecules with pincer iridium complexes were investigated. The kinetic barriers for olefin dissociation from (pincer)Ir(olefin) complexes were measured. The (tBuPOCOP)Ir-catalyzed olefin isomerization of 1-octene was investigated and shows an apparent 2nd order dependence on 1 octene concentration. A synthesis scheme for tBu3MePCP ligand was developed. While H2 did not add to tBu4PCPIr(CO), three isomers were observed when H2 was added to tBu3MePCPIr(CO), and the isomers were assigned using an isotopic labeling experiment and NMR spectroscopy. The thermodynamic and kinetic products of tropone addition to (tBuPCP)IrH2 were synthesized and characterized. The formation of a tropone dimer was investigated. The product of methyl fluoride addition to (tBuPCP)IrH2 was characterized through NMR spectroscopy, LIFDI mass spectrometry, and elemental analysis.

ETD_4389

http://hdl.rutgers.edu/1782.1/rucore10001600001.ETD.000067886

Ph.D.

Includes bibliographical references

by David Yu-Ber Wang

doi:10.7282/T3BC3X7F

ETD doctoral

The author owns the copyright to this work.