Synthesis and reactivity of transition metal complexes containing nitrogen heterocycles

This thesis describes the synthesis, characterization, and reactivity of transition metal complexes containing nitrogen heterocycles. The first project focuses on (cymene)Ru(II) complexes with pi- and sigma-bound indoline. For example, [(cymene)Ru(N-indoline)(CH3CN)2](OTf) 2, 2, has been isolated and characterized by an X-ray diffraction study. Complex 2 rearranged to [(cymene)Ru(eta6-indoline)]-(OTf) 2 when heated in dichloromethane. Ligand exchange reactions of 2 have been studied. Deprotonation of the eta1-indoline ligand in 2 results in further dehydrogenation of the ligand to form free indole and ruthenium hydride products. The deprotonation of 2 in the presence of an alkene has been found to result in a hydrogen-transfer reaction to form an alkane.; The second project involves a study of the structure and reactivity of a Re(III) N-bonded pyrrolyl complex. The complex (PMe2Ph) 3Cl2Re(NC4H4), 5, was characterized by an X-ray diffraction study, confirming that the rhenium was sigma-bound to the pyrrolyl. Reactions of 5 with electrophiles, including halogen and carbon electrophiles, resulted in regioselective substitution to give 3-, 3,4-, and 2,3,4-substituted pyrrolyl derivatives. Reaction of the pyrrolyl complex with triflic acid proceeded at room temperature to form a stable ring protonated product, [(PMe2Ph)3Cl 2Re(NC4H5)]OTf, 14. An X-ray diffraction study helped determine the site of the pyrrolyl ring protonation, which occurred at the alpha-carbon. The synthesis of heteronuclear pyrrolyl derivatives will also be discussed.; The final project focuses on the synthesis and reactivity of molybdenum sulfide dimers that either coordinate pyrrole or that have varying bridging heteroatoms. The complex [(CpMo)2(S2CH2)(mu-SCH 3)(mu-S-(Me-pyrrole))]BF4, 22, was prepared by the reaction of [(CpMo)2(S2CH2)(mu-SCH 3)(mu-S)]2(BF4)2 with Me-pyrrole. Further reactivity of 22 with electrophiles and hydride reagents has been investigated. Also, the thermal reaction of [(CpMo)2(S 2CH2)(mu-SMe)(mu-SMe2)]OTf, 20, with Se results in the formation of [(CpMo)2(S2CH 2)(mu-SMe)(mu-Se)]OTf, 25, which has been isolated and characterized spectroscopically. The reaction of 20 with oxygen donors in the presence of acetonitrile results in the formation of a new unsymmetrically bridged dimer, [(CpMo)2(S2CH 2)(mu-SMe)(mu-eta2-OC(CH3)NH)]OTf, 26. An X-ray diffraction study of 26 confirms the presence of the unsymmetrical acetamide bridge. Lastly, the tetranuclear complex [(CpMo) 2(S2CH2)(mu-SMe)]2S, 27, has been synthesized in an attempt to form extended arrays of the reactive dinuclear Mo-S structures. Complex 27 has been characterized spectroscopically and by an X-ray diffraction study.