Uniform TitleStudies of PNP and PCP pincer complexes: synthesis and C-H activation potential of PNP pincer complexes and a PCP pincer complex applied to alkene hydrogenation
NamePelczar, Elizabeth M. (author), Goldman, Alan (chair), Krogh-Jespersen, Karsten (internal member), Brennan, John (internal member), Sheridan, John (outside member), Rutgers University, Graduate School - New Brunswick,
SubjectChemistry and Chemical Biology,
Ligand binding (Biochemistry),
DescriptionThe ability to break the C-H bond, which is considered one of the most inert bonds in chemistry, has vast applications in a wide variety of chemical processes. (RPCP)Ir pincer complexes have been shown to be highly effective catalysts for C-H activation, in particular in the context of dehydrogenation reactions. Related to the (RPCP)Ir complexes are (RPNP)M complexes which have not been examined in terms of C-H activation potential.
Chapter 2 presents the synthesis and full characterization of two new iron PNP pincer complexes, (tBuPNP)FeCl2 and (tBuPNP)Fe(CO)2. The dichloride complex is paramagnetic with an unusually long Fe-N bond. The blue dicarbonyl complex has significantly bent Fe-C-O angles in the solid state and in solution, and appears to be an equilibrium mixture between square pyramidal and trigonal bipyramidal structures.
Chapter 3 presents the synthesis and full characterization of two new osmium tBuPNP pincer complexes, (tBuPNP)OsCl3 and (tBuPNP)OsH4. The crystal structure of the hydride complex shows that the complex is a purely classical hydride in the solid state.
Chapter 4 follows up on (tBuPNP)OsH4 by discussing the reactivity of this complex. Unlike the (RPCP)Ir complexes, (tBuPNP)OsH4 was not found to be an active catalyst for C-H activation, dehydrogenation, or phenylacetylene dimerization. The difference in reactivity most likely comes from the difference in metal-hydride bond strength.
Chapter 5 discusses the hydrogenation kinetics of trans-5-decene by (tBuPCP)IrH2. The reaction follows second order kinetics and appears to be largely temperature independent. The room temperature activation energy, activation enthalpy, and activation entropy were calculated and show that the main barrier comes from entropic factors.
Chapter 6 presents the synthesis and characterization of a new (tBuPCP)IrH-µ2-Cl2-Ir(COD) dimer. This complex can be thought of as the oxidative addition product of (tBuPCP) with 1/2 [Ir(COD)Cl]2. The complex was found to be an Ir(I) / Ir(III) dimer with the hydride atom coordinated to the Ir(III) atom that was coordinated to the PCP ligand.
NoteIncludes bibliographical references.
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.