Neutron diffraction analysis of transition metal hydrides: Terminal, bridging, and agostic interactions
The High Flux Beam Reactor at Brookhaven National Laboratory located in Upton, New York, was used in all experiments described in this thesis. Two main types of problems were tackled with this technique: (i) the structures of transition metal hydrido complexes and (ii) the determination of the absolute configuration of chiral CHD groups generated via biochemical processes. Transition metal hydrido complexes have been studies extensively due to several reasons: (i) their potential for catalysis in organic synthetic reactions such as hydrogenation, hydroformulation, and olefin isomerization; (ii) their unconventional bonding mode in metal clusters; and (iii) their potential as hydrogen storage materials. Six transition metal hydride complexes have been studied in this work which fall into this category. The compounds studies include: (i) a transition metal dimer containing bridging hydrides, ((C{sub 5}(CH{sub 3}){sub 5}Ir){sub 2} ({mu}-H){sub 3}){sup +}(ClO{sub 4}){sup {minus}}2C{sub 6}H{sub 6}; (ii) compounds suspected to have agostic hydride interactions, (cis-IrH(OH)(PMe{sub 3}){sub 4}){sup +}(PF{sub 6}){sup {minus}}, Cp{sub 3}U = CHPMe{sup 3}, and (C{sub 5}Me{sub 5}){sub 2}Th({mu}-CH{sub 2})({mu}-1-3,4-Me{sub 2}C{sub 5}H{sub 2}) ZrMe(C{sub 5}H{sub 5}); (iii) a metal cluster containing face-bridging hydrogen atoms H{sub 6}Cu{sub 6}(P(p-toyl){sub 3}){sub 6}; and (iv) the complex HRh(P(C{sub 6}H{sub 5}){sub 3}){sub 4}, in which the shortest hydrogen-metal bond distance (1.31(8){angstrom}) was discovered. The appendix section is concerned with the powerful, yet presently under-utilized application of neutron diffraction in the determination of absolute configurations of molecules bearing chiral methylene groups. Here, the systems malate/succinate and acetaldehyde/alcohol have been studied and confirmed to be consistent with previous (non-crystallographic) studies.
- Research Organization:
- University of Southern California, Los Angeles, CA (USA)
- OSTI ID:
- 6910032
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
TRANSITION ELEMENT COMPLEXES
NEUTRON DIFFRACTION
ALKENES
CATALYSIS
CHEMICAL BONDS
HYDRIDES
HYDROGEN STORAGE
HYDROGENATION
IRIDIUM COMPLEXES
ISOMERIZATION
MOLECULAR STRUCTURE
ORGANOMETALLIC COMPOUNDS
RHODIUM COMPLEXES
THORIUM COMPLEXES
ACTINIDE COMPLEXES
CHEMICAL REACTIONS
COHERENT SCATTERING
COMPLEXES
DIFFRACTION
HYDROCARBONS
HYDROGEN COMPOUNDS
ORGANIC COMPOUNDS
SCATTERING
STORAGE
400101* - Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures