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Title: Neutron diffraction analysis of transition metal hydrides: Terminal, bridging, and agostic interactions

Abstract

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 bondmore » 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.« less

Authors:
Publication Date:
Research Org.:
University of Southern California, Los Angeles, CA (USA)
OSTI Identifier:
6910032
Resource Type:
Miscellaneous
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, 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

Citation Formats

Stevens, R C. Neutron diffraction analysis of transition metal hydrides: Terminal, bridging, and agostic interactions. United States: N. p., 1988. Web.
Stevens, R C. Neutron diffraction analysis of transition metal hydrides: Terminal, bridging, and agostic interactions. United States.
Stevens, R C. 1988. "Neutron diffraction analysis of transition metal hydrides: Terminal, bridging, and agostic interactions". United States.
@article{osti_6910032,
title = {Neutron diffraction analysis of transition metal hydrides: Terminal, bridging, and agostic interactions},
author = {Stevens, R C},
abstractNote = {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.},
doi = {},
url = {https://www.osti.gov/biblio/6910032}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Jan 01 00:00:00 EST 1988},
month = {Fri Jan 01 00:00:00 EST 1988}
}

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