Journal ArticleDOI
Dihydrogen Complexes of Metalloporphyrins: Characterization and Catalytic Hydrogen Oxidation Activity
James P. Collman,James P. Collman,Paul S. Wagenknecht,Paul S. Wagenknecht,James E. Hutchison,James E. Hutchison,Nathan S. Lewis,Michel Angel Lopez,Michel Angel Lopez,Roger Guilard,Roger Guilard,Roger Guilard,Maurice L'Her,Maurice L'Her,Maurice L'Her,Aksel A. Bothner-By,Aksel A. Bothner-By,P. K. Mishra,P. K. Mishra +18 more
TLDR
A series of monometallic dihydrogen complexes of the type M(OEP)(L)(H{sub 2}) (M = Ru, Os; L = THF, *Im) was synthesized and characterized by {sup 1}H NMR as mentioned in this paper.Abstract:
A series of monometallic dihydrogen complexes of the type M(OEP)(L)(H{sub 2}) (M = Ru, Os; L = THF, *Im) was synthesized and characterized by {sup 1}H NMR. The H-H bond length was found to increase when Os was replaced by Ru or when *Im was replaced by THF. The bond distances (as determined by T{sub 1}) range from 0.92 to 1.18 {angstrom}. The first example of a bimetallic bridging dihydrogen complex, Ru{sub 2}(DPB)(*IM){sub 2}(H{sub 2}), was also prepared. The H{sub 2} ligand is simultaneously bound to both Ru-metal centers. High-field {sup 1}H NMR experiments (620 MHz) revealed a -7.37 Hz dipolar splitting of the H{sub 2} ligand for this complex. Analysis of this splitting suggests that the H{sub 2} ligand is bound with the H-H axis perpendicular to the Ru-Ru axis. These complexes were examined as possible catalysts for the oxidation of dihydrogen through prior heterolytic activation of H{sub 2}. Only Ru(OEP)(THF)(H{sub 2}) can be conveniently deprotonated. Ru(OEP)(THF)(H{sub 2}) is also implicated in the Ru-(OEP)((THF){sub 2}) catalyzed isotopic exchange between H{sub 2} and D{sub 2}O in THF solution. Each step for this mechanism has been elucidated. We have also achieved catalytic dihydrogen oxidation using [Ru(OEP)]{sub 2} adsorbed onto graphite. Twomore » mechanisms for this ruthenium porphyrin catalyzed dihydrogen oxidation are presented and compared. 54 refs., 12 figs., 5 tabs.« lessread more
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Fundamentals of H2 Binding and Reactivity on Transition Metals Underlying Hydrogenase Function and H2 Production and Storage
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TL;DR: A review of dihydrogen-dihydride reactions can be found in this article, where the authors present a line-shape analysis of a three-hydrogen system M(H,)H.
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Brønsted–Lowry Acid Strength of Metal Hydride and Dihydrogen Complexes
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