Wehrmann, F. ; Albrecht, J. ; Gedat, E. ; Kubas, G. J. ; Eckert, J. ; Limbach, H. H. ; Buntkowsky, G. (2002)
Hydrogen deuterium isotope effect on exchange rates in eta(2) bond transition metal dihydrogen complexes revealed by H-2 solid state NMR spectroscopy.
In: Journal of Physical Chemistry A, 106 (12)
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
A selectively eta(2)-D-2 labeled isotopomer of the complex W(PCy3)(2) (CO)(3)) (eta(2)-D-2) has been synthesized and the H-2 NMR spectra and spin lattice relaxation rates of this complex have been measured in the temperature regime of 50 K to 300 K. The spectra have been analyzed employing a model of a combination of homonuclear dipolar D-D interaction and deuterium quadrupolar interaction and a D-D distance of 0.89 +/- 0.1 Angstrom. The line width of the spectra exhibits a weak temperature dependence at temperatures above 150 K. This temperature dependence is interpreted as a slight decrease of the quadrupolar coupling with increasing temperature, which is an indication of a change of the M-D-2 distance with changing temperatures. The spin lattice relaxation data of the complex exhibit pronounced deviations from a simple Arrhenius behavior at lower temperatures, indicating the presence of a quantum mechanical tunneling process. This process is analyzed in terms of a simple one-dimensional Bell tunnel model. A comparison with INS data from the H-2 complex reveals a strong isotope effect of 2 x 10(3) for the exchange rates of the deuterons.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2002 |
| Autor(en): | Wehrmann, F. ; Albrecht, J. ; Gedat, E. ; Kubas, G. J. ; Eckert, J. ; Limbach, H. H. ; Buntkowsky, G. |
| Art des Eintrags: | Bibliographie |
| Titel: | Hydrogen deuterium isotope effect on exchange rates in eta(2) bond transition metal dihydrogen complexes revealed by H-2 solid state NMR spectroscopy |
| Sprache: | Englisch |
| Publikationsjahr: | 2002 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Journal of Physical Chemistry A |
| Jahrgang/Volume einer Zeitschrift: | 106 |
| (Heft-)Nummer: | 12 |
| URL / URN: | http://apps.webofknowledge.com/full_record.do?product=WOS&se... |
| Kurzbeschreibung (Abstract): | A selectively eta(2)-D-2 labeled isotopomer of the complex W(PCy3)(2) (CO)(3)) (eta(2)-D-2) has been synthesized and the H-2 NMR spectra and spin lattice relaxation rates of this complex have been measured in the temperature regime of 50 K to 300 K. The spectra have been analyzed employing a model of a combination of homonuclear dipolar D-D interaction and deuterium quadrupolar interaction and a D-D distance of 0.89 +/- 0.1 Angstrom. The line width of the spectra exhibits a weak temperature dependence at temperatures above 150 K. This temperature dependence is interpreted as a slight decrease of the quadrupolar coupling with increasing temperature, which is an indication of a change of the M-D-2 distance with changing temperatures. The spin lattice relaxation data of the complex exhibit pronounced deviations from a simple Arrhenius behavior at lower temperatures, indicating the presence of a quantum mechanical tunneling process. This process is analyzed in terms of a simple one-dimensional Bell tunnel model. A comparison with INS data from the H-2 complex reveals a strong isotope effect of 2 x 10(3) for the exchange rates of the deuterons. |
| Freie Schlagworte: | quantum-mechanical exchange h-h bond molecular-hydrogen single-crystal nuclear-dynamics methyl-groups cd3 groups ligand coherent hydride |
| Zusätzliche Informationen: | 534LU Times Cited:18 Cited References Count:70 |
| Fachbereich(e)/-gebiet(e): | 07 Fachbereich Chemie 07 Fachbereich Chemie > Eduard Zintl-Institut > Fachgebiet Physikalische Chemie |
| Hinterlegungsdatum: | 27 Okt 2014 20:52 |
| Letzte Änderung: | 31 Mai 2019 07:48 |
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