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Hydrido-Ruthenium Cluster Complexes as Models for Reactive Surface Hydrogen Species of Ruthenium Nanoparticles. Solid-State H-2 NMR and Quantum Chemical Calculations

Gutmann, T. and Walaszek, B. and Xu, Y. P. and Wächtler, M. and del Rosal, I. and Grünberg, A. and Poteau, R. and Axet, R. and Lavigne, G. and Chaudret, B. and Limbach, H. H. and Buntkowsky, G. (2010):
Hydrido-Ruthenium Cluster Complexes as Models for Reactive Surface Hydrogen Species of Ruthenium Nanoparticles. Solid-State H-2 NMR and Quantum Chemical Calculations.
In: Journal of the American Chemical Society, pp. 11759-11767, 132, (33), ISSN 1520-5126,
DOI: 10.1021/ja104229a,
[Article]

Abstract

The H-2 quadrupolar interaction is a sensitive tool for the characterization of deuterium-metal binding states. In the present study, experimental solid-state H-2 MAS NMR techniques are used in the investigations of two ruthenium clusters, D4Ru4(CO)(12) (1) and D2Ru6(CO)(18) (2), which serve as model compounds for typical two-fold, three-fold, and octahedral coordination sites on metal surfaces. By line-shape analysis of the H-2 MAS NMR measurements of sample 1, a quadrupolar coupling constant of 67 +/- 1 kHz, an asymmetry parameter of 0.67 +/- 0.1, and an isotropic chemical shift of -17.4 ppm are obtained. In addition to the neutral complex, sample 2 includes two ionic clusters, identified as anionic DRu6(CO)(18)(-) (2(-)) and cationic D3Ru6(CO)(18)(+) (2(+)). By virtue of the very weak quadrupolar interaction (<2 kHz) and the strong low-field shift (+16.8 ppm) of 2(-), it is shown that the deuteron is located in the symmetry center of the octahedron spanned by the six ruthenium atoms. For the cationic 2(+), the quadrupolar interaction is similar to that of the neutral 2. Quantum chemical DFT calculations at different model structures for these ruthenium clusters were arranged in order to help in the interpretation of the experimental results. It is shown that the H-2 nuclear quadrupolar interaction is a sensitive tool for distinguishing the binding state of the deuterons to the transition metal. Combining the data from the polynuclear complexes with the data from mononuclear complexes, a molecular ruler for quadrupolar interactions is created. This ruler now permits the solid-state NMR spectroscopic characterization of deuterium adsorbed on the surfaces of catalytically active metal nanoparticles.

Item Type: Article
Erschienen: 2010
Creators: Gutmann, T. and Walaszek, B. and Xu, Y. P. and Wächtler, M. and del Rosal, I. and Grünberg, A. and Poteau, R. and Axet, R. and Lavigne, G. and Chaudret, B. and Limbach, H. H. and Buntkowsky, G.
Title: Hydrido-Ruthenium Cluster Complexes as Models for Reactive Surface Hydrogen Species of Ruthenium Nanoparticles. Solid-State H-2 NMR and Quantum Chemical Calculations
Language: English
Abstract:

The H-2 quadrupolar interaction is a sensitive tool for the characterization of deuterium-metal binding states. In the present study, experimental solid-state H-2 MAS NMR techniques are used in the investigations of two ruthenium clusters, D4Ru4(CO)(12) (1) and D2Ru6(CO)(18) (2), which serve as model compounds for typical two-fold, three-fold, and octahedral coordination sites on metal surfaces. By line-shape analysis of the H-2 MAS NMR measurements of sample 1, a quadrupolar coupling constant of 67 +/- 1 kHz, an asymmetry parameter of 0.67 +/- 0.1, and an isotropic chemical shift of -17.4 ppm are obtained. In addition to the neutral complex, sample 2 includes two ionic clusters, identified as anionic DRu6(CO)(18)(-) (2(-)) and cationic D3Ru6(CO)(18)(+) (2(+)). By virtue of the very weak quadrupolar interaction (<2 kHz) and the strong low-field shift (+16.8 ppm) of 2(-), it is shown that the deuteron is located in the symmetry center of the octahedron spanned by the six ruthenium atoms. For the cationic 2(+), the quadrupolar interaction is similar to that of the neutral 2. Quantum chemical DFT calculations at different model structures for these ruthenium clusters were arranged in order to help in the interpretation of the experimental results. It is shown that the H-2 nuclear quadrupolar interaction is a sensitive tool for distinguishing the binding state of the deuterons to the transition metal. Combining the data from the polynuclear complexes with the data from mononuclear complexes, a molecular ruler for quadrupolar interactions is created. This ruler now permits the solid-state NMR spectroscopic characterization of deuterium adsorbed on the surfaces of catalytically active metal nanoparticles.

Journal or Publication Title: Journal of the American Chemical Society
Volume: 132
Number: 33
Uncontrolled Keywords: gaussian-basis sets dft calculations hartree-fock atoms li adsorption density shifts c-13 v-51 1st-principles
Divisions: 07 Department of Chemistry
07 Department of Chemistry > Physical Chemistry
Date Deposited: 27 Oct 2014 20:42
DOI: 10.1021/ja104229a
Additional Information:

640QL Times Cited:13 Cited References Count:60

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