s-Block metallabenzene: aromaticity and hydrogen adsorption
Rafał Roszak1, Szczepan Roszak
1Institute of Physical and Theoretical Chemistry, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370, Wroclaw, Poland.
Journal of Molecular Modeling
|January 30, 2015
Summary
Metallabenzene compounds exhibit aromaticity derived from their C5H5(-) fragment. These metal-containing rings show strong hydrogen adsorption due to Kubas interactions and π-interactions, with potential for hydrogen storage applications.
Area of Science:
- Computational Chemistry
- Materials Science
- Quantum Chemistry
Background:
- Metallabenzene (C5H6M2) compounds are analogs of benzene where a carbon atom is replaced by a second group metal dimer.
- These complexes exhibit potential aromatic character and promising hydrogen adsorption capabilities.
Purpose of the Study:
- To investigate the aromaticity of metallabenzene compounds.
- To understand the nature of hydrogen-metal interactions for hydrogen adsorption.
- To explore the potential of these compounds in hydrogen storage.
Main Methods:
- Aromaticity indices and molecular orbital analysis were employed to assess aromatic character.
- Variation-perturbational decomposition of interaction energy and ETS-NOCV analysis were used to study hydrogen-metal interactions.
Main Results:
- Aromaticity in metallabenzenes originates from three π orbitals primarily located on the C5H5(-) fragment.
- High hydrogen adsorption energies (up to 6.5 kcal mol(-1)) were observed.
- Hydrogen adsorption is governed by Kubas interactions (metal-H2 σ-orbital interaction) and back-donation, enhanced by H2-π interactions in most cases.
Conclusions:
- Metallabenzene compounds possess significant aromatic character.
- The studied complexes demonstrate strong hydrogen adsorption capabilities, driven by specific metal-ligand interactions.
- These findings highlight the potential of metallabenzene derivatives for applications in hydrogen storage.
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