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Published on: February 7, 2017
Activation of methane by the tantalum trioxide anion, TaO3
Tatsuya Chiba1, Turbasu Sengupta2, Shiying Wang1
1Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, USA. snkhanna@vcu.edu.
Abstract:
To better utilize abundant supplies of methane, a catalyst is needed that can selectively activate it. Studies of the reactivity of methane with ions in the gas phase can provide insight into reaction mechanisms at specific catalytic sites. Recently, He et al. found, through mass spectrometric observations, that out of the 27 [TaxOy]- species investigated, only [TaO3]- formed an anion-methane complex, [TaO3CH4]- (Q. Li, Q.-Y. Liu, A. Zhao, and S.-G. He, Reactions between TaxOy- (x = 1-5, y = 0-7) cluster anions and C1-C3 alkanes, J. Chem. Phys., 2025, 163, 054303). In the present study, where we employed a synergistic combination of anion photoelectron spectroscopy and DFT calculations, the [TaO3]- isomer with a structure of O-Ta-O2, in which the Ta atom is bonded to a terminal O atom and an η1-superoxo [O2-] ligand, was found to form two activation complexes with methane. The geometrical structures of these two activation complexes, in which one and two C-H bonds are cleaved respectively, were determined by comparing the experimental and computational spectra. This reports the first spectroscopic confirmation of C-H bond activation by tantalum oxide anions.
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