In:
Canadian Journal of Chemistry, Canadian Science Publishing, Vol. 82, No. 6 ( 2004-06-01), p. 837-847
Abstract:
A self-igniting DC-electric discharge of C 2 H 2 in Xe (matrix gas) or C 2 H 2 and Xe in Ar or Kr (matrix gas) is used to produce and study the XeC 2 molecule in these various rare gases at 12 K. Unlike in Ar and Kr, the well-known electronic spectra of C 2 is completely absent in a Xe matrix. This together with annealing experiments in Ar matrices indicate that ground state Xe and C 2 react uniquely and without a barrier to form the XeC 2 molecule. The IR-active C-C stretch of this compound is found to be close to the C-C stretching frequency of the C 2 anion, in excellent agreement with our density functional theoretical (DFT) calculations, which yield a XeCC singlet species bent by 148.6° and with substantial charge separation approaching Xe + C 2 and a notably short (2.107 Å) XeC bond. The spectra of the Xe 13 C 12 C, Xe 12 C 13 C, and Xe 13 C 13 C species are also obtained and the isotopic shifts are in excellent agreement with the DFT predictions, although not sufficient to distinguish a bent from a linear structure. Numerous broad absorptions centered near 423 nm (in Xe) are observed, which are clearly due to the XeC 2 molecule. Laser-induced fluorescence studies reveal a near-IR emission likely due to XeC 2 but not yet understood. Infrared spectra in the Xe matrix reveal also formation of the HXeCCH molecule.Key words: matrix-isolation spectroscopy, rare gas compounds, charge transfer compounds, xenoncarbon bonds.
Type of Medium:
Online Resource
ISSN:
0008-4042
,
1480-3291
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
2004
detail.hit.zdb_id:
1482256-8
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