Optical detection of yttrium dicarbide, a {open_quotes}T-shaped{close_quotes} molecule

Journal Article · Sat Feb 01 04:00:00 EST 1997 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.473343· OSTI ID:474641

Steimle, T C; Marr, A J; Xin, J ^[1]; Merer, A J; Athanassenas, K; Gillett, D ^[2]

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1. Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1864 (United States)
2. Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1 (Canada)

The yttrium dicarbide molecule, YC{sub 2}, has been identified in the reactions of laser-ablated yttrium with methane and other small hydrocarbons under supersonic jet-cooled expansion conditions. A parallel-polarized electronic band system with origin at 12889.5 cm{sup {minus}1} has been tentatively identified as an A{sub 1}{endash}{tilde X}{sup 2}A{sub 1} transition of a {open_quotes}T-shaped{close_quote}{close_quote} isomer where the Y atom is bonded to the side of a C{sub 2} molecule. Weak vibronically induced perpendicular bands, representing {Delta}{upsilon}{sub 3}=odd transitions, are also present. Extensive vibrational progressions in the excitation and the resolved fluorescence spectra have been analyzed to give the two lowest vibrational frequencies of the two electronic states: {tilde X}{sup 2}A{sub 1}, {nu}{sub 2} (a{sub 1})=561.1({plus_minus}2.8 cm{sup {minus}1}), {nu}{sub 3} (b{sub 2})=369.6 ({plus_minus}1.7 cm{sup {minus}1}); excited A{sub 1}, {nu}{sub 2}=494.5({plus_minus}5.0 cm{sup {minus}1}), {nu}{sub 3}=331.6({plus_minus}2.2 cm{sup {minus}1}). No bands involving the C{endash}C stretching vibration ({nu}{sub 1},a{sub 1}) have been found. The frequency of the {nu}{sub 3} vibration in the ground state indicates that the barrier to internal rotation of the C{sub 2} group against the Y atom is quite high, but large anharmonic coupling between the {nu}{sub 2} and {nu}{sub 3} vibrations suggests that internal rotation is facilitated by excitation of the Y{endash}C{sub 2} stretching vibration. {copyright} {ital 1997 American Institute of Physics.}

• DOE Contract Number: FG03-94ER14468
• OSTI ID: 474641
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 6 Vol. 106; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
66 PHYSICS
ELECTRONIC STRUCTURE
EXCITED STATES
FLUORESCENCE
FLUORESCENCE SPECTROSCOPY
GROUND STATES
JETS
PHOTOLUMINESCENCE
ROTATION
VIBRATIONAL STATES
VISIBLE SPECTRA
YTTRIUM
YTTRIUM CARBIDES
YTTRIUM COMPOUNDS
rotational isomerism