Electronic spectra of the methylidynes VCH and TiCH

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:456848

Barnes, M; Merer, A J; Metha, G F ^[1]

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1. Univ. of British Columbia, Vancouver (Canada)

The reaction of laser-ablated vanadium and titanium atoms with methane (or methane-d{sub 4}) under supersonic jet-cooled conditions allows spectra of the methylidynes VCH (VCD) and TiCH (TiCD) to be recorded by laser induced fluorescence. The VCH molecule has been shown to have a {sup 3}{Delta}{sub 1} ground state and three excited electronic states ({sup 3}{Delta}, {sup 3}{Phi} and 3{Pi}) which give rise to bands in the 590-800 nm region. Hyperfine-resolved laser induced fluorescence spectra of many of these bands have been assigned with a view to understanding the excited state electron configurations. Following direct pumping from the 01{sup 1} 0 and 01{sup 3} 0 vibronic: components of the ground state bending vibration the authors have determined their separation as 2.6 cm{sup -1}. The substitution structure of the ground state is r{sub s}(V-C) = 1.702{sub 5} {Angstrom}; r{sub s}(C-H) = 1.080 {Angstrom}. The TiCH molecule has been found to possess a {sup 2}{Sigma}{sup +} ground state and several {sup 2}{Pi} vibronic excited states which give rise to bands in the 660-730 nm region. As in VCH the vibrational and rotational structure is heavily perturbed. Fits to high resolution ground state combination differences for TiCH and TiCD have given the substitution structure, r{sub s}(Ti-C) = 1.727{sub 7} {Angstrom}; r{sub s}(C-H) = 1.085 {Angstrom}. Very recently a new band system which may be due to CrCH has been discovered using a chromium target. A comparison of the structures, electron configurations and chemistry of the methylidynes will be presented.

• OSTI ID: 456848
• Report Number(s): CONF-9506113--
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
EXCITED STATES
FLUORESCENCE SPECTROSCOPY
GROUND STATES
ORGANOMETALLIC COMPOUNDS
ROTATIONAL STATES
TITANIUM COMPOUNDS
VANADIUM COMPOUNDS
VIBRATIONAL STATES