Jet spectroscopy of arylmethyl radicals in the visible region: assignment of low-frequency vibrational modes in diphenylmethyl and chlorodiphenylmethyl radicals.
The D(1)-D(0) transitions of diphenylmethyl (DPM) and chlorodiphenylmethyl (CDPM) radicals were studied by laser induced fluorescence (LIF) spectroscopy in a supersonic jet. Laser induced fluorescence excitation and dispersed fluorescence (DF) spectra were obtained for DPM and CDPM radicals produced by ArF excimer laser (193 nm) photolyses of their chlorides. With the aid of the density functional theory (DFT) calculation, vibronic bands are assigned by comparing the observed LIF excitation spectra of the jet-cooled radicals with the single vibronic level DF spectra. Low-frequency vibrations of 55 and 53 cm(-1) in the ground and excited states, respectively, are assigned to the symmetric phenyl torsional mode of the DPM radical. The geometries of DPM in the ground and excited states are discussed with regards to observed spectra and DFT calculations. Similarly for the CDPM radical, symmetric phenyl torsional and Ph-C-Ph bending modes are assigned and the halogen-substitution effect in equilibrium geometry is discussed.
Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-H57 Ohokayama, Meguro-ku, Tokyo 152-8551, Japan.
Masashi
M
Tsuge
Satoshi
S
Hamatani
Akio
A
Kawai
Kazuhide
K
Tsuji
Kazuhiko
K
Shibuya
D001559:Benzhydryl Compounds / Q000737:chemistry* / Q000528:radiation effects; D005617:Chlorofluorocarbons, Methane / Q000737:chemistry*; D005609:Free Radicals; D007834:Lasers; D008027:Light; D008432:Mathematical Computing; D008956:Models, Chemical; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence; D014732:Vibration
D001559:Benzhydryl Compounds; D005617:Chlorofluorocarbons, Methane; D005609:Free Radicals; C009755:fluorocarbon 22