Shin-ichi WADA (Tokyo Inst. Tech.), Yoshihisa MATSUSHITA (Tokyo Inst. Tech.) and Kinichi OBI (Tokyo Inst. Tech. and IMS)
[J. Phys. Chem. A 101, 2423 (1997)]
The D1 <- D0 transition of jet-cooled benzophenone ketyl radical (BPK) and its deuteride was studied by using laser induced fluorescence (LIF) spectroscopy. BPK was generated by the 248 nm photolysis of (alpha)-phenylbenzoin and its vibrationally resolved LIF excitation and emission spectra were obtained for the first time. The 18 451 cm-1 band was assigned to the 000 band of the D1 <- D0 transition of BPK. Two vibrational modes of BPK with 65 and 84 cm-1 in the first excited state were assigned to the in-phase and out-of-phase torsional motions of the phenyl rings, respectively. The vibrational mode with 980 cm-1 was tentatively assigned to the C-O stretching mode. The mode of 74 cm-1 in the ground state was assigned to the in-phase torsional mode. It was confirmed that the torsional motions do not couple with the C-O stretching and O-H rotational motions. The force field analysis and the simple Franck-Condon calculation were made. The measured fluorescence lifetimes of BPK and its deuteride are short and consistent with those in the gas and liquid phases at room temperature.