Laser Induced Fluorescence From CF2 Excited at 248 Nm

Abstract

KrF–laser-induced fluorescence from CF2-radicals was investigated during photolysis of CF2Cl2 and CF2HCl by 193 nm laserlight. In contrast to other publications, which postulated single-vibronic-level fluorescence, the fluorescence is caused by excitation from four closely situated absorption bands. These fluorescence bands of four series, are assigned to Ã1B1(v′1,6−2v′1,0) − X˜1A1(v″1,v″2,0) transitions with Δv1=0 and 0 ≤ v″2 ≤ 30. The Franck – Condon factors of the Ã1B1 (0, 6, 0) –X˜1A1 (0, v″2, 0) transitions, the frequencies of the bending vibration (ω″2 =673± 2cm–1) and the anharmonicity constants x″22 = –0.94 ± 0.08 cm-1 and x′22 = –0.44 ± 0.10 cm–1 were more precisely determined. For the first time higher anharmonicity constants are evaluated with x″12