Laser induced fluorescence (LIF) excitation spectra of the
A2Δ-
X2II transition of SiHhave been measured insupersonic free expansions. We observed the eight vibronic bands, 0-0, 1-0, 0-1, 1-1, 2-1, 1-2, 2-2, and 2-3, thethree Δ
v=-1 bands of which were observed for the first time. The Δ
v=0 sequencedominates the spectra, because of favorable Franck-Condon (F-C) factors. On the other hand, the intensities ofthe Δ
v=- 1transitions are much weaker than those of the Δ
v=+1 transitions in spite of theconsiderable intensity of Δ
v=-1expected from the calculated F-C factors. This behavior is interpreted in terms of the transition momenthaving the strong dependence on internuclear distance.
抄録全体を表示