New vibronic bands of the laser-vaporized C3 cluster. Determination of the ν3 fundamental in the Ã1Πu state

✍ Scribed by Mitsuaki Izuha; Kaoru Yamanouchi

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 552 KB
• Volume: 242
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(95)00758-v

✦ Synopsis

1 " +

The laser-induced fluorescence (LIF) spectrum for the A Ilu-X Xg band of laser-vaporized C 3 was measured under jet-cooled conditions. By careful inspection of the rotationally resolved LIF spectrum, eight vibronically allowed transitions 1~+ 1~+

exhibiting a -u--g type rotational structure were identified. This fmding led to the determination of the vibrational energy for the (v 1, v2, v3)=(0, 1 +, 1) level of the A state, from which the fundamental wavenumber of the v 3 anti-symmetric mode was estimated to be = 539 cm-1, which is considerably smaller than any of the previous estimates, 650, 808 and 890 cm -1. In the high-resolution (~ 0.08 cm -1) measurements for the hot-band region, 11-I 1~+ type bands --g----u exhibiting a characteristic feature for the transitions from the X(0, 0, 1) level were identified. By assigning the .g,(0, 0, 1)-X(0, 0, 1) band, the v 3 fundamental was directly determined to be 541.7(1) cat -1, in excellent agreement with the above prediction from the vibronically 1 + 1 + allowed Xu-~s transitions.