The A2E–X2A1 System of CaOCH3

✍ Scribed by P. Crozet; F. Martin; A.J. Ross; C. Linton; M.J. Dick; A.G. Adam

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 165 KB
• Volume: 213
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.2002.8536

✦ Synopsis

We have recorded laser excitation spectra of the CaOCH 3 free radical in a laser ablation molecular beam apparatus, at a spectral resolution of about 0.010 cm -1 and a rotational temperature estimated at 15 K. The two spin-orbit components of the A 2 E-X 2 A 1 0 0 0 origin band between 625 and 630 nm have been analyzed. Five main subbands were revealed, with K = +1 and K = 0, ±1, ±2. There was clear evidence of lambda-doubling in the

nonlinear least-squares fitting program based on the model developed by Endo et al. [Y. Endo, S. Saito, and E. Hirota, J. Chem. Phys. 81, 122-135 (1984)] fit the experimental data (514 A-X lines, N ≤ 37) with a root mean square deviation of 0.003 cm -1 , using known molecular constants of the ground state. The main vibronic (T 0 = 15 925.1232(5) cm -1 ), spin-orbit (aζ e d = 66.974 48(51) cm -1 ), Coriolis (Aζ t = 5.437 30( 24)) cm -1 , rotational (A = 5.439 97(24) cm -1 , B = 0.117 884(2) cm -1 ), and fine structure constants (ε 1 = -8.208(14) × 10 -3 cm -1 , h 1 = 1.50(12) × 10 -4 cm -1 , ε aa = 3.58(89) × 10 -3 cm -1 , ε bc = 3.20(76) × 10 -3 cm -1 ) for the excited state have been obtained.