Cronin TJ, Wang X, Bethardy GA, Perry DS
Department of Chemistry, University of Akron, Akron, Ohio, 44325-3601
J Mol Spectrosc. 1999 Apr;194(2):236-242. doi: 10.1006/jmsp.1998.7800.
High-resolution, infrared absorption spectra of the nu6 (asymmetric C-H stretch) and 2nu2 (H-C-H symmetric bend overtone) bands of jet-cooled CH2F2 are reported with a sub-Doppler resolution of approximately 0.002 cm-1. More than 600 transitions were observed in the range of 3002-3036 cm-1, of which 268 were assigned the nu6 fundamental and 184 were assigned to the 2nu2 overtone. A fit of the nu6 band to the A-reduced Watson Hamiltonian yielded eight effective constants including nu0 = 3014.0503(1), A' = 1.62868(4), B' = 0.354165(5), and C' = 0.308852(3) cm-1. Similarly, the weaker 2nu2 band was fit to seven parameters including nu0 = 3026.2297(2), and A' = 1.63396(6), B' = 0.35367(1), and C' = 0.31183(1) cm-1. Numbers in parentheses are two standard deviations in units of the last digit. Anomalous values of the A rotational constant and the DeltaK centrifugal distortion constant are attributed to an a-axis Coriolis interaction between the 2nu2 and nu6 bands. The relative intensity of the 2nu2 band is used to estimate the stretch-bend anharmonic interaction with nu1. Copyright 1999 Academic Press.
报道了喷射冷却的CH2F2的ν6（不对称C-H伸缩振动）和2ν2（H-C-H对称弯曲泛音）带的高分辨率红外吸收光谱，亚多普勒分辨率约为0.002 cm-1。在3002 - 3036 cm-1范围内观测到600多个跃迁，其中268个被指定为ν6基频跃迁，184个被指定为2ν2泛音跃迁。将ν6带拟合到A简化的沃森哈密顿量得到八个有效常数，包括ν0 = 3014.0503(1)、A' = 1.62868(4)、B' = 0.354165(5)和C' = 0.308852(3) cm-1。同样，较弱的2ν2带拟合到七个参数，包括ν0 = 3026.2297(2)、A' = 1.63396(6)、B' = 0.35367(1)和C' = 0.31183(1) cm-1。括号中的数字是最后一位数字的两个标准偏差。A转动常数和ΔK离心畸变常数的异常值归因于2ν2和ν6带之间的a轴科里奥利相互作用。2ν2带的相对强度用于估计与ν1的伸缩-弯曲非谐相互作用。版权所有1999年学术出版社。
