Dipartimento di Chimica Fisica, Università Ca' Foscari Venezia, Calle Larga S. Marta 2137, I-30123 Venezia, Italy.
J Chem Phys. 2010 Jul 28;133(4):044310. doi: 10.1063/1.3460922.
The gas-phase infrared spectra of bromodifluoromethane, CHBrF(2), have been examined at medium resolution in the range of 200-9500 cm(-1). The assignment of the absorptions in terms of fundamental, overtone, combination, and hot bands, assisted by quantum chemical calculations is consistent all over the region investigated. Accurate values of integrated band intensities have also been determined for the first time in the range of 500-6000 cm(-1). Structural and molecular spectroscopic properties have been calculated at high level of theory. The coupled cluster CCSD(T) method in conjunction with a hierarchical series of correlation consistent basis sets has been employed and extrapolation to complete basis set has been considered for the equilibrium geometry. Vibrational analysis based on the second order perturbation theory has been carried out with the ab initio anharmonic force constants calculated using the second order Moller-Plesset perturbation as well as coupled cluster [CCSD(T)] theory. A good agreement between the computed and the experimental data also including the integrated infrared band intensities has been obtained.
溴二氟甲烷(CHBrF2)的气相红外光谱在 200-9500cm-1 的中分辨率范围内进行了检查。通过量子化学计算的辅助,对基本振动、倍频、组合和热带的吸收进行了分配,这在整个研究区域都是一致的。在 500-6000cm-1 的范围内,首次确定了积分带强度的准确值。在理论的高水平上计算了结构和分子光谱特性。采用耦合簇 CCSD(T)方法结合层次相关一致基组系列,并考虑了完全基组的外推,以确定平衡几何形状。基于二阶微扰理论的振动分析,使用通过二阶 Møller-Plesset 微扰和耦合簇 [CCSD(T)] 理论计算的从头算非谐力常数进行了计算。计算结果与实验数据(包括积分红外带强度)吻合良好。