Institute for Lasers, Life, and Biophotonics, VU University Amsterdam, De Boelelaan 1081, NL 1081HV Amsterdam, The Netherlands.
J Chem Phys. 2011 Jul 28;135(4):044307. doi: 10.1063/1.3609112.
Rotationally resolved spectra of the B(2)Π - X(2)Π 0(0)(0) electronic origin bands and 11(1)(1) μ(2)Σ-μ(2)Σ vibronic hot band transitions of both C(6)H and C(6)D have been recorded in direct absorption by cavity ring-down spectroscopy through a supersonically expanding planar plasma. For both origin and hot bands accurate spectroscopic parameters are derived from a precise rotational analysis. The origin band measurements extend earlier work and the 11(1)(1) μ(2)Σ-μ(2)Σ vibronic hot bands are discussed here for the first time. The Renner-Teller effect for the lowest bending mode ν(11) is analyzed, yielding the Renner parameters ε(11), vibrational frequencies ω(11), and the true spin-orbit coupling constants A(SO) for both (2)Π electronic states. From the Renner-Teller analysis and spectral intensity measurements as a function of plasma jet temperature, the excitation energy of the lowest-lying 11(1) μ(2)Σ vibronic state of C(6)H is determined to be (11.0 ± 0.8) cm(-1).
已通过腔衰荡光谱法在超音速扩展平面等离子体中直接吸收记录了 C(6)H 和 C(6)D 的 B(2)Π - X(2)Π 0(0)(0)电子基态带和 11(1)(1) μ(2)Σ-μ(2)Σ 振动态热带跃迁的旋转分辨光谱。对于基态带和热带，都从精确的旋转分析中得出了准确的光谱参数。基态带的测量扩展了早期的工作，这里首次讨论了 11(1)(1) μ(2)Σ-μ(2)Σ 振动态热带。分析了最低弯曲模式 ν(11)的 Renner-Teller 效应，得到了两个 (2)Π 电子态的 Renner 参数 ε(11)、振动频率 ω(11)和真实的自旋轨道耦合常数 A(SO)。从 Renner-Teller 分析和作为等离子体射流温度函数的光谱强度测量，确定 C(6)H 的最低 11(1) μ(2)Σ 振动态的激发能为 (11.0 ± 0.8) cm(-1)。
