Zdanovskaia Maria A, Esselman Brian J, Woods R Claude, McMahon Robert J
Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
J Chem Phys. 2019 Jul 14;151(2):024301. doi: 10.1063/1.5100805.
The analysis of phenyl isocyanide (CHNC, μ = 4.0 D) in its ground vibrational state and two lowest-energy excited vibrational states, ν (141 cm) and ν (155 cm), in the 130-370 GHz frequency region has been completed. Over 4500 new rotational transitions have been measured in the ground vibrational state for the most abundant isotopologue, resulting in the determination of the spectroscopic constants for a partial octic Hamiltonian with low error. The Coriolis-coupled ν-ν dyad reported herein, containing over 3500 new transitions for each vibrational state, has been analyzed for the first time. The coupled-state least-squares fit utilizes seven coupling terms (G, G , G , G , G , F, and F ) to address perturbation between the two vibrational states, including resonances and several nominal interstate transitions. This work results in precise determination of the energy separation between the two states, ΔE = 9.682 248(3) cm, and the Coriolis coupling coefficient, |ζ | = 0.858(9). The precise rotational and distortion constants determined in this work provide the foundation for an astronomical search for phenyl isocyanide across the radio band.
对异氰基苯（CHNC，μ = 4.0 D）在其基振动态以及两个最低能量激发振动态（ν = 141 cm⁻¹和ν = 155 cm⁻¹）在130 - 370 GHz频率范围内的分析已经完成。对于最丰富的同位素分子，在基振动态中测量了超过4500条新的转动跃迁，从而确定了具有低误差的部分八次哈密顿量的光谱常数。本文报道的科里奥利耦合的ν - ν二元组，每个振动态包含超过3500条新跃迁，首次得到了分析。耦合态最小二乘法拟合使用七个耦合项（G、G'、G''、G'''、G⁽⁴⁾、F和F'）来处理两个振动态之间的微扰，包括共振和几条名义上的态间跃迁。这项工作精确测定了两个态之间的能量间隔，ΔE = 9.682 248(3) cm⁻¹，以及科里奥利耦合系数，|ζ| = 0.858(9)。在这项工作中确定的精确转动和畸变常数为在射电波段对异氰基苯进行天文搜索奠定了基础。
