Department of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland.
J Phys Chem A. 2011 Sep 1;115(34):9365-9. doi: 10.1021/jp110564q. Epub 2011 Apr 14.
The excitation of the v(3) = 1 (σ(g)(+) C-C stretch) and the v(7) = 2 (π(g)(2) C≡C-C bend) modes in the A(2)Π(u) electronic state of diacetylene cations results in Renner-Teller (R-T) and Fermi interactions. The 3(0)(1) and 7(0)(2) vibronic bands in the A(2)Π(u)-X(2)Π(g) transition of HC(4)H(+) have been measured with rotational resolution using cavity ringdown spectroscopy in a supersonic slit jet discharge. The analysis yields T(00) = 20520.828(4) cm(-1), B' = 0.14047(2) cm(-1), and A' = -17.95(1) cm(-1) for the v(3) = 1 and T(00) = 20573.659(4) cm(-1), B' = 0.14018(3) cm(-1), and A' = -11.55(1) cm(-1) for the v(7) = 2 level in the A(2)Π(u) electronic state. A vibronic analysis has been carried out taking into consideration the R-T, spin-orbit, and Fermi resonance interactions between the ν(3) and ν(7) modes. The levels are fitted to the eigenvalues of an appropriate Hamiltonian matrix. This yields the vibrational frequencies ω(3)′ = 811.8 cm(-1) and ω(7)′ = 403.2 cm(-1), Renner parameter ε(7)′ = 0.065, Fermi coefficients W(1)′ = 10.3 cm(-1) and W(2)′ = 5.1 cm(-1), and spin-orbit interaction constant A(SO)′ = -31.1 cm(-1). A corresponding R-T analysis has been carried out for the X(2)Π(g) ground state of HC(4)H(+) using data available in the literature [Callomon, J. H. Can. J. Phys. 1956, 34, 1046]. This gives ω(3)" = 956.2 cm(-1), ω(7)" = 435.4 cm(-1), ε(7)" = 0.028, W(1)" = 7.2 cm(-1), W(2)" = 10.9 cm(-1), and A(SO)" = -33.3 cm(-1).
乙炔阳离子的 A(2)Π(u) 电子态中 v(3) = 1(σ(g)(+) C-C 伸缩)和 v(7) = 2(π(g)(2) C≡C-C 弯曲)模式的激发导致 Renner-Teller(R-T)和费米相互作用。使用腔衰减光谱法在超音速狭缝射流放电中，以旋转分辨率测量了 HC(4)H(+)的 A(2)Π(u)-X(2)Π(g)跃迁中的 3(0)(1)和 7(0)(2) 带。分析得出，对于 v(3) = 1，T(00) = 20520.828(4)cm(-1)，B' = 0.14047(2)cm(-1)，A' = -17.95(1)cm(-1)；对于 v(7) = 2，T(00) = 20573.659(4)cm(-1)，B' = 0.14018(3)cm(-1)，A' = -11.55(1)cm(-1)。在 A(2)Π(u)电子态中进行了振动态分析，考虑了 ν(3)和 ν(7)模式之间的 R-T、自旋轨道和费米共振相互作用。能级被拟合到适当的哈密顿矩阵的本征值。这给出了振动频率 ω(3)' = 811.8 cm(-1)和 ω(7)' = 403.2 cm(-1)，Renner 参数 ε(7)' = 0.065，费米系数 W(1)' = 10.3 cm(-1)和 W(2)' = 5.1 cm(-1)，以及自旋轨道相互作用常数 A(SO)' = -31.1 cm(-1)。使用文献中提供的数据[Callomon，J.H. Can. J. Phys. 1956，34，1046]，对 HC(4)H(+)的 X(2)Π(g)基态进行了相应的 R-T 分析。这给出了 ω(3)" = 956.2 cm(-1)，ω(7)" = 435.4 cm(-1)，ε(7)" = 0.028，W(1)" = 7.2 cm(-1)，W(2)" = 10.9 cm(-1)，和 A(SO)" = -33.3 cm(-1)。
