Borrelli Raffaele, Peluso Andrea
Dipartimento di Chimica, Università di Salerno, I-84084 Fisciano, Salerno, Italy.
J Chem Phys. 2008 Jan 28;128(4):044303. doi: 10.1063/1.2819061.
The long (approximately 20 000 cm(-1)) vibrational progression observed in the electron photodetachment spectrum of c-C(4)F(8)(-) anion is analyzed in terms of the Franck-Condon factors between the ground electronic states of the anionic and neutral species. The observed spectrum is correctly reproduced and its vibronic structure is assigned in detail. The very simple structure of the spectrum, consisting of a sequence of evenly spaced peaks, at 355 cm(-1) each other, is assigned to a series of overlapping progressions associated with vibrational excitations of two totally symmetric modes rather than to a single mode progression, as originally proposed. The underlying continuum observed in the experimental spectrum is traced back to the excitations of a low frequency ring-puckering vibration, which, in the neutral species, exhibits a double minimum potential energy profile.
根据阴离子和中性物种基态之间的弗兰克-康登因子，对在环丁烷四氟化物阴离子（c-C(4)F(8)(-)）的电子光剥离光谱中观察到的长振动进展（约20000 cm(-1)）进行了分析。观测到的光谱得到了正确再现，并对其振转结构进行了详细归属。光谱的结构非常简单，由一系列等间距的峰组成，彼此间隔为355 cm(-1)，这被归属为与两个完全对称模式的振动激发相关的一系列重叠进展，而不是如最初所提出的单一模式进展。实验光谱中观察到的潜在连续谱可追溯到低频环褶皱振动的激发，在中性物种中，该振动呈现双势阱势能分布。
