對位乙炔基苯胺之第一電子激發態暨離子態振動光譜

Abstract

應用高解析度共振雙光子游離與質量解析臨界游離光譜術來記錄對位乙炔基苯胺的S1第一電子激發態與離子基態光譜，D0離子基態光譜是利用第一電子激發態的 00, 121, and 11分子振動態為中間能階記錄的。藉此，我們精準地量測第一電子躍遷能和游離能分別為32656 ± 2 cm-1，和 61270 ± 5 cm-1。為了標定光譜並且提供合理解釋數據我們也進行量子化學及密度泛函數理論計算，以所測得的對位乙炔基苯胺光譜和及其他苯胺衍生物的實驗數據作比較，以及計算結果顯示大部分較強的光譜譜峰都是苯環的平面振動引起的，此外乙炔基和胺取代基皆會影響分子的躍遷能、游離能以及振動模式與頻率。

We applied the resonant two-photon ionization and mass-analyzed threshold ionization spectroscopic techniques to record the vibronic and cation spectra of p-ethynylaniline. The cation spectra were obtained by ionizing via the 00, 121, and 11 levels of the electronically excited S1 state. The S1 ← S0 electronic excitation and the adiabatic ionization energies were found to be 32 656 ± 2 cm-1 and 61 270 ± 5 cm-1, respectively. We have also performed the quantum chemical and density functional theory calculations to assign spectral bands and to provide reasonable interpretion for our experimental finds. The results show that most of the observed strong spectral bands result from the in-plane ring deformation. In addition, the ethynyl and amino substituents can affect the electronic excitation and the adiabatic ionization energies and molecular vibrations.