Zagorec-Marks Wyatt, Smith James E T, Foreman Madison M, Sharma Sandeep, Weber J Mathias
JILA, University of Colorado, Boulder, CO 80309, USA and Department of Chemistry, University of Colorado, Boulder, CO 80309, USA.
Department of Chemistry, University of Colorado, Boulder, CO 80309, USA.
Phys Chem Chem Phys. 2020 Sep 23;22(36):20295-20302. doi: 10.1039/d0cp03614e.
We present electronic spectra containing the Qx and Qy absorption bands of singly and doubly deprotonated protoporphyrin IX, prepared as mass selected ions in vacuo at cryogenic temperatures, revealing vibronic structure in both bands. We assign the vibronic progression of the Qx band using a Frank-Condon-Herzberg-Teller simulation based on time-dependent density functional theory, comparing the observed bands with those calculated for porphine. A comparison of the electronic spectra of the two charge states allows investigation of the electronic Stark effect with an electric field strength beyond the capabilities of typical laboratory setups. We analyze the differences in the electronic spectra of the two charge states using n-electron valence perturbation theory (NEVPT2) and simulated charge distributions.
我们展示了单质子化和双质子化原卟啉IX的Qx和Qy吸收带的电子光谱，这些光谱是在低温下以真空质量选择离子的形式制备的，揭示了两个吸收带中的振动电子结构。我们基于含时密度泛函理论，通过Frank-Condon-Herzberg-Teller模拟来确定Qx带的振动电子跃迁，并将观测到的谱带与卟吩计算得到的谱带进行比较。两种电荷态电子光谱的比较使得我们能够在电场强度超过典型实验室装置能力的情况下研究电子斯塔克效应。我们使用n电子价态微扰理论（NEVPT2）和模拟电荷分布来分析两种电荷态电子光谱的差异。
