Gallmetzer Hans Georg, Sangiogo Gil Eduarda, González Leticia
Doctoral School in Chemistry (DoSChem), University of Vienna, Währinger Str. 42, 1090 Vienna, Austria.
Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria.
J Phys Chem B. 2025 Jan 9;129(1):385-397. doi: 10.1021/acs.jpcb.4c06924. Epub 2024 Dec 21.
The photoisomerization dynamics of azo-escitalopram, a synthetic photoswitchable inhibitor of the human serotonin transporter, is investigated in both gas-phase and water. We use the trajectory surface hopping method─as implemented in SHARC─interfaced with the floating occupation molecular orbital-configuration interaction semiempirical method to calculate on-the-fly energies, forces, and couplings. The inclusion of explicit water molecules is enabled using an electrostatic quantum mechanics/molecular mechanics framework. We find that the photoisomerization quantum yield of trans-azo-escitalopram is wavelength- and environment-dependent, with → π* excitation yielding higher quantum yields than π → π* excitation. Additionally, we observe the formation of two distinct cis-isomers in the photoisomerization from the most thermodynamically stable trans-isomer, with formation rates influenced by both the excitation window and the surrounding environment. We predict longer excited-state lifetimes than those reported for azobenzene, suggesting that the escitalopram moiety contributes to prolonged lifetimes and slower torsional motions.
对人血清素转运蛋白的合成光开关抑制剂偶氮艾司西酞普兰在气相和水中的光异构化动力学进行了研究。我们使用在SHARC中实现的轨迹表面跳跃方法，并与浮动占据分子轨道 - 组态相互作用半经验方法相结合，以实时计算能量、力和耦合。使用静电量子力学/分子力学框架能够包含明确的水分子。我们发现反式偶氮艾司西酞普兰的光异构化量子产率取决于波长和环境，与π→π激发相比，→π激发产生更高的量子产率。此外，我们观察到在从最热力学稳定的反式异构体进行光异构化时形成了两种不同的顺式异构体，其形成速率受激发窗口和周围环境的影响。我们预测激发态寿命比报道的偶氮苯更长，这表明艾司西酞普兰部分有助于延长寿命和减缓扭转运动。
