密度泛函理论下氯普鲁卡因分子的能级结构和光谱计算

本文基于密度泛函理论，采用B3LYP方法，在6-31G(d,p)基组上对麻醉剂氯普鲁卡因的分子结构进行几何优化，在此基础上以乙醇为溶剂计算分子的前20个激发态，所有计算在Gaussian 09W-D01中进行。利用Multiwfn3.7软件绘制红外光谱图，并对其分子振动进行分析；利用Origin 2018 64Bit软件和Multiwfn3.7软件相结合绘制紫外光谱图，并计算空穴-电子来分析分子的激发态性质；通过计算前线轨道来预测氯普鲁卡因分子的活性位点。结果表明，在所计算得到的激发态中，由基态到第2、3、6、10激发态为局域激发，由基态到第19激发态为电荷转移激发。氯普鲁卡因乙氨基上的N22为亲电反应位点，苯环上的碳原子和脂基上的氧原子为亲核反应位点。本研究对更好的了解氯普鲁卡因分子的反应机理和在医学上的麻醉活性提供理论参考。

Calculation of energy level structure and spectra of chlorprocaine molecules with density functional theory

In this paper, the B3LYP method based on density functional theory was used to optimize the molecular structure of chlorprocaine on 6-31g (d,p) basis set. On this basis, ethanol was used as solvent to calculate the first 20 excited states of the molecule. All the calculations were carried out in Gaussian 09W-D01. Multiwfn3.7 software was used to draw the infrared spectrum and analyze its molecular vibration. Using the combination of Origin 2018 64Bit software and Multiwfn3.7 software to draw the UV spectrum, and calculate the hole-electron to analyze the excited state properties of the molecule. The active site of chlorprocaine was predicted by calculating the frontier orbital. The results show that the excitations from the ground state to the 2nd, 3rd, 6th and 10th excited states are local excitations, and the excitation from the ground state to the 19th excited state is charge transfer excitation. The N22 on the ethyl group of chloroprocaine is the electrophilic reaction site, and the carbon atom on the benzene ring and the oxygen atom on the lipid group are the nucleophilic reaction sites. This study provides theoretical reference for better understanding of the reaction mechanism of chloroprocaine and its anesthetic activity in medicine.