应用量子化学研究雄黄分解产物As2S2的结构与能量  

Structure and energy of realgar decomposition product As2S2 by quantum computational chemistry

作　　者：宋玲玲 韩冬月 姚妮 张谦[1] 关君[1] SONG Ling-ling;HAN Dong-yue;YAO Ni;ZHANG Qian;GUAN Jun(School of Chinese Materia Medica,Beijing University of Chinese Medicine,Beijing 102488)

机构地区：[1]北京中医药大学中药学院,北京102488

出　　处：《中南药学》2020年第3期453-457,共5页Central South Pharmacy

基　　金：国家自然科学基金青年基金项目(No.81403069);2019年北京中医药大学科研发展基金项目(No.2020072120050)。

摘　　要：目的应用量子化学方法进一步验证雄黄(As4S4)分解产物二硫化二砷(As2S2)的存在形式。方法采用量子化学从头算和密度泛函方法,在B3LYP/6-31G*、B3LYP/6-311+G*、B3LYP/6-311+G(3df,2p)、MP2/6-31G*和MP2/6-311+G*水平上计算了5种As2S2异构体的结构参数、振动频率和热力学能量。结果5种As2S2异构体均具有热力学稳定性:最稳定的异构体1具有C2v对称性的蝶形结构;第二稳定的异构体2和第三稳定的异构体3均为平面四元环结构。核独立化学位移(NICS)值表明,异构体2具有芳香性,而异构体3具有反芳香性。结论本研究证明了5种As2S2在热力学上可以稳定存在,可为今后雄黄的研究提供理论依据。Objective To verify the existence of As2S2 obtained by decomposition of realgar(As4S4) by quantum chemistry calculation method. Methods The parameters of structure, the vibrational frequencies and thermodynamic energies of 5 types of As2S2 isomers were investigated with ab initio and density functional theory(DFT) methods at the B3 LYP/6-31 G*, B3 LYP/6-311 + G*, B3 LYP/6-311 + G(3 df, 2 p), MP2/6-31 G* and MP2/6-311 + G* levels of theory. Results The 5 types of As2S2 isomers were thermodynamically stable. The most stable isomer 1 was a butterfly structure with C2v symmetry. The second stable isomer 2 and the third stable isomer 3 were planar four-membered ring structure. Nuclear-independent chemical shift(NICS) values indicated that the second stable isomer 2 was aromatic, while the third stable isomer 3 was antiaromatic. Conclusion The 5 types of As2S2 isomers are stable thermodynamically, and are highly desirable for the future theoretical study of realgar.

关 键 词：AS2S2 AS4S4 异构体 从头算 密度泛函 芳香性 

分 类 号：O641.1[理学—物理化学]