吴茱萸次碱结构和振动光谱的密度泛函理论研究

采用密度泛函理论B3LYP和B3PW91方法对吴茱萸次碱的几何结构进行了全优化,得到吴茱萸次碱的平衡几何结构参数,结果表明,吴茱萸次碱是一个平面结构的分子.在相同水平上计算了吴茱萸次碱的红外和拉曼振动光谱,依据计算结果,对吴茱萸次碱分子的振动基频进行了理论指认和归属.在红外光谱中,所有振动模式均具有红外活性,最强的振动频率为1 729 cm-1,摩尔吸光系数为1 461 L/(mol·cm),归属于C21O22的伸缩振动.在拉曼光谱中,吴茱萸次碱的所有振动模式也表现出了拉曼活性,最强的吸收峰频率为1 630 cm-1,吸收强度为170.8km/mol,由C21O22键的伸缩振动吸收所贡献.该研究结果可为进一步探讨吴茱萸次碱的结构和生物活性关系提供理论参考.

A study of the structure and vibrational spectra of rutaecarpine with the density-functional theory

In the present study,the geometry of rutaecarpine was fully optimized by the density-functional theory at the B3 LYP/6-311 + + G**and B3 PW91/6-311 + + G**level. The calculated results showed that rutaecarpine was a planar structure of molecule. The infrared and Raman spectra of rutaecarpine were calculated at the same level. The assignment of fundamental vibrations for rutaecarpine molecules was obtained according to the calculated results. In the infrared spectrum,the vibration frequency of the strongest absorption peak was 1 729 cm-1,and the molar absorption coefficient was 1 461 L/(mol·cm),which was mainly contributed by the stretching vibration mode of the C21 O22 double bond. In the Raman spectra,all vibration modes presented Raman activities,the frequency of the strongest absorption peak was 1630 cm-1,and the absorption intensity was 170. 8 km/mol-1,which was mainly contributed by the stretching vibration mode of the C21 O22 double bond. The results can provide theoretical insights into the relationship between the structure and bioactivity of rutaecarpine.