7-羟基香豆素红外光谱的密度泛函理论研究

发布时间：2018-04-14 12:41

本文选题：红外光谱 + 密度泛函理论　；参考：《光谱学与光谱分析》2016年01期

【摘要】：红外光谱是化合物结构鉴定的重要信息来源,对天然有机药物的分子结构及其生物活性研究意义重大。而随着理论计算方法更加合理、计算精度不断提高,理论计算在红外光谱模拟、振动模式归属指认等方面优势更加明显,对红外光谱解析等实验研究具有重要参考价值。本研究利用密度泛函理论(density functional theory,DFT)/B3LYP方法,在6-311G(d,p)基组水平对7-羟基香豆素进行了几何结构优化和红外光谱计算,得到稳定结构及全部振动模式。计算结果显示7-羟基香豆素红外光谱吸收峰主要分布于波数3 700~3 500,3 150~3 000,1 750~1 400,1 400~1 000,1 000~50cm~(-1)几个区域。除波数3 700~3 500,3 150~3 000cm~(-1)范围内振动相对独立,分别归属为O—H伸缩振动和芳环C—H伸缩振动外,其他几个区域均较为复杂,谱峰不同程度由多个振动模式叠加而成。最后,根据振动模式理论及振动图像分析,对所有振动模式进行了详细指认。并通过线性回归方法,利用相关系数值r研究了7-羟基香豆素红外光谱主要吸收峰波数理论计算值和实验数据的相关性。结果表明,计算值和实验值基本吻合,相关系数值等于0.998 5,相关性较好;采用密度泛函理论在该基组水平对7-羟基香豆素红外光谱的理论计算较为可靠。
[Abstract]:Infrared spectroscopy is an important source of information for the identification of compounds, which is of great significance to the study of molecular structure and biological activity of natural organic drugs.As the theoretical calculation method is more reasonable and the calculation precision is improved, the theoretical calculation has more obvious advantages in infrared spectrum simulation, vibration mode identification and so on. It has important reference value for the experimental research such as infrared spectrum analysis and so on.Using density functional theory (DFT) / DFT / B3LYP method, 7-hydroxycoumarin was optimized at 6-311G / DX / B3LYP level. The stable structure and all the vibrational modes were obtained.The calculated results show that the absorption peaks of 7-hydroxycoumarin are mainly distributed in the regions of Yu Bo number 3 700 ~ 3 500 ~ 3 150 ~ (3 000) ~ 1 750 ~ 1 400 ~ 1 400 ~ 1 000 ~ 1 000 ~ (50) cm ~ (-1) ~ (-1).With the exception of the wave number of 3 700 ~ 3 500 ~ 3 150 ~ (3 000) cm ~ (-1), which belong to O-H stretching vibration and aromatic ring C-H stretching vibration respectively, the other regions are more complex, and the spectral peaks are superposed by several vibration modes in different degrees.Finally, according to vibration mode theory and vibration image analysis, all vibration modes are identified in detail.The correlation between the theoretical calculated values of the main absorption peaks of 7-hydroxycoumarin infrared spectrum and the experimental data was studied by means of linear regression and correlation coefficient r.The results show that the calculated value is in good agreement with the experimental value, and the correlation coefficient is equal to 0.998, and the theoretical calculation of 7-hydroxycoumarin infrared spectrum using density functional theory at the base group level is more reliable.
【作者单位】：川北医学院化学教研室;四川师范大学化学与材料科学学院;
【基金】：国家自然科学基金项目(21172025) 四川省教育厅科研项目(14ZB0193) 四川省中医药管理局中医药科学技术研究专项项目(2014K042)资助
【分类号】：O657.33;O629

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