金溶胶中邻羟基苯甲酸吸附行为的密度泛函理论与实验研究

发布时间：2018-04-14 02:01

本文选题：邻羟基苯甲酸 + 密度泛函理论　；参考：《光谱学与光谱分析》2017年10期

【摘要】：研究了邻羟基苯甲酸(OHBA)的常规拉曼散射(NRS)光谱以及其吸附在Au纳米颗粒上的表面增强拉曼散射(SERS)光谱。以氯金酸为原料,柠檬酸三钠为还原剂,用化学还原法制备了球形的金纳米粒子溶胶,采用激光显微拉曼光谱仪(激发波长为785nm),测定OHBA分子的NRS光谱及其吸附在Au纳米颗粒上的SERS光谱。同时,应用密度泛函理论(DFT),在B3LYP/6-31+G**(C,H,O)/LANL2DZ(Au)水平上,对OHBA分子进行了结构优化,在此基础上计算了OHBA分子的NRS光谱以及其吸附在Au纳米颗粒上两种不同吸附构型下的SERS光谱,并和实验值进行比较。结果表明,OHBA分子通过羧基吸附构型的计算值比通过羟基吸附构型的计算值与实验值符合的更好。最后,利用GaussView可视化软件对其振动模式进行了全面归属。通过对邻羟基苯甲酸分子拉曼谱峰的详细指认能够得出:Au溶胶中的邻羟基苯甲酸分子,是通过羧基倾斜地吸附在Au纳米颗粒表面的。可视化软件直观形象地展示出了该分子的结构特征和分子基团振动情况,对其振动峰位的归属提供了重要依据。本文工作对推进邻羟基苯甲酸在生物医药等领域进一步的应用具有重要作用。
[Abstract]:The conventional Raman scattering spectroscopy (NRS) of OHBA and its surface enhanced Raman scattering (SERS) spectra adsorbed on au nanoparticles have been studied.The spherical gold nanoparticles sol was prepared by chemical reduction with chlorgold acid as raw material and sodium citrate as reducing agent.The NRS spectra of OHBA molecules and their SERS spectra adsorbed on au nanoparticles were measured by laser microRaman spectrometer (excitation wavelength 785 nm).At the same time, the density functional theory (DFT) is used to optimize the structure of OHBA molecules at the B3LYP/6-31 OHBA / LANL2DZU level. On this basis, the NRS spectra of OHBA molecules and their SERS spectra under two different adsorption configurations on au nanoparticles are calculated.The results were compared with the experimental values.The results show that the calculated values of OHBA molecules adsorbed by carboxyl groups are better than those calculated by hydroxyl groups.Finally, the vibration mode is assigned by GaussView visualization software.By identifying the Raman peaks of o-hydroxybenzoic acid molecules in detail, it can be concluded that the O-hydroxybenzoic acid molecules in the O _ (OH) au sol are adsorbed on the surface of au nanoparticles by carboxyl groups.The visual software shows the structural characteristics of the molecule and the vibration of the molecular group, which provides an important basis for the attribution of the vibrational peak position of the molecule.This work plays an important role in promoting the further application of o-hydroxybenzoic acid in biomedicine and other fields.
【作者单位】：长江大学物理与光电工程学院;中南大学物理与电子学院;四川大学原子与分子物理研究所;
【基金】：国家自然科学基金项目(11447172,41403083) 湖北省教育厅基金项目(Q20151307)资助
【分类号】：O647.31

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