基于密度泛函理论的三聚氰胺结构及振动光谱研究

利用密度泛函(DFT)算法,对三聚氰胺分子的空间结构进行了优化;然后分别用MP2/6-31G和DFT/DGTIVP两种算法计算了它的拉曼光谱与红外光谱,给出光谱强度图;对比了两种算法的拉曼光谱图和其实验光谱图,结果显示了很好的一致性;给出了三聚氰胺分子中的各原子间键长,键角等空间结构参数;并对三聚氰胺分子在550～3 800cm-1区间的振动谱做了指认。上述工作将有助于食品中三聚氰胺含量测量技术的研究。

Optimization of melamine structure using density functional theory and vibrational spectra studies

Melamine was used in foodstuff and feed industry as a feed additive occasionally. In the present work, melamine geometry structure was optimized by density functional theory (DFT) method. Raman and infrared spectra were calculated based on MP2/6-31G sets and DFT/DGTIVP sets, and then two theoretical Raman spectra were carefully compared with other experimental spectra. Good agreements were obtained between the theoretical and experimental results. Melamine structure parameters were given also in the paper including bond lengths and bond angles. Vibrational modes were assigned to all bands in the 550-4 000 cm(-1) range. This work will benefit the measurement research of the content of melamine in foods.