3,5-二甲氧基苯甲醇振动光谱的研究

实验测量了3,5-二甲氧基苯甲醇(L₁OH)分子的拉曼和红外光谱，运用密度泛函理论(DFT)采用B3LYP混合泛函和6-311G(d, p)基函数组，计算了该分子的平衡构型和振动频率。结果表明：理论计算出的振动频率值和实验观测值吻合得较好。同时采用简正振动分析方法得到了各振动频率的势能分布(PED)，从而对L₁OH分子的振动频率归属做出了全面指认。已有文献中还未见有对L₁OH分子振动光谱研究的报道。

Study on the Vibrational Spectra of 3,5-Dimethoxybenzyl Alcohol

3,5-dimethoxybenzyl alcohol (L₁OH) is a kind of important pharmaceutical intermediate and it is also the starting material of a family of dendrimer LnOH (integer n means the layers of “branch”). A number of articles reported the structure and properties of the L₁OH. However, its molecular vibrational spectra have not been reported up to date. Study of vibrational spectra on L₁OH at the molecular level can provide new information, which is significant for the in-depth study of related molecules of drug and the dendrimer. Recent studies indicated a morphology effect on the light-harvesting functions of dendritic macromolecules. In the present report, the Raman and FTIR spectra of 3,5-dimethoxybenzyl alcohol were measured experimentally. And the density functional theory (DFT) method (B3LYP/6-311G(d,p)) were used to calculate the equilibrium geometry and vibration frequencies of L₁OH. The results showed that the calculated frequencies agree well with the experimental ones. Potential energy distribution of each frequency was worked out by normal mode analysis. Thereafter the authors got a detail assignment of the vibrational frequencies for L₁OH for the first time. Also, the results showed that the DFT is really a useful method in the study of molecular vibrational spectra.