2-氟-5-溴吡啶分子振动光谱的密度泛涵理论研究

用密度泛函理论方法B3LYP以及6-311++G(2df，2pd)基组对2-氟-5-溴吡啶分子 的平衡几何构型进行了优化并计算了该分子的振动谐力场。使用Pulay的标度方法 对理论力场进行了标度。采用Wilson的GF矩阵方法，根据标度后的理论力场进行了 简正坐标分析，对2-氟-5-溴吡啶分子的振动基频进行了理论研究，得到了势能分 布和红外振动频率。与红外频率的实验值相比较，理论频率的均方差为24 cm~(-1) 。此外，根据振动模式的势能分布对此分子的振动基频进行了理论归属，并对前人 的指认进行了修正和补充。

Density Functional Theory Studies on Vibrational Spectra of 2- Fluoro-5-bromopyridine

The optimized geometries, vibrational force fields and infrared intensities of 2-fluoro-5-bromopyridine molecule were calculated by using density functional theory B3LYP method with 6-311++G(2df,2pd) basis set. The theoretical force field was scaled using the scaled quantum mechanical force field. The root-mean-squares deviation was found to be 24 cm -1 for calculated frequencies. The assignment of the vibrational fundamentals for 2-fluoro-5-bromopyridine molecule was also performed according to the potential energy distributions.