P.G. & Research Department of Physics, A A Government Arts College, Musiri 621 211, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2012 Nov;97:1023-32. doi: 10.1016/j.saa.2012.07.111. Epub 2012 Aug 4.
The FT-IR and FT-Raman spectra of 2,6-Bis(chloromethyl)pyridine (BCMP) have been recorded in the regions 4000-400 cm(-1) and 3500-100 cm(-1), respectively. The total energy calculations of BCMP were tried for the possible rotational isomers. The molecular structure, geometry optimization, vibrational frequencies were obtained by the HF and density functional theory (DFT/B3LYP) method with 6-311+G(d,p) basis set for the most stable rotational isomer "R3". The harmonic frequencies were calculated and the scaled values were compared with experimental FT-IR and FT-Raman spectra. The observed and the calculated frequencies are found to be in good agreement. The calculated HOMO and LUMO energies show that charge transfer occurs in the molecule. The stability of the molecule was analyzed using NBO analysis. The thermodynamic functions (heat capacity, entropy, vibrational partition function and Gibbs energy) were obtained for the range of temperature 100 K-700 K.
2,6-二（氯甲基）吡啶（BCMP）的 FT-IR 和 FT-Raman 光谱分别在 4000-400 cm(-1) 和 3500-100 cm(-1)范围内记录。尝试对 BCMP 的所有可能的旋转异构体进行了总能量计算。通过 HF 和密度泛函理论（DFT/B3LYP）方法，在 6-311+G(d,p)基组上对最稳定的旋转异构体“R3”进行了分子结构、几何优化和振动频率的计算。计算了谐振动频率，并将缩放值与实验 FT-IR 和 FT-Raman 光谱进行了比较。观察到的和计算出的频率吻合得很好。计算出的 HOMO 和 LUMO 能量表明电荷在分子中转移。通过 NBO 分析研究了分子的稳定性。在 100 K-700 K 的温度范围内，获得了热力学函数（热容、熵、振动配分函数和吉布斯能量）。
