Department of Physics, Annamalai University, Annamalai Nagar, Tamil Nadu 608002, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2011 Nov;82(1):260-9. doi: 10.1016/j.saa.2011.07.046. Epub 2011 Jul 23.
FT-Raman and FT-IR spectra were recorded for 3-pentyl-2,6-diphenylpiperidin-4-one (PDPO) sample in solid state. The equilibrium geometries, harmonic vibrational frequencies, infrared and the Raman scattering intensities were computed using DFT/6-31G(d,p) level. Results obtained at this level of theory were used for a detailed interpretation of the infrared and Raman spectra, based on the total energy distribution (TED) of the normal modes. Molecular parameters such as bond lengths, bond angles and dihedral angles were calculated and compared with X-ray diffraction data. This comparison was good agreement. The intra-molecular charge transfer was calculated by means of natural bond orbital analysis (NBO). Hyperconjugative interaction energy was more during the π-π* transition. Energy gap of the molecule was found using HOMO and LUMO calculation, hence the less band gap, which seems to be more stable. Atomic charges of the carbon, nitrogen and oxygen were calculated using same level of calculation.
FT-Raman 和 FT-IR 光谱记录了 3-戊基-2,6-二苯基哌啶-4-酮（PDPO）在固态下的光谱。使用 DFT/6-31G(d,p)水平计算了平衡几何形状、谐波振动频率、红外和拉曼散射强度。基于正则模式的总能量分布（TED），根据该理论水平获得的结果对红外和拉曼光谱进行了详细解释。计算了键长、键角和二面角等分子参数，并与 X 射线衍射数据进行了比较。这种比较是很好的一致。通过自然键轨道分析（NBO）计算了分子内电荷转移。在π-π*跃迁过程中，超共轭相互作用能更大。通过 HOMO 和 LUMO 计算得到了分子的能隙，因此能带隙较小，分子似乎更稳定。使用相同的计算水平计算了碳、氮和氧的原子电荷。
