Zhang Ying-Hui, Li Zhi-Yun, Wu Yang, Zhu Yi-Zhou, Zheng Jian-Yu
Department of Chemistry, Nankai University, Tianjin 300071, People's Republic of China.
Spectrochim Acta A Mol Biomol Spectrosc. 2005 Nov;62(1-3):83-91. doi: 10.1016/j.saa.2004.12.009.
The ground state geometric, electronic structure and Raman spectra of 5,15-diphenylporphine (H(2)DPP) have been studied using B3LYP/6-31G(d) method and compared with that of well-studied free base porphine (H(2)P) and meso-tetraphenylporphine (H(2)TPP). Calculation shows that 5,15-substitution causes remarkable in-plane distortion, whereas the resulting out-of-plane distortion is negligible. The calculated electronic structure of H(2)DPP is consistent with the absorption spectra compared with H(2)P and H(2)TPP. The calculated vibrational frequencies of H(2)DPP scaled with a single factor of 0.971 agree well with experimental data (the rms error is 8.0 cm(-1)). The assignment of experimental Raman bands of H(2)DPP was discussed on the basis of theoretical calculation and the comparison with that of H(2)P and H(2)TPP. The splitting of some vibrational modes involving the motion of C(m) atom, such as nu(1), nu(8), and nu(10), was observed and was attributed to the diversification of the environment around C(m) atoms. As the shift of absorption peaks, the shift of some structure-sensitive Raman bands of H(2)DPP form that of H(2)TPP and H(2)P was attributed to the in-plane nuclear reorganization (IPNR) induced by phenyl-substitution, though the contribution of nonplanarity mechanism could not be excluded completely.
采用B3LYP/6 - 31G(d)方法研究了5,15 - 二苯基卟啉（H₂DPP）的基态几何结构、电子结构和拉曼光谱，并与已深入研究的游离碱卟啉（H₂P）和中位 - 四苯基卟啉（H₂TPP）进行了比较。计算表明，5,15 - 取代导致显著的面内畸变，而由此产生的面外畸变可忽略不计。与H₂P和H₂TPP相比，H₂DPP的计算电子结构与吸收光谱一致。H₂DPP经0.971单一因子缩放后的计算振动频率与实验数据吻合良好（均方根误差为8.0 cm⁻¹）。基于理论计算以及与H₂P和H₂TPP的比较，讨论了H₂DPP实验拉曼谱带的归属。观察到一些涉及C(m)原子运动的振动模式（如ν₁、ν₈和ν₁₀）的分裂，这归因于C(m)原子周围环境的多样化。与吸收峰的位移类似，H₂DPP某些结构敏感拉曼谱带相对于H₂TPP和H₂P的位移归因于苯基取代引起的面内核重排（IPNR），尽管不能完全排除非平面性机制的贡献。
