物理化学学报 >> 2012, Vol. 28 >> Issue (05): 1085-1093.doi: 10.3866/PKU.WHXB201203024

理论与计算化学 上一篇    下一篇

间位取代卟啉及其锌卟啉的电子吸收光谱

曹振锋, 陈启斌, 卢运祥, 刘洪来, 胡英   

  1. 华东理工大学, 结构可控先进功能材料及其制备教育部重点实验室, 上海 200237
  • 收稿日期:2011-12-12 修回日期:2012-02-29 发布日期:2012-04-26
  • 通讯作者: 陈启斌 E-mail:qibinchen@ecust.edu.cn
  • 基金资助:

    国家自然科学基金(20806025, 21103047)和中国高校111计划(B08021)资助项目

Electronic Absorption Spectra of Meso-Substituted Porphyrins and Their Zinc Derivatives

CAO Zhen-Feng, CHEN Qi-Bin, LU Yun-Xiang, LIU Hong-Lai, HU Ying   

  1. Key Laboratory for Advanced Material and Development of Chemistry, East China University of Science and Technology, Shanghai 200237, P. R. China
  • Received:2011-12-12 Revised:2012-02-29 Published:2012-04-26
  • Contact: CHEN Qi-Bin E-mail:qibinchen@ecust.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20806025, 21103047) and National 111 Project of China's Higher Education (B08021).

摘要: 取代的卟啉类衍生物在气敏传感器方面具有广泛的应用前景. 本文采用了密度泛函理论(DFT)和含时密度泛函理论(TD-DFT)研究了四种不同取代基的卟啉衍生物(meso 位四硝基苯基/四氨基苯基卟啉(NO2PP,NH2PP)及其相应的锌金属卟啉衍生物(NO2ZnPP, NH2ZnPP))的紫外和近紫外光谱特征. 利用两种不同的交换相关泛函(广义梯度近似泛函(PBE)和杂化密度泛函(B3LYP))优化了上述四种物质的结构, 并应用TD-DFT计算了相应的电子激发能量和振动强度. 结果表明, 取代卟啉的吸收光谱与大量的电子跃迁有关; 与B3LYP泛函预测的光谱相比, PBE泛函所得B带以及Q带的波长位置与实验值更为接近. 另外, 计算所得硝基取代基卟啉的B带相对于氨基取代基卟啉的B带发生了红移, 这与实验现象也保持一致. 由于卟啉衍生物的三重激发态在电子转移中有很重要的应用, 因此在PBE/6-31G(d)水平上计算了四种物质的最低三重激发态能量, 分别为1.426、1.469、1.608和1.581 eV.

关键词: 含时密度泛函理论, 电子吸收光谱, 电子跃迁, 红移, 三重激发态

Abstract: Meso-substituted porphyrin derivatives have demonstrated great potential as sensing materials for toxic gas detection. In this paper, density functional theory (DFT) and its time-dependent DFT approach (TD-DFT) were employed to investigate the ultraviolet-visible (UV-Vis) or the near-ultravioletvisible (near-UV-Vis) absorption spectra of Meso-tetra (o-nitrophenyl/o-aminophenyl) porphyrins (NO2PP, NH2PP) and their corresponding zinc derivatives, NO2ZnPP and NH2ZnPP. The geometry optimizations for these four molecules were obtained from two different exchange-correlation functionals, the generalizedgradient approximation functional PBE (Perdew-Burke-Ernzerhof) and the hybrid functional B3LYP (Becke, three-parameter, Lee-Yang-Parr). The excitation energies and oscillation strengths were obtained from TD-DFT calculations. Calculations show that the optical absorptions are associated with numerous electronic transitions. In addition, the PBE-predicted wavelengths of the B and Q bands are more consistent with experiment than those predicted by B3LYP. The B band of NO2-substituted derivative exhibits a bathochromic shift different from that of NH2-containing material, also consistent with experimental results. In addition, at the PBE/6-31G(d) level of theory, the calculated energies of the lowest triplet excited states of NO2PP, NH2PP, NO2ZnPP, and NH2ZnPP are 1.426, 1.469, 1.608, and 1.581 eV, respectively.

Key words: TD-DFT, Electronic absorption spectrum, Electronic transition, Bathochromic shift, Triplet state

MSC2000: 

  • O641