物理化学学报 >> 1996, Vol. 12 >> Issue (04): 325-328.doi: 10.3866/PKU.WHXB19960408

研究论文 上一篇    下一篇

桥链冠醚卟啉胆固醇酯的表观质子化常数

胡珍珠,胡宗球,刘法彬,黄素秋   

  1. 湖北师范学院化学系，黄石 435000|襄阳师范专科学校化学系，襄阳 431100|武汉大学化学系，武汉 430072
  • 收稿日期:1995-08-30 修回日期:1995-10-12 发布日期:1996-04-15
  • 通讯作者: 胡珍珠

Overall Protonation Constants of Bridged Crowned Porphyrins and Porphyrin-cholesterol Ester

Hu Zhen-Zhu,Hu Zong-Qiu,Liu Fa-Bin,Huang Su-Qiu   

  1. Department of Chemistry,Hubei Normal University,Huangshi 435000|Department of Chemistry,Xiangyang Teacher's Training School,Xiangyang 441100|Department of Chemistry,Wuhan University,Wuhan 430072
  • Received:1995-08-30 Revised:1995-10-12 Published:1996-04-15
  • Contact: Hu Zhen-Zhu

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摘要：

用光度法测得三种桥链冠醚卟啉和二种卟啉胆固醇酯的质子化常数，并用HMO法进行了量子化学计算，讨论了取代基的电子效应及空间效应对常数的影响．

关键词: 卟啉, 质子化常数, 共轭效应, 空间效应, 电子吸收光谱

Abstract:

 The overall protonation constants of three bridged crowned porphyrins and two cholesterol-porphyrins were determined by spectrometric methods and the quantum chemistry computation with HMO were made by 486 type microcomputer. The influence of electron effect and steric hindrance of substituting group on overall protonation constants was discussed.Experimental data and theoretical discussion showed that simple portonated cation (PH3+ ) has been formed before the formation of double protonated cation (PH42+ ), but simple protonated cation (PH32+) is unstable. Degree of porphyrins protonation depend on electron and steric effect. Protonation constants are increased by the donor groups through conjugate effect, while steric hindrance of substituting group reduces the constants decrease.

Key words: Porphyrin, Apparent protonation constants, Conjugate effect, Steric hindrance, UV-VIS spectra