物理化学学报 >> 1998, Vol. 14 >> Issue (07): 615-619.doi: 10.3866/PKU.WHXB19980708

研究论文 上一篇    下一篇

光声量热法测定辅酶B12光解的焓变和体积变化

李刚, 罗来斌, 陈慧兰, 傅少伟, 张淑仪   

  1. 南京大学化学系,配位化学国家重点实验室,南京 210093|南京大学声学研究所,近代声学国家重点实验室,南京 210093
  • 收稿日期:1997-10-27 修回日期:1998-02-23 发布日期:1998-07-15
  • 通讯作者: 陈慧兰

Determination of Enthalpy and Volume Changes in Photolysis of Coenzyme B12 Using Photoacoustic Calorimetry

Li Gang, Luo Lai-Bin, Chen Hui-Lan, Fu Shao-Wei, Zhang Shu-Yi   

  1. State Key Laboratory of Coordination Chemistry,Nanjing University,Nanjing 210093|Laboratory of Modern Acoustics and Institute of Acoustics,Nanjing University,Nanjing 210093
  • Received:1997-10-27 Revised:1998-02-23 Published:1998-07-15
  • Contact: Chen Hui-Lan;

摘要:

用时间分辨的光声量热法研究了辅酶B12的光解反应,首次测定了脉冲激光诱导辅酶B12光解反应的焓变和反应体积变化,其值分别为131±12kJ•mol-1和6±1mL•mol-1,推测该反应体积变化可能与Co-C健断裂引起的柔性咕啉环构象变化有关.

关键词: 辅酶B12, 光声量热, 焓变, 体积变化

Abstract:

The photolysis of coenzyme B12 (5'-deoxyadenosylcobalamin, AdoCbl) at 355nm in aqueous solution is investigated by Photoacoustic Calorimetry (PAC). Both enthalpy and reaction volume change for this photoinitiated reaction have been determined to be 131±12 kJ.mol-1 and 61 mLmol-1 , respectively. It can be suggested that the reaction volume change is related tothe conformational change of corrin ring which accompanies the homolytic cleavage of the cobalt-carbon(Co-C) bond.

Key words: Coenzyme B12, Photoacoustic calorimetry, Enthalpy, Volume change