Hasinoff B B, Chishti S B
Biochemistry. 1982 Aug 31;21(18):4275-8. doi: 10.1021/bi00261a015.
The kinetics of the reaction of CO with myoglobin have been studied by laser flash photolysis in glycerol-water as a function of solvent viscosity and temperature. At high viscosities and low temperatures the second-order rate constant is inversely proportional to the viscosity raised to approximately the 0.5 power. This result parallels the behavior of the oxygen diffusion coefficient in glycerol-water. It is concluded that the reaction kinetics in high viscosity glycerol-water are largely diffusion controlled. At higher temperatures, though, the effect of simultaneous chemical activation control of the reaction is observed. The diffusion-controlled rate constant is 1.4 X 10(-3) of that predicted from simple von Smoluchowski theory based on diffusion coefficients and molecular radii. Several models with steric requirements for diffusion-controlled reactions are examined.
通过激光闪光光解技术，在甘油 - 水体系中研究了一氧化碳与肌红蛋白反应的动力学，该反应是溶剂粘度和温度的函数。在高粘度和低温下，二级反应速率常数与粘度的约0.5次方成反比。这一结果与甘油 - 水体系中氧扩散系数的行为相似。可以得出结论，在高粘度甘油 - 水体系中的反应动力学主要受扩散控制。然而，在较高温度下，可以观察到反应同时受化学活化控制的影响。扩散控制的速率常数是基于扩散系数和分子半径的简单冯·斯莫卢霍夫斯基理论预测值的1.4×10⁻³ 。研究了几种对扩散控制反应有空间位阻要求的模型。
