Using the Simplified Transition State Theory (STST), the activation entropies and A factors of the title reactions have been first calculated according to the con-certed mechanism.

• 用简化的过渡态理论(STST)；按协同机制；对几种桥环化合物裂解反应的活化熵、A因子作了首次估算.；并和实验结果作比较讨论了反应可能进行的机理:解释了反应的A因子递变现象