直链小碳簇Cn(n=3～6)微正则解离速率常数的RRKM理论计算(Ⅰ)

摘要

Ab initio calculation has been applied to calculate the dissociated pathways of small carbon clusters. Linear C3, C4, C5 and C6 and their transition states were optimized at MP2/6-31G* level, and their vibration frequencies were also calculated and analyzed. Based on the calculations, the energy barriers of the clusters were computed and their microcanonical decomposition rates of different dissociation pathways were estimated by RRKM theory, and the result shows that the small carbon clusters tend to dissociate to the fragments with closer sizes.%用从头计算法研究小碳簇的解离通道及其动力学. 以MP2/6-31G*精度优化直链C3, C4, C5, C6及其过渡态的结构, 并对它们进行振动分析. 在此基础上计算了各解离通道的能垒, 并根据RRKM理论估算各个通道的微正则解离速率. 计算结果表明, 这些小碳簇的解离主要表现为均裂方式.