Olefin polymerization catalyzed by Group 4 transition metals is studied here as test case to reveal the entropy effects when bimolecular and unimolecular reactions are computed for processes occurring in solution. Catalytic systems characterized by different ligand frameworks, metal, and growing polymeric chain for which experimental data are available have been selected in order to validate the main approaches to entropy calculation. Applying the “standard” protocol results in a strong disagreement with the experimental results and the methods introducing a direct correction of the translational entropy term based on a single experimental parameter emerge as the most reliable. The general and powerful computational tool achieved in this study can represent a further step towards the “catalyst design” to control and predict the molecular mass of the resulting polymers.

本文以第4组过渡金属催化的烯烃聚合作为测试案例进行研究，以揭示当计算溶液中发生的双分子和单分子反应时的熵效应。选择了以不同的配体骨架，金属和不断增长的聚合物链为特征的催化体系，并为其提供了实验数据，以验证熵计算的主要方法。应用“标准”协议会导致与实验结果存在强烈分歧，引入基于单个实验参数的平移熵项直接校正的方法是最可靠的方法。