Role of Solvents on the Thermodynamics and Kinetics of Forming Frustrated Lewis Pairs
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- 作者：Liem X. Dang ; Gregory K. Schenter ; Tsun-Mei Chang ; Shawn M. Kathmann ; Tom Autrey
- 刊名：The Journal of Physical Chemistry Letters
- 出版年：2012
- 出版时间：November 15, 2012
- 年：2012
- 卷：3
- 期：22
- 页码：3312-3319
- 全文大小：458K
- 年卷期：v.3,no.22(November 15, 2012)
- ISSN：1948-7185
文摘
To enhance our understanding of the role of solvents on the thermodynamics and kinetics of forming frustrated Lewis pairs (FLP), we carried out a systematic simulation study on these systems in dichloromethane and toluene solvents. These molecular systems are of particular interest due to their relevance in the catalytic hydrogenation and hydrogen storage processes. While the computed structural observables for both molecules are very similar, the slow molecular reorientation was consistent with the size of the species. The computed free-energy profiles for the FLP in both solvents show similar gross characteristics but differ in details. We observe two well-defined contact regions and a solvent-separated regions with different well depths and barrier heights to dissociation. The kinetics of solute鈥損air interconversion was studied using transition-state theory, comparing Kramers and Grote鈥揌ynes treatments of the dynamic response of the solvent. These rate results were used to predict solvent effects on dynamical features of contact solute鈥損air association.