The electrophilic aromatic substitution (SEAr) is a cornerstone reaction discovered by Friedel and Crafts in the 19th century. Despite its industrial importance for ethylbenzene production, the reaction mechanism is still debated. The proposed mechanistic pathway, relying on the formation of arenium ion intermediates, was recently challenged on experimental and theoretical grounds. The formation of the commonly assumed Wheland intermediate may critically depend on the reaction medium and process conditions. Herein, we will theoretically study SEAr intermediates in solvent and zeolite environments. Reactivity will be studied by an ingenious coupling of conceptual reactivity descriptors and construction of free energy profiles by means of advanced molecular dynamics methods. Such techniques allow following chemical transformations in-situ, thus closely mimicking experimental conditions. Complementary qualitative insights into reactivity will be obtained with a conceptual density functional theory approach. The combined approach will yield insights into governing reaction mechanisms and its dependency on the molecular environment and operating conditions. The theoretical work will be performed in close synergy with a prominent experimental partner, who recently spectroscopically identified the Wheland intermediate for benzene ethylation in zeolites. The outcome of the project will provide a general approach to unravel chemical reactivity in complex reaction environments.
|Effective start/end date||1/01/19 → 31/12/22|
Flemish discipline codes
- Quantum chemistry
- quantum chemistry