Foreseeing the future of green Technology. Molecular dynamic investigation on passive membrane penetration by the products of the CO2 and 1,3-butadiene reaction

The use of carbon dioxide as a reagent in organic synthesis is a useful strategy for attenuating its rising atmospheric levels and satisfying modern climate change goals. One of the most promising reactions for this reason is the telomerisation of CO2 with 1,3-butadiene, which yields the highly functionalized delta-lactone, 3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one (EVL). Aside from EVL, several byproducts can form during this reaction such as acids, lactones and the covalent butadiene dimer (BDDI); however, their properties and possible harmful effects on biological systems are still unknown. In this work, the membrane structure altering properties and the passive transport of these compounds across the membrane is investigated by molecular dynamics (MD) simulations and well-tempered metadynamics (WT-MD). In addition, the pure liquid densities and hydration free energies of these compounds are determined by using MD simulations and ab initio calculations. It was found that in high concentrations, aside from the BDDI, all investigated compounds can penetrate the membranes, out of which the two acids prefer the membrane interior to the bulk phase. All the other compounds have formed micelles in the membrane exterior. Even though BDDI does not penetrate the bilayer, all of the investigated compounds disturb the membrane structure. The concentration-dependence of the passive penetration was calculated in the case of four compounds, and it can generally be said that at higher concentrations the permeation barriers are lower. Density-based (D2E) free energy calculations based on classical MD simulations were found to reproduce the results of the WT-MD simulations within the limits of chemical accuracy. (C) 2022 The Authors. Published by Elsevier B.V.