Prediction of Propagation Rate Coefficients in Free Radical Solution Polymerization Based on Accurate Quantum Chemical Methods: Vinylic and Related Monomers, Including Acrylates and Acrylic Acid

Abstract

The simulation of polymerization processes is of enormous industrial importance. A quantum chemical method based on density functional theory is developed and validated that provides almost chemical accuracy for radical polymerization propagation of industrially relevant monomers in aqueous solution. The necessary corrections are computed using the CC level of theory. Solvent effects are accounted for by the solvation model COSMO‐RS. The method is capable of reproducing and rationalizing, for example, monomer concentration effects on the propagation rate for NVP. A comparison is performed with recent PLP experimental data. The method does not rely on error compensation effects or empiric corrections and is suitable for industrially relevant systems.

Brick by brick computation of the gibbs free energy of reaction in solution using quantum chemistry and COSMO‐RS

“…We have benchmarked the accuracy that can be achieved by different level of theory separately for the three parts. The findings for the benchmark systems and the example shown in the previous section are in accordance with recent studies on reaction energies and activation energies . It can be concluded that a well‐chosen combination of DFT and high level WFT for the gas phase and thermodynamic energy contribution with COSMO‐RS calculated free energy of solvations can yield and within an error range of 10 kJ/mol.…”

“…The findings for the benchmark systems and the example shown in the previous section are in accordance with recent studies on reaction energies and activation energies. 81,[84][85][86][87][88][89] It can be concluded that a well-chosen combination of DFT and high level WFT for the gas phase and thermodynamic energy contribution with COSMO-RS calculated free energy of solvations can yield DG soln and within an error range of 10 kJ/mol. An even better prediction quality drawing close to "chemical" accuracy < 5 kJ/mol, can be achieved if no major rearrangements of the molecules geometric and electronic structures occur during the course of the reaction, as in the hydrogenation example presented above.…”

Differences in Reactivity of Epoxides in the Copolymerisation with Carbon Dioxide by Zinc‐Based Catalysts: Propylene Oxide versus Cyclohexene Oxide

“…A solvation treatment was performed using the COSMO-RS method, [52] which means an explicit consideration of electrostatic effects on intermolecular interactions for multinary mixtures. [46] This requires further calculations at the BP86 level with a TZVP [53] basis set, assuming both a gas and an electric conductor environment. As a model solvent, toluene was chosen.…”

“…Computational methods: All calculations at the Becke-Perdew-86 functional [45][46][47][48] (BP86) level of theory were performed with the program package TURBOMOLE [49] by employing the efficient RI-J approximation. [48] This comprises all structure optimizations for which an SV(P) [50] basis set was used in combination with the assumption of an electric conductor (dielectric constant e = 1) according to the solvation model COSMO.…”

Mechanistic Aspects of a Highly Active Dinuclear Zinc Catalyst for the Co‐polymerization of Epoxides and CO2

“…For CO 2 ,t he partial pressure was assumed to be 10 bar.As olvation treatment of the reaction thermodynamics was performed by using the COSMO-RS method, [43] which means an explicit consideration of electrostatic effects on intermolecular interactions and can be highly beneficial for am ore quantitative picture of the kinetics and thermodynamics in the condensed phase. [44] This requires further calculations at the BP86 level with ad ef-TZVP [45] basis set, assuming both ag as and an electric conductor environment. As DFT method for single-point energy calculations, the B3-LYP [40,[46][47][48] functional was chosen in combination with ad ef2-TZVP [49] basis set, which, however,w as corrected by energetic shifts obtained for small molecular models by comparing the B3-LYP results with am ore accurate coupled cluster level(s) of theory (see the Supporting Information).…”