DFT calculations in solution systems: solvation energy, dispersion energy and entropy

Abstract

DFT calculations on reaction mechanisms in solution have always been the hot topic, especially for the transition-metal-catalyzed reactions. The calculation of solvation energy is adopted by either polarizable continuum model(PCM)...

Iodine(i)-based and iodine(iii)-based halogen bond catalysis on the Friedel–Crafts reaction: a theoretical study

“…All energies presented include the translation entropy correction of the free volume of solute molecules moving along three axes in the cavity was obtained using Fang's THERMO program. 51,52 In these computational studies, the electrostatic potential 2,53 of the initial reactant and halogen bond donor catalysts were calculated on the 0.001 a.u. isosurfaces of the electron density using the WFA program.…”

The treatment of dispersion terms for solution systems

“…23 Herein, one should note that modern quantum programs deal with the E es term in eqn (9) correctly, but the Gaussian program calculates the E SSD term without the factor of . 24 In fact, only half of the solvent–solute dispersion energy E SSD belongs to the solute molecule, as indicated in eqn (9).…”

“…The cavity volume ( V cav ) and molecule volume ( V mol ) can be estimated by the overlapping spheres 46 with our IDSCRF radii 26 and Bader's radii, 47,48 respectively, and the detailed methodology is described in our recent perspective paper. 24…”

“…. 24 In fact, only half of the solvent-solute dispersion energy E SSD belongs to the solute molecule, as indicated in eqn (9). The comparison for 621 solvation energy data sets is shown in Fig.…”

“…The cavity volume (V cav ) and molecule volume (V mol ) can be estimated by the overlapping spheres 46 with our IDSCRF radii 26 and Bader's radii, 47,48 respectively, and the detailed methodology is described in our recent perspective paper. 24 Table 2 lists the estimated activation free-barriers DG est and the calculated values DG cal , the latter of which are based on the TOF-determining transition state (TDTS) and intermediate (TDI) of the energy span model. [49][50][51] It can be observed from Table 2 that B3LYP-D3+IDSCRF/TZP-DKH(-dfg) (column 5, eqn ( 6)) provides quite low activation free-energy barriers for all reactions (except M7).…”