QRC: a rapid method for connecting transition structures to reactants in the computational analysis of organic reactivity

Computational Study of the Palladium‐Catalyzed Carbonylative Synthesis of Aromatic Acid Chlorides: The Synergistic Effect of PtBu3 and CO on Reductive Elimination

“…Geometries of minima and transition states were optimized and the stationary points were verified by vibrational analysis. The products and reactants of transition states were verified by intrinsic reaction coordinate (IRC) analysis or quick reaction coordinate (QRC) . Thermal corrections to the enthalpy and free energies were calculated with the optimization method and added to the electronic energy.…”

Exploring the mechanism of the Pd-catalyzed spirocyclization reaction: a combined DFT and experimental study

“…Furthermore, transition states were confirmed by either intrinsic reaction coordinates (IRC) 25 or quick reaction coordinate (QRC) calculations. 26 The latter calculations were performed by small manual displacement (0.05–0.10 Bohr) of the geometry on the vibration of the imaginary frequency followed by regular optimization. Single point energies were calculated on the optimized structures at 298 K and 1 atm at the M06L level of theory, 27 a method in which dispersion effects are included in the parameterization scheme.…”

DFT Study of Nickel‐Catalyzed Low‐Temperature Methanol Synthesis

“…In all cases analytical frequency calculations were performed to verify the structure optimizations and to obtain corrections to zero‐point and Gibbs free energies (final free energies contain vibrational contributions calculated using BS1). All minima contained no imaginary frequencies, and all transition structures contained only one imaginary frequency that exhibited vibrational modes consistent with the anticipated reaction pathway (further verified by QRC and IRC calculations). Single‐point energies for all structures were calculated with the ωB97XD functional with the quadruple‐ζ valence def2‐QZVP basis set and SDD ECP on Ni, and the 6‐311+G(2d,p) basis set on all other atoms (referred to as BS2, again with solvent corrections).…”