Journal Article10.1021/JP012533F
Accurate Prediction of Acidity Constants in Aqueous Solution via Density Functional Theory and Self-Consistent Reaction Field Methods
270
TL;DR: In this article, the acidity constant (pKa) of organic compounds is computed via ab initio quantum chemistry and continuum solvation methods. But the intrinsic accuracy of these approaches is quite impressive (errors on the order of a few kcal/mol), it is not quite good enough to achieve the target accuracy that we have set for pKa prediction of 0.5 pKa units.
read more
Abstract: We have developed a protocol for computing the acidity constant (pKa) of organic compounds via ab initio quantum chemistry and continuum solvation methods. Density functional (DFT) calculations employing large basis sets are used to determine the gas-phase deprotonation energies. Solvation effects are treated via a self-consistent reaction field (SCRF) formalism involving accurate numerical solution of the Poisson−Boltzmann equation. Dielectric radii are parametrized for each functional group of interest to optimize solvation free energy calculations for neutral and charged species. While the intrinsic accuracy of these approaches is quite impressive (errors on the order of a few kcal/mol), it is not quite good enough to achieve the target accuracy that we have set for pKa prediction of 0.5 pKa units. Consequently, two further empirical parameters, scaling and additive factors, are determined for every functional group of interest by linear fitting directly to pKa data for a training set. With this additi...
read more
Chat with Paper
AI Agents for this Paper
Find similar papers on Google Scholar, PubMed and Arxiv
Write a critical review of this paper
Analyze citations of this paper to find unaddressed research gaps
Citations
Theoretical Calculation of pKa Using the Cluster−Continuum Model
TL;DR: In this article, the pKa's of 17 species from −10 to 50 were calculated using the ab initio MP2/6-311+G(2df,2p) level of theory and inclusion of solvent effects by the cluster−continuum model, a hybrid approach that combines gas-phase clustering by explicit solvent molecules and solvation of the cluster by the dielectric continuum.
Theoretical Exploration of 2,2’-Bipyridines as Electro-Active Compounds in Flow Batteries
Mariano Sánchez-Castellanos,Martha M. Flores-Leonar,Zaahel Mata-Pinzón,Humberto G. Laguna,Karl García-Ruiz,Sergio S. Rozenel,Víctor M. Ugalde-Saldívar,Rafael Moreno-Esparza,Joep J. H. Pijpers,Carlos Amador-Bedolla +9 more
TL;DR: Researchers theoretically explored 2,2'-bipyridines as electro-active compounds in flow batteries using DFT calculations, analyzing molecular energies and vibrational frequencies, and optimizing geometries with PCM and SMD models in water solvent.
A reliable and efficient first principles-based method for predicting pK(a) values. 1. Methodology.
TL;DR: This article fits a small training set of 34 experimentally well-characterized molecules to determine the best level of theory among those tested to establish a standard linear regression fit using only calculated energies of deprotonation and experimental pK(a) values.
Absolute pKa Values and Solvation Structure of Amino Acids from Density Functional Based Molecular Dynamics Simulation
Martina Mangold,Leslie Rolland,Francesca Costanzo,Michiel Sprik,Marialore Sulpizi,Jochen Blumberger +5 more
TL;DR: The solvation structures of the protonated and deprotonated amino acids are analyzed in terms of radial distribution functions, which can serve as reference data for future force field developments.
Predicting the pKa of Small Molecules
TL;DR: This work surveys the literature on computational methods to predict the pKa of small molecules, and addresses data availability, molecular representations, prediction methods, as well as pKa-specific issues such as mono- and multiprotic compounds.
References
Density‐functional thermochemistry. III. The role of exact exchange
TL;DR: In this article, a semi-empirical exchange correlation functional with local spin density, gradient, and exact exchange terms was proposed. But this functional performed significantly better than previous functionals with gradient corrections only, and fits experimental atomization energies with an impressively small average absolute deviation of 2.4 kcal/mol.
Gaussian basis sets for use in correlated molecular calculations. I. The atoms boron through neon and hydrogen
TL;DR: In this paper, a detailed study of correlation effects in the oxygen atom was conducted, and it was shown that primitive basis sets of primitive Gaussian functions effectively and efficiently describe correlation effects.
30.2K
Density-functional thermochemistry. I. The effect of the exchange-only gradient correction
TL;DR: In this paper, an extensive survey of density functional atomization energies on the 55 molecules of the Gaussian-1 thermochemical data base of Pople and co−workers is presented.
New Model for Calculation of Solvation Free Energies: Correction of Self-Consistent Reaction Field Continuum Dielectric Theory for Short-Range Hydrogen-Bonding Effects
Bryan Marten,Kyungsun Kim,Christian Cortis,‖,⊥ and,Richard A. Friesner,Robert B. Murphy# and,Murco N. Ringnalda,Barry Honig +6 more
TL;DR: In this article, the authors present self-consistent reaction field (SCRF) calculations, utilizing correlated ab initio quantum mechanics, of aqueous solvation free energies for a large data base of molecular solutes.
976