Journal ArticleDOI
Ab Initio Calculations of Absolute pKa Values in Aqueous Solution I. Carboxylic Acids
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In this article, a thermodynamic cycle was proposed to calculate absolute pKa values for a Bronsted acid in aqueous solution, where the solvent (water) was represented by a dielectric using the polarizable continuum model (PCM).Abstract:
A thermodynamical cycle is proposed to calculate absolute pKa values for a Bronsted acid in aqueous solution. The solvent (water) was represented by a dielectric using the polarizable continuum model (PCM), and the absolute pKa values of some aliphatic carboxylic acids were computed. The results indicate that the proposed methodology seems to be capable of predicting reasonably good absolute pKa values, although in some cases appreciable deviations are observed, which can be related to neglecting the molecular motion contributions (ΔGMm) to the solvation energy (ΔGsolv).read more
Citations
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Accurate pKa Calculations for Carboxylic Acids Using Complete Basis Set and Gaussian-n Models Combined with CPCM Continuum Solvation Methods
TL;DR: Complete Basis Set and Gaussian-n methods were combined with CPCM continuum solvation methods to calculate pK(a) values for six carboxylic acids, resulting in values accurate to less than half a pK (a) unit.
Journal ArticleDOI
Quantitative Correlation of Physical and Chemical Properties with Chemical Structure: Utility for Prediction
Alan R. Katritzky,Minati Kuanar,Svetoslav Slavov,C. Dennis Hall,Mati Karelson,Iiris Kahn,Dimitar A. Dobchev +6 more
Journal ArticleDOI
Single-Ion Solvation Free Energies and the Normal Hydrogen Electrode Potential in Methanol, Acetonitrile, and Dimethyl Sulfoxide
TL;DR: In this paper, the relative solvation free energies of ions and ion−solvent clusters in methanol, acetonitrile, and dimethyl sulfoxide (DMSO) have been determined using a combination of experimental and theoretical gas-phase free energies, solution-phase reduction potentials and acid dissociation constants.
Journal ArticleDOI
A universal approach for continuum solvent pK a calculations: are we there yet?
Junming Ho,Michelle L. Coote +1 more
TL;DR: The results indicate that the direct method is unsuitable for general pKa calculations, although moderately accurate results (MAD <3 units) are possible for certain classes of acids, depending on the choice of solvent model.
Journal ArticleDOI
Adding Explicit Solvent Molecules to Continuum Solvent Calculations for the Calculation of Aqueous Acid Dissociation Constants
TL;DR: The calculated pK(a) value suggests that for some anions, particularly those concentrating charge on a single exposed heteroatom, augmenting implicit solvent calculations with a single explicit water molecule is required, and adequate, to account for strong short-range hydrogen bonding interactions between the anion and the solvent.
References
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Electrostatic interaction of a solute with a continuum. A direct utilizaion of AB initio molecular potentials for the prevision of solvent effects
TL;DR: In this article, a method is presented which utilizes the calculation of the molecular electrostatic potential or the electric field at a discrete number of preselected points to evaluate the environmental effects of a solvent on the properties of a molecular system.
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Harmonic Vibrational Frequencies: An Evaluation of Hartree−Fock, Møller−Plesset, Quadratic Configuration Interaction, Density Functional Theory, and Semiempirical Scale Factors
Anthony P. Scott,Leo Radom +1 more
TL;DR: In this paper, scaling factors for fundamental vibrational frequencies, low-frequency vibrations, zero-point vibrational energies (ZPVE), and thermal contributions to enthalpy and entropy from harmonic frequencies determined at 19 levels of theory have been derived through a least-squares approach.
Journal ArticleDOI
A new integral equation formalism for the polarizable continuum model: Theoretical background and applications to isotropic and anisotropic dielectrics
TL;DR: In this paper, a new integral equation formulation of the polarizable continuum model (PCM) is presented, which allows one to treat in a single approach dielectrics of different nature: standard isotropic liquids, intrinsically anisotropic medialike liquid crystals and solid matrices, or ionic solutions.
Journal ArticleDOI
Molecular Interactions in Solution: An Overview of Methods Based on Continuous Distributions of the Solvent
Jacopo Tomasi,Maurizio Persico +1 more
Book
Advanced Organic Chemistry: Reactions, Mechanisms, and Structure
TL;DR: Localized Chemical bonding Delocalized Chemical Bonding Bonding Weaker than Covalent Stereochemistry Carbocations, Carbanions, Free Radicals, Carbenes and Nitrenes Mechanisms and Methods of Determining them Photochemistry Acids and Bases Effects of Structure on Reactivity Aliphatic Nucleophilic Substitution Aromatic Electrophilic Substitutes Aliphatically Electrophilic Substitution Free-Radical Substitution Addition to Carbon-Carbon Multiple Bonds Adding to Carbon Hetero Multiple Bonds Eliminations Rearrangements Ox