Quantum chemical descriptors for linear solvation energy relationships

Lowrey, Alfred H.; Cramer, Christopher J.; Urban, Joseph J.; Famini, George R.

doi:10.1016/0097-8485(94)00058-m

Cited by 42 publications

(23 citation statements)

References 30 publications

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“…See, for example the QSPR (quantitative structure-property relationship) [191], TLSER (theoretical linear solvation energy relationship) [192], GIPF (general interaction properties function) [193] and related methods [194][195][196]. The use of computationally derived parameters in the study of basicity, or related fields, has seen much investigation.…”

Section: Quantum Chemical Descriptors For Basicity Scalesmentioning

confidence: 99%

Lewis Basicity and Affinity Measurement: Definitions and Context

Laurence

Gal

2009

Lewis Basicity and Affinity Scales

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Two definitions of acids and bases are used nowadays, the Brönsted definition and the Lewis definition. This book deals with the quantitative behaviour of Lewis bases. However, since Lewis bases are also Brönsted bases, this chapter begins with a short presentation of the Brönsted definition and of the quantitative behaviour of Brönsted bases [1]. The Lewis definition and the many ways for its quantification will then be studied. This introductory chapter is intended to help in the understanding and use of the tables in Chapters 2-6, which contain quantitative data on Lewis basicity and affinity, and not to discuss the Lewis acid/base concept in depth. This subject has been excellently treated in a book [2] and a review [3] by Jensen, and books and chapters by Mulliken and Person [4], Gur'yanova et al. [5], Drago [6], Finston and Rychtman [7] and Weinhold and Landis [8], to quote just a few.As far as possible, we have followed the IUPAC recommendations for the names and symbols of physical and chemical quantities (http://goldbook.iupac.org/) and have used the international system of units (SI) and the recommended values of the fundamental physical constants (http://physics.nist.gov/cuu/). Units that are not part of the SI have been used in appropriate contexts. These are: litre (1 l = 10 −3 m 3 ),ångström (1Å = 10 −10 m), electronvolt (1 eV ≈ 1.602 18 × 10 −19 J), Debye (1 D ≈ 3.336 × 10 −30 C m) and bar (1 bar = 10 5 Pa).In tabulating thermodynamic and spectroscopic basicity scales, 1 : 1 complexation constants, Gibbs energies, enthalpies, entropies and ultraviolet (UV) and infrared (IR) spectral shifts are therefore given in l mol −1 (identical with dm 3 mol −1 ), kJ mol −1 , J K −1 mol −1 and cm −1 , respectively. Logarithms of equilibrium constants (log K) are to base 10 and without units since the calculated quantity is log (K/1 l mol −1 ).In naming compounds, we have not always followed the nomenclature rules. We have sometimes preferred the common name found in most chemical catalogues. For clarity, the Lewis Basicity and Affinity Scales: Data and Measurement a In the formulae, R is an alkyl group and Ar an aryl group. and the base NH 3 reacts with water acting as an acid:In the gas-phase reaction 1.5, the proton is exchanged between the ammonium ion/ammonia and the pyridinium ion/pyridine pairs:Any compound containing hydrogen can, in principle, be regarded as a Brönsted acid, but in many of them (e.g. most hydrocarbons) the tendency to lose a proton is so small that they do not show acidic behaviour under ordinary conditions. Examples of neutral Brönsted acids are given in Table 1.2.The same kind of practical restriction should be applied to Brönsted bases. Neutral molecules or atoms can attach a proton in the gas phase because of the tremendous acidity of the bare proton: even rare gases may be protonated in the gas phase. For the liquid phase, superacid systems (such as HF/SbCl 5 that are more acidic than 100% sulfuric acid) can also protonate many molecules [10]. For example, the protonated form of me...

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Section: Quantum Chemical Descriptors For Basicity Scalesmentioning

confidence: 99%

Lewis Basicity and Affinity Measurement: Definitions and Context

Laurence

Gal

2009

Lewis Basicity and Affinity Scales

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“…By applying a two-step statistical procedure to the descriptors generated for a set of 153 representative solvents, a clustering into computed on molecular surfaces to generate theoretical descriptors [13] that were found to be highly correlated to Kamlet and Taft solvatochromic parameters. [14] More recently, Katritzky et al built quantitative structure-property relationship (QSPR) models to predict 127 polarity scales based on theoretical descriptors. They carried out principal component analysis (PCA) of 100 solvent scales based on 703 solvents, missing experimental values being approximated, thanks to the QSPR.…”

Section: Introductionmentioning

confidence: 99%

Classification of Organic Solvents Revisited by Using the COSMO‐RS Approach

Durand

Molinier

Kunz

et al. 2011

Chemistry A European J

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A new approach for the classification of solvents is proposed, based solely on the solvent molecular structure and relying on the "COnductor-like Screening MOdel for Real Solvents" (COSMO-RS), in which solvents are considered in their liquid state. This approach provides an a priori classification without requiring the knowledge of any experimental data. The theoretical descriptors of the proposed classification are generated through the analysis of the COSMO-RS σ-potential profiles. By applying a two-step statistical procedure to the descriptors generated for a set of 153 representative solvents, a clustering into 10 classes leads to an optimal classification that is compared to the classical Chastrette's classification. The investigation of nitrocellulose solubility allows a validation of the proposed classification, which can be extended also to solvent mixtures. This new approach for solvent classification, thus, appears as a consistent tool for the design of new solvents and their formulation.

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“…This opens the possibility to make use of theoretical descriptors for correlating solvent effects. Theoretical descriptors can be derived from molecular electronic or structural information, which can be correlated with experimentally determined solvent parameters . Because theoretical descriptors are easy‐to‐generate and do not require experimental data, they allow for the screening and design of solvents in a very large molecular structure space.…”

Section: Introductionmentioning

confidence: 99%

Integrated solvent and process design exemplified for a Diels–Alder reaction

et al. 2014

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A new kind of solvent descriptor obtained from quantum chemical calculations is introduced. Group contributions to each solvent descriptor are regressed for 71 UNIFAC groups. A reaction kinetic model is built by correlating a set of experimentally determined reaction rate constants in various solvents with the corresponding theoretical solvent descriptors. Based on the kinetic model and the developed group contribution method, a computer-aided molecular design problem is formulated and optimal solvents to achieve highest reaction rates are identified. For considering the multiple and complicated effects of solvents on a chemical process, an integrated solvent and process design is performed. Solvent molecular structures and process operations are simultaneously optimized by the formulation and solution of a mixed-integer nonlinear program. The proposed design methodology is exemplified for a selected Diels-Alder reaction.

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Quantum chemical descriptors for linear solvation energy relationships

Cited by 42 publications

References 30 publications

Lewis Basicity and Affinity Measurement: Definitions and Context

Lewis Basicity and Affinity Measurement: Definitions and Context

Classification of Organic Solvents Revisited by Using the COSMO‐RS Approach

Integrated solvent and process design exemplified for a Diels–Alder reaction

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