Determining the Gibbs Energies of Hydrogen-Bonding Interactions of Proton-Accepting Solutes in Aqueous Solutions from Thermodynamic Data at 298 K with Regard to the Hydrophobic Effect

Sedov, Igor A.; Solomonov, Boris N.

doi:10.1021/je1011532

Cited by 12 publications

(7 citation statements)

References 22 publications

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“…The values of Δ G HB as a function of temperature are plotted in Figure . In Table our results are compared at 298.15 K with the values proposed by Sedov et al, − which are based on a correlation involving experimental quantities such as Gibbs free energy of solvation. The values show that this model has a fair agreement with the experimentally obtained Gibbs energy of hydrogen bonding.…”

Section: Gibbs Energy Of Hydrogen Bondingmentioning

confidence: 89%

A New PC-SAFT Model for Pure Water, Water–Hydrocarbons, and Water–Oxygenates Systems and Subsequent Modeling of VLE, VLLE, and LLE

et al. 2016

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Accurate analytic thermodynamic modeling of water and its mixtures with hydrocarbon and oxygenates is difficult even with new and advanced equations of state such as the perturbed-chain statistical associating fluid theory (PC-SAFT). Several attempts have been made in the past by various authors to solve this issue. However, current models generally fail to describe simultaneously and accurately pure water properties (especially its liquid density) and liquid–liquid equilibria for mixtures involving water, hydrocarbons, and oxygenates. In the current work, this problem is dealt with by modification in the fundamental structure of the model. It was established that the temperature dependent diameter d(T) does not behave in the same way for water as it inscribed in the original model. Hence, a modification was proposed for d(T) of water in order to correctly represent the phase behavior of pure water and its mixtures with hydrocarbons and oxygenates. The deviations in saturated liquid densities and vapor pressure for pure water were reduced to 0.6% and 2.2%, respectively, in a large temperature range. The results for liquid–liquid equilibrium (LLE), vapor–liquid equilibrium (VLE) and vapor–liquid–liquid equilibrium (VLLE) of various water–hydrocarbons and oxygenates show the accuracy of this new model and its predictive capability when coupled with a group contribution approach. For certain oxygenated mixtures such as water with aldehydes, ketones, ethers, and esters a new contribution to the Helmholtz energy, known as the “non-additive hard sphere” contribution, was used. The cross-interaction parameters obtained for mixtures were validated qualitatively by calculating octanol/water partition coefficients and the Gibbs free energy of hydrogen bonding (ΔG HB). Results are found in good agreement with experimental data.

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Section: Gibbs Energy Of Hydrogen Bondingmentioning

confidence: 89%

A New PC-SAFT Model for Pure Water, Water–Hydrocarbons, and Water–Oxygenates Systems and Subsequent Modeling of VLE, VLLE, and LLE

et al. 2016

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“…We see that once K eq , z AB , and z C are specified, all of the derivative activities of the reaction products are uniquely determined. However, the constraint of incompressibility further renders only one of the two fundamental activities independent, so we make the simple choice of the arbitrary constant, z C and define

K_{e q} = normale normalx normalp true(- \frac{Δ G_{normalH - normalb normalo normaln normald normals}}{normalR normalT} true)

, where

Δ G_{normalH - normalb normalo normaln normald normals} = - 5.0 normalk normalJ / normalm normalo normall

approximately from the general ether oxygen and hydrogen from carboxylic acid, so that the binding of C beads toward B is preferential.…”

Section: Methodsmentioning

confidence: 99%

Improved self‐assembly of poly(dimethylsiloxane‐b‐ethylene oxide) using a hydrogen‐bonding additive

Luo

Kim

Montarnal

et al. 2016

J. Polym. Sci. Part A: Polym. Chem.

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Block copolymers with increased Flory-Huggins interaction parameters (v) play an essential role in the production of sub-10 nm nanopatterns in the growing field of directed self-assembly for next generation lithographic applications. A library of PDMS-b-PEO block copolymers were synthesized by click chemistry and their interaction parameters (v) determined. The highest v measured in our samples was 0.21 at 150 8C, which resulted in phase-separated domains with periods as small as 7.9 nm, suggesting that PDMS-b-PEO is a prime candidate for sub-10 nm nanopatterning. To suppress PEO crystallization, PDMS-b-PEO was blended with (L)-tartaric acid (LTA) which allows for tuning of the self-assembled morphologies. Additionally, it was observed that the order-disorder transition temperature (T ODT ) of PDMS-b-PEO increased dramatically as the amount of LTA in the blend increased, allowing for further control over self-assembly. To understand the mechanism of this phenomenon, we present a novel field-based supramolecular model, which describes the formation of copolymeradditive complexes by reversible hydrogen bonding. The mean-field phase separation behavior of the model was calculated using the random phase approximation (RPA). The RPA analysis reproduces behavior consistent with an increase of the effective v in the PDMS-b-(PEO/LTA suprablock).

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“…The kinetic traces of reactions with known amounts of added water (5, 10, and 15 equiv) to anhydrous 2-PPA were best fit to the mechanism described by eqs and 2 using Reactlab multiwavelength global analysis, yielding rate constants k 1 = 6 ± 2 M –1 s –1 and k 2 = 0.83 ± 0.05 M –1 s –1 and K eq = 24 ± 5 M –1 . This mechanistic model (with A reasonably proposed to be a hydrogen-bonded PPA/H 2 O adduct) was then used to fit all data for [wet 2-PPA] 0 (5−200 mM; Figure S9), using an assumed [H 2 O] 0 , which resulted in a similarly fitted K eq (6.7 ± 0.3 M –1 ; Figure S16 and Table S3). Attempts to fit the kinetic data using a nucleophilic attack model without substrate activation (eq S1) were unsuccessful.…”

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confidence: 99%

Revisiting the Synthesis and Nucleophilic Reactivity of an Anionic Copper Superoxide Complex

et al. 2019

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The addition of 1 equiv of KO 2 and Kryptofix222 (Krypt) in CH 3 CN to a solution of LCu(CH 3 CN) [L = N,N′-bis(2,6-diisopropylphenyl)-2,6-pyridinecarboxamide] in tetrahydrofuran at −80 °C yielded [K(Krypt)][LCuO 2 ], the enhanced stability of which enabled reexamination of its reactivity with 2-phenylpropionaldehyde (2-PPA). Mechanistic and product analysis studies revealed that [K(Krypt)][LCuO 2 ] reacts with wet 2-PPA to form [LCuOH] − , which then, deprotonates 2-PPA to yield the copper(II) enolate complex [LCu(OC=C(Me)Ph)] − . Acetophenone was observed upon workup of this complex or mixtures of KO 2 and 2-PPA alone, in support of an alternative mechanism(s) to the one proposed previously involving an initial nucleophilic attack at the carbonyl group of 2-PPA.Elucidating the structure and function of putative monocopper−oxygen intermediates is imperative for understanding many oxygenase enzymes 1 and abiological oxidation catalysts. 2 Common to all mechanistic schemes for the activation of O 2 in such systems is the initial formation of a 1:1 Cu/O 2 species, typically formulated as a copper(II) superoxide comprising a [CuO 2 ] + core. 3 Significant appreciation of the structures and spectroscopic properties of [CuO 2 ] + cores has been achieved through studies of synthetic complexes. 4 Some features of the reactivity of such complexes also have been examined, but many questions concerning detailed mechanisms, supporting ligand effects, 5 and other aspects remain unanswered because of their thermal instability, challenges associated with isolating the complexes in pure form, and complicated side reactions.

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Determining the Gibbs Energies of Hydrogen-Bonding Interactions of Proton-Accepting Solutes in Aqueous Solutions from Thermodynamic Data at 298 K with Regard to the Hydrophobic Effect

Cited by 12 publications

References 22 publications

A New PC-SAFT Model for Pure Water, Water–Hydrocarbons, and Water–Oxygenates Systems and Subsequent Modeling of VLE, VLLE, and LLE

A New PC-SAFT Model for Pure Water, Water–Hydrocarbons, and Water–Oxygenates Systems and Subsequent Modeling of VLE, VLLE, and LLE

Improved self‐assembly of poly(dimethylsiloxane‐b‐ethylene oxide) using a hydrogen‐bonding additive

Revisiting the Synthesis and Nucleophilic Reactivity of an Anionic Copper Superoxide Complex

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