Solvation thermodynamics of ions: free energies in water, ammonia, and fused LiCl–KCl eutectic

1969 ◽  
Vol 47 (8) ◽  
pp. 1401-1410 ◽  
Author(s):  
James A. Plambeck
Keyword(s):  
Thermodynamic Data ◽  
Liquid Ammonia ◽  
Statistical Tests ◽  
Free Energies ◽  
Solvation Thermodynamics ◽  
Solvation Of Ions

Conventional free energies of solvation of ions are calculated from appropriate thermodynamic data in water, liquid ammonia, and fused LiCl–KCl eutectic. These are fitted to a modified Born-charging equation, whose origin and significance are discussed. Statistical tests are applied to certain aspects of the form of the equation. Parameters obtained from the equation can be used to calculate the free energies of solvation of single ions.

scholarly journals Affine-response model of molecular solvation of ions: Accurate predictions of asymmetric charging free energies

2012 ◽  
Vol 137 (12) ◽  
pp. 124101 ◽  
Author(s):  
Jaydeep P. Bardhan ◽  
Pavel Jungwirth ◽  
Lee Makowski
Keyword(s):  
Response Model ◽  
Free Energies ◽  
Solvation Of Ions

Thermodynamics of metal-ligand bond formation. II. Zinc, cadmium, and mercury(II) complexes of o,o-dialkyldithiophosphates

1971 ◽  
Vol 24 (10) ◽  
pp. 2077 ◽  
Author(s):  
DR Dakternieks ◽  
DP Graddon
Keyword(s):  
Metal Atom ◽  
Alkyl Group ◽  
Thermodynamic Data ◽  
Benzene Solution ◽  
Bond Formation ◽  
Free Energies ◽  
Zinc Cadmium ◽  
Metal Ligand ◽  
Ligand Bond

The reactions of 0,O-dialkyldithiophosphato complexes, {(R0)2PSz}zM (M = Zn, Cd, Hg), to form dimers and 1 : 1 and 1 : 2 adducts with pyridine have been studied calorimetrically in benzene solution a t 30�C. While variation of the alkyl group has little effect, variation of the metal atom causes marked changes in both free energies and enthalpies of reaction. Average values of thermodynamic data obtained are as follows (AGOao3 and AH0300 in k J mol-l, AS0a03 in J K-l mol-l) :

Improved identification of evaporation rates and thermodynamic data by Monte-Carlo method

2020 ◽  
Author(s):  
Anna Shcherbacheva ◽  
Tapio Helin ◽  
Heikki Haario ◽  
Hanna Vehkamäki
Keyword(s):  
Monte Carlo ◽  
Sulfuric Acid ◽  
Thermodynamic Data ◽  
Particle Formation ◽  
Forward Problem ◽  
Dependent Data ◽  
New Particle Formation ◽  
Free Energies ◽  
Wide Range ◽  
Cluster Composition

<p>Atmospheric new particle formation and successive cluster growth to aerosol particles is an important field of research, in particular due to climate change phenomena and air quality monitoring. Recent developments in the instrumentation have enabled quantification of ionic clusters formed in the gas phase at the first steps of particle formation under atmospherically relevant mixing ratios. However, electrically neutral clusters are prevalent in atmospheric conditions, and thus must be charged prior to detection by mass spectrometer. The charging process can lead to cluster fragmentation and thus alter the measured cluster composition.</p><p>Even when the cluster composition can be measured directly, this does not quantify individual cluster-level properties, such as cluster collision and evaporation rates. Collision rates contain relatively small uncertainties in comparison to evaporation rates, which are computed using detailed balance assumption together with the free energies of cluster formation, which can in turn be obtained from Quantum chemistry (QC) methods. As evaporation rates depend exponentially on the free energies, even difference by several kcal/mol between different QC methods results in orders of magnitude differences in evaporation rates.</p><p>On the other hand, in spite of the error margins associated with the evaporation rates, simulations of cluster populations, which incorporate collision and evaporation rates as free parameters (such as Becker-Döring models), have demonstrated good qualitative agreement with experimental data. The Becker-Döring equations are a system of Ordinary Differential equations (ODE) which account for cluster birth and death processes, as well as external sinks and sources. In mathematical terms, prediction of cluster concentrations using kinetic simulations with given cluster collision and evaporation rates is called a forward problem.</p><p>In the present study, we focus on the so-called inverse problem of how to derive the evaporation rates and thermodynamic data (enthalpy change and entropy change due to addition or removal of molecule) from available measurements, rather than on the forward problem. We do this by Delayed Rejection Adaptive Monte Carlo (DRAM) method for the system containing sulfuric acid and ammonia with the maximal size of the pentamer. Initially, we tested the method on the synthetic data created from Atmospheric Cluster Dynamic Code (ACDC) simulations. By so doing, we identify the combination of fitted parameters and concentration measurements, which leads to the best identification of the evaporation rates. Additionally, we demonstrated that the temperature-dependent data yield better estimates of the evaporation rates as compared to the time-dependent data measured before the system has reached the steady state.</p><p>Next, we apply the technique to improve the identification of the evaporation rates from CLOUD chamber data, which contain cluster concentrations and new particle formation rates measured at different temperatures and a wide range of atmospherically relevant sulfuric acid and ammonia concentrations. As a result, we were able to obtain the probability density functions (PDFs) that show small standard variations for thermodynamic data. By using the values from the PDFs as parameters in the ACDC model, we achieve a fair agreement with the measured NPFs and cluster concentrations for a wide range of temperatures.</p>

scholarly journals Long-ranged contributions to solvation free energies from theory and short-ranged models

2016 ◽  
Vol 113 (11) ◽  
pp. 2819-2826 ◽  
Author(s):  
Richard C. Remsing ◽  
Shule Liu ◽  
John D. Weeks
Keyword(s):  
Electrostatic Interactions ◽  
Large Contribution ◽  
Thermodynamic Quantities ◽  
Coulomb Interactions ◽  
Free Energies ◽  
Lattice Sum ◽  
Solvation Thermodynamics ◽  
Simulation Cell ◽  
Solvation Free Energies ◽  
Ionic Solutes

Long-standing problems associated with long-ranged electrostatic interactions have plagued theory and simulation alike. Traditional lattice sum (Ewald-like) treatments of Coulomb interactions add significant overhead to computer simulations and can produce artifacts from spurious interactions between simulation cell images. These subtle issues become particularly apparent when estimating thermodynamic quantities, such as free energies of solvation in charged and polar systems, to which long-ranged Coulomb interactions typically make a large contribution. In this paper, we develop a framework for determining very accurate solvation free energies of systems with long-ranged interactions from models that interact with purely short-ranged potentials. Our approach is generally applicable and can be combined with existing computational and theoretical techniques for estimating solvation thermodynamics. We demonstrate the utility of our approach by examining the hydration thermodynamics of hydrophobic and ionic solutes and the solvation of a large, highly charged colloid that exhibits overcharging, a complex nonlinear electrostatic phenomenon whereby counterions from the solvent effectively overscreen and locally invert the integrated charge of the solvated object.

Solvation of ions. XXII. Solvation of cations by hard N,N-dimethylformamide and soft N,N-dimethylthioformamide

1974 ◽  
Vol 27 (5) ◽  
pp. 933 ◽  
Author(s):  
R Alexander ◽  
DA Owensby ◽  
AJ Parker ◽  
WE Waghorne
Keyword(s):  
Electrochemical Cell ◽  
Linear Free Energy Relationship ◽  
Free Energies ◽  
Univalent Cations ◽  
Liquid Junction Potential ◽  
Liquid Junction ◽  
Linear Free Energy ◽  
Solvation Of Ions ◽  
Solvation Mechanisms ◽  
Junction Potential

The free energies of transfer of some univalent cations from N,N-dimethylformamide to N,N- dimethylthioformamide at 25� are Li+, 64.0; Na+, 50.2; K+, 37.2; Cs+, 23.4; TI+, -4.2 and Ag+, - 87.0 kJ g-ion-1. The values are based on the assumption of negligible liquid junction potential in an electrochemical cell. Certain ones of these values can be interpreted in terms of general interactions of hard and soft cations with hard and soft basic solvents. A linear free energy relationship, ΔGtr(M+) = mΔGtr(K+), is roughly obeyed by many cations for transfer to a variety of solvents. Deviations from this relationship, for example ΔGtr(Ag2+) to acetonitrile, ΔGtr (Ph4As+) to water and ΔGtr (Ag+) to N,N-dimethylthioformamide, allow specific solvation mechanisms to be detected.

scholarly journals Heats, Free Energies, and Entropies in Liquid Ammonia.

1952 ◽  
Vol 50 (3) ◽  
pp. 351-361 ◽  
Author(s):  
William A. Jolly
Keyword(s):  
Liquid Ammonia ◽  
Free Energies
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