Partial Molar Volumes Research Articles

Application of ERAS-model and PFP theory on excess and deviation properties for binary systems of ionic liquid + amine derivatives

Thermodynamics of mixtures includes ionic liquid 2-hydroxyethylammonium propionate [2-HEAPr] + 1-propanol, 3-amino-1-propanol [AP], 1-amino-2-propanol [MIPA], and monoethanolamine [MEA] were studied. Density ρ, speed of sound u, and refractive index nD of pure and mixtures were measured at T = (298.15, 308.15, 318.15) K. Excess molar volume VmE, excess partial molar volume Vm,iE, excess thermal expansion coefficient αE, isothermal coefficient of excess molar enthalpy (∂Hm∂P)T,x, deviations in isentropic compressibility Δ ks, and refractive index Δ nD were calculated and data correlated with Redlich-Kister polynomial relation. The Prigogine-Flory-Patterson (PFP) and Extended Real Associated Solution (ERAS) models were applied to analyze intramolecular and intermolecular interactions between like and unlike molecules. The accuracy of theoretical models were found to be in agreement with empirical results. Finally, the study confirmed the structures of the ILs using FT-IR and HNMR analysis.

Separation potential of 1,5-pentanediol-based deep eutectic solvent: Infinite dilution activity coefficients and excess thermodynamic data

In the present study, the new data of the infinite dilution activity coefficient for 32 different solutes in {1-ethyl-1-methylpyrrolidinium bromide +1,5-pentanediol}, [[EMPYR] Br + 1,5-PDO] DES, were measured using the gas liquid chromatography (GLC) method with pre-saturation of the helium gas. The list of selected solutes included alkanes, alkenes, alkynes, cycloalkanes, cycloalkenes, aromatics, ketones, alcohols, and water. Because the solvents were volatile at the temperatures used for measurements, pre-saturation was deemed necessary. The measurements were taken at temperatures T = (313.15–343.15) K and atmospheric pressure. Values of partial molar properties, i.e., enthalpy, entropy, and Gibbs free energy, were computed at a reference temperature of Tref = 333.15 K. Moreover, the values of capacity and selectivity relating to [[EMPYR] Br + 1,5-PDO] DES for different sets of binary systems that are normally problematic in the separation through solvent extraction or distillation were also computed. These include cyclohexane/benzene; acetone/methanol; and hexane/benzene. The obtained data in the present work was then compared to the literature data, at similar temperatures. Thus, the thermodynamical data is important for pre-selecting solvents for industrial purposes.

Thermodynamic and physicochemical characteristics of 2-butoxyethanol/2-phenoxyethanol in aqueous maltitol solutions

In this study, interactions occurring among solute and solvent in aqueous solutions containing maltitol and 2-butoxyethanol (2-BE) and 2-phenoxyethanol (2-PhE) as a solute were studied (Viz volumetric, acoustic and spectroscopic study). Density, ρ, and speed of sound,s, of 2-BE and 2-PhE in aqueous solutions of maltitol with concentrations (0.01, 0.02, and 0.03) mol∙kg-1 were measured at various temperatures ranging from 288.15 K to 308.15 K at 0.1 MPa.The data was used to calculate acoustic and thermodynamic parameters, such as the apparent molar volume (Vϕ), apparent molar isentropic compression (Kϕ,s), partial molar volume (Vϕ0) and partial molar isentropic compression at infinite dilution (Kϕ,s0). This analysis helped us understand the solvation behaviour of maltitol, which is a key component in sugar-free products. Additionally, the co-sphere overlap model was used to examine several intermolecular interactions in the ternary systems. We investigated the partial molar expansibilities (Eϕ0) and their first-order derivatives ∂Eϕ0/∂Tp to examine the solute's structure-making and structure-breaking properties. Finally, we also carried out spectroscopic studies for both binary and ternary mixtures. The observed molar properties indicate the presence of significant interactions between the solute and solvent components within the ternary mixture. This is further supported by the positive values of partial molar expansibility. Moreover, the partial molar properties of the mixture strongly imply the occurrence of hydrogen bond formation.

Thermodynamic and molecular simulation analysis of molecular interactions between methyl 2–hydroxyisobutyrate + water or n–alkanol (C1–C2) mixtures

Methyl 2–hydroxyisobutyrate (HBM) is essential as a photoresist thinner in semiconductor fabrication. In this study, we examined the density and viscosity of HBM combined with water or alkanol (C1–C2) at a pressure of 0.1 MPa and temperatures ranging from 288.15 K to 323.15 K. Based on experimental data, we calculated the excess molar volume, as well as apparent, partial, and excess partial molar volumes, and deviations in viscosity. These derived thermodynamic properties were then modeled using the Redlich-Kister (RK) polynomial equation. The VmE values of HBM + water mixtures are more negative compared to HBM + alkanol mixtures because of the stronger H–bonding interactions in HBM–water than in HBM–alkanol. With increasing temperature, the VmEbecome more negative, whereas the Δη values lower with a temperature rise. The values for excess molar volume and deviation in viscosity were analyzed through a graph theoretical method. Additionally, the excess free energy of activation was determined from the viscosity data. FTIR spectral analysis validated the findings related to intermolecular interactions and the graph theoretical method. Lastly, molecular dynamics simulations shed light on the intermolecular interaction energies and their differences in the studied binary systems.

Volumetric and viscometric properties of L-glutamic acid in aqueous L-arabinose and D-xylose solutions between the temperature range of (293.15–313.15) K at atmospheric pressure

To investigate the molecular interaction among nonessential amino acids and carbohydrates in this article we report the density and viscosityresultsof L-glutamic acid in aqueous solutions of L-arabinose and D-xylose over an integral composition regime (2.00 wt%, 2.50 wt% and 3.01 wt%)at atmospheric pressure (101 kPa) and at temperature range of 293.15, 298.15, 303.15, 308.15 and 313.15 K. The experimental density values were used to evaluate apparent molal volume (V∅), partial apparent molal volume (V∅0), limiting apparent molal expansibility (E∅0) and Hepler’s constant (∂2V∅0/∂T2)P. The values of viscosity were used to calculate viscosity coefficients AF (Falkenhagen coefficients) and BJ (Jones-Dole coefficients), temperature derivative of BJ, Gibbs free energy of activation (Δμ10,#,Δμ20,#) and thermodynamic parameters like ΔH20# and ΔS20#. A thorough interpretation of the results obtained from the thermodynamic as well as physicochemical properties reveal a potent ion–solvent interactions in the aqueous solution of Glu andGlubehaves as a structure maker in the presence of L-arabinose/D-xylose.

Physicochemical studies of propylene and hexylene glycols in methanol solutions of hexachlorophene at different temperatures

The current study investigates the molecular interactions of glycol molecules (propylene (PG) and hexylene (HG) glycols) in hexachlorophene solutions at different temperatures and experimental pressure 0.1 MPa by merging acoustic and thermodynamic processes. The density and speed of sound of liquid mixtures are measured using an Anton Paar DSA 5000 M. These experimental values are used to calculate a variety of thermodynamic and acoustic parameters. The apparent molar volume (Vϕ), partial molar volume (Vϕ0), apparent molar isentropic compression (Kϕ,s), and partial molar isentropic compression (Kϕ,s0) are calculated with the help of experimentally determined density and speed of sound, as well as the partial molar expansibility (Eϕ0) is also calculated. The apparent molar parameters show the existence of strong interactions between solute and solvent in the ternary mixture, and it is also supported by the positive partial molar expansibility data, whereas the partial molar parameters indicate the hydrogen bonding formation in the mixture.

Isothermal vapor-liquid equilibrium measurements and PC-SAFT, PR78, and CPA phase behavior modeling of n-tricosane + SC CO2 mixtures

This study reports the isothermal VLE (PTxy) data of n-tricosane (heavy n-alkane, n-C23H48) in supercritical (SC) CO2 at two selected temperatures of (323 and 343) K over the pressure range from (1.66 to 34.88) MPa. The measurements were made using a high-temperature and high-pressure VLE optical cell. The combined expanded uncertainty of the temperature, pressure, and phase concentration measurements at 0.95 confidence level with a coverage factor of k = 2 is estimated to be 0.2 K, 0.22 %, and 3.5 %, respectively. The measured VLE data has been used to estimate the critical parameters (TC, PC, xC) of the binary n-tricosane + CO2 mixture. The derived L-G critical properties data of the binary n-tricosane + CO2 mixture are: TC = 323.15 K, PC = 34.02 MPa, xC=0.060 mole fraction of n-tricosane; and TC = 343.15 K, PC = 40.14 MPa, xC=0.071 mole fraction of n-tricosane. The measured solubility data for the mixture has been used to estimate the physical meaning Krichevskii parameter ∂P∂xTCVC∞=-75.93MPa. Based on the derived Krichevskii parameter the thermodynamic (partial molar volumes, V¯2∞,H¯2∞,C¯P2∞) and structural (cluster size,Nexc∞) properties of the infinite dilution mixture of n-tricosane + CO2 near the critical point (CP) of pure solvent (CO2) have been calculated. The measured vapor – liquid equilibrium data for n-tricosane + CO2 was modeled using three equations of state (PC-SAFT, PR78, and CPA). The best prediction option with PC-SAFT was obtained with kij=0.12, while kij=0 was the best using PR78 and CPA EoS.

Excess properties, spectral analyses, and CO2 capture performance of N-methyldiethanolamine + polyethylene glycol 300 binary system

Density (ρ) and viscosity (η) data of polyethylene glycol 300 (PEG300) + N-methyldiethanolamine (MDEA) binary system at T = (298.15–318.15) K with a step of 5 K were measured at P = 1005 hPa. After that, the experimental ρ and η values were correlated and predicted by several semi-empirical models. Meanwhile, the Jouyban-Acree model presented a better fitting for the density, and the McAllister four-body equation presented a better fitting for the kinematic viscosity. Based on the ρ and η values, excess molar volume (VmE), partial molar volume (V1¯ and V2¯), viscosity deviation (Δη), and excess Gibbs energy of activation of viscous flow (ΔG∗E) of PEG300 (1) + MDEA (2) binary system were systematically calculated and analyzed. These excess properties showed the predominance of intermolecular self-conjugation in PEG300 (1) + MDEA (2) binary system, and it was further demonstrated by various spectral characterizations. Importantly, the PEG300 + MDEA aqueous system was used for 5 CO2 absorption (room temperature)-desorption (371.15 K) cycles at a CO2 flow rate of 200 mL/min, with the average CO2 capture performance of 0.65 mol CO2/mol MDEA of per cycle, demonstrating excellent absorption capability, and remained stable throughout the entire cycle.

Volumetric and viscometric properties of aqueous choline chloride + methyldiethanolamine deep eutectic solvents

Amine-based deep eutectic solvents have the advantages of easy preparation, extremely low vapor pressure, stable biodegradation and high CO2 loading, which has become the most potential CO2 absorbent. In this work, the amine-based functionalized DES of choline chloride + methyldiethanolamine with different molar ratios were successfully prepared, and the densities and viscosities of DES aqueous solutions were measured from 303.15 K to 333.15 K. The effects of DES composition, water content and temperature on the excess molar volume, partial molar volume, apparent molar volume, limiting partial molar volume and viscosity deviation were investigated. The hydration and intermolecular interaction in DES solution were analyzed. The critical concentration of water in solution was determined under the premise of maintaining DES hydrogen bond network.

Thermodynamically Traceable Calorimetric Results for Aqueous Sodium Chloride Solutions from T = (273.15 to 373.15) K up to the Saturated Solutions: Part 1—The Quantities Associated with the Partial Molar Enthalpy

The three-parameter extended Hückel equations with parameters B, b1, and b2 have recently been successfully tested against existing vapor pressure, electrochemical, and solubility data for aqueous NaCl solutions at temperatures from (273 to 373) K (Partanen and Partanen in J. Chem. Eng. Data 65:5226–5239, 2020). In the present study, we extend this model to the apparent and partial molar enthalpy data of these solutions. The enthalpy equations were determined using a new calculation method that gives practically the same results as that used in another previous study (Partanen et al. in J. Chem. Eng. Data 62:2617–2632, 2017), but the new method is much simpler. In the previous enthalpy study, dilute NaCl solutions up to m = 0.2 mol⋅kg−1 were considered in the range from T = 273 to 353 K. Following the success of the three-parameter extended Hückel model within the whole concentration range at various temperatures, we tabulate new values for relative apparent and partial molar enthalpies for NaCl solutions at rounded molalities. The resulting values are extensively tested against the literature ones. The best agreement is obtained for temperatures below 288 K and between 313 and 353 K. Elsewhere, at least a reasonable agreement is obtained. As no enthalpy or heat capacity data were used in the estimation of our model’s parameters and as the model has excelled in explaining other high-precision thermodynamic data, we argue that the recommended enthalpy values should be preferred even for the temperatures where the agreement is only reasonable due to potential problems associated with the literature values. These problems are also considered in the study.Graphical

Volumetric-acoustic study of Disodium Ethylenediaminetetraacetic acid with Propylene and Hexylene glycol at different temperatures

The present study shows the molecular interactions at constant pressure of 0.1 megapascals (MPa) and a range of temperatures from (288.15, 298.15, 308.15, 318.15 K) in aqueous solution of Disodium EDTA in (0.01, 0.02, 0.03) mol.kg-1 along with Propylene glycol and Hexylene glycol. Speed of sound and density data is determined using Anton Paar DSA 5000 M. Various thermo-acoustic parameters are calculated using the obtained data. Experimental density values determined apparent Molar Volume (Vϕ), Partial Molar Volume (Vϕ°) as well as Partial Molar Volume of Transfer (ΔVϕ°) along with Partial Molar Expansibility (Eϕ°) and thermal expansion coefficient (α). While speed of sound determined the Apparent Molar Isentropic Compression (Kϕ,S), Partial Molar Isentropic Compression (Kϕ,S°) as well as Partial Molar Isentropic Compression of Transfer (ΔKϕ.S°). Pair and Triplet Coefficients along with Empirical constants have also been estimated. FTIR spectroscopic research had been carried out in the binary mixture. From propylene through hexylene glycols, these factors provide data related to significant interactions between solute and solvent.

Volumetric, transport and acoustic properties of binary mixtures containing alkanol at 298.15–318.15 K

The measurement of density (ρ), viscosity (η) and ultrasonic speed (u) have been conducted at T = 298.15 K–318.15 K and at 0.1 MPa to study the intermolecular interactions between p–chlorotoluene with alkanol (C1–C2). These data were utilized to derive the excess properties like excess molar volume (VmE), deviation in viscosity (Δη), excess free energy of activation (ΔG*E), deviation in ultrasonic speed (Δu), and excess isentropic compressibility (κsE) for binary mixtures. Utilizing the VmE values, partial molar volume and excess partial molar volume were calculated. The Δη and κsE were investigated using theoretical models such as the Singh model and ab initio approach, which yielded interactional parameters that not only indicate the extent of unlike interactions and depolymerization of self–associated alkanol but also predicts the Δη and κsE for these systems. The conclusions of the ab initio approach were further validated by the Singh model for viscosity. The u data were further interpreted by various correlations and theories. Regarding correlation, Nomoto’s correlation demonstrated high predictive power for ultrasonic speed data, respectively, compared to other correlations. The resulting excess properties were fitted to Redlich–Kister polynomial equations. The VmE values were observed to be negative for p–chlorotoluene + alkanol systems at all temperatures. The study of the binary mixtures is significant because it sheds light on the nature of intermolecular interactions which has practical implications in areas such as chemical synthesis, solvent selection, and understanding the effects of solvents on reaction rates and product yields.

Influence of tetrabutylammonium bromide based ionic liquid on the aggregation behavior of dodecyltrimethylammonium bromide in the range (293.15 K–313.15 K): acoustic and volumetric investigation

Abstract The effect of the ionic liquid analogue tetrabutylammonium bromide on the aggregation behaviour of the cationic surfactant dodecyltrimethylammonium bromide in aqueous medium was investigated with volumetric and compressibility measurements over a wide temperature range (293.15–313.15) K. The data obtained were used to obtain density data. Based on the density data obtained, the volumetric properties (apparent molar volumes and partial molar volumes) of the surfactant in unimeric and micellar forms were evaluated and discussed in terms of the respective ionic and dipolar interactions. The data obtained were analysed to determine the effects of (i) temperature and (ii) salt added to the surfactant. The results were also interpreted in terms of the molecular interactions occurring in the binary mixtures of the present study. The addition of tetrabutylammonium bromide has a lowering effect on the CMC values of the surfactant studied in aqueous medium.

(Invited) Thermodynamic Properties of Rare-Earth Alloys Relevant for Efficient Rare-Earth Recovery in Molten Salts

Electrode materials of Fe, liquid Bi, and Sn were investigated to enhance the electrochemical recovery of rare-earth elements in molten salts (eutectic LiCl-KCl) at 500‒700 °C, leveraging their chemical interactions with rare-earth elements. Using Nd as a prototypical example, the degree of interactions was quantified based on electromotive force (emf) measurements of Nd alloys (Nd-Fe, Nd-Bi, and Nd-Sn). Temperature-dependent emf values of the Nd alloys were used to determine the thermodynamic properties such as the partial molar Gibbs energy (chemical potential), entropy, and enthalpy of Nd. In addition, the phase behavior of Nd alloys was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) to determine transition temperatures and microstructures of Nd alloy electrodes. Based on these fundamental properties of Nd alloys, the Nd-Sn alloy at mole fraction, x Nd = 0.10 was selected as the reference electrode and employed for electrochemical measurements in three-electrode cells in molten chloride salt (LiCl-KCl-NdCl3). The stability of Nd-Sn reference electrode was maintained less than 1 mV deviation between identical constructs during entire measurements, originating from the two phase (liquid + NdSn3) stability of the binary Nd-Sn alloy at 500‒700 °C. Finally, electrodeposition of Nd onto these interacting electrode materials was conducted to assess the recovery efficiency of Nd from molten chloride salt.

Solute–solvent interactions of glycine, L–alanine, and L–valine in aqueous 1–butyl–3–methylimidazolium methylsulfate ionic liquid solutions at different temperatures

The intermolecular interactions of amino acids (glycine, L–alanine, and L–valine) in aqueous solutions of an ionic liquid, 1–butyl–3–methylimidazolium methylsulfate [Bmim][MeSO4] as a function of temperature have been investigated by combination of volumetric and acoustic methods. The density, ρ, and speed of sound, u, of glycine, L–alanine and L–valine in aqueous 1–buytl–3–methylimidazolium methylsulfate solutions have been measured in the temperature interval T = (288.15, 298.15, and 308.15) K and atmospheric pressure. These data have been used to calculate apparent molar volume (V∅), and apparent molar adiabatic compressibility (K∅,s) of these mixtures at different temperatures. Later, the standard partial molar volume (V∅0), standard partial molar volumes of transfer (ΔV∅0), standard partial molar adiabatic compressibility (K∅,s0), and standard partial molar adiabatic compressibility (ΔK∅,s0) of transfer have been determined for these amino acid solutions from density and speed of sound data. Also, hydration number (nH) and various group contribution have been calculated. Finally the results have been interpreted in terms of solute - solvent interactions that exist among the currently investigated systems.

Diphenylsulfoxide exhibits an outstanding solubility in Methanol: Physicochemical and quantum chemical evidences. Comparison to acetonitrile

Diphenylsulfoxide (Ph2SO) represents a noteworthy organic substance composed of bulky amphiphilic molecules. The chemical interest in Ph2SO arises from a peculiar combination of the strongly polar and strongly nonpolar moieties which are uniquely packed. The solubility of Ph2SO in conventional organic solvents is a cornerstone of its prospective applications. In the present work, the full concentration ranges of the possible homogeneous solutions of diphenylsulfoxide (Ph2SO) in acetonitrile (ACN) and methanol (MEOH) have been investigated by densitometry, UV–vis, FTIR spectroscopy, and quantum-chemical calculations. For the first time, we unraveled an outstanding solubility of Ph2SO in MEOH. The homogeneous solutions form up to the molality of 0.9 mol kg−1. This observation is unexpected from the conventional chemical wisdom because Ph2SO contains twenty-two non-polar interaction sites vs. two polar interaction sites. Based on the volumetric measurements, we revealed that the partial molar volumes of Ph2SO depend somewhat on solvent (MEOH, ACN) peculiarities. The effects of solvent on the spectral characteristics of diphenylsulfoxide have been considered. The numerical simulations based on the systematic potential landscape exploration corroborate the existence of several types of supramolecular species involving Ph2SO and solvent molecules simultaneously. The peculiar anisotropic Ph2SO-MEOH coupling, which is a strong hydrogen bonding, along with the small size of the solvent molecules is responsible for the recorded outstanding solubility in the methanol media. In turn, the performance of ACN is somewhat less encouraging notwithstanding the way higher dipole moment of its molecules. As an amphiphilic solute, Ph2SO may boost the solubilities of hydrophobic solutes by interfacing its coupling with polar media. The reported results inspire further explorations of Ph2SO to design task-specific liquid systems.

Basic physicochemical properties, excess properties, and intermolecular interactions of n-propanol/isopropanol and ethylenediamine binary mixtures

Density (ρ) and viscosity (η) values of binary mixtures composed of n-propanol/isopropanol and ethylenediamine (EDA) were measured at T = (298.15–318.15) K and P = 1005 hPa (atmospheric pressure in Tianjin, China). The excess properties, including viscosity deviation (Δη), excess molar volume (VmE), and excess Gibbs energy of activation of viscous flow (ΔG*E), were then obtained. The least-squares method and Jouyban–Acree model were used to correlate the experimental ρ values and kinematic viscosity associated with three semi-empirical models, and a superior fitting was obtained by comparing the model parameters. VmE, Δη, and ΔG*E were fitted to the Redlich–Kister equation, and partial molar volumes, apparent molar volumes, and viscous activation parameters of n-propanol/isopropanol and EDA binary mixtures were calculated. Raman spectroscopy, fluorescence spectroscopy (FLS), 1H NMR spectroscopy, and computational chemistry methods were used to demonstrate the existence of intermolecular hydrogen bonds (IHBs) in n-propanol/isopropanol and EDA binary mixtures, and the form of IHBs was confirmed as –OH···NH2–. Finally, the CO2 uptake rate was measured for binary mixtures at the molar fractions with strong intermolecular interactions.

Interactions of ammonium based ionic liquids with DNA in aqueous medium through Volumetric, acoustic and viscometric properties

Ionic liquids (ILs) have emerged as a promising alternative solvent for DNA based studies as most of the studied ILs enhance the stability of DNA and act as a media for extraction and storage. Investigation of IL-DNA interactions through spectroscopic and computational analysis have been carried out earlier and we here attempt to explore the interaction through physicochemical properties of IL-DNA mixture in water medium that provide fundamental knowledge of the solvation behaviour. Properties such as density, ρ, speed of sound, u and viscosity, η, of two ILs, Benzyltributylammonium chloride ([BTBA]Cl) and Tetrabutylammonium bromide ([TBA]Br) in water as well as in aqueous DNA solutions with varying concentrations were measured over a temperature range from 293.15 − 323.15 K and at atmospheric pressure. The derived volumetric properties were calculated to understand the strength and extent of the solute–solvent interactions prevail in the solution. The analysis of partial molar volume at infinite dilution, V2∞, helped in the comparison of the strength of the interactions in between the studied solutes. The second derivative of V2∞ with respect to temperature, (∂2V2∞/∂T2)P facilitated in identifying the influence of the solutes in water structure formation around the solute and it was interesting to note that, although both the ILs behaved similarly in water as structure makers, [TBA]Br showed variation in the presence of DNA by demonstrating water structure breaking effects. Similar results were obtained from the analysis of viscometric properties as well. Further, the capability of the ILs to stay solvated in the DNA aqueous solution was confirmed by the results from the solvation number calculations.

Study of Excess Molar Volumes of the Binary Mixture of 1-Hexanol and Benzene at 303.15 K Temperature

The densities, ρ of pure 1-Hexanol, Benzene and their binary mixture covering the whole composition range have been measured at 303.15 K temperature. Excess molar volumes VmE, partial molar volumes, Vi have been calculated from the ρ data. To obtain correlation coefficients and standard deviations VmE was fitted to Redlich–Kister type function in terms of mole fraction. In the whole range of composition the values of VmE were found to be positive. The positive values of VmE were shown due to depolymerization of the network structures and disrupt their H-bonding and resulting into volume expansion.

Empirically Optimized One-Electron Pseudopotential for the Hydrated Electron: A Proof-of-Concept Study.

Mixed quantum-classical molecular dynamics simulations have been important tools for studying the hydrated electron. They generally use a one-electron pseudopotential to describe the interactions of an electron with the water molecules. This approximation shows both the strength and weakness of the approach. On the one hand, it enables extensive statistical sampling and large system sizes that are not possible with more accurate ab initio molecular dynamics methods. On the other hand, there has (justifiably) been much debate about the ability of pseudopotentials to accurately and quantitatively describe the hydrated electron properties. These pseudopotentials have largely been derived by fitting them to ab initio calculations of an electron interacting with a single water molecule. In this paper, we present a proof-of-concept demonstration of an alternative approach in which the pseudopotential parameters are determined by optimizing them to reproduce key experimental properties. Specifically, we develop a new pseudopotential, using the existing TBOpt model as a starting point, which correctly describes the hydrated electron vertical detachment energy and radius of gyration. In addition to these properties, this empirically optimized model displays a significantly modified solvation structure, which improves, for example, the prediction of the partial molar volume.