Tuning Solvation Dynamics of Electrolytes at Their Eutectic Point Through Halide Identity

Pandian, Rathiesh [Case Western Reserve University, Cleveland, OH (United States)] (ORCID:0000000296191491); Hansen, Benworth B. [The Ohio State University, Columbus, OH (United States)] (ORCID:0000000301129300); de Araujo Lima e Souza, Giselle [Hunter College of the City University of New York, NY (United States)] (ORCID:0000000192125334); Sangoro, Joshua R. [The Ohio State University, Columbus, OH (United States)] (ORCID:0000000254839528); Greenbaum, Steven [Hunter College of the City University of New York, NY (United States)] (ORCID:0000000154975274); Burda, Clemens [Case Western Reserve University, Cleveland, OH (United States)] (ORCID:0000000273422840)

doi:10.3390/molecules30102113

DOE OSTI · 3028372

Tuning Solvation Dynamics of Electrolytes at Their Eutectic Point Through Halide Identity

Pandian, Rathiesh [Case Western Reserve University, Cleveland, OH (United States)] (ORCID:0000000296191491)·Hansen, Benworth B. [The Ohio State University, Columbus, OH (United States)] (ORCID:0000000301129300)·de Araujo Lima e Souza, Giselle [Hunter College of the City University of New York, NY (United States)] (ORCID:0000000192125334)·Sangoro, Joshua R. [The Ohio State University, Columbus, OH (United States)] (ORCID:0000000254839528)·Greenbaum, Steven [Hunter College of the City University of New York, NY (United States)] (ORCID:0000000154975274)·Burda, Clemens [Case Western Reserve University, Cleveland, OH (United States)] (ORCID:0000000273422840)

View original source ↗Read source document ↗Export metadata ↓

Abstract

Deep eutectic solvents (DESs) are regarded as highly promising solvent systems for redox flow batteries. DESs, composed of choline halides (ChX, X = F − , Cl − , Br − , I − ) and ethylene glycol (EG), exhibit distinct physicochemical properties at their eutectic points, including halide-dependent phase behavior, viscosity, polarity, conductivity, and solvation dynamics. In this study, we investigate the effects of the halide identity on the solvation properties of ChX:EG mixtures at varying mol % of ChX salt content. The solvatochromic polarity based on ET(30) measurements indicates higher polarity for larger halides (I − > Br − ) than for smaller halides (Cl − > F − ), which exhibit larger compensating solvation shells. The ionic conductivity follows the trend of the solvent fluidity (the inverse of the viscosity), namely ChCl > ChBr > ChI > ChF, influenced by the ion mobility and solvodynamic radii. Measurements of the liquidus temperatures (T L ) reveal that the system with ChCl exhibits the deepest eutectic point (at ~20 mol % ChCl), while ChBr and ChI have shallower minima at ~10 mol % ChBr and ~3 mol % ChI, respectively. ChF does not display a eutectic transition but instead appears to readily supercool at salt concentrations above 30 mol % ChF. Consistent with the phase transition measurements, femtosecond transient absorption spectroscopy shows that in the ChCl system, the solvation dynamics become faster with an increasing salt concentration up to ~16.67 mol %, after which the dynamics slow down with further increases in the salt content. The ChF-based system exhibits similar behavior, though with slower dynamics. In contrast, the solvation dynamics of the systems containing ChBr and ChI monotonously slow down with an increasing salt concentration, in agreement with the phase transition measurements, which show that the eutectic points occur at low salt concentrations. These measurements suggest that the solvent composition and, in particular, the identity of the halide anion play a significant role in the solvation behavior of these ethylene-glycol-based DESs, offering a foundation for tuning the DES properties for specific applications.

Explore related subjects

Biochemistry & Molecular Biology Chemistry ET(30) polarity Reichardt’s dye betaine-30 choline halides deep eutectic solvents differential scanning calorimetry femtosecond transient absorption spectroscopy pulsed-field gradient NMR spectroscopy self-diffusion solvation dynamics solvent structure

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Pandian, Rathiesh [Case Western Reserve University, Cleveland, OH (United States)] (ORCID:0000000296191491), Hansen, Benworth B. [The Ohio State University, Columbus, OH (United States)] (ORCID:0000000301129300), de Araujo Lima e Souza, Giselle [Hunter College of the City University of New York, NY (United States)] (ORCID:0000000192125334), Sangoro, Joshua R. [The Ohio State University, Columbus, OH (United States)] (ORCID:0000000254839528), Greenbaum, Steven [Hunter College of the City University of New York, NY (United States)] (ORCID:0000000154975274), Burda, Clemens [Case Western Reserve University, Cleveland, OH (United States)] (ORCID:0000000273422840). 2025-05-09. Tuning Solvation Dynamics of Electrolytes at Their Eutectic Point Through Halide Identity. https://doi.org/10.3390/molecules30102113

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

DOE OSTI2025

Matrix Metalloproteinases as Candidate Antigenic Determinants for Anti‐Tumor Autoantibodies in Human Ovarian Cancer: A Post Hoc Analysis

Circulating antibodies in patients with cancer can facilitate the identification of accessible epitopes on autoantigens expressed by tumors. To identify previously unrecognized protein targets in ovarian cancer, we computationally assessed a heptapeptide consensus motif (VPELGHE, flanked by two cysteine residues yielding a cyclic nonapeptide under oxidizing conditions) previously discovered via phage display-based epitope mapping of autoantibodies in patients. Eight proteins associated with ovarian cancer encompass amino acid sequences similar to the consensus motif and were, therefore, considered as candidate native autoantigens. Among these candidate targets, however, matrix metalloproteinase 14 (MMP14) demonstrates gene expression that is both high and negatively correlated with survival in ovarian cancer patient cohorts. MMP14 protein levels are also stable in tumor versus non-tumor tissues. Moreover, the corresponding heptapeptide mimic in MMP14 occurs within an α-helical secondary structural element observed in its catalytic domain. These findings demonstrate that a subset of patient-derived autoantibodies may interact with a previously unknown antigenic epitope found in MMP14 and other MMPs, thereby providing opportunities for the development of new targeted agents.

Biochemistry & Molecular Biology↗

DOE OSTI2025

Structures of a synthetic antibody selected against and bound to the C‐terminal domain of Clostridium perfringens enterotoxin

Abstract Clostridium perfringensenterotoxin (CpE) causes cytotoxic gastrointestinal disease in mammalian epithelium by binding membrane protein receptors called claudins. Claudins direct the formation of cell/cell tight junctions through oligomerization and govern the transport of molecules between individual cells. CpE binds claudins through its C‐terminal domain (cCpE) and induces cytotoxicity through its N‐terminal domain. The non‐toxic cCpE is a useful tool to study claudins, tight junctions, and for translational applications, such as increasing the permeability of restrictive tissues like the blood–brain barrier or selective targeting of claudin overexpressing cancers. Conversely, there are no specialized molecular tools to study CpE or cCpE, or to modulate or inhibit their functions. We previously reported the development of synthetic antigen‐binding fragments (sFabs) that bind cCpE, and low‐resolution structures of them bound to claudin/cCpE complexes. Here, we determine high‐resolution structures of sFab COP‐2 bound to cCpE using X‐ray crystallography and cryogenic electron microscopy. The structures and biophysical findings provide the mechanism of COP‐2 binding to cCpE and the molecular determinants driving their interactions. These insights can advance the design of new antibody‐based tools from our COP‐2 scaffold to study or alter cCpE function and give rise to a “Trojan horse” strategy that exploits cCpE's tight junction barrier disrupting function to selectively deliver conjugated therapeutics through normally impermeable tissues.

Biochemistry & Molecular Biology↗

DOE OSTI2025

Functional Relevance of CASP16 Nucleic Acid Predictions as Evaluated by Structure Providers

ABSTRACT Accurate biomolecular structure prediction enables the prediction of mutational effects, the speculation of function based on predicted structural homology, the analysis of ligand binding modes, experimental model building, and many other applications. Such algorithms to predict essential functional and structural features remain out of reach for biomolecular complexes containing nucleic acids. Here, we report a quantitative and qualitative evaluation of nucleic acid structures for the CASP16 blind prediction challenge by 12 of the experimental groups who provided nucleic acid targets. Blind predictions accurately model secondary structure and some aspects of tertiary structure, including reasonable global folds for some complex RNAs; however, predictions often lack accuracy in the regions of highest functional importance. All models have inaccuracies in non‐canonical regions where, for example, the nucleic‐acid backbone bends, deviating from an A‐form helix geometry, or a base forms a non‐standard hydrogen bond (not a Watson‐Crick base pair). These bends and non‐canonical interactions are integral to forming functionally important regions such as RNA enzymatic active sites. Additionally, the modeling of conserved and functional interfaces between nucleic acids and ligands, proteins, or other nucleic acids remains poor. For some targets, the experimental structures may not represent the only structure the biomolecular complex occupies in solution or in its functional life cycle, posing a future challenge for the community.

Biochemistry & Molecular Biology↗