Article
Chemistry, Physical
Zifan Ma, Liangyi Chen, Chuzhi Xu, Joseph A. Fournier
Summary: This study presents the analysis of mass-selected, cryogenically cooled molecular ions using 2D IR spectroscopy. Nonlinear response pathways were isolated and coherent coupling between vibrational modes was observed. Well-resolved 2D IR features in the congested fingerprint region were also reported. These experiments provide a more precise method for studying molecular interactions and dynamics.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Shahab Alizadeh, Mahmoud Abdollahy, Ahmad Khodadadi Darban, Mehdi Mohseni
Summary: The number and positioning manner of the ligands in the first coordination shell of rare earth element cations play a crucial role in determining the stoichiometry of solvent extraction reactions, especially with acidic extractants. By combining molecular dynamics simulations and solvent extraction experiments, this study found that lanthanum and yttrium each have one and two nitrate ligands in their first hydration shells, respectively. The results also identified specific ionic complexes for lanthanum and yttrium in the electrolyte, shedding light on the extraction process requirements for these rare earth elements.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Physical
Luca Sagresti, Lorenzo Peri, Giacomo Ceccarelli, Giuseppe Brancato
Summary: Ion microsolvation is a fundamental process in ionic solutions, which affects various phenomena in biological and nanotechnological applications. This study presents a computational strategy to investigate the coordination and exchange of solvents around aqua ions, providing insights into the structural, thermodynamic, and dynamic properties of ion microsolvation. The proposed stochastic model successfully captures the thermodynamics and kinetics of ion-water coordination, allowing for the accurate prediction of rare ion-water complexes and slow water exchange rates.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Biophysics
Benjamin Philipp Fingerhut, Jakob Schauss, Achintya Kundu, Thomas Elsaesser
Summary: The interaction between RNA and its aqueous environment is crucial for defining macromolecular structure and function. Investigating the interaction between a short RNA duplex and magnesium ions, a combined theoretical and experimental study revealed detailed hydration geometries and electrostatic characteristics of phosphate-Mg2+ pairs. The results highlight the importance of local electric field mapping and molecular-level simulations for accurately understanding the electrostatics at the RNA-water interface.
BIOPHYSICAL JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Woochul Song, Manish Kumar
Summary: This article provides a brief overview of recent developments in artificial water channels (AWCs) and introduces the potential of AWC designs that surpass biological water channels (AQPs). By mimicking the water transport properties of AQPs, AWCs demonstrate unique advantages in practical applications.
Article
Chemistry, Inorganic & Nuclear
Olga A. Blatova, Vladislav T. Osipov, Valeria E. Pavlova, Maria A. Solodovnikova, Ilya I. Trofimychev, Ekaterina M. Egorova, Vladislav A. Blatov
Summary: We analyzed 21,697 intermetallic crystal structures using a combined geometrical-topological approach. Three typical polyhedral atomic environments (icosahedral, cuboctahedral, or twinned cuboctahedral shape) and multi shell local atomic configurations (LACs) were considered. We found that half of the intermetallic structures contain one of these configurations, with icosahedral LACs being the most frequent. Two-shell configurations strongly determine the overall connectivity of an intermetallic crystal structure.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Olga A. Blatova, Vladislav T. Osipov, Valeria E. Pavlova, Maria A. Solodovnikova, Ilya I. Trofimychev, Ekaterina M. Egorova, Vladislav A. Blatov
Summary: We have analyzed a large number of intermetallic crystal structures using a combined geometrical-topological approach. Our results show that the presence of two to four shell configurations strongly determines the connectivity and overall structure of the intermetallic crystals. The chemical composition of the multi-shell configurations generally follows the close-packing model, with deviations providing valuable insights into crystallographic information and potential stability of different phases.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Bharath Ravikumar, Mahesh Mynam, Sravani Repaka, Beena Rai
Summary: Electrolytes composed of LiPF6 salt and carbonate solvents like EC and DMC, with a ratio of 3:7, exhibit peak ionic conductivity. The key factor behind this phenomenon is the residence time of solvent molecules in the solvation shell of ions.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Medicinal
Stuart J. McElhany, Thomas J. Summers, Richard C. Shiery, David C. Cantu
Summary: AFICS is a Python 3 tool for analyzing the structural and geometric features of the first coordination sphere of an ion in molecular dynamics simulations. It quantifies the distortion of the coordination geometry compared to uniform polyhedra. This tool was used to analyze the well-defined coordination structure of aqueous Cr3+ and the ambiguous structure of aqueous Eu3+ chelated to ethylenediaminetetraacetic acid.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2023)
Article
Chemistry, Physical
Stephen E. Weitzner, Tuan Anh Pham, Christine A. Orme, S. Roger Qiu, Brandon C. Wood
Summary: Ion (de)hydration is a key step in interfacial processes, and predicting its kinetics remains challenging. Static proxies like hydration energy and valence are useful but cannot fully capture the dynamic softness of the hydration shell. Dynamic descriptors are essential for correctly describing ion transfer processes.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Biochemistry & Molecular Biology
Stephani Stamboroski, Kwasi Boateng, Jana Lierath, Thomas Kowalik, Karsten Thiel, Susan Koeppen, Paul-Ludwig Michael Noeske, Dorothea Brueggemann
Summary: The interaction between divalent salts and fibrinogen affects the morphology of fibrinogen precipitates, with divalent ions being removed from smooth fibrinogen films while monovalent species are present in fibrinogen fibers. The study suggests that direct ion-protein contact is the decisive factor controlling the morphology of fibrinogen precipitates, with monovalent ions having a more direct impact compared to divalent ions.
Article
Chemistry, Applied
Eva Kutalkova, Marek Ingr, Alena Kolarikova, Josef Hrncirik, Roman Witasek, Martina Hermannova, Ondrej Strympl, Gloria Huerta-Angeles
Summary: Hyaluronan (HA), a natural polysaccharide widely used in the cosmetic and pharmaceutic industries, is being chemically modified using reactions incompatible with aqueous solutions. Molecular-dynamics (MD) simulations show that the composition of mixed solvents can modify the interaction and reactivity of HA by altering the dynamics and causing observable conformational changes in the HA oligosaccharide.
CARBOHYDRATE POLYMERS
(2023)
Article
Chemistry, Physical
Yasuo Kameda, Yuko Amo, Takeshi Usuki, Yasuhiro Umebayashi, Hikari Watanabe, Kazutaka Ikeda, Toshiya Otomo
Summary: Time-of-flight neutron diffraction measurements were used to obtain experimental information on the intramolecular structure of D2O molecules in the first hydration shell of Ni2+ in a 6 mol% NiCl2 solution in D2O. The O-D bond length was determined to be longer than that of pure liquid D2O, suggesting strong hydrogen bonding between D2O molecules in the first- and second hydration shell of Ni2+. These findings are consistent with the relationship between the v(OD)-r(OD) obtained from infrared spectra and the neutron diffraction results.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Chemistry, Multidisciplinary
Daniel Konstantinovsky, Ethan A. Perets, Ty Santiago, Luis Velarde, Sharon Hammes-Schiffer, Elsa C. Y. Yan
Summary: Understanding the role of water in biological processes is a central challenge in the life sciences, and chiral SFG spectroscopy can be used to investigate hydration shell structures around proteins, providing new possibilities to address grand research challenges in biology.
ACS CENTRAL SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Debasish Das Mahanta, Dennis Robinson Brown, Simone Pezzotti, Songi Han, Gerhard Schwaab, M. Scott Shell, Martina Havenith
Summary: Based on experimental and theoretical study, it is found that global thermodynamic mixing properties of glycerol and water are determined by local solvation structures. Three hydration water populations, including bulk water, bound water, and cavity wrap water, are identified. The study shows a 1:1 connection between the population of bound waters and the mixing enthalpy, which can be further confirmed by simulation results. This allows for rational design of polyol water and other aqueous mixtures to optimize technological applications.
Article
Chemistry, Multidisciplinary
Federico Sebastiani, Chun Yu Ma, Sarah Funke, Alexander Baumer, Dominique Decka, Claudius Hoberg, Alexander Esser, Harald Forbert, Gerhard Schwaab, Dominik Marx, Martina Havenith
Summary: This study demonstrates the sensitivity of the N-C-C-O open/close mode at 315 cm(-1) as a label-free probe for the local protonation of the amide group using precise terahertz measurements and molecular dynamics simulations. The approach is shown to be more general, as it can also be applied to other amino acids and allows for direct correlation of titration spectra with pK(a) values, showcasing the potential of terahertz spectroscopy for label-free probing of the charge state of natural amino acids in water.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Physics, Multidisciplinary
Gerhard Schwaab, Ricardo Perez de Tudela, Devendra Mani, Nitish Pal, Tarun Kumar Roy, Fabio Gabas, Riccardo Conte, Laura Duran Caballero, Michele Ceotto, Dominik Marx, Martina Havenith
Summary: We investigate the microsolvation of glycine with water molecules under astrophysical conditions in our laboratory. By analyzing the infrared spectra, we identify two bands that correspond to specific stretching modes, confirming the formation of zwitter ions with only few water molecules under extreme conditions.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Simone Pezzotti, Federico Sebastiani, Eliane P. van Dam, Sashary Ramos, Valeria Conti Nibali, Gerhard Schwaab, Martina Havenith
Summary: Hydration free energies are determined by the delicate balance between hydrophobic and hydrophilic interactions. A spectroscopic approach using THz spectroscopy allows direct access to the contributions of cavity formation and hydrophilic interactions, and enables the separate determination of the thermodynamic effects of hydrophobic and hydrophilic interactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Devendra Mani, Tarun Kumar Roy, Jai Khatri, Gerhard Schwaab, Sebastian Blach, Christoph Hoelzl, Harald Forbert, Dominik Marx, Martina Havenith
Summary: The application of external electric and magnetic fields is a powerful tool for controlling the alignment of molecules when thermal fluctuations are small. This study demonstrates that internal electric fields in a molecular cluster can also be used for such control. By utilizing the electric field of a single molecular dipole, researchers were able to manipulate the aggregation mechanism of subsequently added acetonitrile molecules. The presence of the internal electric field created by an HCl molecule resulted in the formation of exotic linear acetonitrile chains at 0.37K.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Philipp Schienbein
Summary: Vibrational spectroscopy is a key technique to understand microscopic structure and dynamics, but often difficult without theoretical approaches. This study uses the E(3)-equivariant neural network e3nn to fit the atomic polar tensor of liquid water on existing molecular dynamics simulations. The introduced methodology overcomes computational cost and enables direct assignment of IR spectral features to nuclear motion.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Multidisciplinary
Hongxia Hao, Ellen M. Adams, Sarah Funke, Gerhard Schwaab, Martina Havenith, Teresa Head-Gordon
Summary: Transport mechanisms of solvated protons in reverse micelles containing NaAOT or CTABr were studied using reactive force field simulations. The proton hopping events were found to be suppressed for NaAOT and completely ceased for CTABr. The sluggish proton dynamics in both charged reverse micelles were attributed to the expulsion of hydronium and chloride ions from the interface, resulting in increased pH of the acid pools compared to nonionic reverse micelles. The localized oscillatory hopping dominated in the charged micelles, especially for CTABr, where the proton residence time was significantly increased.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Simone Pezzotti, Benedikt Koenig, Sashary Ramos, Gerhard Schwaab, Martina Havenith
Summary: Water actively participates in liquid-liquid phase separation (LLPS) by driving and being involved in the process. LLPS is governed by changes in hydration entropy and enthalpy. To tune LLPS for biological and medical applications, a general model is required to quantify thermodynamic driving forces. In this study, we develop such a model based on measured THz features of hydration populations, revealing the thermodynamic changes and providing a rational means to manipulate LLPS.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Simon Schulke, Melinda Nolten, Gerhard Schwaab, Martina Havenith
Summary: This study demonstrates the potential of using Terahertz-FTIR spectroscopy as a label-free probe to measure the pH-dependent spectra of solvated amine compounds and correlate them with pKa values, thus allowing investigation of the charge state of biomolecules in water.
Article
Chemistry, Physical
Sampad Bag, Simone Pezzotti, Debasish Das Mahanta, Simon Schulke, Gerhard Schwaab, Martina Havenith
Summary: This study reports the THz measurement results of aqueous acetic acid solutions and explores the spectral characteristics of hydration motifs. By quantitatively correlating these changes to mixing entropy and enthalpy, a quantitative relationship between the balance of local hydrophobic and hydrophilic solvation motifs and macroscopic mixing thermodynamic properties is established.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Multidisciplinary
Debasish Das Mahanta, Dennis Robinson Brown, Simone Pezzotti, Songi Han, Gerhard Schwaab, M. Scott Shell, Martina Havenith
Summary: Based on experimental and theoretical study, it is found that global thermodynamic mixing properties of glycerol and water are determined by local solvation structures. Three hydration water populations, including bulk water, bound water, and cavity wrap water, are identified. The study shows a 1:1 connection between the population of bound waters and the mixing enthalpy, which can be further confirmed by simulation results. This allows for rational design of polyol water and other aqueous mixtures to optimize technological applications.
Article
Chemistry, Physical
Svenja Jaeger, Philipp Meyer, Kai-Stephan Feichtner, Stefan Henkel, Gerhard W. Schwaab, Viktoria H. Gessner, Martina Havenith
Summary: The study demonstrates that the reaction of alkali metal amides with water is close to barrierless even at ultra-cold conditions, leading to aggregation induced reaction to form specific products in helium nanodroplets at ultra-low temperatures.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Eliane P. van Dam, Benedikt Koenig, Sashary Ramos, Ellen M. Adams, Gerhard Schwaab, Martina Havenith
Summary: The conformational changes of the hydrogen bond network during gelation of aqueous hyaluronan solutions were studied using Terahertz reflection absorption spectroscopy. It was found that solvated protons form ion pairs with hyaluronan within a specific pH range (2.4-2.8) when it forms a hydrogel. The elasticity of hyaluronan solutions can be altered by adding urea or glucose, which is attributed to the formation and destruction of these ion pairs.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Sergi Ruiz-Barragan, Federico Sebastiani, Philipp Schienbein, Jijo Abraham, Gerhard Schwaab, Rahul R. Nair, Martina Havenith, Dominik Marx
Summary: The properties of water at interfaces differ from those of bulk water, and specific confinement effects have been discovered when water is enclosed in nanotubes and slit pores. This study uses experimental and theoretical THz spectroscopy to investigate the nanoconfinement effects on the H-bond network of stratified water lamellae hosted within graphene-based two-dimensional pores. The results show characteristic changes in the THz response due to the structural dynamics and molecular effects, providing insights into the impact of nanoconfinement on water.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Philipp Schienbein, Jochen Blumberger
Summary: Metal oxide/water interfaces play a crucial role in various fields, but their atomistic structure is challenging to characterize experimentally. This study utilizes a neural network potential to simulate the dynamics at the hematite/water interface, revealing solvation dynamics and diffusion of water molecules.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)