01604nas a2200169 4500008004100000022001400041245009300055210006900148260000800217300001100225490000800236520100800244100002301252700002101275700001801296856012001314 2023 eng d a0021-960600aDoes variation in composition affect dynamics when approaching the eutectic composition?0 aDoes variation in composition affect dynamics when approaching t cMAR a1142030 v1583 a

Deep eutectic solvent is a mixture of two or more components, mixed in a certain molar ratio, such that the mixture melts at a temperature lower than individual substances. In this work, we have used a combination of ultrafast vibrational spectroscopy and molecular dynamics simulations to investigate the microscopic structure and dynamics of a deep eutectic solvent (1:2 choline chloride: ethylene glycol) at and around the eutectic composition. In particular, we have compared the spectral diffusion and orientational relaxation dynamics of these systems with varying compositions. Our results show that although the time-averaged solvent structures around a dissolved solute are comparable across compositions, both the solvent fluctuations and solute reorientation dynamics show distinct differences. We show that these subtle changes in solute and solvent dynamics with changing compositions arise from the variations in the fluctuations of the different intercomponent hydrogen bonds.

1 aChatterjee, Srijan1 aChowdhury, Tubai1 aBagchi, Sayan uhttps://library.ncl.res.in/content/does-variation-composition-affect-dynamics-when-approaching-eutectic-composition01619nas a2200241 4500008004100000022001400041245007800055210006900133260000800202300001100210490000800221520084700229100002201076700002501098700001801123700002301141700002101164700002701185700002201212700002301234700001801257856010201275 2023 eng d a1010-603000aSolvation structure and dynamics of a small ion in an organic electrolyte0 aSolvation structure and dynamics of a small ion in an organic el cJUN a1146660 v4403 a

Organic carbonates are commonly used as electrolytes in commercial lithium-ion batteries. A detailed interpretation of the solvation structure and dynamics of the electrolyte around ions is necessary to understand the charge/discharge process in batteries. This work combines infrared absorption spectroscopy with quantum chemical calculations and molecular dynamics simulations to decipher the solvation structure of propylene carbonate, a cyclic carbonate, around the dissolved thiocyanate ion. Two dimensional infrared spectroscopy and polarization-selective pump probe spectroscopies have been utilized to extract the timescales of solvent fluctuation and the solute reorientational dynamics. The similarity in the slow timescales for the solute and the solvent dynamics signifies that similar processes control both dynamics.

1 aKore, Shivshankar1 aSahoo, Rudhi, Ranjan1 aSantra, Binit1 aSarkar, Archishman1 aChowdhury, Tubai1 aDeshmukh, Samadhan, H.1 aHazarika, Sulagna1 aChatterjee, Srijan1 aBagchi, Sayan uhttps://library.ncl.res.in/content/solvation-structure-and-dynamics-small-ion-organic-electrolyte00759nas a2200229 4500008004100000022001400041245007900055210006900134260000900203300001600212490000700228653002700235653002400262653001500286100002700301700001800328700002100346700002000367700001800387700001800405856010600423 2024 eng d a2040-336400aProbing surface interactions in CdSe quantum dots with thiocyanate ligands0 aProbing surface interactions in CdSe quantum dots with thiocyana cAUG  a14922-149310 v1610aCOLLOIDAL NANOCRYSTALS10aSTRUCTURAL DYNAMICS10aThin-films1 aDeshmukh, Samadhan, H.1 aYadav, Sushma1 aChowdhury, Tubai1 aPathania, Akhil1 aSapra, Sameer1 aBagchi, Sayan uhttps://library.ncl.res.in/content/probing-surface-interactions-cdse-quantum-dots-thiocyanate-ligands01793nas a2200169 4500008004100000022001400041245007200055210006900127260000800196300001600204490000800220520122900228100002301457700002101480700001801501856010401519 2024 eng d a1520-610600aSolvation dynamics and microheterogeneity in deep eutectic solvents0 aSolvation dynamics and microheterogeneity in deep eutectic solve cDEC a12669-126840 v1283 a

Deep eutectic solvents have attracted considerable attention due to their unique properties and their potential to replace conventional solvents in diverse applications, such as catalysis, energy storage, and green chemistry. However, despite their broad use, the microscopic mechanisms governing solvation dynamics and the role of hydrogen bonding in deep eutectic solvents remain insufficiently understood. In this article, we present our contributions toward unravelling the micro heterogeneity within deep eutectic solvents by combining vibrational Stark spectroscopy and two-dimensional infrared spectroscopy with molecular dynamics simulations. Our findings demonstrate how the composition, constituents, and addition of water significantly influence the heterogeneous hydrogen bonding network and solvent dynamics within these systems. These insights provide valuable guidance for the design of next-generation solvents tailored to specific applications. By integrating experimental and computational approaches, this work sheds light on the intricate relationship between solvation dynamics and nanostructure in deep eutectic solvents, ultimately paving the way for innovative advances in solvent design.

1 aChatterjee, Srijan1 aChowdhury, Tubai1 aBagchi, Sayan uhttps://library.ncl.res.in/content/solvation-dynamics-and-microheterogeneity-deep-eutectic-solvents03216nas a2200241 4500008004100000022001400041245008500055210006900140260000800209300001200217490000800229520246400237653001302701653001802714653001202732653001702744653001402761100002302775700002702798700002102825700001802846856011002864 2024 eng d a0031-865500aViscosity effects on the dynamics of diols and diol-based deep eutectic solvents0 aViscosity effects on the dynamics of diols and diolbased deep eu cJUL a946-9550 v1003 a

Diols, characterized by the presence of two hydroxyl groups, form extended hydrogen-bonded networks. Increasing hydrocarbon chain length is known to elevate the viscosity of diols. Given the established influence of viscosity on solvent dynamics, it becomes imperative to comprehend the impact of viscosity on the fluctuation dynamics within diols and establish connections with hydrogen bond formation and breaking dynamics. In this study, we employ two-dimensional infrared spectroscopy to investigate the viscosity dependence of the structural evolution dynamics in three diols with varying chain lengths. Complementing our experimental approach, molecular dynamics simulations are conducted to extract hydrogen bond lifetimes. Our findings reveal a linear correlation between bulk viscosity, solvent fluctuation timescales, and hydrogen bond lifetimes. Notably, the selected diols exhibit the capability to form deep eutectic solvents upon mixing with choline chloride at specific molar ratios. In contrast to molecular solvents like diols, deep eutectic solvents are characterized by the formation of heterogeneous nanodomains, comprising various intercomponent hydrogen-bonded networks. Interestingly, our observations indicate that while the fluctuation dynamics decelerate with increasing bulk viscosity in diol-based deep eutectic solvents, the relationship between viscosity and dynamics is not linear, in contrast to the observed linearity in diols. This nuanced understanding contributes to the broader comprehension of the interplay between viscosity and dynamics in both molecular and deep eutectic solvents. We investigate the impact of viscosity on structural evolution dynamics in diols with varying chain lengths. Employing two-dimensional infrared spectroscopy and molecular dynamics simulations, we explore the relationship between bulk viscosity, solvent fluctuation timescales, and hydrogen bond lifetimes. We report a linear correlation in diols between viscosity, fluctuation timescales, and hydrogen bond lifetimes. Diols also form deep eutectic solvents, characterized by heterogeneous nanodomains. While fluctuation dynamics slow down with increasing bulk viscosity in diol-based deep eutectic solvents, the relationship between viscosity and dynamics is nonlinear, contrasting with diols' linearity. This understanding enhances comprehension of viscosity-dynamics interplay in molecular and deep eutectic solvents.image

10aDynamics10aHydrogen bond10asolvent10aspectroscopy10aviscosity1 aChatterjee, Srijan1 aDeshmukh, Samadhan, H.1 aChowdhury, Tubai1 aBagchi, Sayan uhttps://library.ncl.res.in/content/viscosity-effects-dynamics-diols-and-diol-based-deep-eutectic-solvents01901nas a2200181 4500008004100000022001400041245011500055210006900170260000800239300001100247490000800258520123800266100002101504700002001525700002601545700001801571856013001589 2025 eng d a0021-960600aProbing solvent fluctuations in deep eutectic solvents: Influence of probe charge and nano-domain localization0 aProbing solvent fluctuations in deep eutectic solvents Influence cJUL a0445060 v1633 a

Deep eutectic solvents (DESs) segregate into hydrogen bond acceptor or hydrogen bond donor (HBD) rich nano-domains, leading to molecular heterogeneity. Understanding how this heterogeneity affects the DES structure and dynamics is essential. In this study, we used two-dimensional nuclear magnetic resonance (2D NMR) and two dimensional infrared (2D IR) spectroscopies, combined with molecular dynamics (MD) simulations, to investigate solvation structure and dynamics in two choline chloride-based DESs with different HBDs-levulinic acid and glycolic acid. We introduced two thiocyanate vibrational probes, methyl thiocyanate (CH3SCN, neutral) and ammonium thiocyanate (NH4SCN, anionic), which selectively localize in specific nano-domains. 2D NMR provided insights into solvent structure and probe location, while 2D IR captured solvation dynamics. Our results show that these small probes do not alter the solvent structure, regardless of charge. However, solvation dynamics depend on long-range electrostatic ordering in the DES and the local shielding effects of the nano-domain where the probe resides. MD simulations complement experimental findings, providing a molecular-level understanding of solvation in DESs.

1 aChowdhury, Tubai1 aPathania, Akhil1 aRavindranathan, Sapna1 aBagchi, Sayan uhttps://library.ncl.res.in/content/probing-solvent-fluctuations-deep-eutectic-solvents-influence-probe-charge-and-nano-domain