Solvent Environment Research Articles

Insight from Boric Acid into Bioskeleton Formation: Inscribed Circle Effect on the Edge-Base Plate Growth.

Complex morphologies in nature often arise from the assembly of elemental building blocks, leading to diverse and intricate structures. Understanding the mechanisms that govern the formation of these complex morphologies remains a significant challenge. In particular, the edge-base plate growth of biogenic crystals plays a crucial role in directing the development of intricate bioskeleton morphologies. However, the factors and regulatory processes that govern edge-base plate growth remain insufficiently understood. Inspired by biological skeletons and based on the soluble property of boric acid (BA) in both water and alcohols, we obtained a series of novel BA morphologies, including coccolith, and anemone biological skeletons. Here, we unveil the "inscribed circle effect", a concise mathematical model that reveals the underlying causative factors and regulatory mechanisms driving edge-base plate growth. Our findings illuminate how variations in solvent environments can exert control over the edge-base plate growth pathways, thereby resulting in the formation of diverse and complex morphologies. This understanding holds significant potential for guiding the chemical synthesis of bioskeleton materials.

Adsorption performance and fitting of thermal runaway gases in power batteries on CuO-doped SnS monolayer: A DFT study

Thermal runaway failure of power batteries will release a large amount of thermal runaway gas (TRG), causing serious environmental pollution and safety accidents. Therefore, monitoring TRG is crucial to battery safety. In this paper, the adsorption capacity of TRG on SnS monolayer and SnS-CuO monolayer are compared based on DFT. SnS-CuO monolayer exhibits strong adsorption for C2H4 and CO. Compared with the SnS monolayer, the Eads are improved by 285.10 % and 527.24 %, respectively. Meanwhile, the electron affinity of TRG strongly correlates with adsorption properties (SSE < 0.06, R-square > 0.9, and RMSE < 0.2), indicating that it plays a significant role in explaining the adsorption characteristics of different TRG. Furthermore, the dielectric constant of the solvent exhibits a stronger correlation with the adsorptive properties of TRG (R-square > 0.96 and RMSE < 0.004), indicating the environmental tunability of TRG adsorption. In general, this research reveals the potential of SnS-CuO monolayer as a gas sensor for C2H4 and CO and provides theoretical guidance for exploring the impact of various TRG and solvent environments on the adsorption performance of SnS-CuO monolayer. It is expected to be widely used in TRG monitoring of power batteries in the future.

Is lecanoric acid a good antioxidant?

Lecanoric acid (LA), an abundant chemical found in lichens, has demonstrated a wide range of biological activities, including anti-cancer cytotoxic, antibiotic, antimycobacterial, antiviral, and anti-hepatocarcinoma properties. The antioxidant capacity of this molecule, while inferred from certain experimental findings, is doubtful based on structural characteristics and therefore remains to be established. DFT calculations are used in this work to conduct a comprehensive evaluation of the mechanism and kinetics governing the antiradical activity of LA in lipidic and aqueous solvent environments. Although the DPPH/ABTS+ assays revealed good antioxidant activity in vitro, the modeling yielded mixed results. The data suggests that LA is an efficient scavenger of the HO radical with rate constants of 2.01 × 1010 and 2.80 × 108 M−1 s−1 in polar and lipid media, respectively, by the FHT and RAF mechanisms. However, the data also suggests that LA exhibits only weak activity against the HOO radical in all physiological environments. This is consistent with structural features that predict low activity.

Photophysical study of lumichrome in 1,4-dioxane-water mixtures

In this work, we have reported the photophysics and dynamics of lumichrome (LUM) in 1,4-dioxane-water solvent mixtures. LUM fluorescence is sensitive to solvent properties such as proton-donating ability (α), proton-accepting ability (β), and viscosity. These properties play a significant role in the conversion of alloxazine-isoalloxazine photo-tautomerization. We have observed an intriguing change in the photophysics of LUM, which varies with the mole fraction of 1,4-dioxane (XD) in the solvent mixture. Different conformers of LUM have been identified in the solvent environment and explained with the help of spectroscopic techniques.

Radical scavenging activity of bromophenol analogs: analysis of kinetics and mechanisms.

This theoretical study explores the antioxidant activity of five bromophenol analogs, with a particular focus on their interaction with different solvent environments of varying polarities. Key findings include the correlation between increased solvent polarity and enhanced antioxidant activity of these analogs, comparable in some instances to ascorbic acid. Notably, compound 5, developed by our research team, demonstrates superior antioxidant activity in both lipid and aqueous solutions, surpassing that of ascorbic acid and other tested analogs. This research contributes to the understanding of bromophenol analogs, presenting the first known kinetic and chemical stability data such as rate constants, pKa values, and branching ratios for reactions with the methylperoxyl radical (CH3OO•). The computational analyses were conducted using the Gaussian 09 software suite at the M05-2X/6-31 + G(d) computational level. These analyses employed conventional transition state theory to account for various potential mechanisms and effects of solvent polarity on the antioxidant activities of bromophenol analogs. The study meticulously calculated enthalpy under standard conditions (298.15K and 1atm) with necessary thermodynamic corrections. Additionally, the Quantum Mechanics-based Test for Overall Radical Scavenging Activity (QMORSA) protocol guided the evaluation of radical scavenging activity, ensuring a comprehensive assessment of the antioxidant potential of the compounds.

Solvent structure and dynamics over Brønsted acid MWW zeolite nanosheets

In the liquid phase of heterogeneous catalysis, solvent plays an important role and governs the kinetics and thermodynamics of a reaction. Although it is often difficult to quantify the role of the solvent, it becomes particularly challenging when a zeolite is used as the catalyst. This difficulty arises from the complex nature of the liquid/zeolite interface and the different solvation environments around catalytically active sites. Here, we use ab initio molecular dynamics simulations to probe the local solvation structure and dynamics of methanol and water over MWW zeolite nanosheets with varying Brønsted acidity. We find that the zeolite framework and the number and location of the acid sites in the zeolite influence the structure and dynamics of the solvent. In particular, methanol is more likely to be in the vicinity of the aluminum (Al3+) at the T4 site than at T1 due to easy accessibility. The methanol oxygen binds strongly to the Al at the T4 site, weakening the Al–O for the bridging acid site, which results in the formation of the silanol group, significantly reducing the acidity of the site. The behavior of methanol is in direct contrast to that of water, where protons can easily propagate from the zeolite to the solvent molecules regardless of the acid site location. Our work provides molecular-level insights into how solvent interacts with zeolite surfaces, leading to an improved understanding of the catalytic site in the MWW zeolite nanosheet.

Short Peptide and Amino Acid-Based Supramolecular Ionogels and Eutectogels.

The capability of peptide and amino acid-based molecules to act as ionogelators and eutectogelators entrapping ionic liquids (ILs) and deep eutectic solvents (DESs) forming ionogels and eutectogels has gathered attention in recent decades. The self-assembly process, primarily driven by non-covalent interactions as hydrogen bonding, remains serendipitous in nature. This review provides a comprehensive and detailed report on self-assembly of unmodified and modified amino acids and peptides in the non-conventional solvents, ILs and DESs. Understanding these processes holds great promise for the development of innovative soft-materials, and to the progress of supramolecular systems in non-conventional solvent environments.

Sub-100-fs energy transfer in coenzyme NADH is a coherent process assisted by a charge-transfer state

Excitation energy transfer (EET) is a key photoinduced process in biological chromophoric assemblies. Here we investigate the factors which can drive EET into efficient ultrafast sub-ps regimes. We demonstrate how a coherent transport of electronic population could facilitate this in water solvated NADH coenzyme and uncover the role of an intermediate dark charge-transfer state. High temporal resolution ultrafast optical spectroscopy gives a 54±11 fs time constant for the EET process. Nonadiabatic quantum dynamical simulations computed through the time-evolution of multidimensional wavepackets suggest that the population transfer is mediated by photoexcited molecular vibrations due to strong coupling between the electronic states. The polar aqueous solvent environment leads to the active participation of a dark charge transfer state, accelerating the vibronically coherent EET process in favorably stacked conformers and solvent cavities. Our work demonstrates how the interplay of structural and environmental factors leads to diverse pathways for the EET process in flexible heterodimers and provides general insights relevant for coherent EET processes in stacked multichromophoric aggregates like DNA strands.

A new organic compound (C9H12N2O2): Crystal structure, characterization, Hirshfeld surface analysis, electronic properties, NLO properties, DFT calculation and molecular docking

A crystal of the organic chromophore N-propyl-4-nitroaniline was synthesized via the process of gradual solvent evaporation. The parameter values of the cell were calculated using single-crystal X-ray diffraction. In order to learn more about the band gap energy and optical quality, a UV–Vis–NIR spectral study was carried out. The lower cut-off wavelength is shown to be as low as 233 nm, and the direct optical band gap is determined to be 4.89 eV. This study delves into the intricate interplay between solvent polarity and the electronic properties of the titled compound, employing TD-DFT calculations. Notably, the analysis unveils a nonlinear correlation between solvent polarity and absorption wavelength, with an observed red-shift of up to 22 nm in select polar solvents. Furthermore, a distinct trend emerges in the variation of the energy gap between HOMO and LUMO, revealing a solvent-specific impact ranging from 0.279 eV to 0.378 eV. These findings offer a nuanced understanding of how solvent environments intricately modulate electronic behavior. Using FTIR spectrum analysis, the frequencies of the vibrations were determined. The Kurtz-Perry powder method verified the existence of Second Harmonic Generation (SHG). At the B3LYP/6–311++G (d, p) level of theory, DFT was also used to look at the crystal molecular structure geometry, charge transfer interactions between molecules, thermodynamic properties and hyperpolarizability.

Constant potential energetics of metallic and semiconducting electrodes: A benchmark study on 2D materials.

Grand-canonical (GC) constant-potential methods within an implicit solvent environment provide a general approach to compute the potential-dependent energetics at electrified solid-liquid interfaces with first-principles density-functional theory. Here, we use a mindfully chosen set of 27 isostructural 2D metal halides MX2 to analyze the variation of this energetics when the electronic structure changes from metallic to semiconducting and insulating state. Apart from expectable changes due to the opening up of the electronic bandgap, the calculations also show an increasing sensitivity to the numerical Brillouin zone integration and electronic smearing, which imposes computational burdens in practice. We rationalize these findings within the picture of the total interfacial capacitance arising from a series connection of the electrochemical double-layer capacitance and the so-called quantum capacitance resulting from the filling of electronic states inside the electrode. For metals, the electrochemical double-layer capacitance dominates at all potentials, and the entire potential drop takes place in the electrolyte. For semiconductors, the potential drop occurs instead fully or partially inside the electrode at potentials within or just outside the bandgap. For 2D semiconductors, the increased sensitivity to numerical parameters then results from the concomitantly increased contribution of the quantum capacitance that is harder to converge. Fortunately, this understanding motivates a simple extension of the CHE + DL approximation for metals, which provides the approximate GC energetics of 2D semiconductors using only quantities that can be obtained from computationally undemanding calculations at the point of zero charge and a generic double-layer capacitance.

The role of microenvironments on computed vibrationally-resolved emission spectra: The case of oxazines.

Oxazine dyes act as reporters of their near environment by the response of their fluorescence spectra. At the same time, their fluorescence spectra exhibit a pronounced vibrational progression. In this work, we computationally investigate the impact of near-environment models consisting of aggregated water as well as betaine molecules on the vibrational profile of fluorescence spectra of different oxazine derivatives. For aggregated betaine and a water molecule located above the plane of the dyes, we observe a distinct modification of the vibrational profile, which is more pronounced than the effect of a continuum description of a solvent environment. Our analysis shows that this effect cannot be explained by a pure change in the electronic structure, but that also vibrational degrees of freedom of the environment can be decisive for the vibrational profile and should, hence, not generally be neglected.

1H, 1, 2, 3- Triazole Tethered imidazole-Isatin conjugates: Synthesis, DFT and optical properties

Novel functional materials, namely TPI-TAZ-ISA, NADPI-TAZ-ISA, ADPI-TAZ-ISA, and DMAPDPI-TAZ-ISA, were synthesized utilizing click chemical reactions and subjected to thorough characterization. The optical properties of these organic materials, TPI-TAZ-ISA, NADPI-TAZ-ISA, ADPI-TAZ-ISA, and DMAPDPI-TAZ-ISA, were investigated in various solvent environments. Notably, ADPI-TAZ-ISA exhibited a maximum absorption wavelength of 390 nm attributed to π – π* electronic transitions, primarily originating from the fluorophore group, while displaying a blue fluorescence at 465 nm. A comprehensive investigation combining experimental and theoretical approaches was conducted for these compounds, revealing a non-planar molecular structure and theoretical energy band gaps ranging from 4.10 to 4.73 eV. DFT studies demonstrated well-defined spatial separation of the HOMO and LUMO for all compounds in the ground state (S0). NTO studies further elucidated the spatial separation of the HONTO and LUNTO for DMAPDPI-TAZ-ISA at the excited state (S2), corroborated by CDD, hole and electron contributions, and the overlap of hole and electron densities. These findings hold promise for the development of novel luminescent materials. Moreover, on-going research is exploring the integration of ISA to enhance the functionality of these materials further.

Vibrational Self-Consistent Field (VSCF) and Post-VSCF Method Calculations Combined with the Reference Interaction Site Model Self-Consistent Field Method Coupled with the Constrained Spatial Electron Density Distribution: Applications to NaHCOO in Aqueous Phase.

Investigating vibrational behavior in solution is crucial for understanding molecular dynamics within a solvent environment. Notably, the analysis of Raman spectra for molecules in solution is important owing to its ability to unveil intricate solute-solvent interactions. Previous studies have effectively employed frequency calculations utilizing the reference interaction site model self-consistent field method in conjunction with constrained spatial electron density distribution (RISM-SCF-cSED) to understand molecular vibrations in solution, primarily focusing on fundamental vibrational modes. However, the oversight of overtones and combination tones in these studies prompted us to combine the vibrational self-consistent field (VSCF) and vibrational second-order Mo̷ller-Plesset perturbation (VMP2) methods with RISM-SCF-cSED to address these aspects theoretically. Illustrating the efficacy of this integrated approach, we computed the Raman spectra of sodium formate (NaHCOO) in water, revealing the necessity of accounting for molecular anharmonicity in solution vibrational analysis. Our findings underscore the potency of VSCF and VMP2 in conjunction with RISM-SCF-cSED as a robust theoretical framework for such calculations.

Metal and solvent dependent formation of imidazolidine or hemiaminal ether complexes

The coordination chemistry of the imidazolidinylpyridine ligand with Ni(II), Cu(II), Cd(II), and Zn(II) ions was investigated in both protic and aprotic solvents. Interestingly, the coordination environment around the metal center varied significantly depending upon the nature of metal ion and solvent used for synthesis. In acetonitrile the imidazolidinylpyridine bound to Cu(II) and Ni(II) remains intact, while in methanol it formed ring-opened hemiaminal ether. The Cd(II) and Zn(II) ion stabilized the imidazolidinylpyridine as a face-capping tridentate ligand regardless of the nature of the solvent. The imidazolidinylpyridine and the complexes formed were characterized by NMR spectroscopy, high resolution electrospray ionization mass spectrometry and single-crystal X-ray crystallography, appropriately. The structural features in the solid-state structures were particularly intriguing, shedding light on the complex interplay between the ligand, metal ions, and solvent environments in coordination chemistry.

Mouldable multicomponent low molecular weight supergelators

ABSTRACT A significant drawback of gels formed from low molecular weight gelators (LMWGs) is their typically poor mechanical stability due to the weak non-covalent interactions responsible for forming the gel. Here, we present a rare example of bicomponent gels prepared from LMWGs that show excellent mechanical stability even at <0.7 wt.% gelator loading. The gels can be moulded into any desired shape, without creep deformation. Dynamic diffusion of a guest, like β-carotene, from a spiked gel into its submerged solvent environment is explored through UV–vis spectrophotometry and NMR techniques, showing that the integrity of the gel network remains in the presence of the guest.

Structural Changes in 2-Acetoxybenzoic Acid (2ABA) in the Presence of Various Solvents: A Quantum Chemical and Spectroscopic Study

2-Acetoxy benzoic acid (2ABA) can produce structural changes in the molecule when dissolved in different solvents depending on factors such as solvent polarity, Hydrogen bonding and solvent interactions. Therefore, quantum chemical calculations were performed using Gaussian 09: AS64L-G09RevD.01 software. The structural changes of the 2ABA molecule in the presence of solvents were recorded by Fourier Transform Infrared (FT-IR) Spectroscopy in the 4000-0 cm-1 range. Additionally, Nuclear Magnetic Resonance (NMR) Spectroscopy was employed to examine changes in chemical shift values associated with the dissolution of the molecule. In another phase of the study, the geometric parameters of the optimized molecules, atomic charges, intensities of the vibrational bands, and vibrational frequencies were calculated using Density Functional Theory (DFT). These calculations were performed at the DFT/B3LYP level with the LanL2DZ basis set, providing a detailed analysis of solvent effects at the molecular level. This study offers significant insights into the interactions of solvent environments with molecular structures and contributes to potential drug development processes.

Тионирование 4-((4-оксо-4H-хромен-3-ил) метилен)-2-фенилоксазол-5(4H)-она с применением реагента LAWESSON’S

Analysis of periodicals has showed that there is no information on the behavior of hybrid heterocyclic systems containing several pharmacophore fragments based on oxazol-5(4H)-ones and chromen-4(4H)-ones in reactions with thionizing reagents under various conditions. The interaction of 4-((4-oxo-4H-chromen-3-yl)methylene)-2-phenyloxazol-5(4H)-one with Lawesson’s reagent (LR) (2,4-bis-[pmethoxyphenyl]) has been studied for the first time – 1,3- dithiaphosphetane-2,4-disulfide) under conditions of thermal activation of the reaction mixture and the use of a closed reactor in the environment of non-polar solvents. Lawesson’s reagent is used as a mild thioniation agent. The scheme of the interaction has been discussed. Initially, it is assumed that the Lawesson reagent (LR) molecule dissociates into the particles of ylide structure, then the interaction with the carbonyl group of the chromen-4-one fragment of the initial substrate takes place, resulting in the formation of a spirocyclic intermediate, the subsequent decomposition of which produces the final product. It has been established that the use of a closed reactor makes it possible to reduce the transformation time and achieve an increase in the yield of the target product compared to the conventional type of activation of the reaction mixture. It has been shown that under the chosen conditions the transformation proceeds with the preservation of the oxazol-5(4H)-one ring. The composition and structure of the resulting compound have been established on the basis of complex data from elemental analysis, IR and NMR spectroscopy.

Computational Evaluation of the Structural, Topological, and Solvent Effects on the Nonlinear Optical Properties of 1-Methylurea Butanedioic Acid Crystal

In silico investigation of the effects of a molecule’s framework and surroundings on its nonlinear optical (NLO) response is still an active topic of study in the fields of photonics and optoelectronics. NLO materials play a crucial role in modern photonics and optoelectronic technologies. Presented here is a comprehensive theoretical analysis of the structural, topological, and NLO features of 1-methylurea butanedioic acid (MUBA) alongside solvent effects (water, DMSO, and benzene) using the DFT method at the B3LYP(D4)/6–311++G(d,p) level. Geometric and infrared parameters were calculated and compared with experimental values. The analysis using atoms in molecules (AIM) and the independent gradient model (IGM) reveals the presence of two noncovalent intermolecular interactions: N4–H16⋯O12 and O6–H25⋯O3, which stabilize the crystal structure. The natural bond orbital (NBO) analysis reveals that the LP(1)N4 ⟶ π∗(C2-O3) interaction is the most stabilizing and is enhanced in solvent environments. NLO data show that the first (βtot) and second (γ) hyperpolarizability values of MUBA are approximately 0.6–1.1 and 8.3–17.0 times higher than those of urea. In addition, the quadratic and cubic responses of MUBA are significantly reduced and increased, respectively, in solvent environments. Based on its NLO susceptibilities, MUBA exhibits SHG, EOPE, OKE, and EFISHG properties, suggesting its potential application in the production of optoelectronic devices and optical limiting. This study enhances our understanding of the factors influencing the NLO behaviour of organic crystals, providing valuable insights for designing materials with enhanced NLO characteristics. The implications extend to industries such as telecommunications and computing, where faster data transmission rates are in high demand.

Ultrafast planarization of photoexcited ligands in metal–organic frameworks gates charge transfer to promote photocatalysis

Metal–organic frameworks (MOFs) have emerged as a highly tunable class of porous materials with wide-ranging applications from gas capture to photocatalysis. Developing these exciting properties to their fullest extent requires a thorough mechanistic understanding of the structure–function relationships. We implement an ultrafast spectroscopic toolset, femtosecond transient absorption and femtosecond stimulated Raman spectroscopy (FSRS), to elucidate the correlated electronic and vibrational dynamics of two isostructural 1,3,6,8-tetrakis(p-benzoic acid)pyrene (TBAPy)-based MOFs, which manifest drastically different photocatalytic behaviors. Systematic comparisons between the M3+-TBAPy MOFs and bare ligands in various environments reveal the unproductive dimer formation in Al-TBAPy, whereas Sc-TBAPy is dominated by a catalytically active charge-transfer (CT) process. Two ground-state FSRS marker bands of the TBAPy ligand at ∼1267 and 1617 cm−1 probe the chromophore environment at thermal equilibrium. For comparison, the excited-state FSRS of Sc-TBAPy suspended in neutral water unveils a key ∼300 fs twisting motion of the TBAPy peripheral phenyl groups toward planarity, promoting an efficient generation of CT species. This motion also exhibits high sensitivity to solvent environment, which can be a useful probe; we also showed the CT variation for ultrafast dynamics of Sc-TBAPy in the glyphosate aqueous solution. These new insights showcase the power of table-top tunable FSRS methodology to delineate structural dynamics of functional molecular systems in action, including MOFs and other photosensitive “nanomachines.” We expect the uncovered ligand motions (ultrafast planarization) to enable the targeted design of new MOFs with improved CT state characteristics (formation and lifetime) to power applications, including photocatalysis and herbicide removal from waterways.

Restructuring Electrolyte Solvation by a Partially and Weakly Solvating Cosolvent toward High-Performance Potassium-Ion Batteries.

Ether-based electrolytes are among the most important electrolytes for potassium-ion batteries (PIBs) due to their low polarization voltage and notable compatibility with potassium metal. However, their development is hindered by the strong binding between K+ and ether solvents, leading to [K+-solvent] cointercalation on graphite anodes. Herein, we propose a partially and weakly solvating electrolyte (PWSE) wherein the local solvation environment of the conventional 1,2-dimethoxyethane (DME)-based electrolyte is efficiently reconfigured by a partially and weakly solvating diethoxy methane (DEM) cosolvent. For the PWSE in particular, DEM partially participates in the solvation shell and weakens the chelation between K+ and DME, facilitating desolvation and suppressing cointercalation behavior. Notably, the solvation structure of the DME-based electrolyte is transformed into a more cation-anion-cluster-dominated structure, consequently promoting thin and stable solid-electrolyte interphase (SEI) generation. Benefiting from optimized solvation and SEI generation, the PWSE enables a graphite electrode with reversible K+ (de)intercalation (for over 1000 cycles) and K with reversible plating/stripping (the K||Cu cell with an average Coulombic efficiency of 98.72% over 400 cycles) and dendrite-free properties (the K||K cell operates over 1800 h). We demonstrate that rational PWSE design provides an approach to tailoring electrolytes toward stable PIBs.