Hydrogen Atoms Research Articles

In-situ atomic hydrogen generation: A key to elevating membrane cleaning via citric acid-modified Fenton-like system

Oxidation process has been widely used to clean irreversible membrane fouling, and the development of novel oxidative cleaning process has attracted worldwide attention. In this study, a novel cleaning process with the combination of sodium percarbonate (SPC), citric acid (CA), and ferrous ion (Fe(II)) was introduced to remove organic fouling derived from the complexation of humic acid (HA) and calcium ions (Ca2+) for the first time. Remarkably, both flux recovery and resistance removal could reach 99 % within one hour. The efficiency and durability of this novel cleaning system were confirmed through comprehensive characterization and cyclic cleaning test of the ultrafiltration membranes. Furthermore, it effectively removed various natural organic matter-induced fouling and performed well in long-term experiments. This outstanding performance is due to the synergy between oxidative hydroxyl radicals (HO) and reductive atomic hydrogen (H*) in SPC/CA/Fe(II). Analysis of intermediate/final products confirmed that H* is generated through the reaction of CA and HO and absorbed by HA. Confocal laser scanning microscopy (CLSM) revealed that this absorption makes HA more susceptible to HO attack, resulting in enhanced cleaning performance. This mechanism demonstrates the potential of advanced reduction–oxidation systems for membrane cleaning, offering new insights for the development of novel cleaning methods.

Pressure-induced generation of heterogeneous electrocatalytic metal hydride surfaces for sustainable hydrogen transfer

Metal hydrides are crucial intermediates in numerous catalytic reactions. Intensive efforts have been dedicated to constructing molecular metal hydrides, where toxic precursors and delicate mediators are usually involved. Herein, we demonstrate a facile pressure-induced methodology to generate a cost-effective heterogeneous electrocatalytic metal hydride surface for sustainable hydrogen transfer. Taking carbon dioxide (CO2) electroreduction as a model system and zinc (Zn), a well-known carbon monoxide (CO)-selective catalyst, as a model catalyst, we showcase a homogeneous-type hydrogen atom transfer process induced by heterogeneous hydride surfaces, enabling direct hydrogenation pathways traditionally considered “prohibited”. Specifically, the maximal Faradaic efficiency for formate is enhanced by ~fivefold to 83% under ambient conditions. Experimental and theoretical analyses reveal that unlike the distal hydrogenation route for CO2 to CO over pristine Zn, the Zn hydride surface enables direct hydrogenation at the carbon site of CO2 to form formate. This work provides a promising material platform for sustainable synthesis.

Fluorescence of Atomic Hydrogen in Aqueous Media

It is shown that aqueous solutions of atomic hydrogen fluoresce under the action of UV irradiation. It is also shown that the spectra of this fluorescence have peaks whose maxima are close to the 5th and 6th lines of the Balmer series. All this made it possible to propose using this fluorescence to determine the concentration of atomic hydrogen in aqueous media, which seems relevant for both hydrogen energy and medicine. In addition, the possible involvement of this fluorescence in such phenomena as the blueness of the daytime sky, Cherenkov radiation and the Kirlian aura is analyzed here.

Harmonizing Visible‐Light in Green Synthesis: Unrevealing the Brilliance of Metal‐Free Cross‐Coupling of Unsaturated Hydrocarbons for C–C Bonds Formation

Visible‐light induced, photoredox catalysis has opened a wide range in the transformation of organic compounds in recent times. In synthetic organic chemistry HAT (hydrogen atom transfer) and SET (single electron transfer) mechanisms are a very noteworthy routes that has opened a window in favor of C‐C single bond formations. Usually, a major role of unsaturated hydrocarbons is to participate in carbon‐carbon bond formation as they carry reactive π‐bond. Under visible‐light, metal‐free cross‐coupling reactions are particularly favorable because of their atom economy, increased efficiency, and environmentally friendly procedures that result in the construction of C‐C bonds. The review emphasizes the latest advancements of visible‐light mediated, cross‐coupling reactions of unsaturated hydrocarbons in metal‐free conditions for constructing carbon‐carbon single bonds.

The structure of water-ammonia mixtures from classical and abinitio molecular dynamics.

The structure of aqueous ammonia solutions is investigated through classical molecular dynamics (MD) and abinitio molecular dynamics (AIMD) simulations. We have preliminarily compared three well-known classical force fields for liquid water (SPC, SPC/E, and TIP4P) in order to identify the most accurate one in reproducing AIMD results obtained at the Generalized Gradient Approximation (GGA) and meta-GGA levels of theory. Liquid ammonia has been simulated by implementing an optimized force field recently developed by Chettiyankandy et al. [Fluid Phase Equilib. 511, 112507 (2020)]. Analysis of the radial distribution functions for different ammonia concentrations reveals that the three water force fields provide comparable estimates of the mixture structure, with the SPC/E performing slightly better. Although a fairly good agreement between MD and AIMD is observed for conditions close to the equimolarity, at lower ammonia concentrations, important discrepancies arise, with classical force fields underestimating the number and strength of H-bonds between water molecules and between water and ammonia moieties. Here, we prove that these drawbacks are rooted in a poor sampling of the configurational space spanned by the hydrogen atoms lying in the H-bonds of H2O⋯H2O and, more critically, H2O⋯NH3 neighbors due to the lack of polarization and charge transfer terms. This way, non-polarizable classical force fields underestimate the proton affinity of the nitrogen atom of ammonia in aqueous solutions, which plays a key role under realistic dilute ammonia conditions. Our results witness the need for developing more suited polarizable models that are able to take into account these effects properly.

Minocycline mitigates Aβ and TAU pathology, neuronal dysfunction, and death in the PSEN1 E280A cholinergic-like neurons model of familial Alzheimer’s disease

Familial Alzheimer’s disease (FAD) presenilin 1 E280A (PSEN1 E280A) is a severe neurological condition due to the loss of cholinergic neurons (ChNs), accumulation of amyloid beta (Aβ), and abnormal phosphorylation of the TAU protein. Up to date, there are no effective therapies available. The need for innovative treatments for this illness is critical. We found that minocycline (MC, 5 μM) was innocuous toward wild-type (WT) PSEN1 ChLNs but significantly (i) reduces the accumulation of intracellular Aβ by −69%, (ii) blocks both abnormal phosphorylation of the protein TAU at residue Ser202/Thr205 by −33% and (iii) phosphorylation of the proapoptotic transcription factor c-JUN at residue Ser63/Ser73 by −25%, (iv) diminishes oxidized DJ-1 at Cys106-SO3 by −29%, (v) downregulates the expression of transcription factor TP53, (vi) BH-3-only protein PUMA, and (vii) cleaved caspase 3 (CC3) by −33, −86, and −78%, respectively, compared with untreated PSEN1 E280A ChLNs. Additionally, MC increases the response to ACh-induced Ca2+ influx by +92% in mutant ChLNs. Oxygen radical absorbance capacity (ORAC) and ferric ion-reducing antioxidant power (FRAP) analysis showed that MC might operate more efficiently as a hydrogen atom transfer agent than a single electron transfer agent. In silico molecular docking analysis predicts that MC binds with high affinity to Aβ (Vina Score −6.6 kcal/mol), TAU (VS -6.5 kcal/mol), and caspase 3 (VS -7.1 kcal/mol). Taken together, our findings suggest that MC demonstrates antioxidant, anti-amyloid, and anti-apoptosis activity and promotes physiological ACh-induced Ca2+ influx in PSEN1 E280A ChLNs. The MC has therapeutic potential for treating early-onset FAD.

A Strongly Coupled Metal/Hydroxide Heterostructure Cascades Carbon Dioxide and Nitrate Reduction Reactions toward Efficient Urea Electrosynthesis

The direct coupling of nitrate ions and carbon dioxide for urea synthesis presents an appealing alternative to the Bosch–Meiser process in industry. The simultaneous activation of carbon dioxide and nitrate, however, as well as efficient C–N coupling on single active site, poses significant challenges. Here, we propose a novel metal/hydroxide heterostructure strategy based on synthesizing an Ag‐CuNi(OH)2 composite to cascade carbon dioxide and nitrate reduction reactions for urea electrosynthesis. The strongly coupled metal/hydroxide heterostructure interface integrates two distinct sites for carbon dioxide and nitrate activation, and facilitates the coupling of *CO (on silver, where * denotes an active site) and *NH2 (on hydroxide) for urea formation. Moreover, the strongly coupled interface optimizes the water splitting process and facilitates the supply of active hydrogen atoms, thereby expediting the deoxyreduction processes essential for urea formation. Consequently, our Ag‐CuNi(OH)2 composite delivers a high urea yield rate of 25.6 mmol gcat.–1 h–1 and high urea Faradaic efficiency of 46.1%, as well as excellent cycling stability. This work provides new insights into the design of dual‐site catalysts for C–N coupling, considering their role on the interface.

Sodium Hypophosphite as a Halogen Atom Transfer (XAT) Agent under Photocatalytic Conditions.

The ability of sodium hypophosphite to generate the phosphorus-centered radical, which can activate the carbon-halogen bond via the halogen atom transfer (XAT) is described. The hydroalkylation of nonactivated alkenes with methyl bromoacetate was performed using sodium hypophosphite as reducing agent under photocatalytic conditions. The key phosphorus centered radical is formed from the hypophosphite anion by hydrogen atom abstraction.

Photocatalyzed Direct C(sp3)-H Alkenylation of Unactivated Alkanes via Tandem C-C Activation of Cyclopropenes.

A highly adaptable method has been developed for the alkenylation of a broad spectrum of inert alkanes, employing milder reaction conditions. Tetrabutylammonium decatungstate (TBADT) serves as a photocatalyst for hydrogen atom transfer (HAT), instigating the formation of transient alkyl radicals through C(sp3)-H functionalization. These radicals exhibit regioselective addition to cyclopropenes, followed by the subsequent activation of C-C bonds, forming the corresponding vinylated derivatives. This methodology accommodates diverse unreactive C(sp3)-H bond motifs and multisubstituted cyclopropenes, enabling the efficient synthesis of highly functionalized olefins with high diastereoselectivity.

Recent Advances in Synthetic Methods by Photocatalytic Single-Electron Transfer Chemistry of Pyridine N-Oxides.

By adoption of the enabling technology of modern photoredox catalysis and photochemistry, the generation of reactive and versatile pyridine N-oxy radicals can be facilely achieved from single-electron oxidation of pyridine N-oxides. This Synopsis highlights recent methodologies mediated by pyridine N-oxy radicals in developing (1) pyridine N-oxide-based hydrogen atom transfer catalysts for C(sp3)-H functionalizations and (2) β-oxyvinyl radical-mediated cascade reactions. In addition, recent research revealed that direct photoexcitation of pyridine N-oxides allowed for the generation of alkyl carbon radicals from alkylboronic acids.

The inhibitory potential of 4,7-dihydroxycoumarin derivatives on ROS-producing enzymes and direct HOO•/o2 • – radical scavenging activity – a comprehensive kinetic DFT study

This study examined the antiradical activity of three synthesized coumarin derivatives: (E)-3-(1-((2-hydroxyphenyl)amino)ethylidene)-2,4-dioxochroman-7-yl acetate (A1-OH), (E)-3-(1-((3-hydroxyphenyl)amino)ethylidene)-2,4-dioxochroman-7-yl acetate (A2-OH), and (E)-3-(1-((4-hydroxyphenyl)amino)ethylidene)-2,4-dioxochroman-7-yl acetate (A3-OH) against HOO•/O2•− radical species. The investigation included electron spin resonance (ESR) measurements and a DFT kinetic study. Thermodynamic and kinetic parameters of antiradical mechanisms—Formal Hydrogen Atom Transfer (f-HAT), Radical Adduct Formation (RAF), Sequential Proton Loss followed by Electron Transfer (SPLET), and Single-Electron Transfer followed by Proton Transfer (SET-PT)—were evaluated using the Quantum Mechanics-based test for Overall Free Radical Scavenging Activity (QM–ORSA) under physiological conditions. ESR results indicated antiradical activity decreased in the sequence A1–OH (58.7%) > A2–OH (57.5%) > A3–OH (53.1%). Kinetic analysis revealed the f-HAT mechanism dominated HOO• inactivation. A newly formulated Sequential Proton Loss followed by Radical Adduct Formation (SPL-RAF) mechanism described interactions with O2 •−. The activity toward O2 •− was A2–OH (1.26 × 106 M−1s−1) > A3–OH (7.71 × 105 M−1s−1) > A1–OH (4.22 × 105 M−1s−1). Molecular docking and dynamics studies tested inhibitory capability against enzymes producing reactive species: Lipoxygenase (LOX), Myeloperoxidase (MPO), NAD(P)H oxidase (NOX), and Xanthine Oxidase (XOD). Affinity to enzymes decreased in the order: XOD > LOX > NOX > MPO.

Cheminformatics approaches to predict the bioactivity and to discover the pharmacophoric traits crucial to block NF-κB

Many human disorders include NF-kB signaling pathways, making IKK a therapeutic target in cancer treatment. Inflammatory illnesses and cancer are examples. COVID-19 is one of several triggers that stimulate NF-kB signaling. The activation of the NF-kB pathway is necessary for COVID-19 to cease its development. To learn more about the mechanism and structural features essential to IKK inhibition (IC50), molecular modeling studies have been undertaken on experimentally reported 503. QSAR analysis explores certain reported and hidden structural features critical for IKKβ inhibition. The OECD guidelines guided the construction of the QSAR model, which achieved all the endorsed threshold values for all validation parameters (R2tr:0.81, R2LMO:0.80, and R2ext:0.78). The present QSAR study shows that IKK inhibitory activity is linked to the following structural features: lipophilic hydrogen atoms within 2 A units of the molecule's center of mass; ring nitrogen atoms within one bond of planar nitrogen atoms; ring carbon atoms exactly four bonds from the non-ring nitrogen atoms; planar nitrogen atoms exactly four bonds from sp2 hybridized carbon atoms; and so on. Pharmacophore modeling highlighted QSAR-identified structural characteristics. To investigate binding, we docked all 503 molecules. The observation indicates that the QSAR and molecular docking/pharmacophore modeling findings are in agreement. Following this, we conducted 200 ns of molecular dynamics simulation to validate the molecular docking protocol. MMGBSA analysis determined the binding energy of the dock complex. Thus, the current study found unique pharmacophoric properties that may assist in optimizing lead/hit compounds for anti-IKKβ activity.

The phase transformation of the electron forms an atomic capacitor

Reinterpretation of existing experimental results suggests that the electron goes through a phase transformation in the vicinity of the nucleus and forms a nonrevolving surface charge electron shell from point charge and vice versa. Experimental results also strongly suggest that the laws of classical physics are valid at the atomic scale. The static, nonrevolving surface charge electron shell around the nucleus is a capacitor. Following a classical physics approach, the energy stored in this atomic capacitor is calculated for the hydrogen atom. The stored energy in the formed atomic capacitor agrees reasonably well with the rest energy of the electron. This agreement is in line with the predicted phase transformation of the electron and shows that the transformation from point to surface charge and vice versa is energetically feasible.

Computational insights into chemoselectivity of Trans-4-Hydroxy-L-Proline dehydratase HypD

The dehydration of trans-4-hydroxy-L-proline (t4L-HP) yielding 1-pyrroline-5-carboxylate in certain gut bacteria requires the glycyl radical enzyme HypD, while isomerisation of trans-4-hydroxy-D-proline (t4D-HP) generating 2-amino-4-ketopentanoate involves a homologous enzyme HplG. Although the former enzyme exhibits high chemoselectivity when catalysing the dehydration and is regarded as a promising target for treating bacteria-caused gut diseases, its catalytic mechanism remains elusive. Herein, we deeply investigated the two reaction pathways by carrying out theoretical studies at the QM/MM level. Our calculations show that, in HypD, a catalytic Cys434 radical facilitates the Cδ–H activation in an initially deprotonated zwitterionic t4L-HP, which is followed by a heterolytic cleavage of t4L-HP’s Cγ–O bond with a water formed being assisted by the conserved Asp279. In the isomerisation pathway, the Cys434 radical would abstract the hydrogen atom from Cγ of zwitterionic t4L-HP, and then Asp279 cleaves the Cδ–N bond by abstracting a proton from the hydroxyl group of t4L-HP. The two reaction paths are calculated to have barriers of 18.0 and 22.8 kcal/mol, respectively, which well explain HypD’s chemoselectivity. In the mechanisms suggested by our study, Asp279 plays a role as “proton shuttle” and regulates the protonation state of t4L-HP in the selective hydrogen atom abstraction invoked by the cysteine radical. Our findings provide an insight of universal significance into radical-based enzymatic catalysis and expand the understanding of how nature wisely modulates catalytic reactivity and selectivity by switching the substrate’s protonation state.

Bifunctional 0D carbon quantum dot cathode electrocatalyst coupled with atomic hydrogen and hydroxyl radicals for efficient removal of oxytetracycline hydrochloride

Efficient removal of antibiotics is difficult to achieve by conventional single-oxidation or reduction processes. Herein, a bifunctional cathodic electrocatalyst coupling atomic hydrogen (H*) reduction with hydroxyl radical (·OH) oxidation in an efficient electrocatalytic process was developed for the effective degradation of oxytetracycline hydrochloride (OTC). Pd particles were dispersed on B-doped carbon quantum dots to prepare a Pd-B-doped carbon quantum dots/titanium (Pd-BCQD/Ti) electrode as a bifunctional cathode catalyst. The electrode can simultaneously generate H* through the H2O/H+ reduction process, H2O2 through the oxygen reduction process, and then generate ·OH. H* performs nucleophilic hydrogenation reduction of OTC molecules, and ·OH performs electrophilic oxidation of the carbon skeleton, and both act synergistically with the active chlorine species (HClO) generated at the anode. The experimental results showed that the electrode achieved 90.50 % removal of OTC within 60 min. In addition, the Pd-BCQD/Ti electrode reduces energy consumption while increasing current efficiency. The degradation effect was more than 85.80 % in the pH range of 3∼9, indicating fairly stable catalytic activity over a wide pH range. The degradation efficiency was basically unchanged after ten cycles, and the reactivity was still high in the actual water. Intermediates were analyzed based on LC-MS to explore the degradation pathways of OTC. The toxicity of the intermediates generated during OTC degradation was predicted based on quantitative conformational relationships. This study provides a feasible strategy for the preparation of bifunctional catalysts based on zero-dimensional BCQD for efficient green antibiotic wastewater treatment.

Variability of Earth’s ionospheric outflow in response to the dynamic terrestrial exosphere

The most abundant neutral constituent in the exospheric region (i.e., beyond ≈ 500 km altitude) is the atomic hydrogen (H); however, its density distributions predicted by physics-based models have been challenged by satellite-based observations of its far ultraviolet emissions. This discrepancy may impact magnetospheric ions’ densities and velocities since numerous chemistry and ion-neutral coupling interactions rely sensitively on the underlying neutral hydrogen population. The Polar Wind Outflow Model a first-principled model for relevant ion species in the high-latitude ionosphere, is employed to investigate the role of neutral H on the ionospheric outflow. Specifically, variability in the outflow of ionospheric H+, He+, N+, and O+ as a response to systematic enhancement and depletion of H number densities were simulated. The altitude-dependent ion density and energy partition profiles vary with neutral H density, solar activities, and ion species. These findings suggest that the exosphere plays a crucial role in controlling the production and loss of ions through ionospheric chemistry, as well as the energy contributions by altering ion-neutral-electron collisions and the ambipolar electric field to the high-latitude ionospheric outflow. As a result, the escape rates of the ionospheric outflow are directly associated with exospheric distributions. This work potentially helps understand the dominant mechanisms of atmospheric escape, particularly during a hydrogen-rich early Earth’s and exoplanet’s atmosphere, which is known to play a significant role in understanding the evolution of Earth’s atmosphere.

Recent Advances in Electrochemical Carboxylation with CO2.

ConspectusCarbon dioxide (CO2) is recognized as a greenhouse gas and a common waste product. Simultaneously, it serves as an advantageous and commercially available C1 building block to generate valuable chemicals. Particularly, carboxylation with CO2 is considered a significant method for the direct and sustainable production of important carboxylic acids. However, the utilization of CO2 is challenging owing to its thermodynamic stability and kinetic inertness. Recently, organic electrosynthesis has emerged as a promising approach that utilizes electrons or holes as environmentally friendly redox reagents to produce reactive intermediates in a controlled and selective manner. This technique holds great potential for the CO2 utilization.Since 2015, our group has been dedicated to exploring the utilization of CO2 in organic synthesis with a particular focus on electrochemical carboxylation. Despite the significant advancements made in this area, there are still many challenges, including the activation of inert substrates, regulation of selectivity, diversity in electrolysis modes, and activation strategies. Over the past 7 years, our team, with many great experts, has presented findings on electrochemical carboxylation with CO2 under mild conditions. In this context, we primarily highlight our contributions to selective electrocarboxylations, encompassing new reaction systems, selectivity control methods, and activation approaches.We commenced our research by establishing a Ni-catalyzed electrochemical carboxylation of unactivated aryl halides and alkyl bromides in conjunction with a useful paired anodic reaction. This approach eliminates the need for sacrificial anodes, rendering the carboxylation process sustainable. To further utilize the widely existing yet cost-effective alkyl chlorides, we have developed a deep electroreductive system to achieve carboxylation of unactivated alkyl chlorides and poly(vinyl chloride), allowing the direct modification and upgrading of waste polymers.Through precise adjustment of the electroreductive conditions, we successfully demonstrated the dicarboxylation of both strained carbocycles and acyclic polyarylethanes with CO2 via C-C bond cleavage. Furthermore, we have realized the dicarboxylative cyclization of unactivated skipped dienes to produce the valuable ring-tethered adipic acids through single-electron reduction of CO2 to the CO2 radical anion (CO2•-). In terms of the asymmetric carboxylation, Guo's and our groups have recently achieved the nickel-catalyzed enantioselective electroreductive carboxylation reaction using racemic propargylic carbonates and CO2, paving the way for the synthesis of enantioenriched propargylic carboxylic acids.In addition to the aforementioned advancements, Lin's and our groups have also developed new electrolysis modes to achieve regiodivergent C-H carboxylation of N-heteroarenes dictated by electrochemical reactors. The choice of reactors plays a crucial role in determining whether the hydrogen atom transfer (HAT) reagents are formed anodically, consequently influencing the carboxylation pathways of N-heteroarene radical anions in the distinct electrolyzed environments.

Single-coated thick superconducting films for metal–organic deposition using trifluoroacetates

Metal-organic deposition using trifluoroacetates (TFA-MOD) is known to yield uniform superconducting wires by a liquid growth mode. However, it has been difficult to prepare thick films because of drying stress during the calcining process. To avoid the drying stress, conventional crack-preventing chemicals such as H(CH2)8COOH are applied in conventional metal–organic deposition. However, large amounts of hydrogen atoms react with fluorine atoms during calcining process in TFA-MOD, and the consequent increased harmful carbon residue decreases superconductivity of the resulting films. To avoid the chemical reaction, new crack-preventing chemicals such as H(CF2)8COOH were applied to prepare single-coated thick films. A low ratio of hydrogen atoms decreases the chemical reaction and generates hydrogen fluorine gas, consequently suppressing the carbon residue. Above the calcining temperature, the crack-preventing chemical is decomposed into low-boiling-point chemicals such as CF2CF2 or CF3CF3. Consequently, single-coated thick film having low carbon residue and sufficient superconducting current per width was realized. For a long time, the authors have studied other possible candidate crack-preventing chemicals. Newly introduced fluorine ion measurement of decomposed materials during the calcining process revealed the nature of the crack-preventing chemicals. Based on the accumulated results, we have concluded that among over one million chemicals there are only two groups suitable for preparing single-coated thick superconducting films by TFA-MOD. One group is hydrogenated perfluoro-carboxylic acids such as H(CF2)8COOH and the other group is perfluoro di-carboxylic acids. With H(CF2)8COOH, using a single-coating process we were able to achieve a 560 nm-thick YBa2Cu3O6.93 film having Jc of 4.70 MA/cm2 (77 K,0T). Compared with a standard 150 nm-thick YBa2Cu3O6.93 film having Jc of 7.70 MA/cm2 (77 K,0T), the critical current per width is improved to about 227 %.

Structural and Electronic Evolution of Ethanolamine upon Microhydration: Insights from Hyperfine Resolved Rotational Spectroscopy

AbstractEthanolamine hydrates containing from one to seven water molecules were identified via rotational spectroscopy with the aid of accurate quantum chemical methods considering anharmonic vibrational corrections. Ethanolamine undergoes significant conformational changes upon hydration to form energetically favorable hydrogen bond networks. The final structures strongly resemble the pure (H2O)3–9 complexes reported before when replacing two water molecules by ethanolamine. The 14N nuclear quadrupole coupling constants of all the ethanolamine hydrates have been determined and show a remarkable correlation with the strength of hydrogen bonds involving the amino group. After addition of the seventh water molecule, both hydrogen atoms of the amino group actively contribute to hydrogen bond formation, reinforcing the network and introducing approximately 21–27 % ionicity towards the formation of protonated amine. These findings highlight the critical role of microhydration in altering the electronic environment of ethanolamine, enhancing our understanding of amine hydration dynamics.

Spectroscopic, computational, docking, and cytotoxicity investigations of 5-chloro-2-mercaptobenzimidazole as an anti-breast cancer medication

The vibrations were attributed to 5-chloro-2-mercaptobenzimidazole using FTIR and FT-Raman spectroscopy. The optimized geometrical parameters, IR intensity, and the Raman activity of the vibrational bands were estimated using the Becke three-parameter Lee-Yang-Parr functional and the 6-311++G(d,p) level of theory. These findings are compared with the experimental data. The molecule’s HOMO-LUMO energy gap is found to be 4.418 eV. UV-Vis analysis reveals that the π→π* transition, which happens when electron density shifts from nitrogen, sulfur, and chlorine atoms in the molecule, to the electrons of the C-C bonds of the ring. Total density of states was used to assess the molecular orbital contributions. There are 47α and 47β electrons totaling 94 electrons in the DOS spectrum. NBO investigations indicate that a considerable stabilizing energy of 30.37 and 30.90 Kcal/mol was revealed by the lone pair transition of N1 and N3 atoms to π*(C7-C8) and π*(C4-C9). The more electrophilic region, as seen by the red zone in MEP mapping, lies in the vicinity of the nitrogen and sulfur atoms. The molecule’s hydrogen atoms are found in the blue nucleophilic area. The theoretical chemical shifts for 1H and 13C NMR ranged from 7.03 to 8.23 ppm and 113.10 to 207.31 ppm, respectively. The docking research showed that the molecule attached to protein 1AQU with a greater binding energy of −6.8 Kcalmol−1. The cytotoxicity of the sample was evaluated against a MCF-7 cell line (IC50 = 16.54 µg/ml) and exhibited a good breast cancer action. In addition, ADMET prediction has been used to estimate the medicinal applicability of the chemical.