Exploring Nanomaterials for Hydrogen Storage: Advances, Challenges, and Perspectives.

Hydrogen energy heralded for its environmentally friendly, renewable, efficient, and cost-effective attributes, stands poised as the primary alternative to fossil fuels in the future. Despite its great potential, the low volumetric density presents a formidable challenge in hydrogen storage. Addressing this challenge necessitates exploring effective storage techniques for a sustainable hydrogen economy. Solid-state hydrogen storage in nanomaterials (physically or chemically) holds promise for achieving large-scale hydrogen storage applications. Such approaches offer benefits, including safety, compactness, lightness, reversibility, and efficient generation of pure hydrogen fuel under mild conditions. This article presents solid-state nanomaterials, specifically nanoporous carbons (activated carbon, carbon fibers), metal-organic frameworks, covalently connected frameworks, nanoporous organic polymers, and nanoscale metal hydrides. Furthermore, new developments in hydrogen fuel cell technology for stationary and mobile applications have been demonstrated. The review outlines significant advancements thus far, identifies key barriers to practical implementation, and presents a perspective for future sustainable energy research. It concludes with recommendations to enhance hydrogen storage performance for cost-effective and long-lasting utilization.

A synthetic approach towards drug modification: 2-hydroxy-1-naphthaldehyde based imine-zwitterion preparation, single-crystal study, Hirshfeld surface analysis, and computational investigation.

The current work is about the modification of primary amine functionalized drugs, pyrimethamine and 4-amino-N-(2,3-dihydrothiazol-2-yl)benzenesulfonamide, via condensation reaction with 2-hydroxy-1-naphthaldehyde to produce new organic zwitterionic compounds (E)-1-(((4-(N-(2,3-dihydrothiazol-2-yl)sulfamoyl)phenyl)iminio)methyl)naphthalen-2-olate (DSPIN) and (E)-1-(((4-amino-5-(4-chlorophenyl)-6-ethylpyrimidin-2-yl)iminio)methyl)naphthalen-2-olate (ACPIN) in methanol as a solvent. The crystal structures of both compounds were confirmed to be imine-based zwitterionic products via single-crystal X-ray diffraction (SC-XRD) analysis which indicated that the stabilization of both crystalline compounds is achieved via various noncovalent interactions. The supramolecular assembly in terms of noncovalent interactions was explored by the Hirshfeld surface analysis. Void analysis was carried out to predict the crystal mechanical response. Compound geometries calculated in the DFT (Density Functional Theory) study showed reasonably good agreement with the experimentally determined structural parameters. Frontier molecular orbital (FMO) analysis showed that the DSPIN HOMO/LUMO gap is by 0.15 eV smaller than the ACPIN HOMO/LUMO gap due to some destabilization of the DSPIN HOMO and some stabilization of its LUMO. The results of the charge analysis implied formation of intramolecular hydrogen bonds and suggested formation of intermolecular hydrogen bonding and dipole-dipole and dispersion interactions.

Benzimidazolium quaternary ammonium salts: synthesis, single crystal and Hirshfeld surface exploration supported by theoretical analysis.

Owing to the broad applications of quaternary ammonium salts (QAS), we present the synthesis of benzimidazolium-based analogues with variation in the alkyl and alkoxy group at N-1 and N-3 positions. All the compounds were characterized by spectroscopic techniques and found stable to air and moisture both in the solid and solution state. Moreover, molecular structures were established through single-crystal X-ray diffraction studies. The crystal packing of the compounds was stabilized by numerous intermolecular interactions explored by Hirshfeld surface analysis. The enrichment ratio was calculated for the pairs of chemical species to acquire the highest propensity to form contacts. Void analysis was carried out to check the mechanical response of the compounds. Furthermore, theoretical investigations were also performed to explore the optoelectronic properties of compounds. Natural population analysis (NPA) has been conducted to evaluate the distribution of charges on the synthesized compounds, whereas high band gaps of the synthesized compounds by frontier molecular orbital (FMO) analysis indicated their stability. Nonlinear optical (NLO) analysis revealed that the synthesized QAS demonstrates significantly improved NLO behaviour than the standard urea.

Solvothermal synthesis of VO2 nanoparticles with locally patched V2O5 surface layer and their morphology-dependent catalytic properties for the oxidation of alcohols.

Vanadium oxides are promising oxidation catalysts because of their rich redox chemistry. We report the synthesis of VO2 nanocrystals with VO2(B) crystal structure. By varying the mixing ratio of the components of a binary ethanol/water mixture, different VO2 nanocrystal morphologies (nanorods, -urchins, and -sheets) could be made selectively in pure form. Polydisperse VO2(B) nanorods with lengths between 150 nm and a few micrometers were formed at large water : ethanol ratios between 4 : 1 and 3 : 2. At a water : ethanol ratio of 1 : 9 VO2 nanosheets with diameters of ∼50-70 nm were formed, which aggregated to nano-urchins with diameters of ∼200 nm in pure ethanol. The catalytic activity of VO2 nanocrystals for the oxidation of alcohols was studied as a function of nanocrystal morphology. VO2 nanocrystals with all morphologies were catalytically active. The activity for the oxidation of benzyl alcohol to benzaldehyde was about 30% higher than that for the oxidation of furfuryl alcohol to furfural. This is due to the substrate structure. The oxidation activity of VO2 nanostructures decreases in the order of nanourchins > nanosheets > nanorods.

Preliminary anticancer evaluation of new Pd(II) complexes bearing NNO donor ligands.

In this study we presented a novel series of NNO tridentate ligands generating imino, amido and oxo donor pocket for Pd(II) coordination. All the compounds were meticulously characterized by elemental analysis and advanced spectroscopic techniques, including FTIR, proton and carbon NMR. The synthesized compounds underwent rigorous evaluation for their potential as anti-cancer agents, utilizing the aggressive breast cancer cell lines MDA-MB (ATCC) and MCF-7 as a crucial model for assessing growth inhibition in cancer cells. Remarkably, the MTT assay unveiled the robust anti-cancer activity for all palladium complexes against MDA-MB-231 and MCF-7 cells. Particularly, complex [Pd(L1)(CH3CN)] exhibited exceptional potency with an IC50 value of 25.50 ± 0.30 µM (MDA-MB-231) and 20.76 ± 0.30 µM (MCF-7), compared to respective 27.00 ± 0.80 µM and 24.10 ± 0.80 µM for cisplatin, underscoring its promising therapeutic potential. Furthermore, to elucidate the mechanistic basis for the anti-cancer effects, molecular docking studies on tyrosine kinases, an integral target in cancer research, were carried out. The outcome of these investigations further substantiated the remarkable anticancer properties inherent to these innovative compounds. This research offers a compelling perspective on the development of potent anti-cancer agents rooted in the synergy between ligands and Pd(II) complexes and presenting a promising avenue for future cancer therapy endeavors.

Synthesis, Characterizations, Hirshfeld Surface Analysis, DFT, and NLO Study of a Schiff Base Derived from Trifluoromethyl Amine.

We synthesized an imine-based (Schiff base) crystalline organic chromophore, i.e., (E)-2-ethoxy-6-(((3-(trifluoromethyl)phenyl)imino)methyl)phenol (ETPMP), and explored its nonlinear optical (NLO) properties. The crystalline structure of ETPMP was determined by the XRD technique and equated with the associated structures utilizing a Cambridge Structural Database search. The supramolecular assembly of ETPMP was investigated regarding intermolecular interactions and short contacts by Hirshfeld surface analysis. Void analysis was performed to check the mechanical response of the crystal. Supramolecular assembly was further inspected by interaction energy calculations that were performed with the B3LYP/6-31G(d,p) functional. Besides this, the NLO properties of ETPMP and other already reported crystal TFMOS were explored utilizing the M06/6-31G(d,p) functional of the DFT approach. An excellent agreement was observed between XRD and DFT results of geometric parameters of the above-mentioned crystals. Narrow band gap along with bathochromic shift (3.489 eV and 317.225 nm, respectively) were investigated in TFMOS than that of ETPMP. Owing to these unique properties, TFMOS possesses higher linear (⟨a⟩ = 3.835 × 10-23 esu) and nonlinear (γtot. = 1.346 × 10-34 esu) response as compared to ETPMP. The outcomes explicitly show the higher nonlinearity in TFMOS, highlighting its importance in potential NLO applications.

Development of Membranes and Separators to Inhibit Cross-Shuttling of Sulfur in Polysulfide-Based Redox Flow Batteries: A Review.

The global rapid transition from fossil fuels to renewable energy resources necessitates the implementation of long-duration energy storage technologies owing to the intermittent nature of renewable energy sources. Therefore, the deployment of grid-scale energy storage systems is inevitable. Sulfur-based batteries can be exploited as excellent energy storage devices owing to their intrinsic safety, low cost of raw materials, low risk of environmental hazards, and highest theoretical capacities (gravimetric: 2600 Wh/kg and volumetric: 2800 Wh/L). However, sulfur-based batteries exhibit certain scientific limitations, such as polysulfide crossover, which causes rapid capacity decay and low Coulombic efficiency, thereby hindering their implementation at a commercial scale. In this review article, we focus on the latest research developments between 2012-2023 to improve the separators/membranes and overcome the shuttle effect associated with them. Various categories of ion exchange membranes (IEMs) used in redox batteries, particularly polysulfide redox flow batteries and lithium-sulfur batteries, are discussed in detail. Furthermore, advances in IEM constituents are summarized to gain insights into different fundamental strategies for attaining targeted characteristics, and a critical analysis is proposed to highlight their efficiency in mitigating sulfur cross-shuttling issues. Finally, future prospects and recommendations are suggested for future research toward the fabrication of more effective membranes with desired properties.

Polymorphs of Substituted p-Toluenesulfonanilide: Synthesis, Single-Crystal Analysis, Hirshfeld Surface Exploration, and Theoretical Investigation.

Polymorphism is an exciting feature of chemical systems where a compound can exist in different crystal forms. The present investigation is focused on the two polymorphic forms, triclinic (MSBT) and monoclinic (MSBM), of ethyl 3-iodo-4-((4-methylphenyl)sulfonamido)benzoate prepared from ethyl 4-amino-3-iodobenzoate. The prepared polymorphs were unambiguously confirmed by single-crystal X-ray diffraction (SC-XRD) analysis. According to the SC-XRD results, the molecular configurations of both structures are stabilized by intramolecular N-H···I and C-H···O bonding. The crystal packing of MSBT is different as compared to the crystal packing of MSBM because MSBT is crystallized in the triclinic crystal system with the space group P1̅, whereas MSBM is crystallized in the monoclinic crystal system with the space group P21/c. The molecules of MSBT are interlinked in the form of dimers through N-H···O bonding to form R22(8) loops, while the MSBM molecules are connected with each other in the form of an infinite chain through C-H···O bonding. The crystal packing of both compounds is further stabilized by off-set π···π stacking interactions between phenyl rings, which is found stronger in MSBM as compared to in MSBT. Moreover, Hirshfeld surface exploration of the polymorphs was carried out, and the results were compared with the closely related literature structure. Accordingly, the supramolecular assembly of these polymorphs is mainly stabilized by noncovalent interactions or intermolecular interactions. Furthermore, a density functional theory (DFT) study was also carried out, which provided good support for the SC-XRD and Hirshfeld studies, suggesting the formation of both intramolecular and intermolecular interactions for both compounds.

Synthesis and Antioxidant Studies of 2,4-Dioxothiazolidine-5-acetic Acid Based Organic Salts: SC-XRD and DFT Approach.

In the current study, two organic salts (1 and 2) are synthesized, and then crystalline structures are characterized by FTIR, UV spectroscopy, and X-ray crystallographic studies. The organic salts 1 and 2 are optimized at the M06/6-311G(d,p)level of theory and further utilized for analysis of natural bond orbitals (NBOs), natural population, frontier molecular orbitals (FMOs), and global reactivity parameters, which confirmed the stability of the studied compounds and charge transfer phenomenon in the studied compounds. The studies further revealed that 1 and 2 are more stable than 3. The lowest energy merged monomer-coformer conformations were docked as flexible ligands with rigid fungal proteins and DNA receptors. The stagnant binding of the monomer through two H bonds with protein was observed for ligands 1 and 3 while different pattern was found with 2. The coformers formed a single H bond with the active site in 2 and 3 and a single pi-arene H interaction in 1. The two-point ligand-receptor interactions hooked the monomer between DNA base pairs for partial intercalation; pi stacking with additive hydrogen bonding with the base pair led to a strong benzimidazole interaction in 1 and 2, whereas ethylene diamine formed weak H bonding. Thus, the molecular docking predicted that the coformer exhibited DNA intercalation reinforced by its salt formation with benzimidazole 1 and methyl benzimidazole 2. Antioxidant studies depicted that 3 has a higher IC50 value than that of 2,4-D and also the largest value among the studied compounds, whereas 2 showed the lowest value among the studied compounds.

Bandgap Engineering of Melon using Highly Reduced Graphene Oxide for Enhanced Photoelectrochemical Hydrogen Evolution.

The uncondensed form of polymeric carbon nitrides (PCN), generally known as melon, is a stacked 2D structure of poly(aminoimino)heptazine. Melon is used as a photocatalyst in solar energy conversion applications, but suffers from poor photoconversion efficiency due to weak optical absorption in the visible spectrum, high activation energy, and inefficient separation of photoexcited charge carriers. Experimental and theoretical studies are reported to engineer the bandgap of melon with highly reduced graphene oxide (HRG). Three HRG@melon nanocomposites with different HRG:melon ratios (0.5%, 1%, and 2%) are prepared. The 1% HRG@melon nanocomposite shows higher photocurrent density (71 µA cm-2 ) than melon (24 µA cm-2 ) in alkaline conditions. The addition of a hole scavenger further increases the photocurrent density to 630 µA cm-2 relative to the reversible hydrogen electrode (RHE). These experimental results are validated by calculations using density functional theory (DFT), which revealed that HRG results in a significant charge redistribution and an improved photocatalytic hydrogen evolution reaction (HER).

Preparation, Crystal Structure, Supramolecular Assembly, and DFT Studies of Two Organic Salts Bearing Pyridine and Pyrimidine.

The effective preparation of two new pyrimidine- and pyridine-based organic crystalline salts with substituted acidic moieties (i.e., (Z)-4-(naphthalen-2-ylamino)-4-oxobut-2-enoic acid (DCNO) and 2-hydroxy-3,5-dinitrobenzoic acid (PCNP)) using methanol as a solvent has been reported. These molecular salts have ionic interactions that are responsible for their structural stabilization in their solid-state assemblies. The crystal structures of DCNO and PCNP were determined by the single-crystal X-ray diffraction (SCXRD) technique. The SCXRD study inferred that cations and anions are strongly packed due to N-H···O, N-H···N, and C-H···O noncovalent interactions in DCNO, whereas in PCNP, N-H···N noncovalent interactions are absent. The noncovalent interactions in both organic crystalline salts were comprehensively investigated by Hirshfeld surface analysis. Further, a detailed density functional theory (DFT) study of both compounds was performed. The optimized structures of both compounds supported the existence of the H-bonding and weak dispersion interactions in the synthesized organic crystalline salt structures. Both compounds were shown to have large and noticeably different HOMO/LUMO energy gaps. The atomic charge analysis results supported the SCXRD and HSA results, showing the formation of intermolecular noncovalent interactions in both organic crystalline salts. The results of the natural bond orbital (NBO) analysis confirmed the existence of (relatively weak) noncovalent interactions between the cation and anion moieties of their organic crystalline salts. The global reactivity parameters (GRPs) analysis showed that both organic crystalline salts' compounds should be quite thermodynamically stable and that DCNO should be less reactive than PCNP. For both compounds, the molecular electrostatic potential (MEP) analysis results support the existence of intermolecular electrostatic interactions in their organic crystalline salts.

Evaluation of Antimicrobial, Anticholinesterase Potential of Indole Derivatives and Unexpectedly Synthesized Novel Benzodiazine: Characterization, DFT and Hirshfeld Charge Analysis.

The pharmacological effectiveness of indoles, benzoxazepines and benzodiazepines initiated our synthesis of indole fused benoxazepine/benzodiazepine heterocycles, along with enhanced biological usefulness of the fused rings. Activated indoles 5, 6 and 7 were synthesized using modified Bischler indole synthesis rearrangement. Indole 5 was substituted with the trichloroacetyl group at the C7 position, yielding 8, exclusively due to the increased nucleophilic character of C7. When trichloroacylated indole 8 was treated with basified ethanol or excess amminia, indole acid 9 and amide 10 were yielded, respectively. Indole amide 10 was expected to give indole fused benoxazepine/benzodiazepine 11a/11b on treatment with alpha halo ester followed by a coupling agent, but when the reaction was tried, an unexpectedly rearranged novel product, 1,3-bezodiazine 12, was obtained. The synthetic compounds were screened for anticholinesterase and antibacterial potential; results showed all products to be very important candidates for both activities, and their potential can be explored further. In addition, 1,3-bezodiazine 12 was explored by DFT studies, Hirshfeld surface charge analysis and structural insight to obrain a good picture of the structure and reactivity of the products for the design of derivatised drugs from the novel compound.

Synthesis, Crystal Structure, DFT Calculations, Hirshfeld Surface Analysis and In Silico Drug-Target Profiling of (R)-2-(2-(1,3-Dioxoisoindolin-2-yl)propanamido)benzoic Acid Methyl Ester.

The work here reflects synthesis, DFT studies, Hirshfeld charge analysis and crystal data exploration of pharmacologically important (R)-2-(2-(1,3-dioxoisoindolin-2-yl)propanamido)benzoic acid methyl ester (5) to understand its properties for further chemical transformations. The methyl anthranilate (2) was produced by the esterification of anthranilic acid in an acidic medium. The phthaloyl-protected alanine (4) was rendered by the fusion of alanine with phthalic anhydride at 150 °C, followed by coupling with (2) furnished isoindole (5). The characterization of products was performed using IR, UV-Vis, NMR and MS. Single-crystal XRD also verified the structure of (5) in which N-H⋯O bonding stabilizes the molecular configuration of (5), resulting in the formation of S(6) hydrogen-bonded loop. The molecules of isoindole (5) are connected in the form of dimers, and the π⋯π stacking interaction between aromatic rings further stabilizes the crystal packing. DFT studies suggest that HOMO is over the substituted aromatic ring, the LUMO is present mainly over the indole side, and nucleophilic and electrophilic corners point out the reactivity of the product (5). In vitro and in silico analysis of (5) shows its potential as an antibacterial agent targeting DNA gyrase and Dihydroorotase from E. coli and tyrosyl-tRNA synthetase and DNA gyrase from Staphylococcus aureus.

Therapeutic potential of 1,3,4-oxadiazoles as potential lead compounds for the treatment of Alzheimer's disease.

Monoamine oxidase and cholinesterase enzymes are important targets for the treatment of several neurological diseases especially depression, Parkinson disease and Alzheimer's. Here, we report the synthesis and testing of new 1,3,4-oxadiazole derivatives as novel inhibitors of monoamine oxidase enzymes (MAO-A and MAO-B) and cholinesterase enzymes (acetyl and butyryl cholinesterase (AChE, BChE). Compounds 4c, 4d, 4e, 4g, 4j, 4k, 4m, 4n displayed promising inhibitory effects on MAO-A (IC50: 0.11-3.46 µM), MAO-B (IC50: 0.80-3.08 µM) and AChE (IC50: 0.83-2.67 µM). Interestingly, compounds 4d, 4e and 4g are multitargeting MAO-A/B and AChE inhibitors. Also, Compound 4m displayed promising MAO-A inhibition with IC50 of 0.11 µM and high selectivity (∼25-fold) over MAO-B and AChE enzymes. These newly synthesized analogues represent promising hits for the development of promising lead compounds for neurological disease treatment.

Efficient Synthesis of Imine-Carboxylic Acid Functionalized Compounds: Single Crystal, Hirshfeld Surface and Quantum Chemical Exploration.

Two aminobenzoic acid based crystalline imines (HMBA and DHBA) were synthesized through a condensation reaction of 4-aminobenzoic acid and substituted benzaldehydes. Single-crystal X-ray diffraction was employed for the determination of structures of prepared Schiff bases. The stability of super molecular structures of both molecules was achieved by intramolecular H-bonding accompanied by strong, as well as comparatively weak, intermolecular attractive forces. The comparative analysis of the non-covalent forces in HMBA and DHBA was performed by Hirshfeld surface analysis and an interaction energy study between the molecular pairs. Along with the synthesis, quantum chemical calculations were also accomplished at M06/6-311G (d, p) functional of density functional theory (DFT). The frontier molecular orbitals (FMOs), molecular electrostatic potential (MEP), natural bond orbitals (NBOs), global reactivity parameters (GRPs) and natural population (NPA) analyses were also carried out. The findings of FMOs found that Egap for HMBA was examined to be smaller (3.477 eV) than that of DHBA (3.7933 eV), which indicated a greater charge transference rate in HMBA. Further, the NBO analysis showed the efficient intramolecular charge transfer (ICT), as studied by Hirshfeld surface analysis.

Photoreforming of Waste Polymers for Sustainable Hydrogen Fuel and Chemicals Feedstock: Waste to Energy.

Energy from renewable resources is central to environmental sustainability. Among the renewables, sunlight-driven fuel synthesis is a sustainable and economical approach to produce vectors such as hydrogen through water splitting. The photocatalytic water splitting is limited by the water oxidation half-reaction, which is kinetically and energetically demanding and entails designer photocatalysts. Such challenges can be addressed by employing alternative oxidation half-reactions. Photoreforming can drive the breakdown of waste plastics and biomass into valuable organic products for the production of H2. We provide an overview of photoreforming and its underlying mechanisms that convert waste polymers into H2 fuels and fine chemicals. This is of paramount importance from two complementary perspectives: (i) green energy harvesting and (ii) environmental sustainability by decomposing waste polymers into valuables. Competitive results for the generation of H2 fuel without environmental hazards through photoreforming are being generated. The photoreforming process, mechanisms, and critical assessment of the field are scarce. We address such points by focusing on (i) the concept of photoreforming and up-to-date knowledge with key milestones achieved, (ii) uncovering the concepts and challenges in photoreforming, and (iii) the design of photocatalysts with underlying mechanisms and pathways through the use of different polymer wastes as substrates.

Synthesis, Characterization, Crystal Structures, and Supramolecular Assembly of Copper Complexes Derived from Nitroterephthalic Acid along with Hirshfeld Surface Analysis and Quantum Chemical Studies.

Two new Cu(II) carboxylate complexes, Cu-NTA and Cu-DNTA, were prepared by treating 2-nitroterephthalic acid with CuSO4·5H2O at room temperature. The synthesized complexes were characterized by elemental (CHN), FT-IR, and thermogravimetric analysis. The crystal structures of both complexes were explored by single crystal X-ray diffraction analysis, which inferred that the coordination geometry is slightly distorted octahedral and square pyramidal in Cu-NTA and Cu-DNTA, respectively. The non-covalent interactions that are the main feature of the supramolecular assembly were investigated by Hirshfeld surface analysis for both complexes. The propensity of each pair of chemical moieties involved in crystal-packing interactions was determined by the enrichment ratio. Quantum chemical computations were performed to optimize the molecular geometry of complex Cu-NTA and compared it with the experimental single crystal structure, which was found to be in sensible agreement with the experimental structure of the complex. The DFT method was used to see the potential of the selected Cu-NTA complex for linear and nonlinear optical properties. The static NLO polarizability <γ> of complex Cu-NTA was calculated to be 86.28 × 10-36 esu at M06 functional and 6-31G*/LANL2DZ basis set, which was rationally large to look for NLO applications of complex Cu-NTA. Additionally, the molecular electrostatic potential and frontier molecular orbitals were also computed with the same methodology to see electronic characteristics and ground-state electronic charge distributions.

Exploring Probenecid Derived 1,3,4-Oxadiazole-Phthalimide Hybrid as α-Amylase Inhibitor: Synthesis, Structural Investigation, and Molecular Modeling.

1,3,4-Oxadiazole moiety is a crucial pharmacophore in many biologically active compounds. In a typical synthesis, probenecid was subjected to a sequence of reactions to obtain a 1,3,4-oxadiazole-phthalimide hybrid (PESMP) in high yields. The NMR (1H and 13C) spectroscopic analysis initially confirmed the structure of PESMP. Further spectral aspects were validated based on a single-crystal XRD analysis. Experimental findings were confirmed afterwards by executing a Hirshfeld surface (HS) analysis and quantum mechanical computations. The HS analysis showed the role of the π⋯π stacking interactions in PESMP. PESMP was found to have a high stability and lower reactivity in terms of global reactivity parameters. α-Amylase inhibition studies revealed that the PESMP was a good inhibitor of α-amylase with an s value of 10.60 ± 0.16 µg/mL compared with that of standard acarbose (IC50 = 8.80 ± 0.21 µg/mL). Molecular docking was also utilized to reveal the binding pose and features of PESMP against the α-amylase enzyme. Via docking computations, the high potency of PESMP and acarbose towards the α-amylase enzyme was unveiled and confirmed by docking scores of -7.4 and -9.4 kcal/mol, respectively. These findings shine a new light on the potential of PESMP compounds as α-amylase inhibitors.

Synthesis, antioxidant activity, antimicrobial efficacy and molecular docking studies of 4-chloro-2-(1-(4-methoxyphenyl)-4,5-diphenyl-1H-imidazol-2-yl)phenol and its transition metal complexes.

Herein, a one-pot synthesis of tetra-substituted imidazole, 4-chloro-2-(1-(4-methoxyphenyl)-4,5-diphenyl-1H-imidazol-2-yl)phenol (HL), is reported by the reaction of benzil, 5-bromosalicylaldehyde, ammonium acetate and anisidine. The synthesized imidazole was reacted with salts of 1st row transition metals (Co(ii), Ni(ii), Cu(ii), Mn(ii) and Zn(ii)) to obtain metal complexes. The structure of the compounds was confirmed using various spectroscopic and analytical techniques. HL, which is crystalline, was characterized by SC-XRD. Subsequently, the synthesized compounds were evaluated for their antioxidant and antimicrobial activities. Antimicrobial studies revealed the more noxious nature of metal complexes compared to ligand against various strains of bacteria and fungi. Molecular docking results based on the binding energy values also supported the experimental results of the antioxidant activities of the compounds. HL was found to be a better antioxidant than metal complexes. For a better insight into the structure, computational studies of the compounds were also carried out. A clear intra-molecular charge transfer was perceived in the ligand and its metal complexes. The transfer integral values for holes (36.48 meV) were found to be higher than the electron transfer integrals (24.76 meV), which indicated that the ligand would be a better hole transporter. According to the frontier molecular orbitals of the dimer, the charge transfer within the molecule is found from monomer 1 to 2.

Acid catalyzed one-pot approach towards the synthesis of curcuminoid systems: unsymmetrical diarylidene cycloalkanones, exploration of their single crystals, optical and nonlinear optical properties.

In the present study crystalline unsymmetrical diarylidene ketone derivatives BNTP and BDBC have been prepared by two sequential acid catalyzed aldol condensation reactions in a one pot manner. The crystal structures of both compounds were confirmed by single crystal X-ray diffraction analysis which revealed the presence of H-bonding interactions of type C-H⋯O, along with weak C-H⋯π and weak π⋯π stacking interactions that are involved in the crystal stabilization of both organic compounds. Hirshfeld surface analysis is carried out for the broad investigation of the intermolecular interactions in both compounds. The quantum chemical investigation was performed on the optimized molecular geometries of BNTP and BDBC to calculate optical and nonlinear optical (NLO) properties. The density functional theory (DFT) study showed that the third-order NLO polarizabilities of compounds BNTP and BDBC are found to be 226.45 × 10-36 esu and 238.72 × 10-36 esu, respectively, which indicates noticeable good NLO response properties. Additionally, the BNTP and BDBC molecules also showed the HOMO-LUMO orbital gaps of 5.96 eV and 6.06 eV, respectively. Furthermore, the computation of UV-visible spectra of the titled compounds indicated a limited and/or no absorption above the 400 nm region, directing a good transparency and NLO property trade-off for both synthesized compounds that may play a significant contribution in the future for optoelectronic technologies.