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Abstract Solid supported catalysts have several synthetic applications. Herein, finely ground eggshells were used as a solid support for the preparation of transition metal (Ni, Zn, Cu, Sn and Co) based catalysts to synthesize 2,4-dinitrophenylhydrazone (3) and dihydropyrimidinones (7 and 8). The effect of catalyst load, time and temperature on product yield was studied. Box Behnken Model was employed, and three predictors named catalyst amount (A), reaction time (B), and reaction temperature (C) were used to find the correlation of the predictors with the yield. Second order polynomial equation was used to estimate the effects of these factors. According to the statistical model, about 12% increase in yield was observed as a result of one-unit increase in reaction time while all other terms were kept constant. The values of S (18.1616) and R2 (71.2%) indicate that the statistical model gave an adequate fit to data. Quadratic model for the response surface was used for the analysis of variance (ANOVA) results, the larger F-values, and smaller p-values indicated that the predictors are in good agreement. The linear model terms of predictors were found to be significantly effective for yield (P

Abstract Herein we have reported a fluorescent probe (MB-M) based on MB derivative for Cu2+ ions detection. The probe was well characterized by 1H NMR, 13C NMR and HR-MS spectrum. Probe MB-M showed naked-eyes recognition to Cu2+ as color change from colorless to indigo. The probe exhibited promising features such as high fluorescence and UV–vis selectivity, fast response (5 mint), workable at pH 2–7, and low limit of detection (LOD = 0.33 µM). Probe MB-M was also used for Cu2+ ions imaging in HepG-2 cells and detection in daily life (Test Strip and lake water). Moreover, non-covalent interaction (NCI) and quantum theory of atoms in molecules (QTAIM) analysis were used to study the interaction between MB-M and Cu2+ ions. By examining the electronic characteristics of the complex using natural bond orbital (NBO), electron density difference (EDD), and frontier molecular orbital (FMO) analysis, the sensitivity of MB-M towards Cu2+ ions were investigated. The results illustrated that the interactions between MB-M and Cu2+ ions involved chemisorption.

Five organotin(IV) derivatives (1–5) of general formula R3SnL and R2SnL2, where R = C4H9 {1, and 3}, CH3 {2 and 4}, C6H5 {5} and L represents 4-fluorophenoxyacetate ligand were synthesized by the condensation reaction of corresponding organotin(IV) chloride and sodium-4-fluorophenoxyaceate salt in dry chloroform under reflux condition. The elemental analysis has confirmed the expected composition of the complexes. The Δν values (less than 200 cm−1) calculated from FT-IR spectra revealed bridging/chelating bidentate coordination of the carboxylate ligand to the tin. The single crystal XRD analysis has shown polymeric chain structures for complexes 1 and 2 with bridging bidentate carboxylate ligand connecting tin atoms having trigonal bipyramidal geometry. In complex 3, the tin atom with chelating anisobidentate ligands adopted a highly distorted octahedral geometry. Quantum chemical studies have shown a good correlation between experimental and theoretically calculated geometric parameters. The Hirshfeld surface and fingerprint plots calculations have shown H…H interactions as the major intermolecular contacts present within the crystal structures of complexes 1–3. The experimental and simulated (1H and 13C) NMR spectra were found to be in good agreement. The in vitro enzyme inhibition {acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase B (MAO-B), alpha-glucosidase, dipeptidyl peptidase-4, cyclooxygenase (COX) and lipoxygenase (LOX)}, antioxidant [DPPH = 2,2-diphenyl-1-picrylhydrazyl and ABTS = 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid] and antileishmanial assays have shown dose dependent responses of the test compounds. Complexes have shown higher activities compared to the free ligand acid. Complexes were particularly more active acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) inhibitors, especially complex 3 (IC50 = 0.60 µg/mL) was even more potent than the standard drug Galantamine (IC50 = 2.82 µg/mL). MTT [MTT= (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide tetrazolium)] assay showed potent anticancer activity for complex 4 (IC50 = 12.54 ± 0.19 µg/mL), complex 5 (IC50 = 16.44 ± 0.17 µg/mL), and free 4-fluorophenoxyacetic acid (HL) (IC50 = 21.95 ± 0.09 µg/mL) among the tested compounds towards the brain cancer cell line (Malignant glioma U87). The nonmalignant human embryonic kidney HEK293 cells were found to be less vulnerable to the test compounds. In the antimicrobial assays, complexes 1 and 2 have shown activities higher than the standard drug Cefixime against C. albicans and P. aeruginosa, respectively.

Gallic acid (GA), an important phenolic component, is gaining popularity due to its biological and industrial applications. However, its rapid expansion can be hazardous, causing cancer and gene damage, making the design of a low-cost and fast GA sensor difficult. We used a single-step hydrothermal approach to synthesize MoS2 nanoparticles for colorimetric detection of GA. The nanoparticles were analyzed using techniques like; UV–Vis spectroscopy, FT-IR spectroscopy, SEM, EDX and XRD. The optimization of key parameters such as MoS2 concentration (2.0 mg), temperature (30 °C), and pH (7) resulted in a limit of detection (LOD) of 0.125 × 10−6 M with a dynamic range of 0.5 to 36 × 10−6 M. MoS2 nanoflowers performed as nanozymes in the filter paper-based sensor, catalyzing 3, 3′, 5, 5′-tetramethylbenzidine (TMB) oxidation, while GA acted as an inhibitor to prevent further reaction progression. The detection was made feasible through capturing an image support by an ordinary smartphone and the steady-state kinetic study validated MoS2 nanoflowers' affinity for sensing H2O2. The sensor performed well in real-world samples such as diet tea, green tea, water, blood serum, and urine, with recovery rates ranging from 93.2 % to 102.1 %. Density functional theory calculations were applied to provide an insight into GA-MoS2 binding interactions and changes in electronic properties. With all of these merits, we believe MoS2 nanoparticles can provide low-cost and portable filter paper-based strips as a sensing platform for visual assessment of GA.

In this work, we investigated Diospyros kaki extract and an isolated compound for their potential as xanthine oxidase (XO) inhibitors, a target enzyme involved in inflammatory disorders. The prepared extract was subjected to column chromatography, and dinaphthodiospyrol S was isolated. Then XO inhibitory properties were assessed using a spectrophotometry microplate reader. DMSO was taken as a negative control, and allopurinol was used as a standard drug. The molecular docking study of the isolated compound to the XO active site was performed, followed by visualization and protein–ligand interaction. The defatted chloroform extract showed the highest inhibitory effect, followed by the chloroform extract and the isolated compound. The isolated compound exhibited significant inhibitory activity against XO with an IC50 value of 1.09 µM. Molecular docking studies showed that the compound strongly interacts with XO, forming hydrogen bond interactions with Arg149 and Cys113 and H-pi interactions with Cys116 and Leu147. The binding score of −7.678 kcal/mol further supported the potential of the isolated compound as an XO inhibitor. The quantum chemical procedures were used to study the electronic behavior of dinaphthodiospyrol S isolated from D. kaki. Frontier molecular orbital (FMO) analysis was performed to understand the distribution of electronic density, highest occupied molecular orbital HOMO, lowest unoccupied molecular orbital LUMO, and energy gaps. The values of HOMO, LUMO, and energy gap were found to be −6.39, −3.51 and 2.88 eV respectively. The FMO results indicated the intramolecular charge transfer. Moreover, reactivity descriptors were also determined to confirm the stability of the compound. The molecular electrostatic potential (MEP) investigation was done to analyze the electrophilic and nucleophilic sites within a molecule. The oxygen atoms in the compound exhibited negative potential, indicating that they are favorable sites for electrophilic attacks. The results indicate its potential as a therapeutic agent for related disorders. Further studies are needed to investigate this compound's in vivo efficacy and safety as a potential drug candidate.

Medicinal plants are the main source of active chemical constituents responsible for curing or mitigating various ailments. To discover new, safe, and effective drug candidates the isolation and screening of natural products are essential. In the current research work, lapachol was isolated from Fernandoa adenophylla, which was evaluated for anti-inflammatory effect followed by molecular docking. The isolated compound was tested for anti-inflammatory effects using in vitro (HRBC assay) and in vivo (xylene-induced ear edema) experimental models. Various concentrations of lapachol demonstrated anti-inflammatory effects with a percent potential of 77.96 at 100 μM. Different concentrations of Lapachol demonstrated a dose-dependent anti-edematous effect with a maximum percent effect of 77.9 % at a higher dose. The histopathological study revealed that the application of xylene led to a significant increase in ear thickness, along with clear signs of ear edema and infiltration of inflammatory cells, as well as epidermal hyperplasia of the dermis when compared to the control group. However, treatment with the investigated compound showed a significant reduction in ear thickness and pathological differences comparable to those observed in the group treated with diclofenac. Density functional theory calculations are accomplished to gain insight into structural and spectroscopic properties. Geometry optimization, FMO, and MEP analyses are performed. Overall, the molecular docking results indicate that lapachol has potential as a COX inhibitor by binding to the active sites of both COX-1 and COX-2 enzymes.

In the ongoing pursuit of novel and efficient NLO materials, the potential of alkali metal-doped {6}cycloparaphenylene ({6}CPP) and methylene bridged {6} cycloparaphenylene (MB{6}CPP) nanohoops as excellent NLO candidates has been explored. The geometric, electronic, linear, and nonlinear optical properties of designed systems have been investigated theoretically. All the nanohoops demonstrated thermodynamic stability, with remarkable interaction energies reaching up to −1.39 eV (−0.0511 au). Notably, the introduction of alkali metals led to a significant reduction in the HOMO-LUMO energy gaps, with values as low as 2.92 eV, compared to 6.80 eV and 6.06 eV for undoped {6}CPP and MB{6}CPP, respectively. Moreover, the alkali metal-doped nanohoops exhibited exceptional NLO response, with the K@r6-{6}CPP complex achieving the highest first hyperpolarizability of 56,221.7 × 10−30 esu. Additionally, the frequency-dependent first hyperpolarizability values are also computed at two commonly used wavelengths of 1550 nm and 1907 nm, respectively. These findings highlight the potential of designed nanohoops as promising candidates for advanced NLO materials with high-tech applications.

Significant efforts are continuously exerted by the scientific community to explore new strategies to design materials with high nonlinear optical responses. An effective approach is to design alkalides based on Janus molecules. Herein, we present a new approach to remarkably boost the NLO response of alkalides by stacking the Janus molecules. Alkalides based on stacked Janus molecule, M-n-M' (where n = 2 & 3 while M and M′ are Li/Na/K) are studied for structural, energetic, electrical, and nonlinear optical properties. The thermodynamic stability of the designed complexes is confirmed by the energetic stabilities, which range between -14.07 and -28.77 kcal/mol. The alkalide character of alkali metals-doped complexes is confirmed by the NBO charge transfer and HOMO(s) densities. The HOMO densities are located on the doped alkali metal atoms, indicating their alkalide character. The absorptions in UV–Vis and near IR region confirm the deep ultraviolet transparency of the designed complexes. The maximum first static and dynamic hyperpolarizabilities of 5.13 × 107 and 6.6 × 106 au (at 1339 nm) confirm their high NLO response, especially for K-2-M′ complexes. The NLO response of alkalides based on stacked Janus molecules is 1–2 orders of magnitude higher than the alkalide based on Janus monomer. The high values of dc-Kerr and electric field-induced response e.g., max ∼107 and 108 au, respectively have been obtained. These findings suggest that our designed complexes envision a new insight into the rational design of stable high NLO performance materials.

The designing of new materials having outstanding nonlinear optical (NLO) response is much needed for use in latest optics. Herein, the geometric, electronic and NLO properties of alkali and alkaline earth metals doped C6O6Li6 (alk-C6O6Li6-alkearth, alkearth = Ca, Mg, Be and alk = K, Na, Li) electrides is studied via quantum chemical approach. The interaction energies (Eint) are examined to illustrate their thermodynamic stability. The strong interaction energy of -39.99 kcal mol-1 is observed for Ca–C6O6Li6–Li electride in comparison to others. Frontier molecular orbitals (FMOs) energy gap of considered complexes is changed due to the electronic density shifting between metals and C6O6Li6 surface, which notifies the semi conducting properties of these electrides. The FMOs isodensities and natural bond orbital (NBO) charge analysis are performed to justify charge transfer between dopants and complexant. UV–Visible study also confirmed the application of these electrides as deep ultra-violet laser devices. NLO response is studied through calculation of first hyperpolarizability (βo). The highest βo value of 1.68 × 105 au is calculated for Mg–C6O6Li6–K electride. NLO response is further rationalized by three- and two-level models approach.

A new series of alkaline earthides based on Cryptand [2.2.2] (C222) containing nine complexes is designed by carefully placing alkali metals and alkaline earth metals inside and outside the C222 complexant, respectively i.e., M1(C222)M2 (M1 = Li, Na, K; M2 = Be, Mg, Ca). The designed complexes are reasonably stable both electronically and thermodynamically, as revealed through their vertical ionization potentials (VIPs) and interaction energies, respectively. Moreover, the true alkaline earthide nature of the complexes is confirmed through NBO and FMO analyses showing the negative charges and HOMOs over the alkaline earth metals, respectively. The further validity of true earthide characteristic is represented graphically by the spectra of partial density of states (PDOS). HOMO-LUMO gaps of the compounds are also very small (from 2.23 to 2.83 eV) when compared with pure cage's (C222) H-L gap i.e., 5.63 eV. All these features award these complexes with very small values of transition energies (ΔE) ranging from 0.68 to 2.06 eV ultimately resulting in remarkably high hyperpolarizability values up to 2.7 × 105 au (for Na+(C222)Mg−). Furthermore, applying external electric field (EEF) on the complexes enhances hyperpolarizability further. A remarkable increase of 1000 folds has been seen when hyperpolarizability of K+(C222)Ca− is calculated after EEF application i.e., from 8.79 × 104 au to 2.48 × 107 au; when subjected to 0.001 au external electric field.

In current work, three N-acetyl pyrazoline derivatives (1–3) have been prepared via 1,4-addition reaction of hydrazine on chalcones, followed by cyclization of the adduct in the presence of acetic acid. The structural interpretation of synthesized compounds was accomplished using various characterization techniques like FT-IR, Ultraviolet/visible spectroscopy, 1H NMR and 13C NMR. The synthesized compounds were evaluated for antioxidant, Urease inhibitory and Lipoxygenase inhibitory activities and results revealed that compound 2 showed promising antioxidant, Urease inhibitory and Lipoxygenase inhibitory activity with IC50 values 33.2 ± 0.45, 32.7 ± 0.11 and 42.2 ± 0.77, respectively. Moreover, DNA binding interactions of the N-acetyl pyrazoline derivatives have also been carried out with SS-DNA (Salmon Sperm DNA) using absorption spectroscopy. Furthermore, molecular docking was conducted for a ready comparison with the experimental data and to determine the interactions involved. ADMET profiling of pyrazoline derivatives was also done using Admet SAR. Besides that, quantum chemical calculations using DFT (density functional theory) were carried out to explore optimized geometries, FMOs (Frontier molecular orbitals), NBOs (Nonbonding orbitals) of synthesized compounds and to predict their NLO (Nonlinear optical) properties. The synthesized compounds showed much better NLO behavior than standard Urea along with a strong agreement between computed and empirically recorded spectral data.

Switchable nonlinear optical (NLO) materials have widespread applications in electronics and optoelectronics. Thermo-switches generate many times higher NLO responses as compared to photo-switches. Herein, we have investigated the geometric, electronic, and nonlinear optical properties of spiropyranes thermochromes via DFT methods. The stabilities of close and open isomers of selected spiropyranes are investigated through relative energies. Electronic properties are studied through frontier molecular orbitals (FMOs) analysis. The lower HOMO-LUMO energy gap and lower excitation energy are observed for open isomers of spiropyranes, which imparts the large first hyperpolarizability value. The delocalization of π-electrons, asymmetric distribution and elongated conjugation system are dominant factors for high hyperpolarizability values of open isomers. For deep understanding, we also analyzed the frequency-dependent hyperpolarizability and refractive index of considered thermochromes. The NLO response increased significantly with increasing frequency. Among all those compounds, the highest refractive index value is observed for the open isomer of the spiropyran 1 (1.99 × 10−17 cm2/W). Molecular absorption analysis confirmed the electronic excitation in the open isomers compared to closed isomers. The results show that reversible thermochromic compounds act as excellent NLO molecular switches and can be used to design advanced electronics.

Novel organic materials have played a tremendous role in developing high-performance nonlinear optical materials. Herein, the geometric, electronic and nonlinear optical properties of designed alkali (Li, Na, and K) and alkaline earth metals (Be, Mg, and Ca) doped cubane (C8H8) complexes have been explored by using density functional theory. Excess electrons generated by doping alkali/alkaline earth metals have significantly enhanced the NLO properties by reducing the crucial excitation energy of the cubane. The HOMO–LUMO energy gap of doped complexes is reduced up to 4.43 eV. It is revealed that the reduction in the HOMO–LUMO energy gap results from the development of the new highest occupied molecular orbital, which is confirmed by the density of state (DOS) analysis. The NBO analysis is carried out to confirm the charge transfer between metal atoms and the cubane ring. Further, the NCI and QTAIM analyses confirmed the nature of intramolecular interaction. The remarkable first hyperpolarizability (βo) of 3.01 × 104 au is observed for K@Cubane. Moreover, frequency dependent first hyperpolarizability (β (ω)), second harmonic generation β (-2ω; ω,ω), electro-optic Pockel's effect β (-ω; ω,0), hyper-Rayleigh scattering coefficient (βHRS), second hyperpolarizability (γ (ω)), electric field-induced second harmonic generation γ(-2ω; ω, ω,0) electro-optic Kerr effect γ(-ω; ω,0,0), and nonlinear refractive indices (n2) were also studied. The highest dc-Kerr (2.69 × 1010 au) and EFISHG (3.69 × 109 au) values observed for K@Cubane along with large n2 (1.73 × 10−9 au) justify the large NLO response. These intriguing outcomes will be advantageous for promoting the possible utilization of designed complexes in the field of high-performance NLO materials.

The toxicity of transition metals, including copper(II), manganese(II), iron(II), zinc(II), hexavalent chromium, and cobalt(II), at elevated concentrations presents a significant threat to living organisms. Thus, the development of efficient sensors capable of detecting these metals is of utmost importance. This study explores the utilization of two-dimensional nitrogenated holey graphene (C2N) nanosheet as a sensor for toxic transition metals. The C2N nanosheet’s periodic shape and standard pore size render it well suited for adsorbing transition metals. The interaction energies between transition metals and C2N nanosheets were calculated in both gas and solvent phases and were found to primarily result from physisorption, except for manganese and iron which exhibited chemisorption. To assess the interactions, we employed NCI, SAPT0, and QTAIM analyses, as well as FMO and NBO analysis, to examine the electronic properties of the TM@C2N system. Our results indicated that the adsorption of copper and chromium significantly reduced the HOMO–LUMO energy gap of C2N and significantly increased its electrical conductivity, confirming the high sensitivity of C2N towards copper and chromium. The sensitivity test further confirmed the superior sensitivity and selectivity of C2N towards copper. These findings offer valuable insight into the design and development of sensors for the detection of toxic transition metals.

Four Ni–phen complexes were prepared and characterized by FTIR and thermal analysis. The X-ray structure determination shows that the geometry around NiII ions in complexes 1, [Ni(phen)2(H2O)(ONO2)](NO3); 2, [Ni(phen)2(H2O)Cl]Cl; 3, [Ni(phen)(CH3CN)(ONO2)(O2NO)] and 4, [Ni(phen)3](NO3)2.H2O.C2H5OH is considerably distorted octahedral. The coordination core geometries in 1, 2, 3 and 4 are NiN4O2, NiN4OCl, NiN3O3 and NiN6, respectively. The crystal packing and crystal supramolecularity analysis of the complexes reveal the importance of aryl∙∙∙aryl interactions, and both offset face-to-face (OFF) and edge-to-face (EF) motifs are dominant. Hydrogen bonding interactions in these structures reinforce aryl∙∙∙aryl interactions. FTIR proved the coordination of M-N and M-Cl as well as the presence of nitro groups in the complexes, while thermal analysis revealed that the loss of water, chloro and nitro groups occurred before the degradation of phenanthroline ligand in the complexes. DFT study indicates that a strong correlation exists among theoretical and experimentally determined geometric parameters with distorted octahedral geometry. The charge density in HOMO is localized on the metal halogen bond and nitrate group (NO3−), whereas the LUMO cloud density is mainly distributed on the phen ring, which indicates the electroactive nature of the ring.

Industrial pollutants pose a serious threat to ecosystems. Hence, there is a need to search for new efficient sensor materials for the detection of pollutants. In the current study, we explored the electrochemical sensing potential of a C6N6 sheet for H-containing industrial pollutants (HCN, H2S, NH3 and PH3) through DFT simulations. The adsorption of industrial pollutants over C6N6 occurs through physisorption, with adsorption energies ranging from −9.36 kcal/mol to −16.46 kcal/mol. The non-covalent interactions of analyte@C6N6 complexes are quantified by symmetry adapted perturbation theory (SAPT0), quantum theory of atoms in molecules (QTAIM) and non-covalent interaction (NCI) analyses. SAPT0 analyses show that electrostatic and dispersion forces play a dominant role in the stabilization of analytes over C6N6 sheets. Similarly, NCI and QTAIM analyses also verified the results of SAPT0 and interaction energy analyses. The electronic properties of analyte@C6N6 complexes are investigated by electron density difference (EDD), natural bond orbital analyses (NBO) and frontier molecular orbital analyses (FMO). Charge is transferred from the C6N6 sheet to HCN, H2S, NH3 and PH3. The highest exchange of charge is noted for H2S (−0.026 e−). The results of FMO analyses show that the interaction of all analytes results in changes in the EH-L gap of the C6N6 sheet. However, the highest decrease in the EH-L gap (2.58 eV) is observed for the NH3@C6N6 complex among all studied analyte@C6N6 complexes. The orbital density pattern shows that the HOMO density is completely concentrated on NH3, while the LUMO density is centred on the C6N6 surface. Such a type of electronic transition results in a significant change in the EH-L gap. Thus, it is concluded that C6N6 is highly selective towards NH3 compared to the other studied analytes.

Carbon-based polynuclear clusters are designed and investigated for geometric, electronic, and nonlinear optical (NLO) properties at the CAM-B3LYP/6-311++G(d,p) level of theory. Significant binding energies per atom (ranging from −162.4 to −160.0 kcal mol−1) indicate excellent thermodynamic stabilities of these polynuclear clusters. The frontier molecular orbital (FMOs) analysis indicates excess electron nature of the clusters with low ionization potential, suggesting that they are alkali-like. The decreased energy gaps (EH-L) with increased alkali metals size revael the improved electrical conductivity (σ). The total density of state (TDOS) study reveals the alkali metals’ size-dependent electronic and conductive properties. The significant first and second hyperpolarizabilities are observed up to 5.78 × 103 and 5.55 × 106 au, respectively. The βo response shows dependence on the size of alkali metals. Furthermore, the absorption study shows transparency of these clusters in the deep-UV, and absorptions are observed at longer wavelengths (redshifted). The optical gaps from TD-DFT are considerably smaller than those of HOMO-LUMO gaps. The significant scattering hyperpolarizability (βHRS) value (1.62 × 104) is calculated for the C3 cluster, where octupolar contribution to βHRS is 92%. The dynamic first hyperpolarizability β(ω) is more pronounced for the EOPE effect at 532 nm, whereas SHG has notable values for second hyperpolarizability γ(ω).

Nonlinear optical (NLO) materials have spanned a large area of science and technology owning to their potential applications in optoelectronics. The invention of the first Ruby laser has sparked a fresh interest in the area of nonlinear optics. The computational designing and experimental synthesis of organic and inorganic NLO materials with higher order nonlinearities come into vogue in the field of materials science. To date, several strategies including metal ligand framework, push pull mechanism, diradical character, and so on have been devised to enhance the NLO response of materials. In addition, introduction of diffuse excess electrons is an efficient approach to design noncentrosymmetric materials for nonlinear optics. The current review highlights a systematic array of different computational studies (covering the last decade of intensive research work) for the theoretical designing of NLO materials. In the present review, theoretical designing from the simplest NLO material to the complex alkali, alkaline earth, transition, and superalkali doped nanomaterials is summarized. The emergence of excess electrons strategy has played a pivotal role in enhancing the NLO properties especially hyperpolarizabilities. We expect that this review will provide a better understanding of the NLO responses of nanoclusters, paving the way for the advancement of hi-tech NLO materials to meet the real challenges in optoelectronics.

Alzheimer’s disease is a major public brain condition that has resulted in many deaths, as revealed by the World Health Organization (WHO). Conventional Alzheimer’s treatments such as chemotherapy, surgery, and radiotherapy are not very effective and are usually associated with several adverse effects. Therefore, it is necessary to find a new therapeutic approach that completely treats Alzheimer’s disease without many side effects. In this research project, we report the synthesis and biological activities of some new thiazole-bearing sulfonamide analogs (1–21) as potent anti-Alzheimer’s agents. Suitable characterization techniques were employed, and the density functional theory (DFT) computational approach, as well as in-silico molecular modeling, has been employed to assess the electronic properties and anti-Alzheimer’s potency of the analogs. All analogs exhibited a varied degree of inhibitory potential, but analog 1 was found to have excellent potency (IC50 = 0.10 ± 0.05 µM for AChE) and (IC50 = 0.20 ± 0.050 µM for BuChE) as compared to the reference drug donepezil (IC50 = 2.16 ± 0.12 µM and 4.5 ± 0.11 µM). The structure-activity relationship was established, and it mainly depends upon the nature, position, number, and electron-donating/-withdrawing effects of the substituent/s on the phenyl rings.

V-series nerve agents are very lethal to health and cause the inactivation of acetylcholinesterase which leads to neuromuscular paralysis and, finally, death. Therefore, rapid detection and elimination of V-series nerve agents are very important. Herein, we have carried out a theoretical investigation of carbon nitride quantum dots (C2N) as an electrochemical sensor for the detection of V-series nerve agents, including VX, VS, VE, VG, and VM. Adsorption of V-series nerve agents on C2N quantum dots is explored at M05-2X/6-31++G(d,p) level of theory. The level of theory chosen is quite adequate in systems describing non-bonding interactions. The adsorption behavior of nerve agents is characterized by interaction energy, non-covalent interaction (NCI), Bader’s quantum theory of atoms in molecules (QTAIM), frontier molecular orbital (FMO), electron density difference (EDD), and charge transfer analysis. The computed adsorption energies of the studied complexes are in the range of −12.93 to −17.81 kcal/mol, which indicates the nerve agents are physiosorbed onto C2N surface through non-covalent interactions. The non-covalent interactions between V-series and C2N are confirmed through NCI and QTAIM analysis. EDD analysis is carried out to understand electron density shifting, which is further validated by natural bond orbital (NBO) analysis. FMO analysis is used to estimate the changes in energy gap of C2N on complexation through HOMO-LUMO energies. These findings suggest that C2N surface is highly selective toward VX, and it might be a promising candidate for the detection of V-series nerve agents.

Currently, hydrogen is recognized as the best alternative for fossil fuels because of its sustainable nature and environmentally friendly processing. In this study, hydrogen dissociation reaction is studied theoretically on the transition metal doped carbon nitride (C2N) surface through single atom catalysis. Each TMs@C2N complex is evaluated to obtain the most stable spin state for catalytic reaction. In addition, electronic properties (natural bond orbital NBO & frontier molecular orbital FMO) of the most stable spin state complex are further explored. During dissociation, hydrogen is primarily adsorbed on metal doped C2N surface and then dissociated heterolytically between metal and nitrogen atom of C2N surface. Results revealed that theFe@C2N surface is the most suitable catalyst for H2 dissociation reaction with activation barrier of 0.36 eV compared with Ni@C2N (0.40 eV) and Co@C2N (0.45 eV) complexes. The activation barrier for H2 dissociation reaction is quite low in case of Fe@C2N surface, which is comparatively better than already reported noble metal catalysts.

Alkene is an attractive substrate for chemists due to its easy availability and reactivity towards large number of reactants affording diverse range of organic compounds. It reacts under ionic and free radical mechanisms including single electron transfer (SET). In this review, strategies used for C–C and C-heteroatom functionalization of alkene has been discussed with emphasis on the regio, stereoselectivity, mechanistic detail and sustainability aspects. These strategies mainly follow the free radical mechanism, and the highly reactive carbon radicals show uncontrollable regio- and stereoselectivities. Thus these strategies still need to be focused; especially in the asymmetric versions. The regio- and stereoselectivities of functionalization of alkenes have been highlighted and debated. In addition, the hazardous reagents such as Cl2, Br2 I2, CO, peroxides, and benzene have also been discussed with the emphasis on their impact on the environment. Their plausible green alternatives have also been suggested, such as MX as halogen replacement; CO surrogates (formaldehyde etc.); sustainable aromatic solvents as benzene replacement. The non-green strategies relying on pre-formed silyl hydride and their green alternative strategies such as transfer hydrogenations have also been indicated. The applications of the functionalization of alkenes for the total synthesis of bioactive compounds have also been discussed in detail. In addition, future perspectives are also highlighted for further developments in the functionalization of alkenes.

Abstract A variety of imine derivatives have been synthesized via Suzuki cross coupling of N-(4-bromophenyl)-1-(3-bromothiophen-2-yl)methanimine with various arylboronic acids in moderate to good yields (58–72%). A wide range of electron donating and withdrawing functional groups were well tolerated in reaction conditions. To explore the structural properties, Density functional theory (DFT) investigations on all synthesized molecules (3a–3i) were performed. Conceptual DFT reactivity descriptors and molecular electrostatic potential analyses were performed by using B3LYP/6-31G(d,p) method to explore the reactivity and reacting sites of all derivatives (3a–3i).

Abstract Thiophene derivatives have shown versatile pharmacological activities. The Suzuki reaction proved a convenient method for C–C bond formations in organic molecules. In the present research work novel derivatives of 2,5-dibromo-3-methylthiophene (3a–k and 3l–p) has been synthesized, via Suzuki coupling reaction in low to moderate yields. A wide range of functional groups were well tolerated in reaction. Density functional theory investigations on all synthesized derivatives (3a–3p) were performed in order to explore the structural properties. The pharmaceutical potential of synthesized compounds was investigated through various bioassays (antioxidant, antibacterial, antiurease activities). The compounds 3l, 3g, 3j, showed excellent antioxidant activity (86.0, 82.0, 81.3%), respectively by scavenging DPPH. Synthesized compounds showed promising antibacterial activity against tested strains. 3b, 3k, 3a, 3d and 3j showed potential antiurease activity with 67.7, 64.2, 58.8, 54.7 and 52.1% inhibition at 50 µg/ml. Results indicated that synthesized molecules could be a potential source of pharmaceutical agents.

Adsorption of SO2 on pure B12P12 and Zn-doped B12P12 is investigated through density functional theory methods. Zn adsorption on BP delivers four optimized geometries: B-Top, P-top, b64, and ring-enlarged geometry with adsorption energies of −57.12 kJ/mol, −14.50 kJ/mol, −22.94 kJ/mol, and −14.83 kJ/mol, respectively. The adsorption energy of SO2 on pristine boron phosphide is −14.92 kJ/mol. Interaction of SO2 with Zn-doped boron phosphide gives four different geometries with adsorption energies of −69.76 kJ/mol, −9.82 kJ/mol, −104.92 kJ/mol, and −41.87 kJ/mol. Geometric parameters such as dipole moment, QNBO, frontier molecular orbital analysis, PDOS, and global indices of reactivity are performed to visualize the changes in electronic properties of B12P12 after Zn and SO2 adsorption.

A novel indigoferamide-A, earlier isolated from the seeds of Indigofera heterantha Wall was characterized using density functional theory, molecular docking and bioassays studies. Density functional theory calculations were performed at B3LYP/6-31G(d,p) to gain geometric insight of the compound. Conformational analyses have been performed around three important dihedral angles to explore the lowest energy structure and conformer. The simulated vibrational spectrum of the compound at B3LYP/6-31G(d,p) was scaled with two scaling factors, and the scaled harmonic vibrations shows nice correlation with the experimental values. 1H and 13C NMR chemical shifts were calculated using Cramer's re-parameterized function W04 at 6- 31G(d,p) basis set. Several conformers lying within 2 kcal mol−1 of the minimum energy conformer were considered; however, the chemical shifts were not significantly different among these conformers. The Gaussian averaged theoretical 1H and 13C chemical shifts correlate nicely with the experimental data. Electronic properties such as band gap, ionization potential and electron affinities were also simulated for the first time, however, no comparison could be made with the experiment. The compound was also screened for urease, antiglycation activities and the theoretical explanation of the results is provided based on molecular docking simulations.

A variety of novel 5-aryl thiophenes 4a–g containing sulphonylacetamide (sulfacetamide) groups were synthesized in appreciable yields via Pd[0] Suzuki cross coupling reactions. The structures of these newly synthesized compounds were determined using spectral data and elemental analysis. Density functional theory (DFT) studies were performed using the B3LYP/6-31G (d, p) basis set to gain insight into their structural properties. Frontier molecular orbital (FMOs) analysis of all compounds 4a–g was computed at the same level of theory to get an idea about their kinetic stability. The molecular electrostatic potential (MEP) mapping over the entire stabilized geometries of the molecules indicated the reactive sites. First hyperpolarizability analysis (nonlinear optical response) were simulated at the B3LYP/6-31G (d, p) level of theory as well. The compounds were further evaluated for their promising antibacterial and anti-urease activities. In this case, the antibacterial activities were estimated by the agar well diffusion method, whereas the anti-urease activities of these compounds were determined using the indophenol method by quantifying the evolved ammonia produced. The results revealed that all the sulfacetamide derivatives displayed antibacterial activity against Bacillus subtiles, Escherichia coli, Staphylococcus aureus, Shigella dysenteriae, Salmonella typhae, Pseudomonas aeruginosa at various concentrations. Furthermore, the compound 4g N-((5-(4-chlorophenyl)thiophen-2-yl)sulfonyl) acetamide showed excellent urease inhibition with percentage inhibition activity ~46.23 ± 0.11 at 15 µg/mL with IC50 17.1 µg/mL. Moreover, some other compounds 4a–f also exhibited very good inhibition against urease enzyme.

We report here a comparative theoretical and experimental study of four triazine-based hydrazone derivatives. The hydrazones are synthesized by a three step process from commercially available benzil and thiosemicarbazide. The structures of all compounds were determined by using the UV-Vis., FT-IR, NMR (1H and 13C) spectroscopic techniques and finally confirmed unequivocally by single crystal X-ray diffraction analysis. Experimental geometric parameters and spectroscopic properties of the triazine based hydrazones are compared with those obtained from density functional theory (DFT) studies. The model developed here comprises of geometry optimization at B3LYP/6-31G (d, p) level of DFT. Optimized geometric parameters of all four compounds showed excellent correlations with the results obtained from X-ray diffraction studies. The vibrational spectra show nice correlations with the experimental IR spectra. Moreover, the simulated absorption spectra also agree well with experimental results (within 10–20 nm). The molecular electrostatic potential (MEP) mapped over the entire stabilized geometries of the compounds indicated their chemical reactivates. Furthermore, frontier molecular orbital (electronic properties) and first hyperpolarizability (nonlinear optical response) were also computed at the B3LYP/6-31G (d, p) level of theory.

Alzheimer's disease (AD) is a fast growing neurodegenerative disorder of the central nervous system and anti-oxidants can be used to help suppress the oxidative stress caused by the free radicals that are responsible for AD. A series of selected synthetic indole derivatives were biologically evaluated to identify potent new antioxidants. Most of the evaluated compounds showed significant to modest antioxidant properties (IC50 value 399.07 140.0±50 µM). Density Functional Theory (DFT) studies were carried out on the compounds and their corresponding free radicals. Differences in the energy of the parent compounds and their corresponding free radicals provided a good justification for the trend found in their IC50 values. In silico, docking of compounds into the proteins acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), which are well known for contributing in AD disease, was also performed to predict anti-AD potential.

New thiosemicarbazide-linked acridines 3a–c were prepared and investigated as chemosensors for the detection of biologically and environmentally important anions. The compounds 3a–c were found selective for fluoride (F−) with no affinity for other anions, i.e. −OAc, Br−, I−, HSO4−, SO42−, PO43−, ClO3−, ClO4−, CN− and SCN−. Further, upon the gradual addition of a fluoride anion (F−) source (tetrabutylammonium fluoride), a well-defined change in colour of the solution of probes 3a–c was observed. The anion-sensing process was studied in detail via UV–visible absorption, fluorescence and 1H-NMR experiments. Moreover, during the synthesis of acridine probes 3a–c nickel fluoride (NiF2), a rarely explored transition metal fluoride salt, was used as the catalyst. Theoretical studies via density functional theory were also carried out to further investigate the sensing and anion (F−) selectivity pattern of these probes.

In the present study, 4-methylpyridin-2-amine was reacted with 3-bromothiophene-2-carbaldehyde and the Schiff base (E)-1-(3-bromothiophen-2-yl)-N-(4-methylpyridin-2-yl)methanimine was obtained in a 79% yield. Coupling of the Schiff base with aryl/het-aryl boronic acids under Suzuki coupling reaction conditions, using Pd(PPh3)4 as catalyst, yielded products with the hydrolysis of the imine linkages (5a−5k, 6a−6h) in good to moderate yields. To gain mechanistic insight into the transition metal-catalyzed hydrolysis of the compounds, density functional theory (DFT) calculations were performed. The theoretical calculations strongly supported the experiment and provided an insight into the transition metal-catalyzed hydrolysis of imines.

Synthesis of hydroazulene derivatives has been carried out through a ring-enlargement route by using carbene adduct intermediates. The protocol can be applied for the construction of functionalized hydroazulene skeletons as key components of many natural products as well as the core system of novel liquid-crystalline materials.

Aromaticities of five membered heterocycles, containing up to three heteroatoms, are quantified through the dimethyldihydropyrene (DHP) probe. Bond fixation caused by the fusion of heterocycles to the dimethyldihydropyrene nucleus (DHPN) was measured by changes in the 1H NMR chemical shifts (magnetic) and bond lengths alterations (structural criterion). Chemical shifts of dihydropyrenes were calculated at GIAO HF/6-31G(d)//B3LYP/6-31+G(d). For 1H NMR chemical shift analysis, two nonaromatic reference models are studied. Among the studied heterocycles, pyrazole and triazole are about 80–85% aromatic relative to benzene, through both magnetic and geometric criteria. Thiazole and oxazoles are found least aromatic where quantitative estimates of aromaticities are about 34–42%, relative to benzene. These quantitative estimates of aromaticities of five membered heterocycles are also comparable to those from aromatic stabilization energies. The quantification of aromaticity through energetic, magnetic, and structural criteria can deliver the similar inferences provided that suitable reference systems are chosen.

The present study describes palladium-catalyzed one pot Suzuki cross-coupling reaction to synthesize a series of novel pyridine derivatives 2a–2i, 4a–4i. In brief, Suzuki cross-coupling reaction of 5-bromo-2-methylpyridin-3-amine (1) directly or via N-[5-bromo-2-methylpyridine-3-yl]acetamide (3) with several arylboronic acids produced these novel pyridine derivatives in moderate to good yield. Density functional theory (DFT) studies were carried out for the pyridine derivatives 2a–2i and 4a–4i by using B3LYP/6-31G(d,p) basis with the help of GAUSSIAN 09 suite programme. The frontier molecular orbitals analysis, reactivity indices, molecular electrostatic potential and dipole measurements with the help of DFT methods, described the possible reaction pathways and potential candidates as chiral dopants for liquid crystals. The anti-thrombolytic, biofilm inhibition and haemolytic activities of pyridine derivatives were also investigated. In particular, the compound 4b exhibited the highest percentage lysis value (41.32%) against clot formation in human blood among all newly synthesized compounds. In addition, the compound 4f was found to be the most potent against Escherichia coli with an inhibition value of 91.95%. The rest of the pyridine derivatives displayed moderate biological activities.