In this study, novel Schiff base compounds (FT1, FT2, and FT3) based on isatin-derived thiosemicarbazone structures were successfully synthesized, and their structures were elucidated using FT-IR and 1H-NMR spectroscopic techniques. The observation of characteristic vibrational bands corresponding to N-H, C--O, C--N, and C=S functional groups in the FT-IR spectra, together with the proton signals attributed to the thiosemicarbazone bridge, aromatic rings, and methoxy groups in the 1H-NMR spectra, confirmed the successful formation of the targeted molecular structures. This work represents the first computational study to evaluate the theoretical performance of these novel molecules, where the structures of FT1, FT2, and FT3 were optimized using Gaussian 09 software at the B3LYP/6-311G+(d,p) level of theory to predict quantum chemical parameters, including HOMO-LUMO energy orbitals and localized inhibitor-metal interaction indices. Furthermore, Monte Carlo (MC) simulations in both dry and explicit acidic environments (160H2O, 5H3O+, 5Cl-) were employed to estimate adsorption behaviors on Fe(110), Pd(111), and Ni(111) surfaces. To benchmark our computational predictions against experimentally validated systems, we compared our calculated HOMO-LUMO energy gaps with those reported for isatin-thiosemicarbazone derivatives in the literature, finding that the energy gap for FT3 (3.2560 eV) falls within or below the range of compounds with confirmed physical inhibition performance. The integration of DFT and MC methods provides a robust, multi-level theoretical prediction that FT3 is the highest-performing compound in the series. Quantitatively, FT3 exhibits the smallest frontier orbital energy gap (3.2560 eV) and the most negative, exergonic adsorption energies across all substrates. Specifically, under dry conditions, the adsorption energies reached-211.598 kcal/mol on Fe,-142.286 kcal/mol on Pd, and-141.120 kcal/mol on Ni, while exceeding-3765 kcal/mol,-3580 kcal/mol, and-3587 kcal/mol respectively in aggressive acidic media. These findings theoretically predict that FT3 possesses higher chemical reactivity and a greater tendency to participate in electron sharing and back-donation, thereby facilitating the formation of protective virtual coordinate bonds with the metallic surfaces. All conclusions presented herein serve as predictive computational tendencies and warrant future experimental validation through electrochemical measurements or mass loss tests.

This study presents the design, synthesis, and theoretical evaluation of three novel isatin-based thiosemicarbazone Schiff bases (Ot-1, Ot-2, and Ot-3) as potential organic corrosion inhibitors. The targeted compounds were successfully synthesized and structurally characterized using FT-IR, ¹H-NMR, and ¹³C-NMR spectroscopy. To assess their chemical reactivity and corrosion inhibition potential on copper Cu (111) and zinc Zn (0001) surfaces, comprehensive computational studies were conducted. Density Functional Theory (DFT) at the B3LYP level with a mixed basis set approach (6-311+G(d,p) for C, H, N, O, S and SDD with effective core potentials for Br, I) was utilized to calculate global reactivity descriptors, molecular electrostatic potential (MEP), and Fukui functions, while Monte Carlo simulations evaluated adsorption energies in acidic environments. The findings reveal that incorporating polarizable halogen substituents (Br in Ot-2, I in Ot-3) significantly narrows the HOMO-LUMO energy gap (reaching 3.198eV for Ot-3) and increases electrophilicity (ω = 6.032eV), thereby enhancing the molecules' charge-transfer capabilities. Compound Ot-3 demonstrated the most negative adsorption energy (−3878.31kcal/mol on Cu (111)) and highly favorable electron transfer parameters, showing a particular affinity for the Cu surface. Topological analyses (QTAIM, RDG, NCI) further corroborated the presence of strong intramolecular charge transfer and highly stable adsorption configurations. Overall, these computational insights establish a robust theoretical framework identifying these novel compounds as promising candidates to guide future experimental corrosion inhibition testing.

ABSTRACT In this study, the corrosion inhibition potential of a series of aromatic and heterocyclic organic compounds was systematically investigated using Density Functional Theory (DFT) and Monte Carlo (MC) simulations. The electronic structures of carbazole, thiophene, azobenzene, coumarin, quinoline, pyridine, resorcinol, benzaldehyde, 4‐nitroaniline, anthracene, Phenothiazine, aniline, hydroquinone, and fluorene were optimized, and their quantum chemical parameters were evaluated. The calculated HOMO and LUMO energies, energy gap (ΔE), dipole moment, electronegativity, global hardness, softness, and electrophilicity index were employed to assess the reactivity and corrosion inhibition capability of the investigated molecules. The results indicate that compounds possessing higher HOMO energies and lower energy gaps exhibit enhanced electron‐donating ability and stronger interaction with the metal surface, favoring effective corrosion protection. Among the studied compounds, quinoline, anthracene, and fluorene demonstrated particularly favorable electronic characteristics for corrosion inhibition. Furthermore, Monte Carlo simulations on the Fe(110) surface revealed strong and stable adsorption behavior for Phenothiazine, azobenzene, and coumarin, as evidenced by their highly negative adsorption energies. The enhanced adsorption performance is attributed to the presence of heteroatoms and extended π‐conjugated systems, which facilitate strong interactions with the metal surface. The combined DFT and MC results provide valuable insight into the structure–activity relationship governing corrosion inhibition and demonstrate the effectiveness of computational approaches for the screening and design of organic corrosion inhibitors.

In this study, two indole–thiosemicarbazone derivatives, namely TSC-I and TSC-OMe, were synthesized and comprehensively characterized using FT-IR, ¹H NMR, and ¹³C NMR spectroscopic techniques. The obtained spectral data confirmed the proposed molecular structures and revealed the influence of iodine and methoxy substituents on the electronic environment of the compounds. Density functional theory (DFT) calculations were performed at the B3LYP/6-311G(d,p) level to investigate the electronic structures, frontier molecular orbitals, and global reactivity parameters of the synthesized derivatives. HOMO–LUMO analyses indicated that TSC-OMe possesses a larger energy gap, suggesting higher electronic stability, whereas TSC-I exhibited relatively greater chemical reactivity. Mulliken charge analysis identified heteroatoms as the major contributors to charge distribution and potential reactive sites within the molecules.The antioxidant activities of the compounds were evaluated using the DPPH radical scavenging assay. TSC-I exhibited stronger radical scavenging activity than TSC-OMe, which may be associated with the electron-withdrawing effect of the iodine substituent and its contribution to radical stabilization. Antibacterial assays revealed selective inhibitory activity against both Gram-positive and Gram-negative bacteria, with TSC-I displaying a broader antibacterial spectrum and slightly higher activity than TSC-OMe. In addition, SwissADME analysis demonstrated that both compounds comply with major drug-likeness criteria and possess favorable pharmacokinetic characteristics, including high gastrointestinal absorption potential.Collectively, the experimental and theoretical results highlight the important role of substituent effects in modulating the electronic, antioxidant, and antibacterial properties of indole–thiosemicarbazone derivatives.

Due to their stable nature and medical applicability properties, coumarin derivatives have fascinated medicinal chemists in the discovery of novel therapeutics. In this study, the cytotoxic/anticancer properties of some newly synthesized coumarin derivatives were aimed at designing, synthesizing, and examining cultured human neuroblastoma cells. Moreover, molecular docking studies were carried out to determine the potential mechanism. In addition, ADMET properties were evaluated to examine the drug-likeness of newly designed coumarin derivatives. To detect the cytotoxic action of compounds, 3-(4,5-dimethylthiazol-2-yl)-2,5 2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) release assays were carried out. In addition, Hoechst 33258 staining was used to detect abnormal nuclear structures. In silico, the estimates for all compounds (3a-3c) used in the study revealed that they possessed desirable physicochemical properties for bioavailability. The results of our study showed that all tested compounds exhibited remarkable cytotoxic effects on human neuroblastoma cell lines (p < 0.05). Additionally, among the compounds tested, 3a and 3c showed selective effects on neuroblastoma cells effectively at all tested concentrations. However, it was found that the selective feature of 3b, unlike the others, was concentration-dependent. Our findings clearly showed that novel coumarin derivatives exerted potent and selective anticancer effects. Results of molecular docking studies were in parallel with in vitro studies. Unlike the majority of hybrid coumarin derivatives reported in anticancer research, the present study introduces minimalist, heteroatom-free coumarins bearing bulky aliphatic substituents. These compounds demonstrated selective cytotoxicity against SH-SY5Y neuroblastoma cells and a favorable multi-target binding profile, highlighting a distinct hydrophobic volume-based SAR. As a result, the obtained data exhibited that all used molecules may be good multitarget drug alternatives for the treatment of neuroblastoma.

This research investigates the chemical and physical characteristics of three recently synthesized coumarin compounds produced via the von Pechmann condensation mechanism. These compounds were successfully and precisely synthesized, as confirmed by a comprehensive understanding of their chemical composition obtained through combined infrared and NMR analyses. The compounds underwent examination regarding their responses to gamma and neutron radiations, and their mass attenuation coefficients (MAC) were determined using both GATE/Geant4 simulation and NIST-XCOM data. Additionally, the effective removal cross-section values for fast neutrons were calculated employing various methods. All acquired data has been compared with that of water and other materials in the existing literature. Although coumarin compounds might not have intrinsic shielding properties, they have the potential to be part of composite materials designed for specific applications. Comparative analysis with established radiation dosimetry systems showed the coumarin compounds’ attenuation coefficients closely aligning with water, indicating their potential suitability for nuclear applications requiring water-equivalent properties. Further assessment with Geant4 simulation under linac photon beams demonstrated the water-equivalent properties of the coumarin compounds for 6 MV and 18 MV.

The aim of the study was to synthesize 4-Coumarinyl-2-methylbenzoate, elucidate the reaction mechanism, perform quantum chemical calculations, and examine the swiss adme properties of the compound. 4-Coumarinyl-2-methylbenzoate compound was synthesized by nucleophilic substitution reaction. The compound 4-coumarinyl 2-methyl benzoate has been characterized both experimentally and theoretically using quantum chemical calculations and spectral techniques. Nuclear magnetic resonances and infrared spectroscopic values of 1H and 13C in the ground state of the compound were calculated both experimentally and theoretically (density functional theory method was used when making theoretical calculations). It was observed that the calculated infrared and nuclear magnetic resonance values were compatible with the experimental values. The energy difference between the HOMO-LUMO of the 4-Coumarinyl-2-methylbenzoate compound was calculated and it was found that this difference was 1.409 Ev. Finally, swiss adme properties of 4-Coumarinyl-2-methylbenzoate compound such as Molecular Mass (Size), Flexibility (FLEX), Polarity, Saturation (Insatu), Lipophilia, Water Solubility were examined.

1-[3-Methyl-3-(2,4,6-trimethylphenyl)cyclobutyl]-2-[4-benzyl(4-methylphenyl)-5-(thiophen-2-yl)-4H-1,2,4-triazol-3-yl]sulfanylethanones were synthesized by the condensation of 2-chloro-1-[3-methyl-3-(2,4,6-trimethylphenyl)cyclobutyl]ethanone with 4-benzyl- and 4-(4-methylphenyl)-5-(thiophen-2-yl)-4H-1,2,4-triazole-3-thiols. The new compounds were characterized by FT-IR and 1H and 13C NMR spectra. The molecular geometry, vibrational frequencies, and gauge-independent atomic orbital (GIAO) 1H and 13C NMR chemical shifts of the title compounds in the ground state were calculated using the density functional method (B3LYP) with the 6–311G(d,p) basis set. The calculated results showed that the optimized geometry well reproduces the theoretical vibrational frequencies, and the calculated chemical shifts were in good agreement with the experimental values.

In the present contribution, novel 1,2,4-triazolethiol-thiophene hybrids, namely 4-ethyl-5-(thiophen-2-yl)-4H-1,2,4-triazole-3-thiol (1) and 4-phenyl-5-(thiophen-2-yl)-4H-1,2,4-triazole-3-thiol (2), which were readily fabricated from addition of isothiocyanatoethane or isothiocyanatobenzene, respectively, to thiophene-2-carbohydrazide followed by addition a KOH solution to provoke the cyclization to the 1,2,4-triazole ring. The formation of compounds 1 and 2 was firmly confirmed by the means of elemental analysis, IR, 1H and 13C{1H} NMR spectroscopy. The DFT-based computations in gas phase were additionally applied to shed light on the structure and electronic features of the title compounds. Theoretical calculations revealed that for both molecules their corresponding thione derivatives, namely 4-ethyl-5-(thiophen-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (1') and 4-phenyl-5-(thiophen-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (2'), are 15.00 and 11.96 kcal/mol, respectively, more energetically favorable in gas phase. However, a comparison of the experimental and calculated IR and NMR spectra testify to the thiol tautomers of compounds 1 and 2 for both compounds in solid state and in DMSO-d6. The chemical activity of 1 and 2 was estimated by reactivity descriptors and MEP surface. ADMET properties of the reported compounds were predicted in silico using online services. Potential inhibition of a series of the tick-borne encephalitis (TBE) proteins by compounds 1 and 2 was studied using molecular docking, which, in turn, allowed to reveal the ligand efficiency scores for the resulting protein-ligand complexes. It was established that compound 1 exhibits the best activity against the tick-borne encephalitis virus Serine protease NS3, while compound 2 is preferable for the RNA-stimulated ATPase activity of tick-borne encephalitis virus helicase.

This work presents the characterization of 8-t-buthyl-4-methyl-2H- chromen 2-one by quantum chemical calculations and spectral techniques. The molecular geometry, vibrational frequencies and gauge including atomic orbital (GIAO) 1H and 13C NMR chemical shift values of title compound in the ground state have been calculated using the density functional method (B3LYP) with the 6-31G(d) basis set. The theoretical vibrational frequencies and chemical shift values show good agreement with experimental values. In addition, DFT calculations of molecular electrostatic potentials and frontier molecular orbitals of the title were carried out at the B3LYP/6-31G(d) level of theory. The title compound was screened for antibacterial, antifungal and antioxidant activities.

Synthesis, characterization and theoretical studies of a novel coumarin-triazole-thiophene hybrid 4-(((4-ethyl-5-(thiophen-2-yl)-4H-1,2,4-triazol-3-yl)thio)methyl)-6,7-dimethyl-2H-chromen-2-one (1), which was fabricated from 4-ethyl-5-(thiophen-2-yl)-4H-1,2,4-triazole-3-thiol and 4-(chloromethyl)-6,7-dimethyl-2H-chromen-2-one, are reported. The resulting compound was characterized by microanalysis, IR, 1H, and 13C APT NMR spectroscopy. The DFT calculations examined the structure and electronic properties of 1 in gas phase. Its reactivity descriptors and molecular electrostatic potential revealed the reactivity and the reactive centers of 1. ADMET properties of 1 were evaluated using the respective online tools. It was established that 1 exhibit positive gastrointestinal absorption properties and negative human blood-brain barrier penetration. The Toxicity Model Report revealed that 1 belongs to toxicity class 4. Molecular docking was additionally applied to study the interaction of 1 with some SARS-CoV-2 proteins. It was established that the title compound is active against all the applied proteins with the most efficient interaction with Papain-like protease (PLpro). The interaction of 1 with the applied proteins was also studied using molecular dynamics simulations. A novel coumarin-triazole-thiophene hybrid 4-(((4-ethyl-5-(thiophen-2-yl)-4H-1,2,4-triazol-3-yl)thio)methyl)-6,7-dimethyl-2H-chromen-2-one (1) is reported. The structure and electronic properties of 1 were examined by the DFT calculations. ADMET properties of 1 were also evaluated. Molecular docking and molecular dynamics simulations were applied to study interactions of 1 with a series of the SARS-CoV-2 proteins.

In this study, the biosorption properties of fast green FCF (FG) dye in an aqueous solution were investigated using cranberry (Cornus mas L.) kernel (CK) as lignocellulosic biowaste. The biosorbent performance of the cranberry (Cornus mas L.) kernel biomass for FG dye molecules was optimized: 500 mg L-1 at natural pH: 6.0 at 25 degrees C. The maximum biosorption capacity for CK biomass was found to be 21.6 mg g(-1) from the Langmuir isotherm model. Biosorption thermodynamics showed that FG dye biosorption to CK biomass was spontaneous, entropy-increasing, and endothermic. The kinetic data were described by the PSO and IPD kinetic models. Thermodynamic parameters were calculated, and it was seen that the biosorption process is spontaneous and endothermic. FT-IR spectrum after biosorption provided data supporting the formation of electrostatic interactions, n-pi interactions, and H-bonds between anionic FG dye molecules and CK biomass. When the results of this study were evaluated as a whole, it was concluded that CK biosorbent is a natural, abundant, low-cost, effective, and potential biosorbent for the removal of FG dye molecules from wastewater.

In this work, we report synthesis, characterization and computational studies of the symmetric thiophene-based compound thiophene-2,5-diylbis((3-mesityl-3-methylcyclobutyl)methanone) (1) obtained from 2,2'-thiobis(1-(3-mesityl-3-methylcyclobutyl)ethan-1-one) and glyoxal using the Hinsberg thiophene ring synthesis approach. The Density Functional Theory (DFT) calculations were performed to probe the structure of 1, as well as its electronic and optical properties. The global reactivity descriptors, as well as molecular electrostatic potential (MEP), were revealed to probe the reactivity and to determine the reactive centers of 1. The DFT calculations were also applied to probe 1 as a potential corrosion inhibitor for some important metals used in implants. Electron charge transfer from the molecule of 1 to the surface of Ni, Au, Co, Cu, Mo, W, Fe and Cr was revealed. Bioavailability, druggability as well as absorption, distribution, metabolism, excretion and toxicity properties of 1 were predicted. Molecular docking was applied to examine the influence of this compound on a series of the SARS-CoV-2 proteins. Compound 1 exhibited the best binding affinity with the Nsp14 (N7-MTase), Papain-like protease (PLpro) and Nsp16 (MGP site) proteins as well as demonstrated a similar efficiency toward both the native and mutated Spike proteins, RDB.

The aim of the study was to synthesize 4- (p-tollyl) -5- (thiophene-2-yl) -2,4-dihydro-3H-1,2,4-triazole-3-thione and detect its experimental and the quantum chemical properties. 4-(p-tollil)-5-(tiyofen-2-il)-2,4-dihidro-3H-1,2,4-triazol-3-tiyon was synthesized using by the nucleophilic sübstitüsyon reaction. The synthesized title compound has been characterized both experimentally and theoretically using quantum chemical calculations and spectral techniques. The molecular geometry, vibrational frequencies, and 1H and 13C NMR chemical shifts of the title compound in the ground state were calculated using the density functional method (B3LYP) with the 6–311G(d, p) basis set. It was seen that the calculated infrared and nuclear magnetic resonance values were compatible with the experimental values. To determine conformational flexibility, the molecular energy profile of 4- (p-tollyl) -5- (thiophene-2-yl) -2,4-dihydro-3H-1,2,4-triazole-3-thione was obtained by DFT calculations with respect to the selected torsion angle, which was varied from 180°to +180°in steps of 20°. In addition, the HOMO- LUMO energies of this conformational structure were calculated.

Synthesis 4-(((4-ethyl-5-(thiophen-2-yl)-4H-1,2,4-triazol-3-yl)thio)methyl)-6,8-dimethyl-coumarin and spectral analysis is carried out using the FT-IR and NMR with the help of quantum chemical calculation by DFT/6-311(d,p). The molecular electrostatic potentials and frontier molecular orbitals of the title compound were carried out at the B3LYP/6-311G(d,p) level of theory. Antimicrobial, antioxidant activity, and In vitro cytotoxic for cell lines were observed. The result shows that the theoretical vibrational frequencies, 1H-NMR and 13C-NMR chemical shift, agree with experimental data. In vitro studies showed that antimicrobial activity was weak, particularly against bacteria such as E. coli, S. aureus, P. aeruginosa, and B. cereus. The test compound's oxidative stress index (OSI) has appeared as 0.079 ± 0.214 in antioxidant and oxidant capacity studies. The compound did not cause a harmful cytotoxic effect on healthy cell lines and showed no potential for anticancer activity on cancerous cell lines such as MCF-7 and MKN-45.

The title compound was synthesized by ring-closure reaction of thiophene-2-carbohydrazide with benzyl isothiocyanate and characterized using spectroscopic methods (NMR and FT-IR). Quantum chemical calculations at the B3LYP/6-311++G( d , p ) level were carried out to examine its molecular and spectroscopic properties, thione–thiol tautomerism, and proton transfer reaction. The structural and spectroscopic results were well consistent with the experimental data. The solvent effect on the proton transfer reaction was examined using three solvents (acetone, ethanol, and dimethyl sulfoxide) through the polarizable continuum model (PCM) approximation (direct solvent effect) and solvent-assisted mechanism. A high energy barrier was determined for the interconversion of the thione and thiol forms in both gas and solution phases. Even though the presence of solvent molecules significantly reduced the barrier to proton transfer, it was insufficient for the reaction to occur. The corresponding thermodynamic parameters and the energy difference between the HOMO and LUMO of the thione and thiol tautomers were calculated.

There is an urgent need for a drug to be used against COVID-19, which negatively affects human life worldwide and causes pandemic leading to the death of many people. Although some drugs are included in the treatment protocols of health institutions, there are currently no specific drugs against COVID-19 or are unknown, and effective treatment options remain very limited. Since designing a novel drug and testing its pharmacological properties may take long years, here we used a faster virtual study approach for some of our compounds with different chemical structures against COVID-19. Moreover, we included some drugs in this study and compared in silico results obtained. The activity potentials of these compounds were further evaluated through molecular docking studies with AutoDock4 and AutoDock Vina software. Among all the compounds studied, compounds 1a, 1b, and 1c demonstrate significant activity like other prodrugs, particularly against COVID-19. The most promising compound 1a has appropriate ADME prediction values and high binding affinity as a potential inhibitor of COVID-19 main protease.

The aim of the study was to synthesize 4-Coumarinyl-4-nitrobenzoate and detect its experimental and theoretical properties. 4-Coumarinyl-4-nitrobenzoate was synthesized using by the nucleophilic adduction-separation reaction of aroyl compounds. In this context 4-coumarinyl 4-nitrobenzoate compound has been characterized both experimentally and theoretically by using quantum chemical calculations and spectral techniques. Quantum chemical calculations such as the molecular geometry, geometric structure, and geometric parameters of the title compound were calculated with the 6-311G (d, p) basis set. Quantum chemical calculations of electronic properties such as energy difference between HOMO-LUMO, chemical hardness and chemical softness were made. Molecular electrostatic potential (MEP) surface of 4-Coumarinyl-4-nitrobenzoate was obtained.

Esterification of D-glucose with oleic- and palmitic acids were carried out in the absence and presence of a biocatalyst, Candida antarctica lipase. The reaction medium was a mixture of dimethyl sulphoxide and tert-butanol (1:4, v/v). The reaction products were analysed by FTIR, 1H-NMR and 13C-NMR, HSQC, and by ESI-MS. Results indicated that the ester products formed were 6-O-glucose oleate and 6-O-glucose palmitate both in the absence and in the presence of the biocatalyst, with yields above 90%.