In the current study, the DFT and TD-DFT methods are used to investigate seven donor–π-acceptor (D–π–A) dyes, named DY01 to DY07, which are planned for utilization in DSSCs. The HOMO-LUMO gaps are decreased due to the solvent effect by 0.05-0.16 eV and are smallest (1.85 eV) for DY01. Frontier molecular orbitals show that charge separation is efficient between triphenylamine donor and cyanoacrylic acid acceptor. The bathochromic shift due to the solvent effects is estimated by the TD-DFT calculations, and DY01 exhibits the maximum red shift (638 nm) as well as DY05 has the highest oscillator strength (f = 1.664). Photovoltaic parameters reveal that DY01 is the most efficient (0.958), and DY02 could receive the relatively better electrons injection strength accompanied with high Voc value. Adsorption on (TiO₂)₈ cluster has an additional decrease the energy gaps and DY01 and DY07 show strong red shifts. Upon adsorption, the orbital distribution shows strong electronic coupling conducive to photo-induced electron transfer to the semiconductor. It can be concluded that DY01 is the most efficient sensitizer showing highest quantum efficiency due to its narrow band gap, effective intramolecular charge transfer (ICT), high light-harvesting efficiency (LHE) and favorable interfacial properties.

In this work, the synthesis of 6,6'-([2,2'-bi(1,3,4-oxadiazole)]-5,5'-diyl)bis(3-chloroaniline) (6a) and 5,5'-([2,2'-bi(1,3,4-oxadiazole)]-5,5'-diyl)bis(benzene-1,3-diamine) (6b) was carried out and characterized by spectral data from 1H NMR, ¹³C NMR, IR and mass spectrometry. The optical properties of these compounds were studied, in particular the evolution of reflectance, absorption and band gap energy, and a scanning electron microscopy (SEM) analysis was performed. A comparative in-silico study combining DFT-based reactivity analysis, ADMET prediction, and molecular docking were employed for compounds 6a and 6b. Both exhibited distinct reactivity profiles and strong binding affinities toward DNA Gyrase B (7C7N) and the DNA-ruthenium complex (4E7Y), highlighting their potential as antibacterial agents, as well their potential use in photovoltaic application and for near infrared light shielding basing on the optical results.

Dye-sensitized solar cells (DSSCs) represent a highly promising new generation of photovoltaic devices that offer an attractive alternative to traditional silicon-based solar cells due to their low production costs, simple manufacturing, and adaptable optoelectronic properties. Titanium dioxide (TiO₂) is extensively utilized as a semiconductor in DSSCs due to the favorable position of its conduction band, high chemical stability, abundance, and non-toxicity. As part of this work, an in-depth computational study was conducted on five organic dyes (D1 to D5) to investigate their potential as effective sensitizers for DSSC applications. Density functional theory (DFT) and time-dependent DFT (TD-DFT) were employed to investigate their structural, electronic, and optical properties, as well as their key photovoltaic parameters. The HOMO energy levels calculated (−5.99 to −6.36 eV) were low enough to allow efficient dye regeneration by the electrolyte, while the LUMO levels (−3.05 to −3.71 eV) were located above the conduction band edge of TiO₂ (−4.0 eV), Calculated band gaps (2.35–2.94 eV) supported strong absorption in the visible range, and open-circuit voltages (0.26–0.94 eV) suggested good photovoltaic potential. Furthermore, all dyes presented positive free electron injection energy (ΔGinject), evidencing thermodynamically favorable charge transfer processes. Benchmarking revealed that structural modifications between dyes were found to be significantly.

The reactions between 2,3-dimethylbutadiene and six azodicarbonyl derivatives give the aromatic α-amino ketone family which presents a great interest in chemical synthesis and especially in polymerization reactions. This reaction was studied using the Molecular Electron Density Theory. The reaction pathways were established using the Intrinsic Reaction Coordinate (IRC) method and confirmed through topological analysis of the Electron Localization Function (ELF). The substituent effect was discussed from the CDFT and GEDT calculations. The temporary formation of hydrogen bonds at TSs is responsible for the mechanistic aspect and the process asynchronous of new bond formation. Consequently, the reaction proceeds via a non-concerted in two-stages mechanism. Finally, we investigated the potential inhibitory effects of six products against HIV-1-Mpro through molecular docking calculations. Then, their medicinal potential and physicochemical properties were scrutinized, employing the SwissADME server, unveiling their non-toxic characteristics and positioning them as promising contenders for drug development.

This study presents the synthesis and characterization of the compound 5,5'-(methylenebis(1,3,4-oxadiazole-5,2-diyl))bis(benzene-1,3-diamine), by ¹H NMR, ¹³C NMR and FTIR-ATR infrared spectroscopy and mass spectrometry. A theoretical study was carried out by a comprehensive and hierarchical methodology in order to evaluate the inhibitory behavior of the molecule 5,5'-(methylenebis(1,3,4-oxadiazole-5,2-diyl))bis(benzene-1,3-diamine) with respect to the corrosion of a Fe(110) type metal surface. Thus, examination of non-covalent interactions by NCI analysis. In addition, the study of adsorption on the metal surface was carried out by the Monte Carlo method.

This study explores the mechanism and solvent effects of the (3+2) cycloaddition between N-(4-(prop-2-yn-1-yloxy)phenyl)-1-(pyridin-2-yl)methanimine and 4-azido-7-chloroquinoline, yielding quinoline–triazole hybrids. DFT/B3LYP/6-311G+(d,p) calculations, supported by ELF and NPA analyses, reveal a one-step mechanism favoring product P1 both kinetically and thermodynamically. Non-covalent interaction (NCI) analysis indicates that TS1 is stabilized by hydrogen-bonding and van der Waals interactions. ADMET screening showed that all cycloadducts are non-toxic (no AMES mutagenicity or skin sensitization). Molecular docking identified P3 and P4 as the most potent ligands for Plasmodium falciparum kinases 5E16 and 5DYK, respectively, with stronger binding affinities than chloroquine. Molecular dynamics simulations further confirmed the structural stability of the P3–5E16 and P4–5DYK complexes, highlighting these derivatives as promising candidates for antimalarial drug development.

Herein, we theoretically design four new π-conjugated thieno[3,4-b]pyrazine derivatives for organic solar cells (OSCs), denoted 2,3-di([2,2′:5′,2″:5″,2‴-quaterthiophen]-5-yl)-5,7-di(thiophen-2-yl)thieno[3,4-b]pyrazine, 2,3-bis(5'''-(4-fluorophenyl)-[2,2':5',2'':5'',2'''-quaterthiophen]-5-yl)-5,7-di(thiophen-2-yl)thieno[3,4-b]pyrazine, 2,3-bis(5'''-(4-methoxyphenyl)-[2,2':5',2'':5'',2'''-quaterthiophen]-5-yl)-5,7-di(thiophen-2-yl)thieno[3,4-b]pyrazine, and 2,3-bis(5'''-(9-methyl-9H-carbazol-2-yl)-[2,2':5',2'':5'',2'''-quaterthiophen]-5-yl)-5,7-di(thiophen-2-yl)thieno[3,4-b]pyrazine. The geometric, electronic, optical, photovoltaic, and nonlinear optical (NLO) properties of the investigated chemical structure were investigated using Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) calculations at the B3LYP/6-31G(d,p) level. Structural changes on the chemical structure induce a narrow energy gap in the range (2.08 – 2.12 eV), and an enhancement of the absorption in the visible range (λmax = 682 – 688 nm). In addition, a low value of exciton binding energies is obtained (Eb = 0.28 – 0.31 eV). Analysis of the density of states (DOS), transition density matrix (TDM), electron localization function (ELF), and localized orbital locator (LOL) showed effective charge delocalization and donor-to-acceptor electron transfer. The photovoltaic performance was assessed using the open circuit voltage (Voc) obtained between Highest Occupied Molecular Orbital (HOMO) donor to Lowest Unoccupied Molecular Orbital (LUMO) acceptor levels and was found promising (Voc = 1.32 – 1.44 V). The large hyperpolarizability and high nonlinearity response of the NLO results also indicated the potential for these molecules to be used in various optoelectronic applications.

This investigation employs Molecular Electron Density Theory (MEDT) to elucidate the stereoselective (4+2) cycloaddition between 1-(furan-2-yl)propan-1-one and 1-R-1H-pyrrole-2,5-dione, combining mechanistic and pharmacological analyses. DFT calculations at the M06/6-311++G(d,p) level identified six distinct reaction pathways, revealing the exo cycloadduct as the thermodynamically favored product, consistent with experimental observations. Transition state analysis through NCI revealed stabilizing CH-π and van der Waals interactions governing the exo preference. Beyond mechanistic insights, the derived norcantharimide analogues exhibit promising anticancer potential, with strong binding affinities against hematological malignancy targets. SwissADME profiling confirmed optimal drug-likeness (QED > 0.6, TPSA < 100 Ų) and low hepatotoxicity risk. Notably, molecular dynamics simulations established exceptional stability for lead compound P2d (RMSD 75%) to key catalytic residues. These integrated computational results position these derivatives as viable candidates for blood cancer therapeutics, merging rigorous mechanistic understanding with preclinical potential assessment.

This study presents the synthesis and characterization of the compound 5-chloro-2-(5-(2-methyl-1H-benzimidazol-5-yl)-1.3.4-oxadiazol-2-yl)aniline, by ¹H NMR, ¹³C NMR, FTIR-ATR infrared spectroscopy and mass spectrometry. The theoretical investigation was evaluated using density functional theory (DFT), electrostatic surface potential (ESP) analysis as well as Fukui indices, ADME/Tox properties, molecular docking and Molecular Dynamics studies of this molecule.

Designing high-efficiency sensitizers remains a central challenge for dye-sensitized solar cells (DSSCs). In this work, nineteen donor motifs commonly employed in the literature were screened to identify optimal donors and to assess the impact of donor substitution on the reference dye D0 (2-cyano-3-[2′-(2″-(4″-(dimethylamino)phenyl)ethynyl)thieno[3,2-b]thiophen-5′-yl]acrylic acid) with the goal of improving device performance. Using DFT/TD-DFT with the CAM-B3LYP functional, we characterized nineteen literature-derived donor motifs via their electronic absorption spectra and key photovoltaic descriptors. Donor substitution, most notably with D1, D3, D5, D6, and D15, substantially improves the electronic and optical properties, yielding lower HOMO energies, a reduced band gap (Egap), enhanced absorption intensity, and a bathochromic shift of the main band. Performance indicators, notably the electron-injection free energy (ΔGinj) and open-circuit voltage (Voc), indicate spontaneous, thermodynamically favorable electron injection from the excited dye into the TiO₂ conduction band.