TD-DFT Method Research Articles

Methoxy triphenylamine hexaazatrinaphthylene based small molecules as donor material for photovoltaic applications

Organic solar cells (OSCs) are capturing huge interest because of their numerous benefits, which include transparency, flexibility, and solution processability. In current project, five new donor molecules (J1-J5) were designed by employing the strategy of end capped alteration of the acceptor moieties on the two sides of the reference molecule. The Methoxy Triphenylamine hexaazatrinaphthylene (MeO-TPA-HATNA) have been used as a reference molecule in this study. DFT and TD-DFT methods employing B3LYP/6-31G (d, p) functional has been applied to perform different analysis. Geometrical, and opto-electronic features of all tailored chromophores were investigated, and comparison was made with the reference J. Among all tailored molecules, J5 shows highest λmax (862 nm) with the least band gap of 1.28 eV. TDM and DOS analysis revealed the high rate of charge transfer. Further, reorganization energy calculations are also executed to examine the charge transfer features of the designed molecules. The results shows that J5 among all these molecules has the highest rate of charge carrier (electron and hole) mobility with least RE values and this molecule can be used as a promising donor material for OSCs with remarkable charge transferring properties. Furthermore, the designed materials showed a suitable HOMO along with higher LUMO energy levels with respect to PC61BM molecule and coupling the PC61BM acceptor with investigated donor molecules gives highly increased Voc (0.66–0.76 V) than reference molecule (0.49 V) and also the power conversion efficiency (PCE) is elevated to 15.09%. The outcomes of current theoretical research have demonstrated that the end capped alteration of different acceptor groups is an excellent strategy to get OSCs with desirable photovoltaic performance. As, all the newly created molecules (J1-J5) have exhibited outstanding electronic and optical properties therefore, these can be expectedly prove excellent material for creating high efficiency future organic photovoltaic devices.

Design new organic material based on triphenylamine (TPA) with D-π-A-π-D structure used as an electron donor for organic solar cells: A DFT approach

Because of the increasing scarcity of fossil fuels and the growing need for energy, it has become necessary to research new renewable energy resources. In this study, five new high-performance materials (TP-FA1F-TP - TP-FA5F-TP) of the D-π-A-π-D configuration based on triphenylamine (TPA) were theoretically investigated by applying DFT and TD-DFT methods for future application as heterojunction organic solar cells (BHJ). The influence of the modification of the acceptor (A) of the parent molecule TP-FTzF-TP on the structural, electronic, photovoltaic and optical properties of the TP-FA1F-TP - TP-FA5F-TP organic molecules was investigated in detail. TP-FA1F-TP - TP-FA5F-TP showed Egap in the interval of 1.44–2.01 eV with λabs in the range of 536–774 nm, open-circuit voltage (Voc) values varied between 0.3 and 0.56 V and power conversion efficiencies (PCE) ranging from (3-6) %. Our results also show that the donor molecules suggested in this research exhibit an improved performance compared to the recently synthesized TP-FTzF-TP, such as a lowest HOMO energy, a smaller Egap, and a greater absorption spectrum, and can lead to higher performance. Indeed, this theoretical research could lead to the future synthesis of better compounds as active substances used in BHJ.

Crystal structure, stability, spectroscopy, electronic structure, and ultrafast excited-state dynamics of the elusive iron(II) phthalocyanine axially coordinated with DABCO ligands

The elusive PcFe(DABCO)2 (Pc = phthalocyaninato(2-) ligand; DABCO = 1,4-diazabicyclo[2.2.2]octane) complex was prepared and characterized by UV-Vis, MCD, 1H NMR, and Mössbauer spectroscopies. The X-ray crystal structure of this complex indicates the longest Fe-N(DABCO) bond distance among all known PcFeL2 complexes with nitrogen donors as the axial ligands. The target compound is only stable in the presence of large access of the axial ligand and rapidly converts into the (PcFe)2O [Formula: see text]-oxo dimer even at a modest temperature. The electronic structure of the PcFe(DABCO)2 complex was elucidated by DFT and TDDFT methods. The DFT calculations predicted a very small singlet-triplet gap in this compound. The femtosecond transient absorption spectroscopy is indicative of extremely fast ([Formula: see text]200 fs) deactivation of the first excited state in PcFe(DABCO)2 with a lack of formation of the long-lived low-energy triplet state.

A theoretical study of the ESIPT mechanism for the 2-butyl-4-hydroxyisoindoline-1, 3-dione probe

For the synthesis of two-photon excited probes, fluorophores based on excited-state intramolecular proton transfer (ESIPT) become critical. The ESIPT process of 2-butyl-4-hydroxyisoindoline-1, 3-dione is analyzed in this paper by DFT and TDDFT methods. We choose three non-protonic solvents to study their solvation effect. By examining infrared vibration spectrum data, optimized geometric structures and reduced density gradient, the hydrogen bond strengthened after photoexcitation and increased gradually with the decrease of solvent polarity. The proton transfer in the excited state is a low-barrier ultrafast process. The observed fluorescence peak in the experiment is derived from the emission of the tautomer form. Compared with the reaction barriers on the potential energy curves for different non-protonic solvents, a weaker polar solvent is more favorable to the ESIPT process.

Molecular engineering of bicarbazole-based donor molecules with remarkable photovoltaic parameters for organic solar cells

Strategies for modeling π-conjugated donor molecules for photovoltaic performance in the community of organic solar cells are well renowned in the literature. The recent study is based on the modeling of five highly conjugated bicarbazole-based donor molecules (XJ1–XJ5) by the alteration of acetylene-linked 9,9′-bicarbazole triphenylamine (XJ) molecule due to the attachment of five different acceptors through thiophene bridging. DFT simulations were conducted to investigate the geometrical, optoelectronic, and photovoltaic properties by using the CAM-B3LYP/6-31G (d, p) level of theory. FMOs and DOS analysis revealed a reduction of band gap and high charge transfer in the newly designed conjugated systems. TD-DFT method was used to investigate the absorption spectra which revealed that freshly modeled molecules owned higher absorption in the visible region than the reference XJ. The designed molecules showed remarkable photovoltaic characteristics due to the lower transition energies (ΔE), reduced band gap (EG), higher absorption maximum (λm), small binding energies (EB) and high dipole moment. The small values of reorganization energy (RE) for hole and electron possessed high charge mobility. The simulated open-circuit voltage (VOC) with PC61BM acceptor and fill factor (FF) for all the designed systems, in the range 1.78–1.91 V and 0.9253–0.9294 respectively, were found to be greater than reference XJ thereby increasing power conversion efficiency (PCE) of the solar cells. Therefore, all the designed molecules (XJ1–XJ5) are highly recommended for experimentation to fabricate efficient organic solar cells with remarkable photovoltaic applications. The current work is one of the few in-depth investigations in the direction of eco-friendly organic photovoltaics development that will pave the way for researchers to design highly efficient materials for future OSCs by structural engineering.

Designing and theoretical study of benzocarbazole-based D-π-D type small molecules donor for organic solar cells

Seven new molecules (S1–S7) of D-π-D type have been designed for organic photovoltaic applications. The DFT and TD-DFT methods were used to investigate the effect of different central bridge groups on the geometric, optoelectronic, and charge transport properties of the constructed molecules. Among them, S4 and S6 have the lowest energy band gap and a red shift in the absorption spectra, revealing the perfect relationship between the central bridge and the strong electron withdrawal character through extended conjugation. Similarly, S6 explored the lowest reorganization energy (RE) value for electron and hole revealing its enhanced charge transition, also shows better ICT characteristics with its highest NLO properties. Compound S4 showed the smallest value of ΔEL−L and Eb, and the highest Voc due to its low HOMO, which improves the photocurrent density of the devices. Thus, the results suggest that bridge modification is a practical strategy to improve the efficiency of OSCs.

Electronic Descriptors for Supervised Spectroscopic Predictions.

Spectroscopic properties of molecules hold great importance for the description of the molecular response under the effect of UV/vis electromagnetic radiation. Computationally expensive ab initio (e.g., MultiConfigurational SCF, Coupled Cluster) or TDDFT methods are commonly used by the quantum chemistry community to compute these properties. In this work, we propose a (supervised) Machine Learning approach to model the absorption spectra of organic molecules. Several supervised ML methods have been tested such as Kernel Ridge Regression (KRR), Multiperceptron Neural Networs (MLP), and Convolutional Neural Networks. [Ramakrishnan et al. J. Chem. Phys. 2015, 143, 084111. Ghosh et al. Adv. Sci. 2019, 6, 1801367.] The use of only geometrical-atomic number descriptors (e.g., Coulomb Matrix) proved to be insufficient for an accurate training. [Ramakrishnan et al. J. Chem. Phys. 2015, 143, 084111.] Inspired by the TDDFT theory, we propose to use a set of electronic descriptors obtained from low-cost DFT methods: orbital energy differences (Δϵia = ϵa - ϵi), transition dipole moment between occupied and unoccupied Kohn-Sham orbitals (⟨ϕi|r|ϕa⟩), and when relevant, charge-transfer character of monoexcitations (Ria). We demonstrate that with these electronic descriptors and the use of Neural Networks we can predict not only a density of excited states but also get a very good estimation of the absorption spectrum and charge-transfer character of the electronic excited states, reaching results close to chemical accuracy (∼2 kcal/mol or ∼0.1 eV).

Solvent effect on ESIPT process of N-(8-Quinolyl) salicylaldimine: A DFT/TD-DFT calculation

• The effects of solvent on ESIPT process of QS are studied by DFT/TD-DFT methods. • The O1–H2⋯N3 Hydrogen bond is strengthened upon photoexcitation. • The ESIPT process becomes favorable when the dielectric constant of the solvent decreases. The investigations of the solvent effect on ESIPT process of N-(8-Quinolyl) salicylaldimine (QS) are carried out using DFT and TD-DFT methods. We choice TOL, THF, ACE and DMSO solvents to simulate the experimental solvent conditions. The normal and tautomeric structures of the QS in the S 0 and S 1 states are optimized by means of DFT and TD-DFT method in four different kinds of solvents. Through the analysis of the critical geometrical parameters related to hydrogen bond interactions, it could be found that QS molecule preform to be planar or nearly planar in the S1 state, and more importantly, the excited-state hydrogen bond is strengthened. By comparing IR vibrational spectra, RDG isosurfaces and scatter graphs in the four solvent conditions, we found that the hydrogen bond is strengthen after photoexcitation, and weakened with the increase of the dielectric constant of the solvents. The calculated absorption and fluorescence spectra are basically agreement with existing evidence from previous experiment. The energy barriers of ground and excited states of QS molecule under the different solvent conditions have been analyzed by established potential energy curves (PECs) in the S 0 and S 1 states, and the corresponding energy barriers are increased with the effect of change from TOL to DMSO solvents. Therefore, with the increasing dielectric constant of solvents, the ESIPT become favored.

Quantum chemical study of tautomeric equilibriums, intramolecular hydrogen bonds, and π-electron delocalization in the first singlet and triplet excited states of 2-selenoformyl-3-thioxo-propionaldehyde

In the present study, the tautomeric process, intramolecular hydrogen bonding (IMHB), and π-electron delocalization (π-ED) of 2-selenoformyl-3-thioxo-propionaldehyde (STP) in the first singlet and triplet excited states were investigated by CIS and TD-DFT methods. The relative energies of hydrogen-bonded tautomers in both excited states indicate that the thiol/enol conformers are the most/least stable forms. In this regard, a detailed analysis of various tautomeric equilibriums, different types of hydrogen bonds, and π-electron delocalization was performed. The electronic energies of different tautomers indicate the thermodynamic preference of thiol with respect to the other forms. Furthermore, the low activation energy barriers of thione⇄thiol equilibrium also show the kinetic preference of thiol. On the other hand, the estimation of different hydrogen bond energies emphasizes the stronger IMHB of enol. Moreover, the evaluation of π-ED by the structural parameter of Gilli (λ) represents the significance of electron mobility in the enol conformers. Consequently, the duality between the IMHB and π-ED with the thermodynamic stability order of tautomers indicates that the tautomeric phenomenons play a dominant role in determining the stability of the benchmark structures in both singlet and triplet excited states.

Chemical Stability of Imidazole-Thiosemicarbazides in Solvents: NBO Studies and Theoretical Absorption Spectrum

This study of chemical stability in solvents was performed on four (4) molecules of a series of halogen-substituted imidazole-thiosemicarbazides (IT) using the TD-DFT method at the B3LYP/6-31+G (d, p) level. The solubility of the imidazole-thiosemicarbazides in solvents across the dipole moment revealed that the ITs have the lowest values of the dipole moment in cyclohexane, indicating that the ITs are more soluble in cyclohexane. This claim was confirmed by the assessment of the energy gap in the different solvents. Analysis of the effect of temperature on the stability of imidazole-thiosemicarbazides showed that temperature has no effect on the stability of the ITs studied. This observation could allow to fight effectively against the different bacteria and to control their storage conditions and also to establish their expiry dates. The NBO analysis and the study of the absorption spectrum were also carried out in order to show the hyperconjugative interactions and the delocalization of atomic charges. In this case, the stabilizing interactions involve the free pairs of nitrogen atoms N16 and N19 and the antibinding single bond are σ*(C18-S21). Analysis of the theoretical absorption spectrum showed that the absorption band representing cyclohexane is more intense for all the compounds studied. This is because cyclohexane better promotes the stabilization of substituted imidazole-thiosemicarbazides. Moreover, the maximum band corresponds to the electronic transition between the HOMO and the LUMO is due to an electron displacement from the LP (N) orbitals towards the σ*(CS) orbitals.

A comparative study on optical properties of AlCl-Pc, AlH-Pc, Al-Pc, and phthalocyanine organic compounds

The role of Cl and H atoms inside AlPc organic molecule by experimental, DFT, and TD-DFT methods is investigated. A detailed study of Pc, AlPc-Cl, and AlH-Pc absorption wavelengths, energies, and oscillator strengths are achieved. To strengthen such investigation, HOMO-LUMO and DOS spectrum analysis are described showing the optical band of 2.01, 2.11, and 2.18 eV for Al-Pc, AlH-Pc, and AlCl-Pc compounds respectively, and nonlinear optical properties are presented. Furthermore, the values of calculated dipole moment, polarizability, and second-order static hyperpolarizability of AlCl-Pc, AlH-Pc, Al-Pc, and Pc compounds are studied. The heterojunctions based on AlPc-Cl and AlPc-H are fabricated by low-cost routes. I-V characteristics are demonstrated under dark and room temperatures. A high rectifying ratio of our heterostructures based on AlPc is exhibited. Non-ideal behavior, [Formula: see text] 1, of the fabricated heterostructures due to the presence of interface states is revealed.

Quantum Computational, Spectroscopic (FT-IR, FT-Raman, NMR, and UV-Vis) Hirshfeld Surface and Molecular Docking-Dynamics Studies on 5-Hydroxymethyluracil (Monomer and Trimer).

For many decades, uracil has been an antineoplastic agent used in combination with tegafur to treat various human cancers, including breast, prostate, and liver cancer. Therefore, it is necessary to explore the molecular features of uracil and its derivatives. Herein, the molecule's 5-hydroxymethyluracil has been thoroughly characterized by NMR, UV-Vis, and FT-IR spectroscopy by means of experimental and theoretical analysis. Density functional theory (DFT) using the B3LYP method at 6-311++G(d,p) was computed to achieve the optimized geometric parameters of the molecule in the ground state. For further investigation and computation of the NLO, NBO, NHO analysis, and FMO, the improved geometrical parameters were utilized. The potential energy distribution was used to allocate the vibrational frequencies using the VEDA 4 program. The NBO study determined the relationship between the donor and acceptor. The molecule's charge distribution and reactive regions were highlighted using the MEP and Fukui functions. Maps of the hole and electron density distribution in the excited state were generated using the TD-DFT method and PCM solvent model in order to reveal electronic characteristics. The energies and diagrams for the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) were also provided. The HOMO-LUMO band gap estimated the charge transport within the molecule. When examining the intermolecular interactions in 5-HMU, Hirshfeld surface analysis was used, and fingerprint plots were also produced. The molecular docking investigation involved docking 5-HMU with six different protein receptors. Molecular dynamic simulation has given a better idea of the binding of the ligand with protein.

Exploring quantum computational, molecular docking, and molecular dynamics simulation with MMGBSA studies of ethyl-2-amino-4-methyl thiophene-3-carboxylate

2-aminothiophenes derivative, Ethyl-2-amino-4-methyl thiophene-3-carboxylate (EAMC) has been synthesized, characterized, and investigated quantum chemically. It was experimentally investigated by different spectroscopic methods like- NMR (1H-NMR and 13C-NMR), FT-IR, and UV-Visible. B3LYP method and 6-311++G(d,p) basis set were employed for optimization of molecular structure and calculation of wave numbers of normal modes of vibrations and various other important parameters. Calculated bond lengths and angles were compared with the experimental bond lengths and Bond Angle Parameters. Optimized bond parameters and experimental bond parameters were found in good agreement. Complete potential energy distribution assignments were done successfully by VEDA. The HOMO/LUMO energy gap emphasizes adequate charge transfer happening within the molecule. A study of donor-acceptor interconnections was done via NBO analysis. MEP surface analysis was done to demonstrate charge distribution and reactive areas qualitatively in the molecule. The degree of relative localization of electrons was analyzed via ELF Diagram. The Fukui function analysis showed possible sites for attacks by different substituents. By using the TD-DFT method and PCM solvent model, the UV–Vis spectrum (gas, methanol, DMSO) and the maximum absorption wavelength was computed and compared with experimental data. 3D and 2D intermolecular interactions in the crystal were analyzed via Hirshfeld surface analysis and fingerprint plots reveal that the EAMC crystal was stabilized by H–-H/H–-H/C–-H bond formation. The molecular docking was done with 7 different protein receptors on the molecule to find the best ligand-protein interactions. Molecular dynamic simulations and MMGBSA calculations were also carried out to find out the best binding of the ligand with the protein. Communicated by Ramaswamy H. Sarma

Synthesis, spectra, crystal, DFT, molecular docking and in vitro cholinesterase inhibition evaluation on two novel symmetrical Azine Schiff bases

The two new azine Schiff bases AZ1 and AZ2 called (1E,2E)-1,2-bis(2,4-dimethylbenzylidene) hydrazine and (1E,2E)-1,2-bis(3-methoxylbenzylidene)hydrazine, respectively were prepared through a condensation of the appropriate substituted aldehyde and the hydrazine hydrate. The two azine structures were investigated by FT-IR, NMR techniques and determined by single crystal X-ray diffraction (XRD). AZ1 and AZ2 structures crystallize in Monoclinic and Orthorhombic systems with space groups P21/c and P212121, respectively. AZ1 molecules are interconnected with hydrogen bonds CH…π and the crystal structure of AZ2 is stabilized by weak intermolecular hydrogen bonds CH…O. Theoretical calculations have been carried out at DFT/B3LYP level for the optimized geometries and TD-DFT methods. The results show an excellent agreement with the experimental data (Spectroscopic and XRD). Docking studies were performed to examine potential inhibitions of the designed azines against cholinesterases. The activities effect considering the enzymes: acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are evaluated in vitro and the results show that both Azines AZ1 and AZ2 are moderate AChE inhibitors (IC50 = 23.60±0.63 µg/mL; IC50 = 28.59±0.07 µg/mL, respectively). The BChE measurements indicated an important inhibition activity of AZ1 (IC50 = 57.88±0.045 µg/mL) and no activity of AZ2.The results of these tests were in sync with the docking.

Synthesis, structure elucidation, Hirshfeld surface analysis, DFT, and molecular docking of new 6-bromo-imidazo[4,5-b]pyridine derivatives as potential tyrosyl-tRNA synthetase inhibitors

Novel 6-bromo-imidazo[4,5-b]pyridine derivatives (2-4, 5a-13a, and 6b, 8b-13b) have been synthesized based on a developed systematic approach involving the condensation of 5-Bromo-2,3-diaminopyridine with a suitable aromatic aldehyde in the presence of molecular iodine in water, followed by alkylation reactions using different alkyl dibromide agents. The synthesized compounds were characterized by the NMR spectroscopy technique. The structures of 8a, 9a, 12a, and 11b were confirmed using monocrystalline X-ray crystallography. Theoretical calculations have been carried out using DFT and TD-DFT methods at the B3LYP/6-31G++(d,p) level of theory. Intermolecular contacts between units of 8a, 9a, 12a, and 11b were determined through the Hirshfeld surface analysis. The molecular docking study has been performed to determine the binding affinity of 8a, 9a, 12a, and 11b into the binding site of S. aureus tyrosyl-tRNA synthetase as a target enzyme, and the results revealed that 9a is the most potent compound among the selected compounds with a binding affinity of −8.74 Kcal/mol. Communicated by Ramaswamy H. Sarma

Quantum control of optoelectronic and thermodynamic properties of dopamine molecule in external electric field : A DFT and TD-DFT study

The effect of external electric field on molecular properties of dopamine is investigated using DFT and TD-DFT methods with B3LYP functional and 6-311++G(d,p) basis set. Optoelectronic properties (energy, polarizability, molecular orbitals, HOMO-LUMO gap, optical gap, electron–hole binding energy, UV-visible and electroabsorption spectra), and thermodynamic properties (zero-point vibrational energy, thermal energy, entropy, and specific heat capacity) were investigated. These properties are useful in developing molecular sensing devices, and understanding molecule receptor binding interaction. Our results using TD-DFT for excited states show that when an external electric field of magnitude F = 0.020 a.u. is applied along the x-axis, there is a shift in the absorption spectra of dopamine from the ultraviolet to the visible region which will be useful in optogenetic stimulation using visible light. The tunneling ionization rate increases and tunneling ionization time decreases with increase in electric field. These studies have potential applications in many of the emerging technologies in neurobiology such as deep brain stimulation and iontophoresis.

Valeramide and Halo-phenol in a Non-polar Liquid: DFT Based Characterization and Reactivity, Non-covalent Interaction, and Dielectric Relaxation Studies

Valeramide and halogenated phenol in solvent benzene have been studied using DFT. Dielectric relaxation studies have also been undertaken. The wave functional characteristics like reduced density gradient (RDG), electron localization function (ELF), localized orbital locator (LOL) are also evaluated. It has been found that the computed FMO energies accurately depict the characteristics of electron excitation which provide an explanation for the charge transfer. MEP analysis is done to identify electrophilic and nucleophilic sites. The theoretical analysis of the UV-Visible spectrum using the TD-DFT method in solution and the computational investigation of spectroscopic wavenumbers was also carried out (IR, Raman). Thermodynamic properties of title compound at different temperatures was carried out. Various dielectric parameters, like the dielectric constant the dielectric loss at microwave frequency, the static dielectric constant ε0 and the dielectric constant ε∞ at optical frequency, were measured across five distinct molar ratios (i.e. 1:3, 1:2, 1:1, 2:1 and 3:1). While the relaxation time τ2 for group rotation is utilized to identify the steric interaction of the proton donor, Higasi’s single-frequency equation is proven to measure multiple relaxation time τ1 to determine the intensity of hydrogen bonding. At a 1:1 (molar ratio) , the values of relaxation time were found to be high. Molecular docking was done in a supplementary effort to support intermolecular interactions.

Effect of green solvents, molecular structure and topological studies on 4-amino-1-β-d-ribofuranosyl-1,3,5 triazin-2(1H)-one - anti-blood cancer agent

The present theoretical work interprets the optimized structure, Vibrational assignments of 4-AMINO-1-β-d-ribofuranosyl-1,3,5 triazin-2(1H)-One (4AβRT) also known by the chemical name azacitidine which has 29 atoms, examined theoretically Via DFT/6–311++G (d, p) simple position level. The spectroscopic data of 4AβRT are verified. Bond parameters are analysed by optimizing the structure in gaussian 09. The charge circulation area of the molecule in a three-dimensional manner and to distinguish the electrophilic and nucleophilic sites of the molecule is done by MESP. The HOMO-LUMO (electron donor and acceptor) is important for the stability and chemical reactivity of the compound. NBO evaluation is used to understand the bonding interlinkage of the fragments. NLO analysis has been carried out. Topological analysis (ELF, LOL, RDG) has been analysed using Multiwave function. The electronic transition of the compounds with different solvents have been investigated by the TD-DFT method. Protein-Ligand docking is performed with different cancer cell-matured proteins by using the AUTODOCK program.

Study of the solar perovskites: XZnF3 (X = Ag, Li or Na) by DFT and TDDFT methods

Study of the solar perovskites: XZnF3 (X = Ag, Li or Na) by DFT and TDDFT methods

Design, Synthesis, Spectroscopic Inspection, DFT and Molecular Docking Study of Metal Chelates Incorporating Azo Dye Ligand for Biological Evaluation.

A new heterocyclic azo dye ligand (L) was synthesized by the combination of 4-amino antipyrine with 4-aminophenol. The new Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) complexes were synthesized in excellent yields. The metal chelate structures were elucidated using elemental analyses, FT-IR, 1H-NMR, mass, magnetic moment, diffused reflectance spectral and thermal analysis (TG-DTG), and molar conductivity measurement. According to the FT-IR study, the azo dye ligand exhibited neutral tri-dentate behavior, binding to the metal ions with the azo N, carbonyl O, and protonated phenolic OH. The 1H-NMR spectral study of the Zn(II) complex supported the coordination of the zo dye ligand without proton displacement of the phenolic OH. Diffused reflectance and magnetic moment studies revealed the octahedral geometry of the complexes, as well as their good electrolytic nature, excepting the Zn(II) and Cd(II) complexes, which were nonelectrolytes, as deduced from the molar conductivity study. The theoretical calculations of optimized HOMO-LUMO energies, geometrical parameters, electronic spectra, natural atomic charges, 3D-plots of MEP, and vibrational wavenumbers were computed and elucidated using LANL2DZ and 6-311G (d, p) basis sets of density functional theory (DFT) with the approach of B3LYP DFT and TD-DFT methods. The ligand and complexes have been assayed for their antimicrobial activity and compared with the standard drugs. Most of the complexes have manifested excellent antimicrobial activity against various microbial strains. A molecular docking investigation was also performed, to acquire more information about the binding mode and energy of the ligand and its metal complexes to the Escherichia coli receptor using molecular docking. Altogether, the newly created ligand and complexes showed positive antibacterial effects and are worth future study.