Electronic Energy Gap Research Articles

Computer-Assisted Drug Discovery of a Novel Theobromine Derivative as an EGFR Protein-Targeted Apoptosis Inducer.

The overexpression of the Epidermal Growth Factor Receptor (EGFR) marks it as a pivotal target in cancer treatment, with the aim of reducing its proliferation and inducing apoptosis. This study aimed at the CADD of a new apoptotic EGFR inhibitor. The natural alkaloid, theobromine, was used as a starting point to obtain a new semisynthetic (di-ortho-chloro acetamide) derivative (T-1-DOCA). Firstly, T-1-DOCA's total electron density, energy gap, reactivity indices, and electrostatic surface potential were determined by DFT calculations, Then, molecular docking studies were carried out to predict the potential of T-1-DOCA against wild and mutant EGFR proteins. T-1-DOCA's correct binding was further confirmed by molecular dynamics (MD) over 100 ns, MM-GPSA, and PLIP experiments. In vitro, T-1-DOCA showed noticeable efficacy compared to erlotinib by suppressing EGFRWT and EGFRT790M with IC50 values of 56.94 and 269.01 nM, respectively. T-1-DOCA inhibited also the proliferation of H1975 and HCT-116 malignant cell lines, exhibiting IC50 values of 14.12 and 23.39 µM, with selectivity indices of 6.8 and 4.1, respectively, indicating its anticancer potential and general safety. The apoptotic effects of T-1-DOCA were indicated by flow cytometric analysis and were further confirmed through its potential to increase the levels of BAX, Casp3, and Casp9, and decrease Bcl-2 levels. In conclusion, T-1-DOCA, a new apoptotic EGFR inhibitor, was designed and evaluated both computationally and experimentally. The results suggest that T-1-DOCA is a promising candidate for further development as an anti-cancer drug.

Analysis of the protection of copper corrosion by using amino acid inhibitors.

Since the human body is one of the highly aggressive environments, the materials utilized for an implant should have high resistance to degradation and corrosion. One of the commonly used biomaterials in medicine is copper (Cu). The Cu corrosion can result in the release of ions in the body with high toxicity, thereby causing inflammatory diseases. Based on the literature, as biomolecules, amino acids act as a corrosion inhibitor in aggressive solutions. The current work aims at scrutinizing the inhibition impact of L-arginine (L-Arg) and L-Valine (L-Val), which have been rarely investigated, upon the corrosion process of Cu. We undertook density functional theory computations to scrutinize the inhibitory impact of L-Arg and L-Val as well as their conformers upon Cu corrosion. Also, we scrutinized the computed parameters according to the back donation of electrons between Cu and the inhibitors, transported electron fraction, energy gap, softness, hardness, EHOMO, and ELUMO. According to the theoretical indices of L-Arg, it prefers adsorption. We examined the inhibitory efficiency of L-Arg against corrosion and found that it is a promising inhibitor.

Design, synthesis, characterizing and DFT calculations of a binary CT complex co-crystal of bioactive moieties in different polar solvents to investigate its pharmacological activity

Imidazole (IM) and salicylic acid (SA) have a significant class among the medical compound. These are widely used as topical drugs like antifungal, antibacterial, anticancer, immunosuppressive agent, etc. These two bioactive organic moieties are combined by a weak hydrogen bond formed by hydrogen transfer. The charge transfer (CT) complex of acceptor (SA) and donor (IM), has been synthesized at room temperature in methanol and confirmed by signal-crystal XRD, conductance and UV–visible spectroscopy. The X-ray crystallography provides the original structural information of CT complex and displays the existence of N+—H––O– bond between IM and SA. The physical properties such as (ECT ), (RN ), (ID ), (f), (D) and ( G0) along with molar extinction coefficient (εCT ) and formation constant (KCT ) were estimated through UV–visible spectroscopy. Job’s method and Benesi-Hildebrand equation suggested 1:1 stoichiometry of ([IM]+[SA]−). The results indicate a complete transfer of hydrogen atom and CT complex formation with 1:1 molar ratio of IM and SA. Antimicrobial activity was veiled against different bacteria like Escherichia coli, Bacillus subtilis and Staphylococcus aureus; and different fungi as Fusarium oxysporum, Candida albicans and Aspergillus niger by disc diffusion method. CT complex was also tested for cytotoxic activity against lung cancer cell lines in comparison to breast cancer cell lines. Molecular docking provides the information of binding of [(IM)+(SA)−] with the cancer marker (1M17), which has substantial application for drug designing. The investigational studies were supplemented through time-dependent density functional theory (TD-DFT) using basis set B3LYP/6-311G**. Through DFT calculations, HOMO→LUMO electronic energy gap ( was obtained.

Steering on-surface reactions through molecular steric hindrance and molecule-substrate van der Waals interactions.

The online version contains supplementary material available at 10.1007/s44214-022-00023-9.

Fluorinated derivatives of tetrahydroaltersolanol molecule on COVID-19, HIV, and HTLV protease by DFT and molecular docking approaches.

Structural, optoelectronic, and biological properties of tetrahydroaltersolanol (C16H20O7) and fluorinated derivatives are calculated using density functional theory (DFT) and molecular docking approaches. It is shown that the pure C16H20O7 molecule has a direct HOMO–LUMO energy gap about 3.1 eV. The substitution of F atom at A category decreases the electronic energy gap, while it is constant at B category. In A category, the behavior of the pure molecule changed from insulator to semiconductor with various substitution of F atom. The electronic properties were depended on the F sites in the pure molecule. The molecular electrical transport properties and charge-transfer possibilities increase with decreasing energy gap. The pure C16H20O7 molecule with high energy gap has low chemical reactivity and substitution of F atom at considered molecule increases chemical reactivity. Obtained results show that F-O bonds in trifurcation bonds of C16H19O7(F14), C16H19O7(F16), and C16H19O7(F17) molecules play a key role in confronting with COVID-19, HIV, and HTLV proteases, respectively. Optical spectra, such as the dielectric functions, electron energy-loss spectroscopy, refractive index, extinction coefficient, and reflection spectra show that fluorinated derivatives of C16H20O7 at B category can be used in the new drugs.Graphical abstract

Spectroscopic and Molecular Docking Analysis of π-Acceptor Complexes with the Drug Barbital

The drug barbital (Bar) has a strong sedative–hypnotic effect. The intermolecular charge transfer compounds associated with the chemical reactions between Bar and some π acceptors, such as 2,6-dibromoquinone-4-chloroimide (DBQ), tetracyanoquinodimethane (TCNQ), chloranil (CHL), and chloranilic acid (CLA), have been synthesized and isolated in solid state. The synthesized products have the molecular formulas (Bar–DBQ), (Bar–TCNQ), (Bar–CHL), and (Bar–CLA) with 1:1 stoichiometry based on Raman, IR, TG, 1H NMR, XRD, SEM, and UV-visible analysis techniques. Additionally, the comparative analysis of molecular docking between the donor reactant moiety, Bar, and its four CT complexes was conducted using two neurotransmitter receptors (dopamine and serotonin). The docking results obtained from AutoDockVina software were investigated by a molecular dynamics simulation technique with 100ns run. The molecular mechanisms behind receptor–ligand interactions were also looked into. The DFT computations were conducted using theory at the B3LYP/6-311G++ level. In addition, the HOMO LUMO electronic energy gap and the CT complex’s optimal geometry and molecule electrostatic potential were examined.

Correlating Local Structure and Electrochemical Performance in Metal-Substituted Vanadium Ferrite Aerogel Electrodes for Lithium-Ion Batteries

Disordered vanadium ferrite (VFe2Ox) materials exhibit promising performance for electrochemical energy-storage applications such as rechargeable lithium-ion batteries.1,2 We employ an epoxide-promoted sol–gel reaction of iron chloride and vanadium isopropoxide to form nanostructured vanadium ferrite gels. Subsequent supercritical-CO2 extraction of the pore fluid yields high surface–area aerogels. Heat treatment under either O2-containing or inert atmosphere yields disordered or nanocrystalline variants, respectively. Electroinactive metal cations such as aluminum, zinc, and zirconium are substituted during the initial sol–gel synthesis to alter the local electronic environment of VFe2Ox. The resulting series of native and substituted VFe2Ox materials are evaluated as powder-composite cathodes versus lithium metal in coin cells with conventional nonaqueous lithium-ion electrolyte. We correlate such critical battery-performance parameters as total specific capacity, high-rate capability, and cycle life as a function of MVFe2Ox composition and its degree of structural order/disorder. In-lab X-ray absorption spectroscopy also provides important information on metal oxidation state and element-specific coordination for these VFe2Ox aerogels, including during operando electrochemical lithiation/delithiation. In parallel with experimental advancements, calculations on VFe2Ox reveal that V incorporation into the defect-induced spinel structure occurs at tetrahedral sites. Further, both disorder of vacancies and Fe/V tetrahedral occupation lower the overall energy, opening an electronic energy gap that establishes the redox sequence during lithiation. N. Chervin, J. S. Ko, B. W. Miller, L. Dudek, A. N. Mansour, M. D. Donakowski, T. Brintlinger, P. Gogotsi, S. Chattopadhyay, T. Shibata, J. F. Parker, B. P. Hahn, D. R. Rolison, and J. W. Long, J. Mater. Chem. A 3, 12059 (2015). C. N. Chervin, R.H. DeBlock, J. F. Parker, B. M. Hudak, N. L. Skeele, J. S. Ko, D. R. Rolison, and J. W. Long, RSC Adv. 11, 14495 (2021).

One-pot synthesis, molecular docking, ADMET, and DFT studies of novel pyrazolines as promising SARS-CoV-2 main protease inhibitors

Pyrazoline and its derivatives have numerous prominent pharmacological effects. Focusing on its anti-viral property, we have designed and synthesized three novel pyrazoline derivatives (A1–A3) through one-pot three components and characterized them using different spectroscopic techniques (FT-IR, 1H NMR, 13C NMR, and UV). These compounds were evaluated against SARS-CoV-2 main protease utilizing in-silico molecular docking studies. The docking results displayed good inhibitory activity of the synthesized compounds. Among them, compound A2 was the most active against targeted protein. The drug-likeness and ADMET properties were predicted to have varied profiles but could still be developed, especially A2. DFT/TD-DFT calculations through B3LYP/6-311G++ level of theory were applied to provide comparable theoretical data along with MEP map and electronic energy gap of HOMO → LUMO.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11164-022-04831-5.

A novel magnetic tunnel junction fabricated by robust intrinsic van der Waals half-metals

Two-dimensional magnetic van der Waals materials (vdW) have attracted considerable attentions in recent years due to their emerging physical properties and great potential application to the spintronics devices. Magnetic tunnel junction (MTJ) is one of the most important devices in spintronics. However, many unknown mechanisms governing its critical performance remain to be elucidated. Here, based on first-principles calculations, vdW materials VBr3 and VCl3 are shown to be the robust intrinsic half-metals with spin down electron's energy gap about 3.3 eV, and the Fermi level is almost located at the center of the spin down electron's energy gap. Based on this, we predict that application of VBr3 to the magnetic electrodes of MTJ would greatly improve the off/on ratio of junction resistance. Moreover, the coercivity of magnetic electrodes used by vdW material VBr3 can be tuned by the number of layers, and an antiferromagnetic layer pinning the ferromagnetic electrode can be omission. This provides a reliable way to study and design the MTJ devices in the future.

Dimethyl fumarate molecule, crystal, and plane: Optical absorption measurement and structural/optoelectronic properties by density functional theory calculations

Dimethyl fumarate (DMF) is the main fumaric acid ester of the Fumaderm advanced medicament for the treatment of psoriasis and multiple sclerosis. Many properties of the DMF molecule and its crystal are still unknown. Here, the structural, electronic, and optical properties of DMF in molecular form and in the form of triclinic van der Waals crystals are addressed within the framework of density functional theory (DFT) formalism. The computations were performed using local density and generalized gradient exchange-correlation functionals, LDA and GGA, respectively, including one dispersion correction scheme for the former and two for the latter. Besides, the Δ-sol correction method was applied to improve the band-gap energy estimated from the DFT computations. The UV/Vis spectra of the DMF molecule solvated in ethanol and in the crystal were measured and compared with theoretical data obtained from time-dependent DFT (molecule) and DFT (crystal) calculations. One of the dispersion-corrected GGA functionals achieved very accurate descriptions of the lattice parameters, while analysis of the Kohn–Sham band structure indicated that the DMF crystal has a direct band-gap energy of 3.12 eV, differing from the experimental band-gap (4.00 eV) by 0.88 eV. By applying the Δ-sol correction method, the band-gap energy increased to 3.95 eV, only 0.05 eV below the experimental value. Lastly, simulations were also carried out for a single DMF monolayer, for which a band-gap of 3.26 eV was predicted. Hence, intermolecular interactions tend to decrease the electronic energy gap according to the sequence Gapcrystal < Gapmonolayer < Gapmolecule.

DFT study of the therapeutic potential of borospherene and metalloborospherenes as a new drug-delivery system for the 5-fluorouracil anticancer drug

Based on extensive first-principles calculations, the potential of borospherene (B40) and its exohedral metalloborospherene ([email protected]40 and Au4@B40) for delivery of 5-fluorouracil (5-FU) is examined using density functional theory (DFT) and time-dependent density functional theory (TD-DFT). To investigate the maximum capacity for delivering 5-fluorouracil (5-FU) molecules, up to four Au atoms can be anchored on the exterior surface of the B40 simultaneously, each of Au has the ability to interact with one 5-FU molecule, using only one B40 molecule. The 5-FU can be easily separated from B40, [email protected]40 and Au4@B40 at ambient temperature due to the moderate binding energies and charge-transfer. To comparatively analyze the interaction properties of 5-FU anti-cancer drug at B40, [email protected]40 and Au4@B40 nanocages, the electronic properties, charge distributions, frontier orbital, energy gaps and dipole moment have been examined. Moreover, the natural bond orbital analyses (NBO), the projected densities of states (PDOS) properties, non-covalent interactions (NCI), quantum theory of atoms in molecules (QTAIM) and statistical thermodynamic of these systems were used to investigate the interaction process. The time-dependent density functional calculations (TD-B3LYP) were utilized to simulate UV–visible electronic absorption spectra in the gas and aqueous phases. The results reveal that the 5-FU can be simply protonated in the tumor tissues, facilitating the drug to be released from the B40, [email protected]40 and Au4@B40 nanocages. The solvent effects tend to reduce the 5-FU binding energies in all (5-FU)@B40, [email protected][[email protected]40], (5-FU)4@B40 and (5-FU)4@[Au4@B40] complexes. This is the first study to show that borospherene (B40) and metalloborospherene have a high capacity for delivering of multiple 5-FU molecules.

Theoretical approach for Fe(II/III) and its chlorophyll-related complexes as sensitizers in dye-sensitized solar cells

Dye is the key to the efficiency of harvesting solar energy in dye-sensitized solar cells (DSSCs). The dye performances such as light absorption, electron injection, and electron regeneration depend on the dye molecule structure. To predict it, one needs to compute the optimized molecule geometry, HOMO level, LUMO level, electron density distribution, energy gaps, and dipole moment in the ground and excited state. Chlorophyll-related chlorin and porphyrin, as well as their κ2O,O’ complexes with Fe(II/III), were investigated with density functional theory (DFT) and time-dependent density functional theory (TD-DFT) computations using the B3LYP method and def2-TZVP basis set. NPA charges also were calculated to know the valence of the metal cations exactly. In general, the calculations show that the metal cations introduced occupied d orbitals with lower oxidation potentials than the chlorophyll ligand orbitals, which are responsible for the emergence of additional absorption bands. The states result in effective band broadening and the redshift of spectrum absorbance that is expected to improve DSSC performance.&#x0D; Another requirement that has to be possessed is the ability of electron regeneration, electron injection, and dipole moment. The Fe(II) complex has fulfilled these requirements, but not the Fe(III) complex due to having a low electron injection capability. However, this work has shown that Fe(III) complex exhibits a non-innocence ligand. It results in trivalent to divalent state change, in the appearance of a ligand radical cation, an extra hole, and a broader absorption spectrum. It also can affect its other electronic properties, such as electron injection capability. Thus, it can be considered an attractive candidate for the sensitizer in DSSCs

Theoretical study of electronic and optical properties of functionalized Indigo and Alizarin as potential organic semi-conductors for solar cells applications

The optical and electronic properties of two conjugated organic molecules, Indigo and Alizarin, as potential organic solar cells were studied theoretically. The electronic properties, reorganization energy (λh and λe), adiabatic Ionization potential (IA), adiabatic Electron affinity (EA),HOMO, LUMO and Energy gap (Eg) were calculated using DFT. The optical properties as the maximum absorption (λmax) along with oscillator strengths (f) at the excited states in vacuum and solvent were also calculated using TD-DFT. The molecules were functionalized by electronegative functional groups to understand the effect of functionalization on the optical and electronic properties. It was found that the functionalization of Indigo and Alizarin has resulted in overall conversion of the materials to better n-type molecules. The Eg for both molecules has been generally reduced upon the introduction of electronegative functional groups. This indicates the possibility of tuning organic molecules optical and electronic properties by introducing functional groups. Also, both studied molecules along with their functionalized molecules show properties that fall among organic semiconductors and thereby, can be potentially used in solar cells.

Intermolecular charge-transfer complexes between chlorothiazide antihypertensive drug against iodine sigma and picric acid pi acceptors: DFT and molecular docking interaction study with Covid-19 protease

The interaction of chlorothiazide (CH) as donor (D) with picric acid (PA) and iodine (I2) as π- and σ-acceptors (A), respectively, gives charge-transfer (CT) complexes as a final products. The reaction of donor and acceptors were studied spectrophotometrically. The complexes are generally of the n-π* and n-σ* types, with the ground state wave function primarily characterized by the non-bonding structure. For the micro determination of chlorothiazide using picric acid and iodine as acceptors, the ideal conditions encouraging the formation of complexes are thoroughly explored. It was discovered that the stoichiometry of the molecular structure is 1:1 (D:A). The equilibrium constant and the molar extinction coefficient were calculated using Benesi-Hildebrand and its modifications. DFT/TD-DFT calculations with B3LYP/LanL2DZ and 6-311G++ level of theory were used to provide comparable theoretical data along with electronic energy gap of HOMO→LUMO. Molecular docking calculations have been performed between CT complexes and Covid-19 protease (6LU7) to study the interaction between them and their inhibitory effect.

Floquet electronic bands and transport in magic-angle bilayer graphene

We theoretically study Floquet band structures and transport properties of twisted bilayer graphene at the magic-angle under the irradiation of variously polarized light. The magic-angle bilayer graphene is depicted by the newly proposed ten-band tight-binding model and the iterative continued fraction method is adopted to facilitate the calculations of electronic properties in the low-frequency regime. The transitions between Floquet sidebands induce discontinuous electronic bands and energy gaps which further give rise to the antiresonances in longitudinal conductivity calculated by the Kubo formula. Furthermore, significant Hall conductivity is generated by circularly polarized light and its magnitude and sign are sensitive to light polarization as well as photoinduced bandgap-opening, offering a feasible way to tune Hall conductivity by manipulating light polarization. We finally take into account the interplay between light irradiation and short-range disorder, and reveal that disorder scattering remarkably enhances the photoinduced Hall conductivity and can be viewed as an extrinsic source to Hall conductivity.

Simple development of eco-friendly dye-sensitized solar cells via controlling thickness of TiO2 nanoparticles and viscosity of electrolyte: Experimental study and DFT calculations

The pigments (N3 dye, anthocyanin, and oleandrin) that absorb light in the visible region, change electrolyte viscosity KI/I2 by adding polyethylene glycol (PEG), and the painting method of TiO2 using the spray and doctor-blade methods was studied. The ultraviolet–visible (UV–VIS) spectra of natural dyes showed strong bands in the visible regions at 350–450 nm. The Fourier-transform infrared (FTIR) spectra confirmed the formation of the N3-triodide complex which was not observed for the other natural dyes. The impact of the changing of viscosity by the addition of PEG improved the current flow in dye-sensitive solar cells (DSSCs). Scanning electron microscopy (SEM) images showed a homogenous and thin film of TiO2 by using the spray method. The efficiency of N3-DSSCs jumped and reached 0.2770% by the sprayed method in PEG-KI/I2 electrolyte. The efficiencies of 0.195 and 0.089 % for BB and NO-DSSCs were recorded in PEG-KI/I2 electrolytes, respectively. A low-cost carbon counter electrode was used in fabricating for DSSCs. The reduction in the values of RSH (shunt resistance) had a negative impact on the performance of DSSCs. Density functional theory (DFT) calculations were studied for optimized geometry of the three dyes. The chemical potential µ of N3 was greater than that of anthocyanin, and oleandrin which reflects the ability of electrons to exchange with TiO2. The Eg (energy gap) of N3 got to a height that slowed the rate of recombination of electron-hole of dye. The electronic chemical potential (µ) and energy gap (Eg) are effective to improve the efficiency of DSSCs.

Covalent Triazine Frameworks with Defective Accumulation Sites: Exceptionally Modulated Electronic Structure for Solar-Driven Oxidative Activation of Peroxymonosulfate.

Precisely tailoring the electronic structure and surface chemistry of metal-free covalent triazine frameworks (CTFs) for efficient photoactivation of oxyanions is environmentally desirable but still challenging. Of interest to us in this work was to construct artificial defective accumulation sites into a CTF network (CTF-SDx) to synchronously modulate both thermodynamic (e.g., band structure) and kinetic (e.g., charge separation/transfer/utilization and surface adsorption) behaviors and probe how the transformation affected the subsequent activation mechanism of peroxymonosulfate (PMS). With the incorporation of terminal cyano (-CN) groups and boron (B) dopants, the delocalized CTF-SD underwent a narrowed electronic energy gap for increased optical absorption as well as a downshifted valence band position for enhanced oxidation capacity. Moreover, the localized charge accumulation regions induced by the electron-withdrawing -CN groups facilitated the exciton dissociation process, while the adjacent electron-deficient areas enabled strong affinity toward PMS molecules. All of these merits impelled the photoactivation reaction with PMS, and a 15-fold enhancement of bisphenol-A (BPA) removal was found in the CTF-SD2/PMS/vis system compared with the corresponding pristine CTF system. Mechanistic investigations demonstrated that this system decomposed organics primarily through a singlet oxygen-mediated nonradical process, which originated from PMS oxidative activation over photoinduced holes initiated by an electron transfer process, thereby opening a new avenue for designing an efficient PMS activation strategy for the selective oxidation of organic pollutants.

Copper(II) Schiff base complex derived from salen ligand: structural investigation, Hirshfeld surface analysis, anticancer and anti-SARS-CoV-2

This work deals with the synthesis and characterization of copper(II) complex [Cu(salen)(H2O)](1) of salen-type Schiff base ligand derived from the condensation of 5-bromo-2-hydroxy-3-methoxybenzaldehyde and ethylenediamine in EtOH. This complex was characterized by different spectroscopic and physicochemical methods. Single crystal X-ray crystallography study revealed that Cu(II) in complex (1) is five-coordinate and adopts a distorted square pyramidal geometry. A DFT calculation was employed to evaluate the optimized electronic structure, HOMO-LUMO, energy gap, and global parameters. A detailed structural and non-covalent interaction on the complex is investigated by single crystal structure analysis and computational approaches. The strength of the interaction and 3D topology of the crystal packing are visualized through an energy framework. Hirshfeld surface and 2D fingerprint plots have been explored in the crystal structure of the complex. The anticancer properties of copper(II) complex was studied against the selected cancerous cell lines of breast cancer, cervical cancer, colon cancer and hepatocellular carcinoma. Additionally, molecular docking and MD simulations was performed on the complex to predict the binding mode and interactions between the ligand and the main protease of the SARS-CoV-2 (PDB ID: 7CBT and 7D1M). The molecular docking calculations of the complex (1) with SARS-CoV-2 virus revealed the binding energy of –8.1 kcal/mol and –7.5 kcal/mol with an inhibition constant of 3.245 µM and 2.318 µM at inhibition binding site of receptor towards 7CBT and 7D1M main protease (Mpro), respectively. Besides this, molecular docking results (–7.6 kcal/mol, 3.196 µM) towards Escherichia coli PBP2 targets (PDB ID: 6G9S) was also studied. Communicated by Ramaswamy H. Sarma

Synthesis, experimental and theoretical analyses of bis(2-ethylphenyl)phosphorodithioates of nickel(II)

Bis(2-ethylphenyl)dithiophosphates of nickel(II) of the composition [{(2-C2H5)C6H4O}2PS2]2Ni (1) and [{(2-C2H5)C6H4O}2PS2(C5H5N)]2Ni (2) were isolated successfully and characterized by experimental and theoretical analyses. Single crystal X-ray diffraction analysis of the complex (2) exhibits that nickel atom is hexa-coordinated with four sulfur atoms of dithio moiety at the equatorial position and two nitrogen atoms of pyridine on axial position. In addition, several non-covalent interactions were also observed that assist to form supramolecular architecture. An exhaustive investigation of the Hirshfeld surface (HS) analysis enables contributions to the crystal packing of the complex (2). The non-covalent interactions were identified using HS and two dimensional finger print plot (2D-FP) analysis. DFT/TD-DFT studies were also used to provide comparable theoretical data along with MEP map and electronic energy gap of HOMO→LUMO.

Effect of Molar Concentration on the Structural and Optical Properties of the Cd2SnO4 Thin Films

In this paper, cadmium stannate (Cd2SnO4) thin films at four different molar concentrations (1:1, 2:1, 3:1, and 4:1) were prepared at a temperature of (400 oC) using a chemical spray pyrolysis technique and have a thickness of about 400±10 nm. XRD patterns of the prepared thin films showed that the thin films have both a polycrystalline and a cubic structure. FE-SEM and AFM were used to investigate the surface morphology of Cd2SnO4 thin films. The measurement of absorbance and transmittance spectra for films in the range of 300–900 nm was part of the optical properties research. The effect of various molar concentrations of these films on transmittance was investigated, and the results revealed a decrease in transmittance. The allowed direct electronic transmission optical energy gap was calculated, and it was discovered that it decreases as the molar concentrations increase, with a value ranging between (2.61-2.91) eV.