LUMO Research Articles

Organically coordinated Cu(II) activated peroxymonosulfate for enhanced degradation of emerging contaminants

Copper ion Cu(II) is generally considered ineffective in activating peroxymonosulfate (PMS). However, our study demonstrates that organically coordinated Cu(II), namely, org-Cu(II) with contaminants such as amoxicillin (AMO), ofloxacin (OFX), sulfadiazine (SDZ), and tetracycline (TET) can efficiently activate PMS under neutral conditions, leading to faster degradation of these emerging contaminants. In contrast, organic contaminants that do not coordinate with Cu(II) do not facilitate PMS activation. Unlike traditional PMS-induced advanced oxidation processes (AOPs), our study identifies trivalent Cu(III) as the primary oxidant intermediate, with monovalent Cu(I) serving as its precursor. In addition, basic conditions was found to be beneficial for the degradation of target pollutants in org-Cu(II)/PMS systems. Moreover, this promotion effect extends to realistic wastewater, suggesting promising application prospects. The potential mechanism of the rate-limiting reduction step from Cu(II) to Cu(I) was further investigated. The interaction strength between the lowest unoccupied molecular orbital (LUMO) of the copper complex formed with organic compounds and the highest occupied molecular orbital (HOMO) of PMS influences the energy of the bonding orbitals. Coordination with organic ligands alters the LUMO of Cu(II), facilitating electron transfer from the HOMO of PMS to copper. This process activates PMS, ultimately leading to the production of Cu(I) and Cu(III). These findings deepen our understanding of PMS-induced AOPs for degrading emerging contaminants and underscore the importance of further research into PMS activation by Org-Cu(II).

Preparation, in vitro and in silico antioxidant and antibacterial studies of 4-aminoacetanilide azo derivatives

A new series of new 4-aminoacetanilide azo derivatives 1–13 were successfully synthesised via a diazo coupling reaction and gave a good to excellent yield of 73 %–93 %. The antioxidant capabilities of the series 1–13 screened through 2,2′-diphenyl-1-picrylhydrazyl (DPPH) assay and ferric reducing antioxidant power (FRAP) assay showed promising data of 12.6–199.4 ppm and 12.65–210.9 mg/ml Trolox equivalent, respectively. The findings supported by in silico docking analysis targeted Heme oxygenase-1 (HO-1) evidenced by a binding score of – 7.2 to – 8.2 kcal/mol outperforming the standard, ascorbic acid scoring only – 5.7 kcal/mol. Among all, compound 11 displayed the highest antioxidant potential with IC25 of 12.6 ppm against DPPH assay and 210.9 mg/ml Trolox for FRAP assay believed owing to the presence of methoxy group at ortho position in the phenolic compound that effectively lowered the ionisation potential and high up energy of highest occupied molecular orbital (HOMO). Nevertheless, the antibacterial potential of the series screened through the Kirby-Bauer disc diffusion method against Escherichia coli and Staphylococcus aureus showed no antibacterial activity postulated due to the presence of amide and acetyl group restricted the ability of the compound to form an interaction with the protein receptor of bacteria tested. This study provided new insight into the development of dual-functional drugs for non-communicable diseases and antimicrobial resistance.

Design and synthesis of novel quinoxaline-piperazine linked isoxazole conjugates: Anti-cancer assessment, tyrosine kinase EGFR inhibitory activity, molecular docking and DFT studies

In this paper, we describe the synthesis of a novel series of quinoxaline-piperazine-isoxazole conjugates. We confirmed the structures of the newly synthesised compounds using 1HNMR, Mass, and 13CNMR spectroscopic techniques. The anti-tumour activity was evaluated on two human cancer cell lines, such as MCF-7 (breast) and A-549 (lung). The anti-cancer evaluation dates show that compounds 7f, 7e, and 7 g have more promising anti-cancer activity than the standard drug Erlotinib. We tested three potent compounds (7f, 7e, and 7 g) against a normal breast cell line in a cell survivability test (MCF-10A). Interestingly, none of them killed the cancer cells significantly (IC50 values greater than 88.91 µM). In addition, in vitro tyrosine kinase EGFR inhibitory activity has shown that compounds 7e and 7f display the highest tyrosine kinase EGFR inhibitory potency with an IC50 value of 1.10 and 0.85 µM, respectively, compared to the reference Erlotinib with an IC50 value of 1.24 µM. Furthermore, molecular docking analyses revealed that compounds (7f, 7e, and 7 g) exhibited a higher number of EGFR binding interactions. In this work 7f, the molecule was characterised by using density functional theory (DFT) with B3LYP/6–311G++ (d, p) basis set. The structural parameters were obtained from geometry optimization. Molecular electrostatic potential (MEP), HOMO-LUMO energy gap, and Mulliken atomic charges were calculated. The potent compounds 7f, 7e, and 7 g were subjected to in silico pharmacokinetic assessment by SWISS, ADME, and pkCSM. The three compounds (7e, 7f, and 7 g) intriguingly matched all four of the above-mentioned conditions exactly, with the exception of compound 7f's Ghose rule.

A [2.2]Isoindolinophanyl-Based Carbene (iPC) Ligand: Synthesis, Electronic and Photophysical Properties, and Application in Photocatalysis.

Cyclic amino(alkyl) and cyclic amino(aryl) carbenes (cAACs/cAArCs) have been established as very useful ligands for catalytic and photonic applications of transition metal complexes. Herein, we describe the synthesis of a structurally related sterically demanding, electrophilic [2.2]isoindolinophanyl-based carbene (iPC) that bears a [2.2]paracyclophane moiety. The latter leads to more delocalized frontier orbitals and intense green fluorescence of (HiPC)OTf (2) from an intra-ligand charge transfer (1ILCT) state in the solid state. Base-promoted synthesis of the free carbene led to an unusual ring expansion and subsequent dimerization reaction, but the beneficial ligand properties can be exploited by trapping in situ at a metal center. The iPC ligand is a very potent π-chromophore, which participates in low energy metal-to-ligand (ML)CT transitions in [RhCl(CO)2(iPC)] (4) and IL-"through-space"-CT transitions in [Au(iPC)2]OTf (5). The steric demand of the iPC leads to high stability of 5 against air, moisture, or solvent attack, and ultralong-lived green phosphorescence with a lifetime of 185 μs is observed in solution. The beneficial photophysical and electronic properties of the iPC ligand, including a large accessible π surface area, were exploited by employing highly efficient energy transfer (EnT) photocatalysis in a [2+2] styrene cycloaddition reaction using 5, which outperformed other established photocatalysts in comparison.

Synthesis of phthalocyanine/C3N4 structures and investigation of photocatalytic activities in the oxidation reaction of 4-nitrophenol

Photocatalytic oxidation is an advanced oxidation technique widely preferred for the removal of pollutants in wastewater. In this work, paramagnetic metallo-phthalocyanines EB2 and EB3 (Co(II)phthalocyanine and Cu(II)phthalocyanine) have been synthesized and characterized. They were interfaced with C3N4 (graphitic carbon nitride) to prepare metallophthalocyanines/C3N4 structures (EB2-C3N4 and EB3-C3N4) using ultrasonic methods. New structures were identified with FT-IR, SEM and TGA. The photocatalytic performances of EB2-C3N4 and EB3-C3N4 for reaction with p-nitrophenol (p-NP) were established. The product selectivity for industrially important benzaldehyde was 85.1% for EB2-C3N4 and 80.6% for EB3-C3N4. EB2-C3N4 showed good potential for p-NP photocatalyic oxidation with high turn-over number (TON) and turn-over frequency (TOF) (390 and 1565) over 15 min. Upon excitation of EB2-C3N4 and EB3-C3N4 with light, 4-nitrophenol was easily reduced to hydroquinone, prompted by electron transfer from C3N4 to phthalocyanine and from phthalocyanine to 4-nitrophenol. Computational investigations were used to determine the energies of the highest occupied molecular orbitals (HOMO) and the lowest unoccupied molecular orbitals (LUMO) of EB2, EB3 and C3N4.

N2O Decomposition on Singly and Doubly (K and Li)-Doped Co3O4 Nanocubes─Establishing Key Factors Governing Redox Behavior of Catalysts.

The intimate mechanism of N2O decomposition on bare and redox-tuned Co3O4 nanocubes (achieved by single (Li or K) and double (Li and K) doping) was elucidated. The catalysts synthesized by the hydrothermal method were characterized by X-ray electron absorption fine structure measurements, X-ray diffraction, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, and Kelvin Probe techniques. TPSR and steady-state isothermal catalytic tests reveal that the N2O turnover frequencies are critically sensitive to the work function of the catalysts, adjusted purposely by doping. For the catalysts obtained by one-pot hydrothermal synthesis, lithiation of the Co3O4 nanocubes leads to the formation of {Li'8a, Co·16d} species, decreasing steadily the work function and the activity, while for the catalysts prepared by postsynthesis impregnation, formation of {Li'8a, Co'16d, Co··16c} species leads to a volcano-type dependence of the catalytic activity and the work function in parallel. The beneficial effect of potassium was discussed in terms of mitigation of surface potential buildup due to the accumulation of ionosorbed oxygen intermediates (surface electrostatics), which hinders the interfacial electron transfer. Analysis of the catalytic activity response to the redox tuning of Co3O4, substantiated by DFT calculations, allowed for a straightforward conceptualization of the redox nature of the N2O decomposition in terms of the lineup of frontier orbitals of the N2O/N2O- and O2-/O2 reactants with the surface DOS structure and the resultant molecular orbital interactions. The positions of the virtual bonding 3πg0(N2O)-α-3dz2 and the occupied 2πg1(O2-)-α-3dz2 states relative to the Fermi energy level play a crucial role in the regulation of the forward and backward interfacial electron transfer events, which drive the redox process.

Structures and stabilities Ru-doped Agn (n = 1–13) clusters: Ag10Ru a 18-ve cluster superatom

The geometrical and stability properties of Ru-doped silver clusters (AgnRu with n = 1–13) are investigated by density functional theory (DFT) calculations. The results show that the Ru dopant adopts central positions in the lowest-energy structures of AgnRu clusters. The most stable structures found are planar and curved for n = 3–6, while for n = 6 onward the structures follow a pentagonal growth pattern. Interestingly for n = 10, we found a cage structure with fulfills the 18 electron rule. The relative stability of the clusters is further evaluated through energetic parameters such as ionization energy, electron affinity, second order energy difference and HOMO–LUMO gap. The results show that the most stable structures in this series are Ag3Ru, Ag6Ru and Ag10Ru, as supported by electronic structure analyses. The plausible formation of the Ag10Ru cluster as a superatomic species is rationalized with 1.64 eV of HOMO–LUMO gap and 6.23 eV of adiabatic ionization energy.

A theoretical approach to study oxide-based perovskite materials XTiO3 (X = Be, Mg, Ca, Sr and Ba) for photovoltaic applications

Oxide-based perovskite materials have a large application in fuel and hydrogen sensors, non-volatile random access memory devices, semiconductor fabrications, optoelectronic, thermoelectric and photovoltaic devices. In this report, equilibrium geometries, and optoelectronic properties of oxide-perovskite materials XTiO3 (X = Be, Mg, Ca, Sr and Ba) are investigated through Conceptual Density Functional Theory (CDFT) technique. The HOMO–LUMO energy gap obtained from functional B3LYP/LANL2DZ and B3PW91/LANL2DZ are observed in the range of 1.201 eV–4.647 eV and 1.519 eV–4.903 eV respectively, which justifies their applications in solar cells and optoelectronic devices. HOMO–LUMO energy gap shows a downward trend when materials travel from Be to Mg to Ca to Sr to Ba, except for BaTiO3 in B3PW91/LANL2DZ. BeTiO3 displays the maximum value of HOMO–LUMO gap, hardness and electronegativity value. Hardness and softness of these substances are found between 0.600–2.452 eV and 0.204–0.788 eV respectively whereas refractive index and dielectric constant of XTiO3 are observed in the range of 2.017–3.684 and 4.067–13.574 respectively. Across all relationships, XTiO3’s dielectric constant and refractive index show a rising pattern from Be to Mg to Ca to Sr to Ba, except for BaTiO3 computed using B3PW91/LANL2DZ. The lowest refractive index and dielectric constant are displayed by the BeTiO3. TD-DFT calculation is performed to understand the absorption spectra of these materials. Optical transition energy and wavelength of XTiO3 are found between 0.339–3.535 eV and 350.68–3656.15 nm respectively. An interesting relationship is established between HOMO–LUMO energy gap, optical transition energy and wavelength of XTiO3 materials. The investigated compounds exhibit a linear pattern between HOMO–LUMO energy gap and optical transition energy whereas wavelength shows an inverse trend. MEP of these compounds are also discussed.

Near‐IR Emissive B–N Lewis Pair‐Functionalized Anthracenes via Selective LUMO Extension in Conjugated Dimer and Polymer

AbstractAcenes are attractive as building blocks for low gap organic materials with applications, for example, in organic light emitting diodes, solar cells, bioimaging and diagnostics. Previously, we have shown that modification of dipyridylanthracene via B–N Lewis pair fusion (BDPA) strongly redshifts the emission, while facilitating self‐sensitized reactivity toward O2 to reversibly generate the corresponding endoperoxides. Herein, we report on the further expansion of the π‐system of BDPA to a vinyl‐substituted monomer, vinylene‐bridged dimer, and a polymer with an average of 20 chromophores. The extension of π‐conjugation results in largely reduced band gaps of 1.8 eV for the dimer and 1.7 eV for the polymer, the latter giving rise to NIR emission with a maximum at 731 nm and an appreciable quantum yield of 7 %. Electrochemical and computational studies reveal efficient delocalization of the lowest unoccupied molecular orbital (LUMO) along the pyridyl‐anthracene‐pyridyl axis, which results in effective electronic communication between BDPA units, selectively lowers the LUMO, and ultimately narrows the band gap. Time‐resolved emission and transient absorption (TA) measurements offer insights into the pertinent photophysical processes. Extension of π‐conjugation also slows down the self‐sensitized formation of endoperoxides, while significantly accelerating the thermal release of singlet oxygen to regenerate the parent acenes.

Two‐Electron Phenothiazine Based Cathode Achieved by Raising HOMO Energy Level for High Performance Lithium Organic Battery

AbstractRedox‐active p‐type phenothiazine based organic cathodes have captured increasing attention for lithium‐organic batteries due to their high voltage output and rich chemical modification. However, their capacities are generally limited to one redox event per molecule; while the di‐cation states are subject to rapid decomposition and cannot be effectively utilized. Herein, a scalable synthesis of phenothiazine‐based polymer (MPT‐CC) is reported, that can fully utilize the two‐electron storage by raising its highest occupied molecular orbital (HOMO). Lithium‐organic batteries using this polymer as cathode displayed a high specific capacity of 178 mAh g−1 at 0.2 A g−1. This polymer also displays excellent cycling stability. After 1000 cycles at 0.2 A g−1, a stable capacity of 194 mAh g−1 with ≈100% capacity retention can be obtained. Even at 2 A g−1 after 10,000 cycles, 98 mAh g−1 can be reversibly achieved. Its practical applicability has been successfully demonstrated in MPT‐CC//graphite full cell, also displaying good performance. This work contributes to a major advancement of phenothiazine‐based polymer design for high performance energy storage devices.

Isolation and Diverse Reactivity of an Unsymmetrical 1,2-Bis(silylene)-Stabilized Pentacarbonyl Chromium(0) Species.

The construction of the unsymmetrical 1,2-bis(silylene) pentacarbonyl chromium(0) complex 1 was achieved through the reaction of chlorosilylene with half an equivalent of K2Cr(CO)5. X-ray diffraction analysis of 1 confirms the formation of the Si-Si bond and the coordination of one of the silicon atoms to the Cr center. Density functional theory (DFT) calculations disclose that highest occupied molecular orbital (HOMO) mainly corresponds to the lone pair of electrons on the silicon atom and the σ-bonding interaction between two Si atoms. Based on its unique electronic structure, its diverse reactivity toward the transition metal compounds and small molecules was investigated in detail. The reactions of 1 with Fe2(CO)9 or CuCl yielded the 1,2-bis(silylene)-stabilized heterobimetallic complex 2 or oxidized product 3, respectively. Additionally, treatments of 1 with selenium, CO2, or Me3SiN3 led to the formation of the corresponding selenium-, oxo-, and nitrogen-bridged complexes 4-7. All compounds were characterized by multinuclear NMR spectroscopy and X-ray crystallography.

Near-IR Emissive B-N Lewis Pair-Functionalized Anthracenes via Selective LUMO Extension in Conjugated Dimer and Polymer.

Acenes are attractive as building blocks for low gap organic materials with applications, for example, in organic light emitting diodes, solar cells, bioimaging and diagnostics. Previously, we have shown that modification of dipyridylanthracene via B-N Lewis pair fusion (BDPA) strongly redshifts the emission, while facilitating self-sensitized reactivity toward O2 to reversibly generate the corresponding endoperoxides. Herein, we report on the further expansion of the π-system of BDPA to a vinyl-substituted monomer, vinylene-bridged dimer, and a polymer with an average of 20 chromophores. The extension of π-conjugation results in largely reduced band gaps of 1.8 eV for the dimer and 1.7 eV for the polymer, the latter giving rise to NIR emission with a maximum at 731 nm and an appreciable quantum yield of 7 %. Electrochemical and computational studies reveal efficient delocalization of the lowest unoccupied molecular orbital (LUMO) along the pyridyl-anthracene-pyridyl axis, which results in effective electronic communication between BDPA units, selectively lowers the LUMO, and ultimately narrows the band gap. Time-resolved emission and transient absorption (TA) measurements offer insights into the pertinent photophysical processes. Extension of π-conjugation also slows down the self-sensitized formation of endoperoxides, while significantly accelerating the thermal release of singlet oxygen to regenerate the parent acenes.

Spectroscopic, computational, docking, and cytotoxicity investigations of 5-chloro-2-mercaptobenzimidazole as an anti-breast cancer medication

The vibrations were attributed to 5-chloro-2-mercaptobenzimidazole using FTIR and FT-Raman spectroscopy. The optimized geometrical parameters, IR intensity, and the Raman activity of the vibrational bands were estimated using the Becke three-parameter Lee-Yang-Parr functional and the 6-311++G(d,p) level of theory. These findings are compared with the experimental data. The molecule’s HOMO-LUMO energy gap is found to be 4.418 eV. UV-Vis analysis reveals that the π→π* transition, which happens when electron density shifts from nitrogen, sulfur, and chlorine atoms in the molecule, to the electrons of the C-C bonds of the ring. Total density of states was used to assess the molecular orbital contributions. There are 47α and 47β electrons totaling 94 electrons in the DOS spectrum. NBO investigations indicate that a considerable stabilizing energy of 30.37 and 30.90 Kcal/mol was revealed by the lone pair transition of N1 and N3 atoms to π*(C7-C8) and π*(C4-C9). The more electrophilic region, as seen by the red zone in MEP mapping, lies in the vicinity of the nitrogen and sulfur atoms. The molecule’s hydrogen atoms are found in the blue nucleophilic area. The theoretical chemical shifts for 1H and 13C NMR ranged from 7.03 to 8.23 ppm and 113.10 to 207.31 ppm, respectively. The docking research showed that the molecule attached to protein 1AQU with a greater binding energy of −6.8 Kcalmol−1. The cytotoxicity of the sample was evaluated against a MCF-7 cell line (IC50 = 16.54 µg/ml) and exhibited a good breast cancer action. In addition, ADMET prediction has been used to estimate the medicinal applicability of the chemical.

The adsorption of amantadine antiparkinsonian drug on the B24N24 and Al24N24 nanoclusters: An investigation using the density functional theory

By employing the density functional theory (DFT), the present investigation studied the adsorption of an anti-Parkinson drug called Amantadine (AM) onto the nanoclusters of B24N24 and Al24N24. Through their –NH2 group, the molecules of Amantadine interacted with the B or Al head of the AlN(BN) nanoclusters, and it was found that the change in the free Gibbs energy was –32.3 (−27.2) kcal/mol. The increased dosage of Amantadine led to weaker AM/cluster interactions, which is attributable to the steric effect. The molecule of Amantadine was subjected to electrostatic adsorption onto the nanoclusters of AlN and charge transfer adsorption onto the nanoclusters of BN. The Amantadine adsorption led to a dramatic decrease from 4.47 eV to 3.63 eV in the work function of the AlN nanoclusters. As a result, the electron field emission improved. Thus, one may use AlN nanoclusters as an Φ-type chemical sensor for the detection of Amantadine molecules. The AM adsorption onto the BN nanoclusters resulted in noticeable HOMO destabilization and decreased HOMO-LUMO energy gap from 6.84 eV to 5.67 eV. Consequently, a great increase was observed in the electrical conductivity of the BN nanoclusters. As a result, one may use BN nanoclusters as a suitable candidate for manufacturing electronic sensors with the capability of detecting Amantadine.

Structural, optical spectroscopic, and density functional theory calculations of squaraine dye for organic electronic applications

The structural, optical spectroscopic, and density functional theory calculations of 2,4-Bis[4-(N,N-diisobutylamino)−2,6-dihydroxyphenyl] squaraine dye (SQ) are promising investigations that can be useful in photochemical mechanisms explanation and in designing promising chemosensors. The nature of the bonds, the chemical composition of SQ, crystallographic structure, morphology, and quality characteristics were explored by FTIR, XRD, and SEM investigations. The crystallite size, the dislocation density, and the lattice strain were found to be 57.3 nm, 3.045 × 10−4 nm−2, and 3.065 × 10−3, respectively. The spectrum behavior of the absorbance and molar absorption coefficient spectra of SQ in DCM with three concentrations were analyzed to get some important optical properties of SQ dye. The determined optical gap transition equals Egapopt=1.81eV. Quantum chemical computations and optimized molecular geometries identified where electrophilic attacks are likely and analyzed the molecule’s electrostatic potential. Using DFT calculations at the B3LYP/6-31+G(d,p) level, the electronic structure of the squaraine molecule was confirmed, showing a HOMO–LUMO gap of 1.73 eV. MEP analysis indicated that the oxygen atoms are electron-rich, suggesting potential for hydrogen bonding and electrophilic interactions.

Synthesis and Density Functional Theory Study on the Functionalization of Carbon Nanotube Conjugates with Amino Compounds and Their Application in Dyeing Processes

AbstractThis study investigates the functionalization of graphene nanotube (GNTs) conjugates with an amino compound called 1‐amino‐2‐hydroxy‐4‐naphthalene sulfonic acid (AHNSA‐GNTs). The study also evaluates the potential application of these conjugates in dyeing processes. The goal is to modify GNTs to enhance their interaction with dyes, thus improving the efficiency of dyeing textiles and the colorfastness of the resulting products. Multiple characterization methods, such as X‐ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to get a better look at the composites. The findings of the study indicate that AHNSA‐GNTs composites improve dye retention on wool fibers, which leads to a reduction in the consumption of excess dye and water. Density Functional Theory (DFT) calculations were utilized to investigate the electronic properties and binding energies of the functionalized CNTs, providing insights into the molecular interactions between the CNTs and amino compounds. Overall, this study highlights the promising applications of graphene nanotubes in sustainable textile processes. Frontier molecular orbitals (FMOs) and global reactivity descriptors serve as key tools for understanding the stability and chemical reactivity of compounds. These tools were used to calculate FMOs and electronic parameters of compounds 1 and 2 at the B3LYP/6‐31G(d) level of theory. The study examined the highest occupied molecular orbital (HOMO)‐lowest unoccupied molecular orbital (LUMO) energy gap, which provides insights into molecular stability and reactivity. Various physical properties were derived from these calculations, including electron affinity (EA) and ionization potential (IP) to LUMO and HOMO energies. Compound 2 emerged as the most efficient electron donor, possessing the highest HOMO energy, while compound 1 excelled as the best electron acceptor with the highest LUMO energy.

Investigation of spectroscopic characterization, crystal structure, and antitumor activity of a novel 2ATP molecule

In this section, the spectroscopic characteristics of 2-amino-toysl-pyridine (2ATP) are fully examined, using both experimental and computational investigations guided by density functional theory (DFT). It will facilitate our computational research using the B3LYP approach to use the basis set 6–311++G(d,p). Comprehensive assignments of vibrational modes were obtained from the vibrational spectra, which comprised FT-Raman and FT-IR spectroscopy and were recorded in the region of 3500–400 cm−1 and 4000–500 cm-1, respectively, using the Vibrational Energy Distribution Analysis (VEDA) approach. The net atomic charges inside the molecule were ascertained by using Mulliken population analysis, natural atomic charges, and electrostatic potentials (CHELPG). The structural conformations of 2ATP were determined using NMR spectroscopy in a CDCl3 solvent. The donor-acceptor interactions of the 2ATP molecule at the 6–311++G(d,p) level were studied by means of a Natural Bond Orbital (NBO) study. Studies of the ultraviolet (UV) spectrum in ethanol were used to assess the effects of the solvent. An assessment was made of the energy difference between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) in order to understand charge transfer processes that suggest the molecule may have biological activity. Molecular electrostatic potential (MEP) surfaces were used to predict the nucleophilic and electrophilic sites in molecules. The non-covalent interactions were evaluated using the reduced density gradient (RDG) approach. The Multiwfn software was used to analyze the topological properties of the 2ATP, including the Localized Orbital Locator (LOL) and Electron Localization Function (ELF). Further attention was drawn to the compound's exceptional pharmacological potential when its ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) characteristics were evaluated. Not to add, molecular docking experiments were carried out to evaluate the feasibility of 2ATP as a bioactive material with possible uses in the pharmaceutical business.

Unveiling the photoexcitation mechanism of COF-2CN material: From the perspective of molecular structure

Covalent organic frameworks (D-A COFs) with electron donor–acceptor structures possess electron transfer channels between the donor and acceptor components, making them potential candidates for applications requiring high photocatalytic activity. In this paper, COF-2CN is selected as a representative material, and computational studies are conducted based on density functional theory (DFT) to gain further insight into its excitation mechanism. First, we used first-principles calculations to determine the molecular structure of COF-2CN. The results reveal that the material has a hexagonal pore shape with a pore size of 25.81 Å, and all atoms in the monolayer structure lie in the same plane. Next, we plotted the density of states (DOS) for COF-2CN and determined that the highest occupied molecular orbital (HOMO) energy level is −0.22 eV. Additionally, we calculated the oscillator strengths for the first 100 excited states and selected 8 states with values greater than 0.2 for further analysis. Subsequently, we analyzed the distribution of electron holes in these excited states and found that, in most cases, the electrons and holes are distributed along the edges of the six-membered rings, with the holes having a broader distribution than the electrons. Finally, we simulated the UV–visible absorption spectrum of COF-2CN, finding that maximum light absorption occurs at a wavelength of 466.1 nm, with an intensity of approximately 454,057 L mol−1 cm−1.

Improvement of Perovskite Solar Cells Efficiency by Management of the Electron Withdrawing Groups in Hole Transport Materials: Theoretical Calculation and Experimental Verification.

Management of functional groups in hole transporting materials (HTMs) is a feasible strategy to improve perovskite solar cells (PSCs) efficiency. Therefore, starting from the carbazole-diphenylamine-based JY7 molecule, JY8 and JY9 molecules are incorporated into the different electron-withdrawing groups of fluorine and cyano groups on the side chains. The theoretical results reveal that the introduction of electron-withdrawing groups of JY8 and JY9 can improve these highest occupied molecular orbital(HOMO)energy levels, intermolecular stacking arrangements, and stronger interface adsorption on the perovskite. Especially, the results of molecular dynamics (MD) indicate that the fluorinated JY8 molecule can yield a preferred surface orientation, which exhibits stronger interface adsorption on the perovskite. To validate the computational model, the JY7-JY9 are synthesized and assembled into PSC devices. Experimental results confirm that the HTMs of JY8 exhibit outstanding performance, such as high hole mobility, low defect density, and efficient hole extraction. Consequently, the PSC devices based on JY8 achieve a higher PCE than those of JY7 and JY9. This work highlights the management of the electron-withdrawing groups in HTMs to realize the goal of designing HTMs for the improvement of PSC efficiency.

Rosmarinic Acid as a Potential Multi-targeted Inhibitor for SAR-CoV-2: An In silico Virtual Screening Approach

Background: Rosmarinic acid, a natural compound found in various plants like rosemary and lemon balm, may have potential as a multi-targeted inhibitor for SARS-CoV-2, a strain of virus responsible for COVID-19. SARS-CoV-2, a fusion protein of S1 and S2 subunits, has multiple precursors angiotensin-converting enzyme2 (ACE2), transmembrane serine protease 2 (TMPRSS2), papain-like protease (PLpro), and 3-chymotrypsin-like protease (3CLpro). The chemical interaction of Rosmarinic acid with SARS-CoV-2 is of major interest reported here. Objective:: The quantitative study of Rosmarinic acid with various precursors of SARS-CoV-2 has been accounted for in detail. Furthermore, the conformational flexibility of Rosmarinic acid has also been investigated during the interaction with four different precursors of SARS-CoV-2. Methods: This investigation delves deeply into the analysis of various aspects, including geometric parameters, atomic charge, the energy gap between the highest occupied and lowest unoccupied molecular orbitals, dipole moments, and the analysis of non-covalent interactions (NCI). Furthermore, the study incorporates molecular docking techniques in conjunction with thorough quantum chemical calculations to provide comprehensive insights. Results: Rosmarinic acid shows promise as a versatile inhibitor of SARS-CoV-2, the virus responsible for COVID-19. It can target multiple key precursors of the virus, including TMPRSS2, angiotensin- converting enzyme2, 3CLpro, and PLpro, found in the fusion protein comprising S1 and S2 subunits. This study delves into the quantitative analysis of Rosmarinic acid's interactions with these precursors. Its adaptable structure allows it to engage with them effectively. Various molecular parameters, including atomic charge, energy gap between molecular orbitals, dipole moment, and noncovalent interactions, are comprehensively explored. Conclusion: Combining molecular docking and quantum mechanics, the findings suggest Rosmarinic acid's potential as a multi-targeted SARS-CoV-2 inhibitor.