LUMO Research Articles

Theoretical Investigation on Carbazole Derivatives as Charge Carriers for Perovskite Solar Cell

The study explores carbazole‐based organic molecules as transport layers in durable perovskite solar cells, focusing on their optoelectronic and charge transfer properties. Thirteen carbazole derivatives are systematically analyzed via density functional theory (DFT) calculations to understand their structure and optoelectronic characteristics. Substituents like bromo, phenyl, thiophenyl, and pyridyl at positions 3,6‐ and 2,7‐ of carbazole were studied. Phenyl and thiophenyl substitutions lowered highest occupied molecular orbital (HOMO) energy levels, while bromo and pyridyl increased them, tuning HOMO energies from −5.45 to −6.03 eV. These energies align well with perovskite materials valence bands, with absorbance primarily below 400 nm, complementing perovskite absorption. The compounds showed high light‐harvesting efficiencies (LHEs) (0.22 to 0.94) and improved radiative lifetimes. Theoretical investigations identified most compounds as effective p‐type hole‐transport materials (HTM), except 3,6‐ and 2,7‐dithiophenyl carbazoles, which exhibited n‐type behavior due to low hole reorganization energies. Overall, the study highlights computational design's role in developing carbazole derivatives as promising charge carrier precursors for perovskite solar cells.

Preparation, Characterization, In Vitro Biological Evaluation, DFT Calculations, and Molecular Docking Investigations of 1H-Imidazole-2-Carboxylic acid and Histidine-Based Mixed-Ligand Complexes.

Mixed-ligand complexes incorporating 1H-Imidazole-2-Carboxylic acid (IMCA) and Histidine (LHIS) show promise for biomedical and biotechnological applications. This study synthesizes and characterizes FeIMCALHIS, CoIMCALHIS, and NiIMCALHIS coordination compounds using metal chloride salts (FeCl3.6H2O, CoCl2.6H2O, NiCl2.6H2O) in ethanolic solutions. The complexes are characterized by spectroscopic methods (IR, UV-vis, and mass spectra), elemental analysis, conductivity, magnetic, and thermal analysis. Molar conductivity indicates their non-electrolytic nature. UV-vis spectra reveal absorption bands with pathochromic shifts, and electronic spectra show characteristic metal-ligand transitions, indicating their structural configuration and coordination geometry. 3D geometry optimization shows six-coordination around Fe(III) and Co(II) in FeIMCALHIS and CoIMCALHIS, and four-coordination around Ni(II) in NiIMCALHIS. Analysis of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) suggests decreased electron donation ability upon coordination. Electronic structure parameters (HOMO, LUMO, ionization potential, energy gap, electron affinity, chemical potentials, and electronegativity) provide further insights into stability and reactivity. The metal complexes exhibit enhanced antimicrobial, antioxidant, and anti-inflammatory activity compared to individual ligands, with FeIMCALHIS showing notable antimicrobial activity. Molecular docking analysis reveals strong binding interactions with target proteins, highlighting their potential therapeutic applications.

Probing the Electric Field Response of a Water Molecule Confined in Small Carbon Nanocages: A Density Functional Theory Investigation.

We consider a water molecule under tight confinement in the small-sized fullerenes (C28, C30, C32) within the density functional theory (DFT) calculations with suitable exchange-correlation functionals. Such nanoscopic molecular cages provide an ideal setup to study their characteristic properties not present in the condensed phase. The water molecule entirely loses its feature of typical water when it is confined in small fullerenes of size equal to C30or smaller, in which the asymmetric O-H stretching vibration occurs at a lower wavenumber than the symmetric stretching. We study the response of the confined water molecule to the applied electric fields in terms of change in geometrical parameters, NMR spin-spin coupling constants, dipole moment, HOMO-LUMO (HL) gap, and vibrational frequency shift. The electric field shielding property of small-sized fullerene cages is explored and found to be strongly correlated with the HL gap. Since the electric field modulates the gap to decrease generally, shielding efficiency varies with field strength, thereby making large fields better shielded than small fields for the small penetration factor at large fields. The results that hold significance for technological applications are discussed.

Synthesis, crystal structure, spectroscopic, electronic and vibrational properties of N′-[(E)-3-pyridinylmethylene]nicotinohydrazide trihydrate: Experimental and computational study

N′-[(E)-3-pyridinylmethylene]nicotinohydrazide trihydrate (C12H10N4O·3(H2O)) was synthesized and its structure was determined by single crystal X-ray diffraction method. X-ray analysis showed that the compound crystalized in the triclinic system P-1 with a = 7.1134 (3) Å, b = 10.0208 (4) Å, c = 10.3601 (4) Å, α = 96.386 (3)°, β = 96.995 (3)°, γ = 101.219 (4)°, V = 712.05 (5) Å3 and Z = 2 and exhibits that the title compound (I) consists of N′-[(E)-3-pyridinylmethylene]nicotinohydrazide (II) (C12H10N4O), and three water molecules of crystallization. The two water molecules are attached to the third water molecule through intermolecular two OH…O hydrogen bonds. At the same time, this water molecule is linked to the NH amide group of the hydrazone by an intermolecular NH…O hydrogen bond. Hirshfeld surface (HS) analyses were carried out are to visualise the intermolecular interactions in the crystals of Compound I. The geometric optimization of the titled compound has been carried out by different computational methods such as by Hatree Fock (HF) and Density Functional Theory (DFT) methods with the 6–311++G (d,p) basis set. The vibrational frequency, dipole moment (μ), polarizability (α), hyperpolarizability (β), and electronic properties including the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO–LUMO) of the compound have been calculated at the level of both theories. In the results of crystal analysis and geometry calculations of the compound I, it was observed that intermolecular hydrogen bonds, N2H2A…O3, O3H31…O2 and O3H32…O4, were formed. The energy band gap (Eg = ELUMO-EHOMO) values were also obtained by using ELUMO and EHOMO at the level of both theories. The value of equilibrium (ground state) dipole moment of the studied molecule was calculated to be 8.31 Debye in B3LYP and 7.55 Debye in HF. The calculated hyperpolarizability values at the B3LYP/6–311++G(d,p) of the compound are 2.53 × 10−30 esu and this value corresponds to 6.79 times the hyperpolarizability value of urea.

Theoretical investigation of norfloxacin hybrid compounds with silver, copper, and gold metals as potential anticancer agents

The strategy of drug repurposing and repositioning in developing hybrid molecules is significant in drug discovery. Norfloxacin (Nor) hybrids, part of the fluoroquinolone class of antibiotics, have demonstrated anticancer properties. Various norfloxacin metal complexes have been synthesized and evaluated for their anticancer potential through docking simulations using AutoDock Vina. To preliminarily identify potential molecular targets for these anticancer compounds, docking studies were conducted with a variety of enzymes and receptor proteins associated with the cell cycle, cell growth, and DNA replication. These targets included cyclin dependent protein kinase-2 (CDK-2), CDK-6, DNA topoisomerases I and II, B cell lymphoma-2 (Bcl-2), and vascular endothelial growth factor receptor-2 (VEGFR-2). Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were conducted utilizing the B3LYP functional with the 6-311G++ and LanL2DZ basis sets. This study investigated the optimized geometries, molecular electrostatic potential (MEP) maps, key molecular properties, and HOMO-LUMO energy gaps of Nor, Nor zwitterionic structure, and its synthesized compounds ([Ag2(Nor)2](NO3)2, [Cu(Nor)2(H2O)2]SO4.5H2O, and [Au(Nor)2(H2O)2]Cl3). KEY WORDS: Norfloxacin, Anticancer agents, DFT/ TD-DFT, Molecular docking Bull. Chem. Soc. Ethiop. 2024, 38(6), 1775-1790. DOI: https://dx.doi.org/10.4314/bcse.v38i6.21

Theoretical investigation of complexes of uranyl(II), vanadyl(II) and zirconyl(II) with vitamin B13 as candidate compounds as anti-nonalcoholic fatty liver disease and Diabetes mellitus targets

Density functional theory (DFT) calculations were carried out utilizing the B3LYP functional in conjunction with the 6-311G++ and LanL2DZ basis sets to explore the molecular properties and geometries of Vitamin (Vit) B13 and its complexes with Uranyl (II), Vanadyl (II), and Zirconyl (II). The optimized structures, molecular electrostatic potential maps, key molecular properties, and HOMO-LUMO energy gaps of these compounds were systematically examined to gain insights into their electronic characteristics and stability. Bioactivity screenings of the synthesized complexes were performed using molecular docking studies to investigate their interactions with diabetes mellitus (DM) target proteins, specifically the Insulin Receptor (IR) (PDB ID: 1IR3) and the peroxisome proliferator-activated receptor-γ (PPARγ) (PDB ID: 3K8S). These receptors play pivotal roles in the PPAR and AMP-activated protein kinase (AMPK) signaling pathways, which are essential for protecting against nonalcoholic fatty liver disease (NAFLD). The docking results highlighted the binding affinities and potential bioactivity of Vit B13 and its metal complexes, suggesting their promise as therapeutic agents against DM and NAFLD. This comprehensive computational study provides valuable insights into the molecular interactions and electronic properties of these compounds, paving the way for further experimental validation and potential pharmaceutical applications. KEY WORDS: Vitamin B13, Metal complexes, Diabetes mellitus, Molecular docking, DFT Bull. Chem. Soc. Ethiop. 2024, 38(6), 1743-1757. DOI: https://dx.doi.org/10.4314/bcse.v38i6.19

Synthesis, structural characterization and computational studies of half- sandwich Ru(II) (η6-p–cymene) TPA appended benzhydrazone complex

A ruthenium complex of the type Ru[η6(p–cymene)Cl(L)] where L = Triphenylamine (TPA) appended O^N bidendate benzhydrazone ligand was synthesized and characterized by various analytical and spectral [UV, FT-IR, NMR (1H and 13C) and HRMS] methods. The solid state molecular structure of the ruthenium complex was investigated with the aid of X-ray crystallography results with pseudo-octahedral geometry around the metal centre. FT-IR spectroscopy confirms the coordination via the azomethine nitrogen and imidolate oxygen. Density Functional theory (DFT) calculations have been used to analyse the composition of frontiers orbitals. The bonding interactions between the ligand and ruthenium complex fragments have been examined by EDA. The spin-allowed singlet transitions were calculated with the TD-DFT method. NBO analysis shows that the donation from ligand to metal has value of 136.64 kcal/mol and the back donation is equal to 109.61 kcal/mol. Hence the ligand is a σ-donor with weak π-acceptor properties. The DOS spectrum of both ligand and complex were plotted in terms of Mullikan population analysis were calculated using the GassSum program. Further, the relative contributions to the Hirshfeld surface area for the various close intermolecular contacts of ruthenium complex are investigated and H…H interactions plays an important role for the construction of the crystal structure of the ruthenium complex.

Synthesis, Stable Radical Anion and Energy Storage Performance of Pentacene Tetraimides

Imide functionalization has been widely proved to be an effective approach to enrich optoelectronic properties of polycyclic aromatic hydrocarbons (PAHs). However, appending multiple imide groups onto linear acenes is still a synthetic challenge. Herein, we demonstrate that by taking advantage of a “breaking and mending” strategy, a linear pentacene tetraimides (PeTI) was synthesized through a three‐step sequence started from the naphthalene diimides (NDI). Compared with the parent pentacene, PeTI shows a deeper‐lying lowest unoccupied molecular orbital (LUMO) energy level, narrower bandgap and better stability. The redox behavior of PeTI was firstly evaluated by generating a stable radical anion specie with the assistance of cobaltocene (CoCp2), and the structure of the electron transfer (ET) complex was confirmed by the X‐ray crystallography. Moreover, due to the presence of multiple redox‐active sites, we are able to show that the state‐of‐the‐art energy storage performance of the dealkylated PeTI (designated as PeTCTI) in organic potassium ion batteries (OPIBs) as an anode. Our results shed light on the application of multiple imides functionalized linear acenes, and the reported synthetic strategy provides an effective way to get access to longer nanoribbon imides with fascinating electronic properties.

Synthesis, Stable Radical Anion and Energy Storage Performance of Pentacene Tetraimides.

Imide functionalization has been widely proved to be an effective approach to enrich optoelectronic properties of polycyclic aromatic hydrocarbons (PAHs). However, appending multiple imide groups onto linear acenes is still a synthetic challenge. Herein, we demonstrate that by taking advantage of a "breaking and mending" strategy, a linear pentacene tetraimides (PeTI) was synthesized through a three-step sequence started from the naphthalene diimides (NDI). Compared with the parent pentacene, PeTI shows a deeper-lying lowest unoccupied molecular orbital (LUMO) energy level, narrower bandgap and better stability. The redox behavior of PeTI was firstly evaluated by generating a stable radical anion specie with the assistance of cobaltocene (CoCp2), and the structure of the electron transfer (ET) complex was confirmed by the X-ray crystallography. Moreover, due to the presence of multiple redox-active sites, we are able to show that the state-of-the-art energy storage performance of the dealkylated PeTI (designated as PeTCTI) in organic potassium ion batteries (OPIBs) as an anode. Our results shed light on the application of multiple imides functionalized linear acenes, and the reported synthetic strategy provides an effective way to get access to longer nanoribbon imides with fascinating electronic properties.

Investigation of the adsorption of miglitol anti-diabetic drug on the surface of X12Y12 (X = B, Al; Y = N, P) nanocages: A DFT and COSMO insights

A DFT investigation has been carried out to understand the adsorption nature of the miglitol (MT) anti-diabetic drug on the surface of B12N12, B12P12, Al12N12, and Al12P12 nanocages in the gas and water phase. MT drug is physically adsorbed on the surface of B12N12 and B12P12 while chemisorption is observed for Al12N12 and Al12P12 nanocages. Al12N12 shows the highest adsorption energy of −2.08 eV in gas and −1.96 eV in water media respectively. The electronic HOMO–LUMO energy gaps were extremely reduced by about 48.21 %, 41.67 %, 4.02 %, and 9.92 % in the gas phase after the adsorption of MT drug onto the surface of the studied nanocages respectively which implies the increase in electrical conductivity of these nanocages. Dipole moment and COSMO surface analysis forecasted that Al12N12 and Al12P12 show more solubility in water media. Therefore, all the studied nanocages are favorable drug carriers and among them, Al12N12 can be used as a promising nano-vehicle for MT drug.

Topological Transition in Aromatic and Quinonoid π-Conjugated Polymers Induced by Static Strain.

A topological quantum phase transition has been identified for the first time for 24 π-conjugated polymers as a function of external longitudinal strain due to a level crossing of the frontier orbitals at the topological phase transition. Topological phase is determined by the presence/absence of edge states. Out of the 24 polymers 15 are traditionally assigned an aromatic character, and 9 are traditionally assigned a quinonoid character. We find that all aromatic ones correspond to the trivial topological phase (Zak invariant, Z2 = 0), while all of the quinonoid ones to the nontrivial topological phase (Z2 = 1) replacing the intuitive characterization of aromatic/quinonoid with the physically well-defined Zak invariant. Unique topological phase transition as a function of tensile strain can be achieved for four of the quinonoid ones. Tensile strain in these cases leads to a reduction of the bandgap. We introduced a figure of merit for indicating the efficiency of achievable very small bandgap upon the application of external strain.

Tunable Properties of New Cyano‐Substituent Heptahelicenes for Optoelectronic Devices: A Combined Experimental and DFT Computational Study

AbstractHere, we describe a set of coupled experimental and theoretical analyses. The introduction of one and two additional cyano groups in the carboheptahelicene backbone enhance its electron‐accepting properties. New carboheptahelicene derivatives are synthesized, and relevant characterizations of structural features, photophysical and electrochemical properties, and structure‐property relationships are described. This present work concerns the use of the density functional theory (DFT) to highlight the structural and the optoelectronic properties of carboheptahelicene derivatives and comparing the obtained findings with the experimental ones. The experimental and theoretical spectra (UV‐Vis absorption and photoluminescence) provide excellent concurrence. Afterward, molecular structures, structural parameters, molecular electrostatic potential (MEP), highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies of frontier molecular orbitals (FMOs) are constructed. Some other optoelectronic parameter including electron affinity (EA), ionization potential (IP), and some reactive descriptor such as chemical potential (μ), global hardness (η), electronegativity (χ) and the overall electrophilicity index (ω) are determined and indicating its potential uses as an active layer in optoelectronic efficient devices. The topological methods such as electron localization function (ELF), localization orbital locator (LOL) and the reduced density gradient method (RDG) were also conducted to clarify the strengths and kinds of interactions.

Multifunctional fluorinated phosphonate-based localized high concentration electrolytes for safer and high-performance lithium-based batteries

This study introduces a novel fluorinated phosphonate-based additive, Bis(2,2,2-trifluoroethyl)(methoxycarbonylmethyl)phosphonate (BTCMP), in a localized high-concentration electrolyte (LHCE) to address key challenges in lithium metal batteries (LMBs), such as dendritic lithium growth and porous electrode morphology. The pristine LHCE forms a fluorine-rich solid electrolyte interphase (SEI) layer, primarily composed of lithium fluoride (LiF). However, the pristine LHCE suffers from severe electrolyte decomposition, forming a thicker and more resistive cathode electrolyte interphase (CEI), leading to increased impedance and reduced cyclability. Interestingly, Density Functional Theory (DFT) investigations revealed that the BTCMP inclusion modifies the solvation structure by dispersing the aggregates into smaller fragments, facilitating easier Li+ migration than the pristine LHCE. The addition of BTCMP suppresses solvent decomposition as confirmed by an increasing trend in the lowest unoccupied molecular orbital (LUMO) of corresponding LHCE molecules. Further, the presence of BTCMP results in a thinner and more stable CEI, reducing electrolyte decomposition, maintaining better ion transport, and preserving the cathode's structural integrity, as supported by TEM and XPS analysis. The BTCMP-based F-rich LHCE retained 82 % of its initial capacity while maintaining a coulombic efficiency of 99.5 % after 200 cycles in a Li||LNMO cell while the pristine LHCE only retained 47.2 % of initial capacity post-150 cycles. Additionally, the flame-retardant properties of BTCMP-based LHCE highlight its safety compared to commercial electrolytes.

Energy Level Tuning in CsPbBr3 Perovskite Solar Cells through In Situ-Polymerized PEDOT Hole Transport Layer.

The all-inorganic CsPbBr3 perovskite solar cells exhibit excellent stability against humidity and thermal conditions as well as relatively low production cost, rendering them a gradually emerging research hot spot in the field of photovoltaics. However, the absence of a hole transport layer (HTL) in its common structure and the substantial energy level difference of up to 0.6 eV between the highest occupied molecular orbital (HOMO) level of CsPbBr3 and the work function of the carbon electrode have emerged as the primary factor limiting the improvement of its power conversion efficiency (PCE). In this work, the monomer 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) is spin-coated onto the surface of the CsPbBr3 film directly and then subjected to annealing; DBEDOT undergoes in situ polymerization to form poly(3,4-ethylenedioxythiophene) (PEDOT), which aims to ameliorate the issue of excessive energy level difference between CsPbBr3 and the carbon electrode, and to facilitate the extraction and transport efficiency of holes between the CsPbBr3 perovskite and the carbon electrode. Compared to the pristine device, the PCE of the device based on in situ polymerization is enhanced and achieves a maximum efficiency of 9.81%. Furthermore, the unencapsulated devices based on in situ polymerization maintain 95.9% of their original efficiency after 40 days of stability testing.

Fluorinated ester additive to regulate nucleation behavior and interfacial chemistry of room temperature sodium-sulfur batteries

Room temperature sodium-sulfur (RT Na-S) batteries are considered as advanced energy storage technology due to their low cost and high theoretical energy density. However, challenges such as the growth of sodium dendrite and dissolution of sodium polysulfides significantly hinder the electrochemical performance. Herein, we developed a propylene carbonate (PC)-based electrolyte with Methyl 2-Fluoroisobutyrate (MFB) as an additive. The ester group in the MFB additive is capable of participating in and reconfiguring the coordination of their Na+ solvated structures, thereby lowering the desolvation barrier and regulating the Na anode’s interfacial reaction and nucleation behavior. The polar C−F bond at the other end helps to reduce the lowest unoccupied molecular orbital (LUMO) energy of the MFB additive, enabling the preferential decomposition of MFB to form the F-rich inorganic phase strong polar solid electrolyte interphase (SEI), contributing to the inhibition of Na dendrite growth, the accumulation of dead Na. In addition, NaF-riched cathode electrolyte interphase (CEI) was also observed on sulfur-based cathode, which can effectively inhibited the shuttle effect. Consequently, the developed RT Na-S battery exhibit excellent electrochemical performance.

Oxygen-Binding Sites of Enriched Gold Nanoclusters for Capturing Mitochondrial Reverse Electrons.

Reverse electron transfer (RET), an abnormal backward flow of electrons from complexes III/IV to II/I of mitochondria, causes the overproduction of a reduced-type CoQ to boost downstream production of mitochondrial superoxide anions that leads to ischemia-reperfusion injury (IRI) to organs. Herein, we studied low-coordinated gold nanoclusters (AuNCs) with abundant oxygen-binding sites to form an electron-demanding trapper that allowed rapid capture of electrons to compensate for the CoQ/CoQH2 imbalance during RET. The AuNCs were composed of only eight gold atoms that formed a Cs-symmetrical configuration with all gold atoms exposed on the edge site. The geometry and atomic configuration enhance oxygen intercalation to attain a d-band electron deficiency in frontier orbitals, forming an unusually high oxidation state for rapid mitochondrial reverse electron capture under a transient imbalance of CoQ/CoQH2 redox cycles. Using hepatic IRI cells/animals, we corroborated that the CoQ-like AuNCs prevent inflammation and liver damage from IRI via recovery of the mitochondrial function.

Computational, molecular docking and spectroscopic insights of drug–drug interaction between Ibuprofen and Paracetamol

The combination of existing drugs or drug–drug interaction enthralls researcher because of their potential applications in multiple diseases and better efficacy. The present work is undertaken to study the interaction between two drugs, Ibuprofen and Paracetamol, using Density Functional Theory and spectroscopic techniques (Infrared and Raman spectroscopy). The molecular modeling of the two drugs indicates their interaction through intermolecular hydrogen bonds (O34-H53-O2 and (O1-H33-O34), which is observed in Natural Bond Orbital and atoms in molecules analysis of the compound (Ibuprofen + Paracetamol). The experimental Raman, Surface Enhanced Raman Spectroscopy and Infrared spectra of the physical mixture (Ibuprofen + Paracetamol) are found close to their computed wavenumbers. The interacting state, that is, Ibuprofen + Paracetamol is optimized using B3LYP/6-31G ++ (d, p) model under density functional theory framework and different computed quantum chemical parameters such as, dipole moment, ionization energy, electron affinity, electrophilicity index, chemical potential, hardness and the Highest Occupied and Lowest Unoccupied Molecular Orbital energies and energy gaps are calculated and compared to the monomer state of the drugs. The lowering of energy gap and increased in dipole moment of combined drug molecules show potency as an effective hybrid drug. The molecular docking study of the combined drug molecule against the 4PH9 receptor shows a better binding affinity with its residues through hydrogen bonding and hydrophobic interaction.

A unique approach to address avoided crossings in the charge stabilization curve for LUMO identification.

In quantum chemistry, Lowest Unoccupied Molecular Orbital (LUMO) is important for studying various chemical processes, including photochemical reactions, electron attached states, and electron excites states. Recently, an effective method has been introduced that involves the use of the Parametric Equation of Motion (PEM) in conjunction with the nuclear charge stabilization method for precise identification of true LUMO. However, the inclusion of extra diffuse functions in the basis set, which is necessary for describing electron-attached and electron-excited states, can cause issues due to the presence of the same symmetry states, leading to avoided crossing. Identifying the true LUMO among these avoided crossings is challenging due to the mixing of states and the exchange of their orbital character. This article introduces a modification of the PEM to identify the true LUMO by preventing the stabilization of specific states involved in avoided crossings. The present method is highly effective and requires minimal computational cost.

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.