Search

In this work, the mechanisms for creating a combined electronic–radiative local state beneath the conduction band, consisting of intrinsic and activator electron–hole states, are experimentally substantiated. In the first part of this work, the mechanisms of the formation of intrinsic and activator electron–hole trapping centers are experimentally demonstrated in all four matrices with activators. Intrinsic electronic states are localized on activators and anions of the matrix, forming intrinsic and activator electronic states. The hole component of the electron–hole pairs is localized near the activators. Thus, the energy of intrinsic electronic excitations localized in the matrix in the form of combined electronic–radiative states is observed at 3.06–3.1 eV and 2.92–2.95 eV. Radiative states are excited by photon energies of ~4.5 eV and ~4.0 eV, resulting in recombination emissions at 3.06–3.1 eV and 2.92–2.95 eV, as well as activator emissions at 2.06 eV for M n 2 + , 2.5 eV for T b 3 + , and 2.56 eV and 2.16 eV for D y 3 + . Energy transfer from the matrix to emitters or activators occurs during the decay of the combined radiative state. Upon heating, electrons localized on anions and activators delocalize at temperatures of 200–350 K. The energy released during the recombination of an electron with a hole near the activators is transferred to the activators. This process facilitates energy transfer to activators in dosimeters and detectors. [ABSTRACT FROM AUTHOR]

Abstract Hydrochar from waste biomass is a promising material for removing emerging contaminants (e.g., antibiotics) in water/soil environment. Abundant small-sized hydrochar particles (HPs) with a high content of reactive functional groups and high mobility are easily released into ecosystems through hydrochar applications. However, the photodegradation ability and corresponding structures of HPs are largely unknown, which hinder accurate estimation of the remediation effect of hydrochar in ecosystems. Herein, photodegradation performance of HP towards targeted norfloxacin (NOR, a typical antibiotic) under light irradiation (visible and UV light) were investigated after adsorption processes upon release into soil/water, and its reactive species and photoactive structures were clarified and compared with those of residual bulk hydrochar (BH) comprehensively. The results showed that: (1) photodegradation percentages of HPs were 4.02 and 4.48 times higher than those of BHs under UV and visible light, in which reactive species of both HPs and BHs were ·OH and ·O2 −; (2) density functional theory (DFT) results identified that the main photoactive structure of graphitic-N decreased the energy gap (Eg) of HPs, and C=O, COOH groups improved electron donating ability of BHs; (3) well-developed graphitization structure of HP resulted from higher polymerization reaction was an significant photoactive structure involving its superior photodegradation ability relative to that of BH. The distinct heterogeneities of photodegradation ability in HP and BH and underlying photoactive structures provide an in-depth understanding of hydrochar application for removing emerging contaminants in soil/water environment. Identifying photoactive structures is helpful to predict photodegradation ability of hydrochar according to their abundance. Graphical Abstract

Hydrochar from waste biomass is a promising material for removing emerging contaminants (e.g., antibiotics) in water/soil environment. Abundant small-sized hydrochar particles (HPs) with a high content of reactive functional groups and high mobility are easily released into ecosystems through hydrochar applications. However, the photodegradation ability and corresponding structures of HPs are largely unknown, which hinder accurate estimation of the remediation effect of hydrochar in ecosystems. Herein, photodegradation performance of HP towards targeted norfloxacin (NOR, a typical antibiotic) under light irradiation (visible and UV light) were investigated after adsorption processes upon release into soil/water, and its reactive species and photoactive structures were clarified and compared with those of residual bulk hydrochar (BH) comprehensively. The results showed that: (1) photodegradation percentages of HPs were 4.02 and 4.48 times higher than those of BHs under UV and visible light, in which reactive species of both HPs and BHs were ·OH and ·O2−; (2) density functional theory (DFT) results identified that the main photoactive structure of graphitic-N decreased the energy gap (Eg) of HPs, and C=O, COOH groups improved electron donating ability of BHs; (3) well-developed graphitization structure of HP resulted from higher polymerization reaction was an significant photoactive structure involving its superior photodegradation ability relative to that of BH. The distinct heterogeneities of photodegradation ability in HP and BH and underlying photoactive structures provide an in-depth understanding of hydrochar application for removing emerging contaminants in soil/water environment. Identifying photoactive structures is helpful to predict photodegradation ability of hydrochar according to their abundance. Highlights: Photodegradation percentage of HP from hydrochar application was ~4 times superior to that of BH in degradation of NOR. Major reactive species of HPs and BHs (·OH and ·O2−) were generated from graphitic-N and C=O/COOH groups, respectively. Photoactivity of HPs superior to BHs was mainly generated from well-developed graphitization structure of former. [ABSTRACT FROM AUTHOR]

In this work, the mechanisms for creating a combined electronic–radiative local state beneath the conduction band, consisting of intrinsic and activator electron–hole states, are experimentally substantiated. In the first part of this work, the mechanisms of the formation of intrinsic and activator electron–hole trapping centers are experimentally demonstrated in all four matrices with activators. Intrinsic electronic states are localized on activators and anions of the matrix, forming intrinsic and activator electronic states. The hole component of the electron–hole pairs is localized near the activators. Thus, the energy of intrinsic electronic excitations localized in the matrix in the form of combined electronic–radiative states is observed at 3.06–3.1 eV and 2.92–2.95 eV. Radiative states are excited by photon energies of ~4.5 eV and ~4.0 eV, resulting in recombination emissions at 3.06–3.1 eV and 2.92–2.95 eV, as well as activator emissions at 2.06 eV for Mn2+, 2.5 eV for Tb3+, and 2.56 eV and 2.16 eV for Dy3+. Energy transfer from the matrix to emitters or activators occurs during the decay of the combined radiative state. Upon heating, electrons localized on anions and activators delocalize at temperatures of 200–350 K. The energy released during the recombination of an electron with a hole near the activators is transferred to the activators. This process facilitates energy transfer to activators in dosimeters and detectors.

Piperazin-1-ium 4-aminobenzoate monohydrate (PPAB) single crystals were grown by slow evaporation method. The grown crystal PPAB has been characterized by single-crystal X-ray diffraction, FTIR, FT-Raman, and UV-visible analysis. The B3LYP method and 6-311G (d, p) basis set were used to optimize the structure. The title compound was investigated theoretically and experimentally by FT-IR, FT-Raman, and UV-Vis spectral analysis. The presence of various functional groups in the structure was elucidated by FTIR and FT-Raman spectral studies. The intermolecular interactions within the crystal structure were investigated using Hirshfeld surface analysis. The crystal packing diagram reveals interesting non-covalent interactions involving C–H···O, N–H···O, and N–H···N hydrogen bonds, leading to the generation of 3D supramolecular architecture. The charge transfer within the molecule was deeply analyzed by using the NBO approach. The molecular electrostatic potential (MEP) and the local reactivity descriptors, such as Fukui function (fk+, fk−) analyses were performed to determine the reactive sites within the molecule. The HOMO and LUMO analysis was used to determine the chemical reactivity and bioactivity of the molecule. Hole-electron analysis was performed to analyze the charge transfer in an excited state. Based on the hole-electron analysis, the inter-fragment charge transfer (IFCT) analysis establishes the amount of charge transfer among different fragments. Topological analyses, such as AIM, RDG, and ELF were carried out to identify the non-covalent interaction within the molecule. The molecular docking studies of the molecule are performed to investigate the binding affinity of the ligand with the protein receptor. Drug-likeness properties, such as Lipinski's rule of five, adsorption, distribution, metabolism, excretion, and toxicity (ADMET) have been investigated by in silico web-based tools like SwissADME and ADMETlab. [ABSTRACT FROM AUTHOR]

The construction of heterojunction is considered to be an effective strategy for achieving efficient photocatalyst. The pure CdS shows low hydrogen production activity, for the low charges separation efficiency and the short electron and hole lifetime, which greatly limit its practical application. Therefore, we constructed heterojunction photocatalysts of NiMoO4/CdS by a simple solvothermal method. The photocatalytic hydrogen production activity of CdS was obviously improved by NiMoO4 loaded. The NiMoO4/CdS‐2 sample shows the highest H2 generation rate, which could reach 5830.49 μmolg−1 h−1, which is 122.3 times higher than that of pure CdS. The construction of heterojunction between CdS and NiMoO4 inhibits the recombination of photogenerated charges, prolongs the lifetime of photogenerated charges and improves photocatalytic hydrogen production performance. This work is important for the construction of an efficient catalytic system for the photocatalytic H2 evolution from water splitting. [ABSTRACT FROM AUTHOR]

BeO ceramics in the wurtzite (w -BeO) form either pure or doped with lanthanide ions present high Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) sensitivity. However, the mechanism of defect formation governing the charge carrier dynamics associated with the TL and OSL signals is not well understood yet. Thus, this work aims to develop a study on the structural, mechanical, dielectric, and defect properties of Europium ion–doped w -BeO ceramics. We develop a new set of potential parameters to describe the Be–O bond. By using these potential parameters, we describe the physical and chemical properties with good agreement. Defect calculations employing the Mott and Littleton two-region strategy show that the distorted structure of pure w -BeO ceramics favours the Frenkel–type defect formation in the basal plane of the crystal lattice. When doped with Eu3+, we observed a change in the defect arrangement. It replaces preferentially two Be sites, eliminating beryllium interstices and keeping the beryllium vacancy from the initial configuration. We also observed that it is unlikely the Eu3+/Eu2+ coexist due to the solution energy values. Lastly, we have observed a most significant electron–hole interaction which may be associated with the intrinsic luminescence band of the w -BeO ceramics. In addition, TL and OSL measurements are presented to corroborate the defect calculations. The results presented here bring new insight to elucidate the charge carrier dynamic associated with the luminescent properties. [ABSTRACT FROM AUTHOR]

A theoretical evaluation of radical scavenging activity and UV absorbing ability of chalcone named 2ʹ, 5ʹ, 3, 4-Tetrahydroxychalcone has been performed in the gas phase and aqueous media. The DFT-B3LYP/6–311+G (d, p) level of theory was utilized for geometry optimization and the calculation of reaction enthalpies, while the CAM-B3LYP/6–311+G (d, p) level of theory was employed for TDDFT analysis. Three potential working mechanisms of radical scavenging activity, hydrogen atom transfer mechanisms (HAT), stepwise electron transfer proton transfer (SET-PT), and sequential proton loss electron transfer mechanisms (SPLET) were investigated within the gas phase and aqueous phase. The results obtained demonstrate that the HAT will be the probable mechanism in the gas phase whereas SPLET will be in the water medium. Using the same level of theory, explicit surface analysis of the title compound was performed. The compound wave function analysis and molecular docking investigations were also performed in the optimized structure. The theoretical UV spectra were recorded in both the solvents and the compound's electronic absorption spectrum was analyzed using the TD-DFT method. The distribution of hole and electrons in the peaks of maximal oscillator strength corresponds to local excitation within the molecule. The Quantum Theory of Atoms in Molecule (QTAIM) was used to compute the strength of intramolecular hydrogen bonds and non-covalent interactions. The global reactivity parameters and electrostatic potential (ESP) were also included to define the reactivity of the whole molecule. The spin density distribution analysis was come upon to be complementary to the radical scavenging activity. Besides the radical scavenging activity of the compound, it can also be used as a potential UVA filter.

[Display omitted] • Experimental FT-IR, FT-Raman spectral characterizations of CPE are in good agreement with the theoretical vibrational assignments. • Electronic properties were evaluated for the different solvents. • Reactivity analysis-MEP map, and localized molecular orbital (NHO, NLMO, NBO) analyses were estimated. • Topology analyses viz., ELF, LOL, and RDG were estimated. • TD-DFT /MO62X in solvent phases (acetone, water, and DMSO) were discussed with the experimental value. • Molecular Docking was performed for the HNMT inhibitor protein targets for the fungal and bacterial ailments accomplished lesser binding energy interactions. The phenyl-substituted piperazine derivative molecule was taken into consideration in the current investigation of the organic drug molecule (±)-2-(2-{4-[(4-chlorophenyl)-phenylmethyl] piperazin-1-yl} ethoxy) ethanol (CPE), evaluating the spectral characterization using both simulated and recorded FT-IR, FT-Raman, and UV spectral studies. The theoretical computations have been conducted using DFT/B3LYP/6–311++G(d,p)as a basis set. The stable optimized structure was attained by selecting suitable dihedral angles using PES analysis and molecular geometrical parameters were obtained and matched with the available literature data. The vibrational assignments along with the PED contributions were obtained and matched with the recorded values. The electronic properties were analyzed for the various solvents and found that acetone possesses a lesser band energy gap of 5.3637 eV implies the stability of the header composite. Further, the UV–Vis spectra for the various solvents and corresponding parameters were obtained along with excitation analysis with electron-hole isosurface contributions. The maximum absorption wavelength of the CPE obtained in the liquid phase and the recorded wavelength compared with the simulated data. Intermolecular reliability of the molecule emanating from hyperconjugative interactions of charge delocalization by NBO analysis. The accomplishment of nucleophilic and electrophilic regions of the solvents such as acetone, water, and DMSO was implemented using Molecular Electrostatic Potential (MEP) for the molecule. Electron localization function (ELF) Localized orbital locator (LOL) and Reduced density Gradient (RDG) were attained using the above-mentioned basis set for the topological behavior of the title molecule. According to molecular docking studies, the amino acid residues present at the active site region of the ligand (CPE) are particularly suited to Histamine N-methyltransferase (HNMT) with suitable targets (PDB: 2AOT,1JQD, and 2AOU) and the minimum binding energy for the receptor target is 2AOU is −6.90 kcal/mol respectively. [ABSTRACT FROM AUTHOR]

• Synthesized, experimental and theoretical characterizations of 4CNB were performed. • FMO's, electronic properties, MEP map for different solvents elucidated. • NBO, Fukui function, Topology analyses (ELF, LOL) were estimated. • In silico analysis with different protein targets were examined. Being of the benzohyrazide derivatives, the molecule in consideration is quite significant in the pharmaceutical industry. In the present article, a novel compound has been synthesized and compared between the theoretical and experimental characterization such as FT-IR, UV–Vis and NMR techniques were employed. The quantum simulation studies (DFT) have been discussed for a higher basis set as B3LYP/6–311++G(d,p). Molecular vibrational assignments, chemical and electronic characteristics of 4-chloro-N -(2,6-dichlorobenzylidene) benzohydrazide (4CNB) were performed. The potential energy surface, geometrical optimization, wave numbers, and electronic structure stability were calculated by density function theory (DFT) through a higher basis set. The spectral characterizations of the molecule have been correlated with the observed spectrum. The chemical property of frontier orbital theory (FMO's) and electron-hole excitation analysis (D-index, Δr index,t index and excited states) for the different solvents such as DMSO, Chloroform, water and methanol were analysed. The DOS and orbital overlap functions were investigated. The stability of the structure, electrophilic and nucleophilic attacks for the different solvents, intra molecular analysis through NBO, molecular electrostatic potential (MEP) and local descriptors such as Fukui function (f+, f-, f0), topological analyses were performed and discussed. Molecular docking studies were performed by Auto-dock software to establish the information about the interactions between the antifungal and antibacterial inhibitor and lest binding energy is observed for Candida glabrata (−7.50 kcal/mol) protein. [ABSTRACT FROM AUTHOR]

• Geometrical parameters, spectroscopic properties (FT-IR, FT-Raman and UV-visible), and electronic properties of novel Metachlorphenprop-p-anisidine (MCPA) was discussed. • Intermolecular interaction in a molecular crystal package and the percentage of close contact within the molecule were studied using Hrishfeld analysis. • The molecular docking study has been carried out in order to give an insight about the bioactive region and active binding site of the compound. • In silico Physicochemical and drug likeness have been carried out to assess qualitatively the chance for a molecule to become an oral drug with respect to bioavailability. The structural and packing feature of novel Metachlorphenprop-p-anisidine (MCPA) single crystal was grown by refluxing stoichiometric amount of Metachlorphenprop (MCP) and p-anisidine (PAS) in ethanol, was investigated by single crystal X-ray diffraction. The title compound was investigated theoretically and experimentally by FT-IR, FT-Raman, TG-DTA and UV–Vis spectra. The theoretical optimized geometrical parameters and vibrational analysis were performed by density functional theory (DFT) with the B3LYP method at 6–311 G (d,p) basis set. The optimized geometrical parameters obtained by DFT calculations were in good agreement with the experimental data. Various intermolecular interactions involved in MCPA were analysed using different topological analysis atoms-in-molecule (AIM), reduced density gradient (RDG), electron localization function (ELF) and natural bond orbital (NBO) analysis. The stability of the molecule arising from intermolecular interaction and charge delocalization have been analysed using NBO analysis. Molecular electrostatic potentials (MEP) was performed to analyse the reactive area of the title molecule, local chemical reactivity was studied by population analysis and Fukui function analysis. The thermal behaviour of the MCPA crystal was analysed by TG-DTA analysis. Hole-electron interaction study divulge that S1-S4 undergo charge transfer excitation. The mechanical strength of the grown material proves that it is a soft material. Molecular docking was performed to confirm the stability of the protein-ligand complex. The results shows that the title compound has antibacterial properties as well as antifungal activities against Escherichia coli and Aspergillus niger organisms. The pharmacokinetics and drug likeness were also performed on titled molecule for the confirmation of drug-like character of title molecule. [ABSTRACT FROM AUTHOR]