Frontier Molecular Orbital Energies Research Articles

Hydrogen-bonding interaction promoted supercapacitance of polylactic acid-graphene-microcrystalline cellulose/polyaniline nanofiber

Electrospinning polylactic acid-graphene-microcrystalline cellulose/polyaniline (PLA-GN-MCC/PANI) nanofiber is fabricated as superior supercapacitor electrode material, which involves flexible substrate of PLA, conductivity additive of GN, GN dispersion additive of MCC and electroactive substance of PANI. PLA-GN-MCC is optimized as a component mass ratio of 10:0.6:1 to achieve superior interface affinity properties. The ultimate tensile strength and the elongation at break of the optimized PLA-GN-MCC are 568 kPa and 93%, better than the 496 kPa and 87% of PLA, exhibiting both superior strength and flexibility. The PLA, PLA-GN-MCC and PLA-GN-MCC/PANI keep the reduced ohmic resistance from 18.73 to 9.58 to 8.00 Ω, the dwindled charge transfer resistance from 323.2 to 181.7 to 17.8 Ω, the declined electronic band gap from 4.084 to 0.557 to 0.142 eV, the reduced Frontier molecular orbitals energy gap from 3.6505 to 0.7964 to 0.7694 eV, the increased density of states from 4.7983 to 5.7842 to 8.6671 electrons eV−1. These results indicate more feasible electron transition and highly improved electronic conductivity. The hydrogen bonding interaction between PLA-GN-MCC and PANI contributes to increasing interface affinity and decreasing total surface energy, achieving superior electrochemical capacitance increased from 2.72 to 3.72 up to 221.64 mF/cm2. Experimental measurement and simulation calculation keep consistent results, demonstrating the promise of PLA-GN-MCC/PANI nanofibers for electrochemical energy storage.

Mechanism of aniline aerofloat and Cd2+ elimination from mining wastewater by customized S-scheme Halloysite@MoS2/goethite nanotube: Synergy of photo-Fenton decomplexation and adsorption

Aniline aerofloat (AAF) and Cd2+ have caused severe pollution near the mine site, simultaneous remediation technologies are facing enormous challenges due to different reaction conditions of these two pollutants. Herein, a surface optimized Halloysite@MoS2/goethite was established to simultaneously remove AAF-Cd2+ pollution in a photo-Fenton reaction system. The spatial confinement of halloysite nanotube, special surface modulated particle size, acid-base property, and Zeta potential efficiently enhanced photo-Fenton degradation activity and adsorption for cations. 94.2 % of AAF and 94.1 % of Cd2+ were eliminated within 60 min and the adsorption capacity for Cd2+ reached 68.14 mg g−1. The built-in electric field between MoS2 and goethite promoted separation of photogenerated carrier via an S-Scheme separation strategy, which maintained high potential electrons in CB and holes in VB for generating reactive oxidation species (ROS). The photocatalysis of MoS2 facilitate to regulate valence of iron species for sustainable activation of H2O2. Combined with HPLC-MS analysis, theoretical calculation of frontier molecular orbital and adsorption energy, the removal mechanism of AAF-Cd2+ was proposed. This study provides novel insights into simultaneous removal of beneficiation reagents-heavy metals combined pollutants and may contribute to remediation of water pollution near the mine sites.

Design, synthesis, and computational studies of novel imidazo[1,2-a]pyrimidine derivatives as potential dual inhibitors of hACE2 and spike protein for blocking SARS-CoV-2 cell entry

In the present work, a new series of imidazo[1,2-a]pyrimidine Schiff base derivatives have been obtained using an easy and conventional synthetic route. The synthesized compounds were spectroscopically characterized using 1H, 13C NMR, LC-MS(ESI), and FT-IR techniques. Green metric calculations indicate adherence to several green chemistry principles. The energy of Frontier Molecular Orbitals (FMO), Molecular Electrostatic Potential (MEP), Quantum Theory of Atoms in Molecules (QTAIM), and Reduced Density Gradient (RDG) were determined by the Density Functional Theory (DFT) method at B3LYP/6–31 G (d, p) as the basis set. Moreover, molecular docking studies targeting the human ACE2 and the spike, key entrance proteins of the severe acute respiratory syndrome coronavirus-2 were carried out along with hACE2 natural ligand Angiotensin II, the MLN-4760 inhibitor as well as the Cannabidiolic Acid CBDA which has been demonstrated to bind to the spike protein and block cell entry. The molecular modeling results showed auspicious results in terms of binding affinity as the top-scoring compound exhibited a remarkable affinity (-9.1 and -7.3 kcal/mol) to the ACE2 and spike protein respectively compared to CBDA (-5.7 kcal/mol), the MLN-4760 inhibitor (-7.3 kcal/mol), and angiotensin II (-9.2 kcal/mol). These findings suggest that the synthesized compounds may potentially act as effective entrance inhibitors, preventing the SARS-CoV-2 infection of human cells. Furthermore, in silico, ADMET, and drug-likeness prediction expressed promising drug-like characteristics.

Microwave absorption properties and quantum chemistry of organic sulfur compounds in coal

AbstractThe microwave absorption properties of dielectrics determine the promotion degree of microwave energy to chemical reaction. The wave‐absorbing characteristics of organic sulfur compounds in high‐sulfur coking coal need to be studied to improve the efficiency of microwave desulfurization of coal. In this study, the imaginary part of complex dielectric constants (ε′′) and dielectric loss tangent (tan σ) of benzene mercaptan, difurfuryl disulfide, and benzothiophene were characterized. The dipole moment, molecular configuration, and frontier molecular orbital energy of organic sulfur compounds were simulated and calculated under the different external energy fields. The migration law of mercaptan, sulfide, and thiophene in coal in microwave field were analyzed. The results show that the ε'′ and tan σ of benzothiophene slightly changed with the change in microwave frequency in the frequency range of 500–2500 MHz, and the microwave absorption properties are weaker than those of benzene mercaptan and difurfuryl disulfide. Therefore, difurfuryl disulfide and benzene mercaptan molecules are more active in the microwave field than benzothiophene. The sulfur components in benzene mercaptan and difurfuryl disulfide can dissociate in the form of small inorganic sulfur molecules of carbon sulfides and disulfides, respectively. After microwave irradiation, the relative content of mercaptan and thioether in coal was decreased, whereas the relative content of thiophene remained almost unchanged.

New ferrocene integrated amphiphilic guanidines: Synthesis, spectroscopic elucidation, DFT calculation and in vitro α-amylase and α-glucosidase inhibition combined with molecular docking approach

Three N, N’, N″-trisubstituted ferrocenyl guanidines (MG-10, MG-12 and MG-14) were synthesized, characterized by several analytical methods such as FT-IR, 1H and 13C NMR, elemental analysis and UV–visible spectroscopy. These compounds have long chain aliphatic groups therefore their aliphatic nature has been evaluated by determining their critical micelle concentration (CMC). CMC point decreases from 0.036 mM to 0.013 mM with increase in the aliphatic chain length. The quantum mechanical parameters such as the energy of frontier molecular orbitals (EHOMO and ELUMO) and the Mulliken charge distribution on the optimized structures were determined using a DFT/B3LYP method combined with the 6-31G (d,p) basis set in the gas phase. The in vitro antidiabetic activity of synthesized compounds showed that MG-12 has IC50value 23.10 μg/mL against α-amylase while MG-10 has IC50value 27.32 μg/mL against α-glucosidase with the respective standard Acarbose (IC50value 20.12 μg/mL). Theoretical docking analysis demonstrated that MG-10 and MG-12 interacted with α-amylase by 3 types of interaction, including hydrogen bonds, hydrophobic interactions and electrostatic interactions.

Semi-microscopic Theory for the Current Rectification Phenomenon in Nanogap Molecular Devices.

A semi-microscopic theory is developed for heterogeneous electron transfer (HET) kinetics based on the energy level alignment approach at self-assembled monolayer (SAM) covered metal electrodes. Theory provides the electronic and molecular property-dependent equations for the HET rate constant (k0) and the transfer coefficient (α) for potential. k0 is formulated using the activation free energy as a product of the SAM covered metal work function (WF) and fractional electronic charge exchanged at the transition state (attained through the alignment of the frontier molecular orbital (FMO) energy level of the electroactive group with the WF of metal). k0 is a function of the metal jellium electronic screening length and dielectric and of the molecular self-assembly (through its dipole moment, size, and packing density) and the FMO energies of electroactive groups. The operative potential at the transition state is governed by α, which is a function of molecular spacer length and characteristic electronic-dipolar coupling length. The current rectification phenomenon in nanogap molecular devices is theoretically analyzed using equations for k0 and α for SAM covered source and drain electrodes. Theory unravels the LUMO or HOMO dichotomy for a given metal: (i) for the HOMO assisted ET, the metal with a high WF has a high current rectification ratio (RR), while (ii) for the LUMO assisted ET, the metal with a low WF has a high current RR in asymmetrical devices. Theory predicts the reversal in current rectification by altering the dipole moment of the anchoring molecule, the HOMO/LUMO energy of the electroactive groups, and the nature of the metal. Finally, theory shows qualitative and quantitative coherence with the reported experimental current-potential response of molecular device.

One-Bond-Nucleophilicity and -Electrophilicity Parameters: An Efficient Ordering System for 1,3-Dipolar Cycloadditions.

Diazoalkanes are ambiphilic 1,3-dipoles that undergo fast Huisgen cycloadditions with both electron-rich and electron-poor dipolarophiles but react slowly with alkenes of low polarity. Frontier molecular orbital (FMO) theory considering the 3-center-4-electron π-system of the propargyl fragment of diazoalkanes is commonly applied to rationalize these reactivity trends. However, we recently found that a change in the mechanism from cycloadditions to azo couplings takes place due to the existence of a previously overlooked lower-lying unoccupied molecular orbital. We now propose an alternative approach to analyze 1,3-dipolar cycloaddition reactions, which relies on the linear free energy relationship lg k2(20 °C) = sN(N + E) (eq 1) with two solvent-dependent parameters (N, sN) to characterize nucleophiles and one parameter (E) for electrophiles. Rate constants for the cycloadditions of diazoalkanes with dipolarophiles were measured and compared with those calculated for the formation of zwitterions by eq 1. The difference between experimental and predicted Gibbs energies of activation is interpreted as the energy of concert, i.e., the stabilization of the transition states by the concerted formation of two new bonds. By linking the plot of lg k2 vs N for nucleophilic dipolarophiles with that of lg k2 vs E for electrophilic dipolarophiles, one obtains V-shaped plots which provide absolute rate constants for the stepwise reactions on the borderlines. These plots furthermore predict relative reactivities of dipolarophiles in concerted, highly asynchronous cycloadditions more precisely than the classical correlations of rate constants with FMO energies or ionization potentials. DFT calculations using the SMD solvent model confirm these interpretations.

Graphene Embedded with Transition Metals for Capturing Carbon Dioxide: Gas Detection Study Using QM Methods

Carbon dioxide (CO2) adsorption on decorated graphene (GR) sheets with transition metals (TMs) including iron, nickel and zinc was investigated for removing this hazardous gas from the environment. TM-doped GR results in higher activity toward gas detecting than pristine graphene nanosheets. TM embedding restrains hydrogen evolution on the C sites, leaving more available sites for a CO2 decrease. The Langmuir adsorption model with ONIOM using CAM-B3LYP functional and LANL2DZ and 6-31+G (d,p) basis sets due to Gaussian 16 revision C.01 program on the complexes of CO2→(Fe, Ni, Zn) embedded on the GR was accomplished. The changes of charge density illustrated a more considerable charge transfer for Zn-embedded GR. The thermodynamic results from IR spectroscopy indicated that ΔGads,CO2→Zn@C−GRo has the notable gap of Gibbs free energy adsorption with a dipole moment which defines the alterations between the Gibbs free energy of the initial compounds (ΔGCO2 o and ΔGZn@C−GRo) and product compound (ΔGCO2→Zn@C−GRo) through polarizability. Frontier molecular orbital and band energy gaps accompanying some chemical reactivity parameters represented the behavior of molecular electrical transport of the (Fe, Ni, Zn) embedding of GR for the adsorption of CO2 gas molecules. Our results have provided a favorable understanding of the interaction between TM-embedded graphene nanosheets and CO2.

Computational insights into the adsorption mechanisms of anionic dyes on the rutile TiO2 (1 1 0) surface: Combining SCC-DFT tight binding with quantum chemical and molecular dynamics simulations

Metal oxides are gaining momentum rapidly for application in water pollutant remediation. In this study, the adsorption proprieties of two anionic dyes, i.e., acid yellow 36 (AY36) and acid orange 6 (AO6) on the (110) surface of rutile titanium dioxide (TiO2) in an aqueous medium were investigated using computational methods. The density functional theory (DFT) was used to determine the reactivity of organic molecules by calculating the frontier molecular orbital energies, energy gap (ΔEgap), chemical hardness (η), chemical softness (σ), electronegativity (χ), chemical potential (μ), electrophilicity (ω), the fraction of electrons transferred (ΔN), back-donation energy (ΔEback-donation), Mulliken charge, and Fukui indices. The obtained results showed that the AY36 molecule is more reactive than the AO6 molecule and may have a good adsorption capability compared to the AO6 dye. The most favorable adsorption configurations of AY36 and AO6 molecules were investigated using molecular dynamics (MD) simulation. The calculated interaction energies by MD simulation showed that the TiO2 (110) surface has a high sensitivity to interact with the two anionic dyes, with more affinity toward the AY36 molecule. Furthermore, to get deep insights into the chemistry of interactions between the anionic dyes and the TiO2 (110) surface, the self-consistent charge density functional tight-binding (SCC-DFTB) method was carried out. Results showed that anionic dyes adsorbed on the TiO2 (110) surface by forming covalent bonds between oxygen atoms of the sulfonic group and Ti atoms. Theoretical insights from this work would serve as a guide for researchers to explore the application of oxides in water pollutant remediation.

Experimental spectroscopic and quantum computational investigation and molecular docking analysis of N-benzyloxycarbonyl-l-serine – an anticancer agent

This work presents the nature of N-benzyloxycarbonyl-l-serine through quantum chemical calculations and spectral analysis. The optimized geometry and vibrational frequencies were computed by density functional theory. The geometric parameters were theoretically obtained and those values were compared with experimental data. The calculated vibrational wavenumbers of the heading compound display exact agreement with the recorded spectrum. The frontier molecular orbital band gap energy confirmed that the heading compound has a good reactivity and stability of the molecule. The theoretical UV-Vis spectrum turned into analysis in gas and with different solvents. The nuclear magnetic resonance spectrum was calculated. Each evaluation was in comparison with the experimental ones. The molecular electrostatic potential energy map is an effective model to identify electrophilic and nucleophilic sites. Further, natural bond orbital and Mulliken charge analysis had been additionally calculated. Drug-likeness studies were carried out. This result shows that the heading compound has a good biological activity. Anticancer activity was tested based on the molecular docking evaluation and it was diagnosed that the heading compound can act as a potential inhibitor of liver cancer.

A combined DFT and molecular docking study on novel tricarbonylrhenium(I) complexes bearing mono- and bivalent benzenesulfonamide scaffolds as human carbonic anhydrase IX and XII inhibitors

The aim of this study was to determine the reactivity and stability properties of a novel series of tricarbonylrhenium(I) complexes with 1,2,3-triazole-pyridine based on monovalent and bivalent benzenesulfonamide ligands as well as analyze their binding affinity within the active site of carbonic anhydrases IX and XII, using DFT and molecular docking. In the first setup, the DFT method was used to investigate the molecular geometries and vibrational frequencies of ligands and their Re(I) complexes. The basis set used was B3LYP/LanL2DZ-ECP/6-31G(d). The optimized geometric parameters (bond lengths and bond angles) and vibrational frequencies agree well with the experimental results. TD-DFT calculations were also performed to determine the influence of the methylene linker (-CH2-) on the bands found in the electronic spectra of these compounds. Global reactivity indices calculated from the energies of frontier molecular orbitals were used to assess their reactivity and stability properties (FMOs). Molecular electrostatic potential maps of the molecules were calculated to provide information about their chemical reactivity and to explain their intermolecular interactions. The computational data showed that bivalent ligands and their bivalent Re(I) complexes are more reactive than their monovalent counterparts. The second setup involves docking studies of the compounds within the active sites of the receptors (6QN2 for hCA IX and 1JD0 for hCA XII), which are performed using the Molegro Virtual Docker and AutoDock 4.2 programs, respectively. Our results indicate that bivalent ligands and their associated Re(I) complexes have a greater binding affinity than monovalent ligands and their associated Re(I) complexes. Compounds bis-L1 and bis-L2 exhibited the best affinity potential for hCA IX and hCA XII inhibition, making them the most promising candidates among those examined.

Advancing insights towards electrocatalytic activity of La/Ba-Sr-Co-Fe-O-based perovskites for oxygen reduction & evolution process in reversible solid oxide cell

Electrocatalytic activity of La/Ba-Sr-Co-Fe-O-based mixed ionic and electronically conducting (MIEC) perovskites has been studied for selective oxygen reduction (ORR) and evolution (OER) processes applicable in Reversible Solid Oxide Cell (R-SOC). XPS study establishes scavenging of oxygen vacancy in LSCF and generation of the same in BSCF. BSCF enables faster oxygen ion transport and is correlated with lower frontier molecular orbital (FMO) energy gap of 1.18 eV derived from density functional theory (DFT). Relatively higher ΔEFMO(Absolute) 1.75 eV in LSCF accounts for higher charge transfer. Amperometric measurements @800℃ in asymmetric cell configuration exhibit lowest time-dependent current loss of 0.019 mA.h-1 & 0.035 mA.h-1 for BSCF & LSCF under applied anodic (+0.8 V) and cathodic potentials (-0.8 V) for 200 h with respective surface resistances (Rs) of 0.19 Ω.cm2 and 0.081 Ω.cm2. H2 flux of 0.4Nl.h-1.cm-2 obtained with BSCF, establishes its effectivity as OER whereas LSCF is found to be more selective in ORR.

New Insight into the Pharmacological Importance of Atropine as the Potential Inhibitor of AKR1B1 via Detailed Computational Investigations: DFTs, ADMET, Molecular Docking, and Molecular Dynamics Studies.

The aim of this research is to investigate the quantum geometric properties and chemical reactivity of atropine, a pharmaceutically active tropane alkaloid. Using density functional theory (DFT) computations with the B3LYP/SVP functional theory basis set, the most stable geometry of atropine was determined. Additionally, a variety of energetic molecular parameters were calculated, such as the optimized energy, atomic charges, dipole moment, frontier molecular orbital energies, HOMO-LUMO energy gap, molecular electrostatic potential, chemical reactivity descriptors, and molecular polarizability. To determine atropine's inhibitory potential, molecular docking was used to analyze ligand interactions within the active pockets of aldo-keto reductase (AKR1B1 and AKR1B10). The results of these studies showed that atropine has greater inhibitory action against AKR1B1 than AKR1B10, which was further validated through molecular dynamic simulations by analyzing root mean square deviation (RMSD) and root mean square fluctuations (RMSF). The results of the molecular docking simulation were supplemented with simulation data, and the ADMET characteristics were also determined to predict the drug likeness of a potential compound. In conclusion, the research suggests that atropine has potential as an inhibitor of AKR1B1 and could be used as a parent compound for the synthesis of more potent leads for the treatment of colon cancer associated with the sudden expression of AKR1B1.

Designing of silolothiophene-linked triphenylamine-based hole transporting materials for perovskites and donors for organic solar cells-A DFT study

Si-OMeTPA is receiving a lot of interest as potential hole transport materials in perovskite solar cells (PSCs) because of their wide range of energy tuning, strong absorption capacity, and excellent power conversion efficiency (PCE). This work includes eight new donors (PEH1-PEH8) containing 4,4-diphenyl-4H-silolo[3,2-b:4,5-b']dithiophene as the central-core unit has been effectively developed and then theoretically described to probe their electronic and optical performance. These innovative (PEH1-PEH8) materials had lower Eg and more significant extinction coefficients, implying superior phase inversion geometry during sandwich structures. The complete theoretical characterization of these proposed (PEH1-PEH8) and reference (PEH) molecules has been achieved by using quantum chemistry techniques. Density functional theory (DFT) and time-dependent (TD-DFT) computations have explored the photo-physical and optoelectronic properties. The density of states (DOS), optical properties, open-circuit voltage, transition density matrix (TDM), Frontier molecular orbital (FMO) alignment, and hole and electron reorganization energies have all been studied for these materials. PEH8 has an excellent absorbance (λmax) of 699.65 nm and an optical band gap of 0.91 eV. Furthermore, a comprehensive investigation of PEH8/PC61BM has shown the fantastic charge shifting at the donor-acceptor interface. As a result, our suggested strategy is required for developing suitable photovoltaic molecules for proficient PSCs that can be employed as light harvesters and electron and hole transporter.

Interface Engineering via Regulating Electrolyte for High-Voltage Layered Oxide Cathodes-Based Li-Ion Batteries.

Li-rich and Ni-rich layered oxides as next-generation high-energy cathodes for lithium-ion batteries (LIBs) possess the catalytic surface, which leads to intensive interfacial reactions, transition metal ion dissolution, gas generation, and ultimately hinders their applications at 4.7V. Here, robust inorganic/organic/inorganic-rich architecture cathode-electrolyte interphase (CEI) and inorganic/organic-rich architecture anode-electrolyte interphase (AEI) with F-, B-, and P-rich inorganic components through modulating the frontier molecular orbital energy levels of lithium salts are constructed. A ternary fluorinated lithium salts electrolyte (TLE) is formulated by mixing 0.5m lithium difluoro(oxalato)borate, 0.2m lithium difluorophosphate with 0.3m lithium hexafluorophosphate. The obtained robust interphase effectively suppresses the adverse electrolyte oxidation and transition metal dissolution, significantly reduces the chemical attacks to AEI. Li-rich Li1.2 Mn0.58 Ni0.08 Co0.14 O2 and Ni-rich LiNi0.8 Co0.1 Mn0.1 O2 in TLE exhibit high-capacity retention of 83.3% after 200 cycles and 83.3% after 1000 cycles under 4.7V, respectively. Moreover, TLE also shows excellent performances at 45 °C, demonstrating this inorganic rich interface successfully inhibits the more aggressive interface chemistry at high voltage and high temperature. This work suggests that the composition and structure of the electrode interface can be regulated by modulating the frontier molecular orbital energy levels of electrolyte components, so as to ensure the required performance of LIBs.

A comprehensive DFT study on organosilicon-derived fungicide flusilazole and its germanium analogue: A computational approach to Si/Ge bioisosterism

Bioisosterism, a specific molecular alteration processing, is an effective approach used in agrochemical development studies as well as in pharmaceutical sciences. Analyzing some parameters such as size, volume, charge, aqueous/lipid solubility, polarizability, degree of hybridization, intra- and intermolecular interactions, which may be caused by bioisosteric changes, by using quantum chemical methods, provides speed and different perspectives to the studies. Towards this end, this study approached the Si/Ge bioisosterism from a computational perspective by performing DFT-based calculations on flusilazole, a widely used fungicide, and its germanium analogue. The reflections of the replacement of silicon with germanium in the structure of flusilazole on the structural parameters, frontier molecular orbital energies, quantum chemical descriptors and electrostatic surface properties were examined. Additionally, FT-IR spectra of the aforementioned molecules were visualized and investigated in detail. Natural bond orbital analyzes were also performed to determine the intermolecular interactions and their corresponding stabilization energies. Besides, 1-octanol/water partition coefficients (logPow), the quantitative identifier of lipophilicity, were calculated. It was determined that both molecules could exhibit similar lipophilic character with a difference of 0.09 logarithmic units in logPow value.

Visible-light-driven direct decarboxylative carbonylation of carboxylic acids using acridine photocatalysis in oxygen-liquid flow

Photocatalytic direct decarboxylative carbonylation of ubiquitous carboxylic acids is a promising strategy to obtain highly versatile ketone building blocks, but metal-free and efficient conversions are still lacking. Here, density functional theory calculations are used to guide the experimental screening of catalysts, highlighting the potential influence of frontier molecular orbital energy levels on the catalytic process and revealing an acridine photocatalyst capable of realizing value-added conversion of carboxylic acid at room temperature under visible light with excellent performance. The possible mechanism for this conversion was elucidated in depth by combining study of the excited state behavior of the photosensitizer and the results of detection experiments for radicals. Theoretical calculations and mechanistic studies further disclose the kinetically rate-limiting role of oxygen, including its participation in the formation of superoxide radicals for carbonylation and as an electron trapping agent for catalyst cycling. Based on these findings, a flow microreactor platform was ingeniously built to achieve previously inaccessible photocatalytic decarboxylative carbonylation promoted by acridine in concert with oxygen. Interestingly, the gas–liquid segmented microflow is found to enable a significant acceleration (from 14 to 2 h) and higher yield compared to the batch counterpart, resulting in a high space–time yield of 137.4 g/L d-1 for this transformation, which far exceeds the reported values. This study underscores the feasibility of broadening the competence of acridine photocatalysis through the involvement of kinetically adapted oxygen, thus enabling substitution of metal-dependent photocatalysis and even more efficient and high-yield decarboxylative carbonylation of carboxylic acids.

Synthesis of functionalized aminopyrazole and pyrazolopyrimidine derivatives: Molecular modeling and docking as anticancer agents

Three new functionalized 4-aminopyrazole derivatives were synthesized and cyclized with phenyl isothiocyanate to yield the corresponding three pyrazolo[4,3-d]pyrimidine analogues. The DFT quantum chemical calculations were utilized in the determination of the frontier molecular orbital energies and Fukui’s indices. The data showed that they have a low HOMO-LUMO energy gap, ranging from 1.16 to 2.35 eV for 5 and 6, respectively. The newly created analogues' cytotoxic qualities were evaluated in comparison to the reference 5-florouracil (5-Fu) using an in vitro MTT cytotoxicity screening investigation toward four different cell lines, including HCT-116, HepG2, MCF-7, and WI38. The results showed variable potency against human cell lines, with MCF-7 and HepG-2 showing cytotoxic selectivity. The most potent agent against MCF-7 and HCT-116 human cancer cells were found to be aminopyrazole and pyrazolopyrimidine derivatives 4–9. The structure–activity relationships (SAR) for the synthesized compounds were discussed. The examined compounds had superior cytotoxic properties; the most potent derivative 7, had an IC50 ranged from 11.51 ± 0.35 to 21.25 ± 0.37 µM. Meanwhile, quantum chemical computation used independent variables EH, EL, ΔEH-L, χ and η were applied to determine the best way to describe activity. As a result, an increase in the HOMO-LUMO gap and hardness will result in an increase in the anticancer activity. While the EH, EL, and showed negative coefficients, increasing them will decrease the anticancer activity. Furthermore, 5IVE protein's crystal structure for KDM5A was docked with the newly created aminopyrazole and pyrazolopyrimidine derivatives to afford the theoretical prediction on the KDM5A enzyme.

Isomerically Pure Oxindole-Terminated Quinoids for n-Type Organic Thin-Film Transistors Enabled by the Chlorination of Quinoidal Core.

Quinoidal compounds have great potential utility as high-performance organic semiconducting materials because of their rigid planar structures and extended π-conjugation. However, the existence of E and Z isomers adversely affects the charge-transport properties of quinoidal compounds. In this study, three isomerically pure oxindole-terminated quinoids were developed by introducing chlorine atoms in the quinoidal core. The synthesized quinoids were confirmed to have a Z,Z configuration by means of 1 H NMR spectroscopy, density functional theory calculations, and single-crystal X-ray analysis. Importantly, the strategy of chlorination allowed to maintain low-lying frontier molecular orbital energy levels and ensure favorable intermolecular packing. Consequently, all three quinoidal compounds showed n-type transport characteristics in organic thin-film transistors, with electron mobilities up to 0.35 cm2 V-1 s-1 , which is the highest value reported to date for oxindole-terminated quinoids. Our study can provide new guidelines for the design of isomerically pure quinoids with high electron mobilities.

Optoelectronic properties of Portulacaxanthin III (PXIII), GQD/Os-GQD-PXIII nanocomposites, and their coupling with photoanode in dye-sensitized solar cells: Molecular and periodic DFT calculations

In this work, the optoelectronic properties of a naturally occurring dye, Portulacaxanthin III (PXIII), were investigated. To improve the performance of PXIII dye, it was hybridized with graphene quantum dot (GQD) undoped and doped with Os at the central position to form two nanocomposites (PXIII-GQD and Os-GQD-PXIII), and their optoelectronic properties were also investigated. Parameters such as frontier molecular orbital energies and distributions, absorption and emission properties, excited-state lifetimes, and hole and electron reorganization energies were calculated at two molecular (HCTH and CAM-B3LYP) DFT functionals and their counterparts TDDFT functionals in the gas phase and with the PCM model to mimic the effect of the solvent in three solvents: chloroform, acetonitrile, and water. The variation of the abovementioned molecular parameters as a function of media polarities (dielectric constants) was investigated. In addition, the coupling with the photoanode TiO2 anatase (101) with a periodic DFT functional was also investigated. The output from this work demonstrated the better overall performance of the nanocomposites (doped and undoped). Since they have better energy level alignments, red-shifted and broader absorption in the Vis and IR regions, better HOMO and LUMO charge separation, and stronger adsorption on the photoanode.