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Naegleria fowleri is a free-living amoeba that causes primary amoebic meningoencephalitis. Despite combination drug therapies, N. fowleri is not sensitive to current drug therapies, contributing to the pathogen’s mortality rate of 98%. To enable rational drug designing, this study has proposed an integrated track of nanotechnology coupling with the enrichment concept. In the current study, zinc oxide nanoparticles (ZNP) were screened against ERK protein, which is responsible for the production of pro-inflammatory cytokines that cause brain disturbance in N. fowleri infection. Furthermore, an enrichment analysis has been executed to increase the efficiency of the ZNP through the addition of two amines and one chlorine group. The computational prediction of zeta potential, cytotoxicity, organ toxicity, calculations of binding free energy, and ADMET analysis shows that it is stable and possesses no toxic effect. Amine + chlorine enriched ZNP resulted in a binding energy of −7.8 kcal/mol, a zeta potential reliability of −40 mV, a cytotoxicity of −0.0002, inactive against all the targeted organ models, ADMET profiling shows a molecular weight of 320.54 g/mol, a lipophilicity of −0.99, high water solubility, and good gastrointestinal tract absorption. This proposed invention represents the future work for in vitro in combating this devastating disease toward a reliable therapeutic target with drugs that specifically aimed to inhibit the infection.

Owing to the broad applications of quaternary ammonium salts (QAS), we present the synthesis of benzimidazolium-based analogues with variation in the alkyl and alkoxy group at N-1 and N-3 positions. All the compounds were characterized by spectroscopic techniques and found stable to air and moisture both in the solid and solution state. Moreover, molecular structures were established through single-crystal X-ray diffraction studies. The crystal packing of the compounds was stabilized by numerous intermolecular interactions explored by Hirshfeld surface analysis. The enrichment ratio was calculated for the pairs of chemical species to acquire the highest propensity to form contacts. Void analysis was carried out to check the mechanical response of the compounds. Furthermore, theoretical investigations were also performed to explore the optoelectronic properties of compounds. Natural population analysis (NPA) has been conducted to evaluate the distribution of charges on the synthesized compounds, whereas high band gaps of the synthesized compounds by frontier molecular orbital (FMO) analysis indicated their stability. Nonlinear optical (NLO) analysis revealed that the synthesized QAS demonstrates significantly improved NLO behaviour than the standard urea.

Significant efforts are continuously exerted by the scientific community to explore new strategies to design materials with high nonlinear optical responses. An effective approach is to design alkalides based on Janus molecules. Herein, we present a new approach to remarkably boost the NLO response of alkalides by stacking the Janus molecules. Alkalides based on stacked Janus molecule, M-n-M' (where n = 2 & 3 while M and M′ are Li/Na/K) are studied for structural, energetic, electrical, and nonlinear optical properties. The thermodynamic stability of the designed complexes is confirmed by the energetic stabilities, which range between -14.07 and -28.77 kcal/mol. The alkalide character of alkali metals-doped complexes is confirmed by the NBO charge transfer and HOMO(s) densities. The HOMO densities are located on the doped alkali metal atoms, indicating their alkalide character. The absorptions in UV–Vis and near IR region confirm the deep ultraviolet transparency of the designed complexes. The maximum first static and dynamic hyperpolarizabilities of 5.13 × 107 and 6.6 × 106 au (at 1339 nm) confirm their high NLO response, especially for K-2-M′ complexes. The NLO response of alkalides based on stacked Janus molecules is 1–2 orders of magnitude higher than the alkalide based on Janus monomer. The high values of dc-Kerr and electric field-induced response e.g., max ∼107 and 108 au, respectively have been obtained. These findings suggest that our designed complexes envision a new insight into the rational design of stable high NLO performance materials.

Long-term biocompatible scaffolds based on chitosan (CS) encapsulated with hydroxyapatite (HAP) have been developed for orthopedic applications. The biocomposites consisting of magnesium (Mg)/strontium (Sr) co-dopant into HAP@CS were fabricated using a casting technique, whereas Mg(II) contribution was varied. The crystal growth seems to be in the c-axis upon the rising of Mg(II) content, whereas the c/a ratio changed from 0.72 to 0.73. Moreover, it was suggested that Mg(II) ions prefer to substitute Ca(1) rather than Ca(2) sites within HAP crystals. The study of morphology indicated that the Mg/Sr-HAP was formed as agglomerated grains with dimensions around 5.1–9.2, 6.2–11.4, 3.6–7.3, 3.1–18.3, and 6.1–18.3 μm, while the grains of CS were developed as 4.6–7.6, 3–14.3, 2.4–6.1, 9.1–30.5 and 6.2–9.1 μm for 0.0Mg/Sr-HAP@CS, 0.2Mg/Sr-HAP@CS, 0.4Mg/Sr-HAP@CS, 0.6Mg/Sr-HAP@CS, and 0.8Mg/Sr-HAP@CS, respectively. Moreover, the roughness average (Ra) raised from 37.3 to 48.4 nm for the minimum and the highest additional Mg(II). Furthermore, the compressive strength was investigated and exhibited that Mg(II) has induced high resistance to fracture, whereas compressive strength increased from 7.17 ± 1.1 to 15.1 ± 1.5 MPa for the highest Mg(II). The cell viability also was tested, and the high value (105.2 ± 6.8%) was achieved for the highest Mg(II). Finally, the corrosion behavior for the scaffolds through simulated body fluids was investigated and illustrated that the corrosion potential (ECorr) was shifted to positive values from −0.14 to −0.002 V upon the variation of Mg(II) content.

Recently, the development of visible-light-responsive catalysts for the photodegradation of organic pollutants has captured the attention of researchers globally. The ineffectiveness and high costs associated with conventional methods and techniques used for the abatement of water pollution have forced researchers to develop effective and low-cost innovative techniques for this purpose. Photocatalysis is considered an effective protocol for this purpose. Therefore, this study was conducted for the development of the Bi2O3-NiO heterojunction as a visible-light-responsive photocatalyst for the degradation of methyl orange. Ni(NO3)2∙6H2O (Fluka) and Bi(NO3)3∙5H2O (Merck) were used as precursor materials for the synthesis of NiO-Bi2O3. After fabrication, the Bi2O3-NiO heterojunction was characterized using XRD, EDX, SEM, FTIR, and TGA techniques. Then, it was employed as a catalyst for the photodegradation of methyl orange under sunlight irradiation. The fabricated Bi2O3-NiO showed higher photocatalytic activity than Bi2O3 and NiO with 100, 67, and 46% degradation of methyl orange, respectively. The rate constant determined by the non-linear method of analysis for the photodegradation of MO in the presence of Bi2O3-NiO was 3.2-fold and 1.7-fold of the rate constant with NiO and Bi2O3, respectively. The higher photocatalytic activity of Bi2O3-NiO than of its individual components in the present study is also attributed to the separation and transfer of positive holes and electrons. The recycling of spent Bi2O3-NiO under similar experimental conditions exhibited the same photocatalytic activity suggesting the stability of the fabricated Bi2O3-NiO photocatalyst.

Three newly designed pyrochlore oxides, Eu2Tm2O7 (Tm = Hf, Sn, Zr), are analyzed for their magnetic, optical and electronic properties using ab-initio calculations within the context of density functional theory (DFT). We can refer these compounds as direct bandgap materials because there is a very slight difference between the height of bands at the Γ- and M-point. It is observed that bandgap engineering can be performed by replacing Hf with Sn and Zr. It is observed from total density of states (TDOS) plots that shape and height of curves is not the same in spin up and spin down channels, showing significant magnetic moment in these compounds. It is evident from magnetic properties that a major portion of total magnetic moment (mtot) comes from Eu-atoms. In all compounds, the magnetic moment of O, Hf, Sn and Zr atoms is negative, whereas the magnetic moment of Eu-atoms is positive, showing their antiparallel arrangement. In both spin channels, significant absorption of the incoming photons is also shown by these compounds in the ultraviolet (UV) region. We can conclude on the basis of Rω that these compounds can be utilized in applications such as anti-reflecting coatings. These compounds are potential candidates for photovoltaic applications, such as solar cells, due to efficient absorption of incoming photons in visible and UV regions.

Four new carboxylates complexes with general formula R2SnL2 and R3SnL, where R = n-butyl (1, 3), methyl (2, 4) and L = 4-Chlorophenoxyacetate, were synthesized in significant yields. FT-IR analysis revealed a chelating (1 and 2) and a bridging bidentate (3 and 4) coordination modes for the carboxylate ligand in solid state which was further confirmed by the single crystal X-ray analysis of complex 4. The NMR data (1H, 13C and 119Sn) revealed a higher coordination number around the tin center in R2SnL2 (1 and 2) compared to R3SnL (3 and 4). A close matching was observed between the experimental and calculated structures (obtained at B3LYP/6-31G* + LANL2DZ basis set). Quantum chemical analysis indicates that the carboxylate moiety has the major contribution in the formation of filled and unfilled orbitals as well as in ligand to ligand intramolecular charge transfer during the electronic transitions. The cytotoxicity data of the screened compounds evaluated against lung cancer cell line (A549) and normal lung fibroblast cell line (MRC-5) revealed that 1, 3 and 4 have shown dose dependent cytotoxic effects while HL and 2 have shown steady and low cytotoxic activities. The antibacterial activity of complexes 1–4 is higher than that of HL. Molecular docking study showed an intercalation binding mode for complex 3 with DNA (docking score = −3.6005) involving four polar interactions. Complex 3 docking with tubulin (PDB ID 1SA0) with colchicine as a target protein resulted in three polar interactions (docking score −5.2957). Further, the docking analysis of the HL and 1–4 has shown an adequate interactions with the coronavirus SARS-CoV-2 spike protein, nucleocapsid protein and human angiotensin converting enzyme (ACE2).

Liver plays vital role in detoxification of exogenous and endogenous chemicals. These chemicals as well as oxidative stress may cause liver disorders. This study was aimed to evaluate the hepatoprotective effects of various fractions of Aconogonon alpinum methanolic extract against carbon tetrachloride (CCl4)-induced liver toxicity in mice. First, hepatoprotective potential of various fractions of A. alpinum was assessed and then antioxidant activity and profiling of polyphenolic compounds were assessed. A total of 78 male albino mice (BALB/c) were randomly divided into 13 groups (n = 6); Group I (normal control), Group II (CCl4 only), Group III (CCl4 + silymarin 100 mg/kg) and Groups IV–XIII (CCl4 + various fractions [200 and 400 mg/kg]). Hepatic biochemistry and liver injury were assessed by analysis of serum levels of hepatic enzymes and histopathological analysis, respectively. Results showed that polar fractions (ethyl acetate, n-butanol and aqueous fractions) exhibited highly significant (P < 0.01) reduction in increased level of liver biochemical parameters in a dose-dependent manner with consistent histopathological findings. Likewise, these fractions revealed strong antioxidant potential and polyphenolic compound contents. In conclusion, the present work has revealed promising antioxidant activity, polyphenolic profiling and potential hepatoprotective efficacy. Thus, the significant results unveil the study as a step forward towards evidence-based phytomedicine.

The current work is to spotlight the key structure-property features of a novel thiourea complex bis(thiourea) silver(I) nitrate (BTSN) for future applications in nonlinear optical devices through dual approach involving experimental and theoretical techniques. The synthesis and growth of good quality single crystals of a relatively new material BTSN have been done. The crystal structure, quantitative and qualitative, vibrational, optical and dielectric analysis of the grown single crystals was carried out. The optical transparency of the grown crystals is found to be more than 80% confirms its colorless nature and applications in optoelectronic devices. Further, the state-of-art computational methods have been applied to obtain the ground state molecular geometry at B3LYP/6-31G∗, MP2/6-31G∗ and M06/6-31G∗ levels of theory. Various key electro-optical properties (complementary to experimental results) such as IR, Raman, and polarizabilities have been determined at the same levels of theory. The static and dynamic polarizability and first hyperpolarizability both were calculated to comprehend the potential applications of BTSN in nonlinear optics. In addition to the above, numerous novel molecular level insights have been achieved in the form of total and partial density of states, HOMO-LUMO gap and molecular electrostatic potential map. The calculated values of static and frequency dependent dynamic first hyperpolarizability are found to be 8.46 × 10−30 and 2.30 × 10−30 esu which are about 23 times and 13 times greater than those of prototype urea molecule, respectively, calculated at the same B3LYP/6-31G∗ level of theory. From the analyzed results it is clear that the titled compound possesses excellent electro-optic properties that make it a decent contestant for photonic devices. Keywords: Crystal growth, Optical properties, Nonlinear optical material, Density functional theory

We are considering a new COVID-19 model with an optimal control analysis when vaccination is present. Firstly, we formulate the vaccine-free model and present the associated mathematical results involved. Stability results for R0

A first-principles calculation based on DFT investigations on the structural, optoelectronic, and thermoelectric characteristics of the newly designed pyrochlore oxides La2Tm2O7 (Tm = Hf, Zr) is presented in this study. The main quest of the researchers working in the field of renewable energy is to manufacture suitable materials for commercial applications such as thermoelectric and optoelectronic devices. From the calculated structural properties, it is evident that La2Hf2O7 is more stable compared to La2Zr2O7. La2Hf2O7 and La2Zr2O7 are direct bandgap materials having energy bandgaps of 4.45 and 4.40 eV, respectively. No evidence regarding magnetic moment is obtained from the spectra of TDOS, as a similar overall profile for both spin channels can be noted. In the spectra of ε2(ω), it is evident that these materials absorb maximum photons in the UV region and are potential candidates for photovoltaic device applications. La2Tm2O7 (Tm = Hf, Zr) are also promising candidates for thermoelectric device applications, as these p-type materials possess ZT values of approximately 1, which is the primary criterion for efficient thermoelectric materials.

With the focus on tuning the charge transport and optoelectronic properties, various new derivatives were designed by substituting the oligocene moieties at end cores of 2,5-di(pyrimidin-5-yl)thieno[3,2-b]thiophene (Comp.1). The end core substitution effect of benzene, naphthalene, anthracene, tetracene, pentacene and hexacene on Comp.1 was comprehensively studied on the structure-property relationship, electro-optical properties, ionization potential (IP), electron affinity (EA) and hole/electron reorganization energies (λ(h)/λ(e)). The injection barrier was reduced by introducing the oligocene units at end cores. The substitution of anthracene, tetracene, pentacene and hexacene at end cores of Comp.1 significantly minimized the polarization resulting smaller λ(h) (Comp.1c – Comp.1f) than the referenced compound, i.e., pentacene. The smaller λ(h) values are illuminating that newly designed derivatives might be superior/analogous to pentacene, i.e., frequently used hole transport material. The fluorescence spectra, dipole moment, IP, EA and λ(h) values showed that targeted molecules would be not only good for organic light emitters but also efficient for organic semiconductors and photovoltaic devices. Keywords: Semiconductors, Oligocene, Density functional theory, Optoelectronic properties, Reorganization energy, Charge transport properties

This study was aimed to perform the mechanistic investigations of chalcone scaffold as inhibitors of acetylcholinesterase (AChE) enzyme using molecular docking and molecular dynamics simulation tools. Basic chalcones (C1–C5) were synthesized and their in vitro AChE inhibition was tested. Binding interactions were studied using AutoDock and Surflex-Dock programs, whereas the molecular dynamics simulation studies were performed to check the stability of the ligand–protein complex. Good AChE inhibition (IC50 = 22 ± 2.8 to 37.6 ± 0.75 μM) in correlation with the in silico results (binding energies = −8.55 to −8.14 Kcal/mol) were obtained. The mechanistic studies showed that all of the functionalities present in the chalcone scaffold were involved in binding with the amino acid residues at the binding site through hydrogen bonding, π–π, π–cation, π–sigma, and hydrophobic interactions. Molecular dynamics simulation studies showed the formation of stable complex between the AChE enzyme and C4 ligand.

Adsorption of SO2 on pure B12P12 and Zn-doped B12P12 is investigated through density functional theory methods. Zn adsorption on BP delivers four optimized geometries: B-Top, P-top, b64, and ring-enlarged geometry with adsorption energies of −57.12 kJ/mol, −14.50 kJ/mol, −22.94 kJ/mol, and −14.83 kJ/mol, respectively. The adsorption energy of SO2 on pristine boron phosphide is −14.92 kJ/mol. Interaction of SO2 with Zn-doped boron phosphide gives four different geometries with adsorption energies of −69.76 kJ/mol, −9.82 kJ/mol, −104.92 kJ/mol, and −41.87 kJ/mol. Geometric parameters such as dipole moment, QNBO, frontier molecular orbital analysis, PDOS, and global indices of reactivity are performed to visualize the changes in electronic properties of B12P12 after Zn and SO2 adsorption.

Light-emitting diodes based on quantum dots as an active emission can be considered as a promising next generation for application in displays and lighting. We report a theoretical investigation of green emission at 550 nm of microcavity inorganic–organic light-emitting devices based on Zn (Te, Se) alloy quantum dots as an active layer. Distributed Bragg Reflector (DBR) has been applied as a bottom mirror. The realization of high-quality DBR consisting of both high and low refractive index structures is investigated. The structures applied for high refractive index layers are (ZrO2, SiNx, ZnS), while those applied for low index layers are (Zr, SiO2, CaF2). DBR of ZnS/CaF2 consisting of three pairs with a high refractive index step of (Δn = 0.95) revealed a broad stop bandwidth (178 nm) and achieved a high reflectivity of 0.914.

Therapeutic effects of anticancer medicines can be improved by targeting the specific receptors on cancer cells. Folate receptor (FR) targeting with antibody (Ab) is an effective tool to deliver anticancer drugs to the cancer cell. In this research project, a novel formulation of targeting drug delivery was designed, and its anticancer effects were analyzed. Folic acid-conjugated magnetic nanoparticles (MNPs) were used for the purification of folate receptors through a novel magnetic affinity purification method. Antibodies against the folate receptors and methotrexate (MTX) were developed and characterized with enzyme-linked immunosorbent assay and Western blot. Targeting nanomedicines (MNP-MTX-FR Ab) were synthesized by engineering the MNP with methotrexate and anti-folate receptor antibody (anti-FR Ab). The cytotoxicity of nanomedicines on HeLa cells was analyzed by calculating the % age cell viability. A fluorescent study was performed with HeLa cells and tumor tissue sections to analyze the binding efficacy and intracellular tracking of synthesized nanomedicines. MNP-MTX-FR Ab demonstrated good cytotoxicity along all the nanocomposites, which confirms that the antibody-coated medicine possesses the potential affinity to destroy cancer cells in the targeted drug delivery process. Immunohistochemical approaches and fluorescent study further confirmed their uptake by FRs on the tumor cells’ surface in antibody-mediated endocytosis. The current approach is a useful addition to targeted drug delivery for better management of cancer therapy along with immunotherapy in the future.

To eliminate imidacloprid insecticide from wastewater, nanocalcite was grafted onto the surface of pretreated polyester fabric. The process of seeding was followed by the low temperature hydrothermal method for the growth of nanocalcite for the functionalization of fabric. The goal of this study was to improve the hydrophilicity of the nanocalcite photocatalyst that had been grafted onto the surface of polyester fabric (PF) using acidic and basic prewetting techniques. The morphological characteristics, crystalline nature, surface charge density, functional groups of surface-modified nanocalcite @ PF were determined via SEM, XRD, FTIR, and Zeta potential (ZP), respectively. Characterization results critically disclosed surface roughness due to excessive induction of hydroxyl groups, rhombohedral crystal structure, and high charge density (0.721 mS/cm). Moreover, contact angle of nanocalcite @ PF was calculated to be 137.54° while after acidic and basic prewetting, it was reduced to 87.17° and 48.19°. Similarly, bandgap of the as fabricated nanocalcite was found to be 3.5 eV, while basic prewetted PF showed a reduction in band gap (2.9 eV). The solar photocatalytic mineralization of imidacloprid as a probe pollutant was used to assess the improvement in photocatalytic activity of nanocalcite @ PF after prewetting. Response surface methodology was used to statistically optimize the solar exposure time, concentration of the oxidant, and initial pH of the reaction mixture. Maximum solar photocatalytic degradation of the imidacloprid was achieved by basic prewetted nanocalcite @ PF (up to 91.49%), which was superior to acidic prewetted fabric and as-fabricated nanocalcite @ PF. Furthermore, HPLC and FTIR findings further indicated that imidacloprid was decomposed vastly to harmless species by basic prewetted nanocalcite @ PF.

Chalcone derivatives gained significant consideration from scientific community due to their potential applications ranging from better biological activity to the efficient semiconducting properties. Present investigation deals with the in-depth study of three chalcone derivatives (2E)-1-(2,5-Dimethyl-3-thienyl)-3-(2-methoxyphenyl)prop-2-en-1-one (1), (2E)-3-(3,4-Dimethoxyphenyl)-1-(2,5-dimethylthiophen-3-yl)prop-2-en-1-one (2), and (E)-1-(2,5-Dimethyl-3-thienyl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one (3) highlighting their optoelectronic, charge transport (CT) and nonlinear optical (NLO) response. The ground and excited state geometries are optimized by applying density functional theory (DFT) and time dependent DFT, respectively. The effect of electron donating groups on the frontier molecular orbitals, absorption and emission wavelengths are investigated and discussed thoroughly using the quantum chemical calculations. The comprehensive intra-molecular charge transfer (ICT) is perceived from the occupied orbitals to the unoccupied molecular orbitals. A novel structure-property relationship is established on the basis of their calculated electronic structures, frontier orbitals and density of states. The electro-optical and nonlinear optical (NLO) properties are finely tuned in the chalcone derivatives comprising of di- and tri-methoxy groups at peripheral. The nature of the p-type and ambipolar charge transport behavior of the compounds 1–3 is limelighted on the basis of their ionization potentials, electron affinities, reorganization energies, transfer integrals and intrinsic mobility. The mono- and di-substituted methoxy chalcone derivatives show the ambipolar performance owing to the better transfer integral and intrinsic mobility values for hole and electron. Whilst tri-methoxy at peripheral would lead the p-channel characteristics due to the balanced reorganization energy (hole and electron) and superior hole transfer integrals leads to higher hole intrinsic mobility. Keywords: Semiconductors, Density functional theory, Optoelectronic properties, Charge transport properties, Intrinsic mobility

Using experimental and computational techniques, a comparative study of electro-optical properties for glycine glycinium picrate (GGP) and glycinium picrate (GP) compounds has been performed. The single crystal of GGP has been grown using slow evaporation technique that was further subjected to experimental characterization of its electro-optical properties. The good optical transparency and mechanical strength at micro level was confirmed from optical and nanoindentation measurements using the Oliver–Pharr method of the grown single crystals. Differential scanning calorimetric (DSC) analysis was done to probe the thermal stability of the grown single crystals. Using the density functional theory (DFT) methods, we have not only investigated the GGP but also proposed GP molecule. Additionally, we have shed light on the molecular geometries, infrared and Raman spectra, linear and nonlinear optical properties of both GGP and GP at molecular level. The time dependent DFT (TD-DFT) approach was adopted to calculate the excitation energies of the molecules in different phases including gas, water, acetone, cyclohexane and chloroform as well. For GGP, its wavelength of maximum absorption is calculated to be ∼390 nm at B3LYP/6-31G∗ level of theory. The calculated amplitudes of first hyperpolarizability (βtot) for GGP and GP are found to be 712 and 970 a. u., respectively, which are about 16 and 23 times larger than that of the urea molecule (a prototype NLO molecule). Thus the present study not only brings to limelight the optical and nonlinear optical properties of GGP but also sheds light on the possible potential of GP as new NLO molecule.

The oxazole compounds are being used for multifunctional purposes ranging from organic light emitting diodes, organic thin film transistors, and photovoltaic to the nonlinear optical materials. In this study, several structural, electro-optical, charge transport and nonlinear optical properties of (4Z)-4-Benzylidene-2-(4-methylphenyl)-1,3-oxazol-5(4H)-one (BMPO) have been investigated. Density functional theory (DFT) and time dependent DFT are very accurate and reasonable approaches to optimize the ground and excited state geometries, respectively. Thus, in the present study DFT and TDDFT methods with the B3LYP/6-31G∗∗ levels of theory have been applied to shed some light on the structure-property relationship, frontier molecular orbitals (FMOs), optical properties. A clear intra-molecular charge transfer (ICT) from the highest occupied molecular orbitals (HOMOs) to the lowest unoccupied molecular orbitals (LUMOs) has been observed. The ionization potentials (IP), electron affinities (EA), total and partial densities of states have been discussed intensively. The electron reorganization energy of oxazole compound (BMPO) is smaller than the hole reorganization energy revealing that it might be good electron transport contender in OLED. The electron reorganization energy of BMPO is calculated to be 0.223 eV that is smaller than the perfluoropentacene (value is 0.250 eV), which is famous n-type semiconductor material. The first pathway of BMPO has almost comparable hole and electron transfer integral values whereas the calculated electron reorganization energy (0.223 eV) is considerably lower than the hole reorganization energy (0.381 eV) which leads to superior electron intrinsic mobility of the studied oxazole derivative as compared to the hole one. It is expected that BMPO might be excellent electron transport material.

This paper studies a fractional-order chaotic system with sine non-linearities and highlights its dynamics using the Lyapunov spectrum, bifurcation analysis, stagnation points, the solution of the system, the impact of the fractional order on the system, etc. The system considering uncertainties and disturbances was synchronized using dual penta-compound combination anti-synchronization among four master systems and twenty slave systems by non-linear control and the adaptive sliding mode technique. The estimates of the disturbances and uncertainties were also obtained using the sliding mode technique. The application of the achieved synchronization in secure communication is illustrated with the help of an example.

The genome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) encodes 16 non-structural (Nsp) and 4 structural proteins. Among the Nsps, Nsp1 inhibits host gene expression and also evades the immune system. This protein has been proposed as a target for vaccine development and also for drug design. Owing to its important role, the current study aimed to identify mutations in Nsp1 and their effect on protein stability and flexibility. This is the first comprehensive study in which 295,000 complete genomes have been screened for mutations after alignment with the Wuhan-Hu-1 reference genome (Accession NC_045512), using the CoVsurver app. The sequences harbored 933 mutations in the entire coding region of Nsp1. The most frequently occurring mutation in the 180-amino-acid Nsp1 protein was R24C (n = 1122), followed by D75E (n = 890), D48G (n = 881), H110Y (n = 860), and D144A (n = 648). Among the 933 non-synonymous mutations, 529 exhibited a destabilizing effect. Similarly, a gain in flexibility was observed in 542 mutations. The majority of the most frequent mutations were detected in the loop regions. These findings imply that Nsp1 mutations might be useful to exploit SARS-CoV-2′s pathogenicity. Genomic sequencing of SARS-CoV-2 on a regular basis will further assist in analyzing variations among the drug targets and to test the diagnostic accuracy. This wide range of mutations and their effect on Nsp1’s stability may have some consequences for the host’s innate immune response to SARS-CoV-2 infection and also for the vaccines’ efficacy. Based on this mutational information, geographically strain-specific drugs, vaccines, and antibody combinations could be a useful strategy against SARS-CoV-2 infection.

Two lanthanide–glutarate coordination polymers, viz. : {[Eu(C5H6O4)(H2O)4]Cl}n, (1) and [Tb(C5H7O4)(C5H6O4)(H2O)2]n, (2) have been synthesized and characterized by IR spectroscopy, thermogravimetric analysis, and X-ray crystallography. In 1, the Eu(III) ions are coordinated by four O atoms from two bidentate chelating carboxylate groups, one O atom from a bridging carboxylate group and four O atoms from water molecules adopting an EuO9 distorted tri-capped trigonal prismatic coordination geometry. In 2, the Tb(III) ions are coordinated by six O atoms from three bidentate chelating carboxylates, one O atom from a bridging carboxylate and two O atoms from water molecules to generate distorted tri-capped trigonal prismatic TbO9 polyhedron. In both compounds, the metal polyhedra share edges, producing centrosymmetric Ln2O2 diamonds, and are linked into [001] chains by bridging glutarate di-anions. The crystal structures are consolidated by O–H···O and O–H···Cl hydrogen bonds in 1, and O–H···O hydrogen bonds in 2. Compound 1 exhibits a red emission attributed to the 5D0 → 7FJ (J = 1–4) transitions of the Eu(III) ion, whereas 2 displays green emission corresponding to the 5D4 → 7FJ (J = 0–6) transitions of the Tb(III) ion. Both the compounds exhibit high sensitivity and selectivity for Fe3+ ions due to luminescence quenching compared with other metal ions, which include; Na+, Mg2+, Al3+, Cr3+, Mn2+, Fe2+, Co2+, Ni2+, Zn2+ and Cd2+. Compounds 1 and 2 also show high luminescence quenching sensitivity for 4-nitrophenol over the other aromatic and nitroaromatic compounds, namely; bromobenzene, 1,3-dimethylbenzene, nitrobenzene, 4-nitrotolune, 4-nitrophenol, 2,6-dinitrophenol and 2,4,6-trinitrophenol.

Five new Lanthanide(III) complexes of malonic acid (HOOC-CH2-COOH); {[Gd(C3H2O4)(H2O)4]·NO3}n (1), {[Tb(C3H2O4)(H2O)4]·NO3}n (2), {[Ho(C3H2O4)(H2O)4]·NO3}n (3), [Er(C3H2O4)(C3H3O4)(H2O)2]n (4), and {[Eu2(C3H2O4)2(C3H3O4)2(H2O)6]·4H2O}n (5) were synthesized and characterized by elemental, infrared spectral, and thermal analyses. The structures of compounds 1–5 were determined by single crystal X-ray diffraction technique. The X-ray analysis reveals that compounds 1, 2, and 3 are isostructural and crystallized in the orthorhombic space group Pmn21. The lanthanide(III) ions are coordinated by four carboxylate and four water oxygen atoms adopting a distorted square antiprism geometry. The LnO8 square antiprisms are linked into infinite layers by malonate (C3H2O42-) dianions sandwiching sheets of nitrate counter ions. Compound 4 contains ErO8 square antiprisms linked into a two-dimensional network by hydrogen malonate (C3H3O4-) anions and malonate dianions. The europium complex, 5 is dinuclear having the two europium(III) ions (Eu1 and Eu2) bridged by carboxylate groups of hydrogen malonate ligands. The europium ions in 5 are nine-coordinate and exhibit a distorted monocapped square antiprism geometry. All the structures are consolidated by O–H⋯ O hydrogen bonds. The photoluminescence spectra of 1–5 exhibit characteristic emissions in the visible region. The IR spectra and thermal data are consistent with the structural results. The room-temperature effective magnetic moments for 1–4 are in good agreement with those expected for the free ions, while the data for 5 indicates that low-lying excited states contribute to the observed moment. The compound 1 was further subjected to quantum computational calculations to explore its optoelectronic properties including; density of states (DOS), dielectric function, refractive index, extinction coefficient, and absorption spectrum, to highlight the possible applications of such materials in the optoelectronics.

Imidazolidin derivatives gained significant attention in our daily life from better biological activity to the semiconducting materials. The present investigation deals with the in depth study of (Z)-2-sulfanylidene-5-(thiophen-2-ylmethylidene)imidazolidin-4-one (STMI) with respect to their structural, electronic, optical and charge transport properties as semiconducting material. The ground and first excited state geometries were optimized by applying density functional theory (DFT) and time dependent DFT, respectively. The light has been shed on the frontier molecular orbitals (FMOs) and observed comprehensible intramolecular charge transfer (ICT) from the highest occupied molecular orbitals (HOMOs) to the lowest unoccupied molecular orbitals (LUMOs). The absorption, emission, ionization potentials (IP), electron affinities (EA), total and partial densities of states and structure-property relationship have been discussed. Finally, hole as well as electron reorganization energies, transfer integrals and intrinsic mobilities have been calculated then charge transport behavior of STMI was discussed, intensively.

We designed novel derivatives of 4,6-di(thiophen-2-yl)pyrimidine (DTP). Two benchmark strategies including mesomerically deactivating group, as well as the extension of π-conjugation bridge (acene-fusion) have been employed to enhance the electrical and charge transport properties. The density functional theory (DFT) and time dependent DFT methods have been used to get optimized geometries in ground and first excited state, respectively. The structural properties (geometric parameters), electronic properties (frontier molecular orbitals; highest occupied and lowest unoccupied molecular orbitals), photophysical properties (absorption, fluorescence and phosphorescence), and important charge transport properties are discussed to establish a molecular level structure–property relationship among these derivatives. Our calculated electronic spectra i.e., absorption, fluorescence and phosphorescence have been found in good semi-quantitative agreement with available experimental data. All the newly designed derivatives displayed significantly improved electron injection ability than those of the parent molecule. The values of reorganization energy and transfer integral elucidate that DTP is a potential hole transport material. Based on our present investigation, it is expected that the naphtho and anthra derivatives of DTP are better hole transporters than those of some well-known charge transporter materials like naphthalene, anthracene, tetracene and pentacene.

Lignin depolymerization for the purpose of synthesizing aromatic molecules is a growing focus of research to find alternative energy sources. In current studies, the photocatalytic depolymerization of lignin has been investigated by two new iso-propylamine-based lead chloride perovskite nanomaterials (SK9 and SK10), synthesized by the facile hydrothermal method. Characterization was done by Powder X-Ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), UV-Visible (UV-Vis), Photoluminescence (PL), and Fourier-Transform Infrared (FTIR) Spectroscopy and was used for the photocatalytic depolymerization of lignin under UV light. Lignin depolymerization was monitored by taking absorption spectra and catalytic paths studied by applying kinetic models. The %depolymerization was calculated for factors such as catalyst dose variation, initial concentration of lignin, and varying temperatures. Pseudo-second order was the best suited kinetic model, exhibiting a mechanism for lignin depolymerization that was chemically rate controlled. The activation energy (Ea) for the depolymerization reaction was found to be 15 kJ/mol, which is remarkably less than conventional depolymerization of the lignin, i.e., 59.75 kJ/mol, exhibiting significant catalytic efficiencies of synthesized perovskites. Products of lignin depolymerization obtained after photocatalytic activity at room temperature (20 °C) and at 90 °C were characterized by GC-MS analysis, indicating an increase in catalytic lignin depolymerization structural subunits into small monomeric functionalities at higher temperatures. Specifically, 2-methoxy-4-methylphenol (39%), benzene (17%), phenol (10%) and catechol (7%) were detected by GC-MS analysis of lignin depolymerization products.

The corner stone of present study is to tune the electro-optical and charge transport properties of donor-bridge-acceptor (D-π-A) triphenylamine (TPA) derivatives. In the present investigation, an electron deficient moiety (pyrimidine), electron-rich moiety (thiophene) and oligocene (benzene, naphthalene, anthracene, tetracene and pentacene) have been incorporated as π-spacer between the donor TPA unit and cyanoacetic acid acceptor and anchoring group. The elongation of bridge usually affects the energy levels, i.e., higher the highest occupied molecular orbital (HOMO) while lower the lowest unoccupied molecular orbital (LUMO) thus reduces the HOMO–LUMO energy gap. The lowered LUMO energy levels of cyano-{2-[6-(4-diphenylamino-phenyl)-pyrimidin-4-yl]-tetraceno[2,3-b]thiophen-8-yl}-acetic acid (TPA-PTT4) and cyano-{2-[6-(4-diphenylamino-phenyl)-pyrimidin-4-yl]-pentaceno[2,3-b]thiophen-9-yl}-acetic acid (TPA-PPT5) dyes revealed that electron injected from dye to semiconductor surface might be auxiliary stable resulting in impediment of quenching. The broken co-planarity between the π-spacer conceiving LUMO and the TPA moiety would help to impede the recombination process. Moreover, it is expected that TPA derivatives with the tetracenothiophene and pentacenothiophene moieties as π-bridge would show better photovoltaic performance due to lowered LUMO energy level, higher electronic coupling constant, light harvesting efficiency and electron injection values.