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Carboxylic acid supramolecular synthon exhibited dimer or catemer motifs in the crystal lattice depend on the substituent and other functional groups present in the structure. In general, presence of other competing functional groups produced catemer motifs, whereas unsubstituted acids showed dimer. In this manuscript, we have synthesized a new aryl ether amine-based Schiff base with carboxylic acid functionality (1) and demonstrated polymorphic structure via catemer (1a) and dimer (1 b) motifs in the solid state. In both the structure, carboxylic acid group adopted different orientation in the crystal lattice. The different H-bonding lead to modulation of optical properties that was further supported highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) calculation. Further the stability calculation indicates that dimer (1 b) structure was more stable by 8.54 kcal/mole relative to catemer (1a) motifs. Further, the supramolecular interactions in catemer (1a) and dimer (1 b) motifs was studied by Hirshfeld surface and fingerprint plots to gain insight and compare the different functional groups contribution for intermolecular interactions in the polymorphic crystals which clearly showed different intermolecular interactions in polymorphs. [ABSTRACT FROM AUTHOR]

In our research described here nanocomposites containing a newly synthesized methacrylate polymer, poly 2-(4-fluorophenyl)-2-oxoethyl-2-methylprop-2-enoate (PFPAMA) and ZnO nanoparticles in various mass ratios (1, 3 and 5 w %) were synthesized using the hydrothermal method. The synthesized nanocomposites were characterized by Fourier-transform infrared spectroscopy (FTIR), Hydrogen-1 nuclear magnetic resonance (1H-NMR) and X-ray diffraction (XRD) techniques. Both real and imaginary components of the complex dielectric permittivity of pure PFPAMA and the three different PFPAMA/ZnO nanocomposites were measured as a function of frequency. The dielectric study revealed that the ZnO nanoparticles improved the dielectric properties of pure PFPAMA. The variation of electrical conductivity, with frequency showed that the σ value increased linearly with increasing ZnO content. The frequency dependence of the conductivity suggested that the conduction occurs via a barrier hopping process. The obtained results suggest that the ZnO-doped, poly-2-(4-fluorophenyl)-2-oxoethyl-2-methylprop-2-enoate nanocomposites can be used as a dielectric material in dielectric device applications. [ABSTRACT FROM AUTHOR]

We propose a new broadband flexible waterproof antenna suitable for Internet of Things applications. The antenna is comprised of three components: radiating elements fed by a 50-Ω coplanar waveguide transmission line and two layers from an elastomer composite (used as a substrate and top encapsulation) which completely covers the antenna's radiating elements to provide water and dust resistance. An antenna prototype is fabricated and tested. Experimental and numerical results show that the proposed antenna has broad bandwidth (|S11| ≤ −10 dB) over the frequency range of 0.83–2.52 GHz, high radiation efficiency of about 92% and good radiation patterns. The antenna was also immersed into water for 10 s, 10, 30 and 60 min, respectively and reflection coefficient magnitudes were measured, to verify its waterproof capability. The durability and flexibility tests were performed on the antenna prototype. Results show that there is no significant degradation in the antenna performance. [ABSTRACT FROM AUTHOR]

In this paper, we have reported the green synthesis of silver nanoparticles (AgNPs) using silver nitrate and Ficus carica (fig) stem extract at room temperature. We have also explored the effect of volume of extract (1-3 ml) on the formation of AgNPs using various analytical techniques such as Fourier-transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), and energy-dispersive X-ray analyzer (EDX). The formations of AgNPs were monitored by ultraviolet-visible spectrophotometer as well as from color change through the naked eye. The absorption peaks appear between 442 and 455 nm, confirming to surface plasmon resonance (SPR) of AgNPs. It is clear from the FTIR results that the biologically active compounds present in the extract act as capping and reducing agents for AgNPs creation. Electron microscopy results show that by increasing the concentration of extract, the morphology and size of AgNPs changed due to the presence of more phenolic group. The green synthesized AgNPs have been sequentially employed for the selective and sensitive detection of toxic metal ion (Hg2+) in aqueous medium and antimicrobial activity against all tested microbes including five gram negative and two gram positive. Furthermore, the brown color of green synthesized AgNPs turned into colorless with Hg2+ ion by naked eye response and the limit of detection was 1.06 µM. Figure (A) represents the UV-visible spectra of AgNPs with different concentrations of Hg2+ (0.1-10 µM) in aqueous solution and inset shows the variation of the absorbance of AgNPs solution as a function of Hg2+ ion concentration. Figure (B) represents the images of color variations of AgNPs with different concentrations of Hg2+ (10−1-10−7 M) in aqueous solution. [ABSTRACT FROM AUTHOR]

In this paper, we present design and simulation of the compact planar dipole antenna on fully flexible nitrile butadiene rubber polymer composite for body area network applications. A three-layer human tissue model is used to numerically analyse the performance of the antenna, including the human body effect. The proposed antenna achieves stable on-body performance: |S11| varies from -19.45 dB (in free space) at 2.46 GHz resonant frequency to -20.62 dB (on the skin) at 2.44 GHz resonant frequency. Additionally, the specific absorption rate (SAR) of the proposed antenna is evaluated. It was found that the maximum 1 g average SAR value is only 0.20 W/kg for an input power of 100 mW at a distance 2 mm away from tissue model. Simulated and measured results are presented to demonstrate the validity of the proposed antenna. Furthermore, the proposed antenna offer advantages of being compact, of low profile, cheap and easy to fabricate. [ABSTRACT FROM AUTHOR]

The starting material 1,2,4-triazole derivative (3) was used to synthesize some novel condensed triazoles. Thus, treatment of compound (3) with phenyl isocyanate in refluxing pyridine furnished the novel [1,2,4]triazolo[4,3-b][1,2,4]triazole derivative (5). Also, cyclization of compound (3) with phenyl isothiocyanate afforded the [1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivative (7). Hydrazone derivative (9d) was allowed to react with some halogenated reagents such as chloroacetone, ethyl chloroacetate, and chloroacetonitrile to furnish thiazole derivatives (12), (13), and (15), respectively. In a similar manner, bishydrazone (17) was used to prepare the novel bisthiazoles (18) and (19). Some of the synthesized compounds were evaluated for their antibacterial activity. [ABSTRACT FROM AUTHOR]

Green nanotechnology is an eco-friendly method for the biosynthesis of metallic nanoparticles, which are being used due to their unique features and bio-applications in various fields. World Health Organization (WHO) stated that the use of medicinal plants to treat a variety of disorders, such as diabetes mellitus (DM), cancer, HIV infection, hepatitis, tuberculosis (TB), and malaria is very effective. Green synthesis is a cost-effective, environment- friendly, and safe method. There are a wide variety of native medicinal plants around the world, owing to their unique physical, chemical, and biological characteristics, used for gold and silver nanoparticle (NP) synthesis, and are potent among all metal nanoparticles. However, as an alternative to several traditional techniques to synthesize nanoparticles, green chemistry has arisen. This review covers the green synthesis of AuNPs/AgNPs and its significance as a potent anticancer and antidiabetic agent. All literature surveys will be helpful in terms of further progress as to go from summarizing or concluding data along challenges and future perceptions. [ABSTRACT FROM AUTHOR]

Various optoelectronic properties of 10-(1,3-Dithiol-2-ylidene)anthracene based organic light harvesters were probe at solid state bulk surface. Effect of diverse conjugated π-donor-acceptor bridge, 3,4-ethylenedioxythiophene in Comp3 and phenyl for Comps1 and 2, along with two set of electron acceptor entity, an ester moiety for Comp1, a dicyanovinylene moiety for Comp2 and Comp3 was explored on various properties. The 3,4-ethylenedioxythiophene as conjugated π-bridge boost the dielectric constants, conductivity, refractive index and extinction coefficient values significantly. The dicyanovinylene is favorable than the ester group as prior moiety contributes to the p-orbitals from −2.0 to −4.0 eV. The solid states density, relative permittivity's, extinction coefficient, indices of refraction, reflectance, and electrical conductivity displayed that anthracene derivatives may act as proficient objects in multi-purpose organic semiconductors. [ABSTRACT FROM AUTHOR]

Breast cancer (Bca) causes the highest rate of mortality in females owing to the out-of-control cell division in breast cells. In this work, we perform an in-silico screening based on molecular docking and molecular dynamic of curcumin derivatives against ERα. In this study, we carry out, molecular docking of fifty (50) curcumin derivatives having anticancer potential by using virtual screening tools. Ten (10) ligands were selected based on binding energy ranged from (-7.4 kcal/mol to -9 kcal/mol), lower values of inhibition constant (0.23µmol to 3.59µmol), and visualisation of intermolecular interactions. Additionally, we also assess ADMET properties of selected ligands for prediction of their toxicity and drug-likeness. The molecular dynamic simulations (MD) including RMSD, RMSF, Rg, SASA, number of H-bonds and MM-PBSA binding free energy results showed that ligand L2 and L8 bind to estrogen protein ERα more proficiently with good stability over 120 ns. These results suggest lead anticancer compounds L2 (Salicylidenecurcumin) and L8 (Curcumin difluorinated) are the most promising inhibitor against ERα of Bca with ∆Gbind values of (-2.939 and -4.369) kcal/mol. we expect that our findings will evoke the scientific community to further do in-vitro and in-vivo investigations for screened curcumin derivatives against ERα of Bca. [ABSTRACT FROM AUTHOR]

We designed six 4,6-di(pentacenothiophene-2-yl)pyrimidine molecules with excellent charge transport properties. The optimization of ground-state geometries with B3LYP/6-31G** level is adopted with the help of first-principle investigations. The bridge elongation strategy was employed to strengthen intra-molecular charge transfer. The time-dependent density functional theory (TDDFT) was employed for the measurement of absorption spectra (λabs). The λabs, energy gaps (Egaps), frontier molecular orbitals (FMOs) energies, electron injection, ionization energy (IE), electron affinity (EA) along with reorganization energy (λ) values were computed. The substitution of long-chain polyacene cores as well as thiophene enhanced the EA, reduces hole/electron λ along with their IE. The λ(h), and λ(e), were compared with hole and electron transfer within mostly used compounds, like pentacene and tris(8-hydroxyquinolinato)aluminum (mer-Alq3), respectively. It is anticipated that novel designed compounds may be better to be used for hole transfer (as pentacene) and electron transfer (as mer-Alq3) compounds. These derivatives would act as productive materials that can be employed as p- and n-type semiconductors. The elongation of oligothiophene and acene cores act as excellent hole transfer materials that may be better than frequently used p-type reference compounds. These designed derivative also showed lower λ (e) values exhibited that these may be best/comparable with commonly used n-type mer-Alq3. [ABSTRACT FROM AUTHOR]

Charge transport and electronic character of fluorophore chalcogenides 4,4-Difluoro-8-(-XC4H3)-4-bora-3a,4a-diaza-s-indacene (X = O, S, Se) (BODIPY) derivatives were examined at the molecular level. The effect of chalcogenides was investigated on the transfer integrals, electron affinity (EA), frontier molecular orbitals (FMO), ionisation energy (IE), intrinsic mobility along with reorganisation energies. The ring dissimilarities within 4,4-difluoro-8-(-XC4H3)-4-bora-3a,4a-diaza-s-indacene (X = O, 2-/3-furyl (Comp1/Comp4)); (X = S, 2-/3-thienyl (Comp2/Comp4)) and (X = Se, 2-/3-selenenyl (Comp3/Comp6)) were compared systematically. Among BODIPY chalcogenides derivatives, 2-furyl substitution is more beneficial compared with 2-thienyl, 2-selenenyl and 3-furyl as the prior moiety significantly increases intrinsic hole mobility. The –S or –Se substitution at 2- or 3- position in place of –O at equivalent position reduces the structural polarisation from neutral to cation resulting in reduced hole reorganisation energies. The doping of –S or –Se at 2-position decreases the hole transfer integral in comparison to 2-furyl-substituted derivative. The effect of chalcogen atoms on 2- or 3- position is not so significant on the HOMO/LUMO energy levels. It is expected that –O doping at 2-position in furyl is supporting p-type charge transport channel. These results demonstrated that the studied BODIPY derivatives would be efficient hole transfer materials to be used in organic semiconductor devices. [ABSTRACT FROM AUTHOR]

Three novel pyrimidine based bis-uracil derivatives 1–3 were synthesized by the condensation reaction of 2-hydroxynaphthaldehyde with 6-amino-1,3-dimethylpyrimidine-2,-4(1H, 3H)-dione; 6-amino-1, 3-diethylpyrimidine-2,-4(1H, 3H)-dione, and 6-amino-1,-ethyl-3-methylpyrimidine-2,-4(1H, 3H)-dione, respectively and structurally characterized. The preliminary test of compounds was evaluated by SwissADME that can predict rapidly key parameters for a collection of molecules to support their drug discovery endeavors. Antimicrobial, photoluminescence, and molecular docking of compounds were also studied. The kinetic and thermal stabilities along with intramolecular charge transfer characters were obtained for compounds using frontier molecular orbitals, electrostatic potential diagrams as well as their orbital energies. Additionally, we applied state-of-art computational methods to assess the linear and nonlinear optical (NLO) properties of compounds at M06/6-311G** levels of theory. The third-order NLO properties of 1–3 were observed larger as compared to the standard indicating the considerable NLO character of all molecules, which may render the above derivatives as efficient candidates for NLO device fabrications. [ABSTRACT FROM AUTHOR]

In the present study, we report synthesis, characterization, structural and theoretical studies of two copper(II) complexes, [Cu(py)2(L1)2] (1) and [Cu(phen)(Ac)2-Cu2(Ac)4]n (2), and a nickel(II) complex, [Ni(bipy)(L)(Ac)] (3), where py = pyridine, L1 = 3,5-dichloro-2-hydroxybenzaldehyde, phen = 1,10-phenanthroline, Ac = acetate ion, bipy = 2,2'-bipyridine and HL = 4-bromo-2-(Z)-(naphthalene-2-ylimino)methyl) phenol. The new complexes were fully characterized using microanalysis, FAB-mas (m/z), FT-IR, UV-Vis and fluorescence spectra, X-band EPR spectroscopy and then by single crystal X-ray diffraction studies. X-ray studies of 1 and 3 revealed distorted octahedral geometries. Complex 2 is a coordination polymer built by an octahedral copper unit Cu(phen)(Ac)2 alternating with paddle wheel species Cu2(Ac)4, located on a crystallographic center of symmetry, where an acetate anion bridges the two crystallographic independent copper ions. The fluorescence intensities and quantum yields of 1 and 2 were found to be more compared to 3. The preliminary tests in the potential application for theoretical biological activities of compounds have also been studied. Furthermore, we also performed quantum chemical calculations to get insights into the structure-property relationships of the synthesized complexes. The quantum chemical calculations were used for theoretical calculations of linear polarizability and third-order nonlinear optical polarizability (γ) for 1, 2 and 3. Besides this, the theoretical calculations, including the analysis of frontier molecular orbitals and electrostatic potential diagrams, are used to highlight the theoretical aspects of metal to ligand charge transfer (MLCT) processes in the studied complexes. [ABSTRACT FROM AUTHOR]