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Poly(N-isopropylacrylamide-acrylamide-methacrylic acid) [p(NAM)] colloidal particles were synthesized and stabilized in aqueous medium. Ag nanoparticles were fabricated inside the p(NAM) system by in-situ reduction of Ag+ ions with NaBH4 to obtain Ag-p(NAM) organic–inorganic hybrid with fascinating catalytic properties. Various characterization techniques including XRD, FTIR, DLS, TEM and UV–visible spectroscopy were used to confirm the fabrication of p(NAM) and Ag-p(NAM) in aqueous medium. Loading of silver nanoparticles into the p(NAM) does not affect responsive properties of the colloidal system. Ag-p(NAM) system was used as catalyst for reduction of toxic dyes including methyl orange (MO) and Congo red (CR) from aqueous medium. Ag-p(NAM) catalyzed reduction of dyes was carried out under different reaction conditions to explore the catalytic process of degradation. The Ag-p(NAM) catalytic system is recyclable and reusable with almost same catalytic activity up to four cycles.

The purpose of present work is to fabricate rhodium nanoparticles in Poly(N-isopropylmethacrylamide-acrylic acid) [p(NMAA)] microgel system. Synthesized polymer [p(NMAA)] microgels and rhodium nanoparticles loaded [Rh-p(NMAA)] microgels were analyzed by FTIR (Fourier Transform Infra-red) spectroscopy, XRD (X-ray Diffraction) analysis and UV/Vis (Ultraviolet–Visible) spectroscopy. Catalytic reductive conversion of P-nitrophenol (P-Nph) into P-aminophenol (P-Aph) via Rh-p(NMAA) was used to evaluate the catalytic activity of the hybrid microgel [Rh-p(NMAA)]. Kinetic study of catalytic reductive conversion of P-Nph was explored by considering various reaction parameters. It was found that the value of first order observed rate constant (k obs) was varied from 0.019 to 0.206 min−1 with change in concentration of sodium borohydride (SBH) from 3 to 14 mM at given temperature. However, further increment in concentration of SBH from 14 to 17 mM, reduced the value of k obs from 0.206 to 0.156 min−1. The similar dependence of k obs on concentration of P-Nph was observed at specific concentration of SBH and Rh-p(NMAA) at constant temperature. Kinetic study reveals that conversion of P-Nph to P-Aph takes place on the surface of rhodium nanoparticles (RhNPs) by adopting different reactions intermediates and obeys the Langmuir-Hinshelwood mechanism. Reduction efficiency of recycled Rh-p(NMAA) catalytic system was also measured and no significant reduction in the percentage catalytic activity was obtained up to four cycles for P-Nph conversion into P-Aph.

Charge transport and electronic properties of 4-nitro-4′-amino-azobenzene compounds with donor-acceptor backbone were examined at the molecular level. Optical properties of all the studied six azobenzene dyes were also explored at the solid-state bulk level, i.e., dielectric constants, conductivity, refractive index, and extinction coefficient values. The introduction of benzyl group enhances whereas propanenitrile diminishes the values for real and imaginary dielectric functions. Moreover, the substitution of 3-methoxy-3-oxopropyl and propanenitrile at amino group decreases the real conductivity values; however, bis(3-methoxy-3-oxopropyl) improves these values. These 4-nitro-4′-amino-azobenzene compounds showed good refractive indices in the energy range 0–2 eV which revealed that these dyes would be efficient to generate healthier outputs with lower energy inputs. The effect of substituents was also investigated on transfer integrals, frontier molecular orbitals (FMOs), reorganization energies, electron affinity (EA), and ionization energy (IE). The ground-state geometries were optimized by density functional theory at B3LYP/6-31G** level to probe the molecular level properties. The same level of theory was used for the cation and anion optimizations. The hole and electron transfer nature of azo dyes was investigated by evaluating the electron/hole transfer integrals (Velectron/Vhole) as well as hole and electron reorganization energy values. The results exposed that superior Vhole values of Azo2 and Azo4 might lead to these dyes as p-type contenders. Moreover, larger Velectron values of Azo1, Azo3, Azo5, and Azo6 might lead to these dyes as n-type competitors. These results revealed that inspected Azo dyes would be able to serve as competent hole and electron transfer materials within versatile organic semiconductors.

The modification of carbon nitride (CN) for visible light photocatalytic CO2 reduction is an important issue to explore in the context of energy and environmental challenges. The current work describes the fabrication of a butterfly-shaped photocatalyst derived from a heterojunction between the electron-rich organic monomer 2,5-dibromothiophene (TP) and a CN framework via copolymerization (UCN-TP). The successful incorporation of TP within CN means that it acts as a nucleophilic spare entity that provides electron solidity (π-conjugation) via charge allocation and increases the photocatalytic activity of CN (under visible light illumination). Density functional theory (DFT) data provide additional information on the amalgamation of TP inside CN and the reduced band gap. The best sample UCN-TP0.06 generated 68.18 μmole of CO and 18.52 μmole of H2 by photoreduction, demonstrating the highest photocatalytic activity. Moreover, this remarkable modification of the chemical configuration, band gap and surface area encouraged the good detachment of light-produced photons, thereby rendering it the best candidate for the photoreduction of CO2.

The study aimed to characterize the antioxidant properties regarding the Sida cordifolia with special reference to its detailed biochemical analysis. The study revealed that chlorophyll A (0.9 ± 0.3 mg/g), total chlorophyll content (3.0 ± 0.7 mg/g), total carotenoid content (0.3 ± 0.1 mg/g), total soluble proteins (7.5 ± 0.1 mg/g), and total phenolic contents (5.6 ± 1.3 mg/g) were found highest in flower tissue of S. cordifolia. However, peroxidase (POD) contents (118 ± 31 units/g), superoxide dismutase (SOD) activity (64 ± 1.5 units/g) were maximum in the leaf tissues, while catalase (CAT) contents (133 ± 25 units/g), ascorbate peroxidase (APX) contents (145 ± 44 units/g) were also found more in the flowers of S. cordifolia rather than other parts. Our results conclude that leaves, stem, flower of S. cordifolia could be exploited in pharmacology due to presence of different antioxidants reflected in flower and leaf extract make them potent and profound therapeutic agents. KEY WORDS: Alkaloids, Flavonoids, Phenolics, Antioxidant, Sida cordifolia Bull. Chem. Soc. Ethiop. 2020, 34(2), 427-434 DOI: https://dx.doi.org/10.4314/bcse.v34i2.18

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 Aerva plants are exceptionally rich in phytochemicals and possess therapeutics potential. Phytochemical screening shows that Aerva persica (Burm.f.) Merr. contains highest contents i.e., total phenolics, flavonoids, flavonols, tannins, alkaloids, carbohydrates, anthraquinones and glycosides. In-vitro antibacterial and enzymatic (carbonic anhydrase) inhibition studies on methanol extracts of A. persica indicated the presence of biological active constituents within chloroform soluble portions. Investigation in the pure constituents on the chloroform portions of A. persica accomplished by column chromatography, NMR and MS analysis. The bioguided isolation yields four chemical constituents of coumaronochromone family, namely aervin (1-4). These pure chemical entities (1-4) showed significant antibacterial activity in the range of 60.05–79.21 µg/ml against various bacterial strains using ampicillin and ciprofloxacin as standard drugs. The compounds 1-4 showed promising carbonic anhydrase inhibition with IC50 values of 19.01, 18.24, 18.65 and 12.92 µM, respectively, using standard inhibitor acetazolamide. First-principles calculations revealed comprehensive intramolecular charge transfer in the studied compounds 1-4. The spatial distribution of highest occupied and lowest unoccupied molecular orbitals, ionization potential, molecular electrostatic potential and Hirshfeld analysis revealed that these coumaronochromone compounds would be proficient biological active compounds. These pure constituents may be used as a new pharmacophore to treat leaukomia, epilepsy, glaucoma and cystic fibrosis.

Cenobamate, which is a voltage-gated sodium channel (VGSC) blocker, finds its full application in several anti-epileptic medications. This manuscript tries to look at the structure and other physicochemical properties of this compound with electronic structure methods and molecular mechanics tools. Density functional theory was used to optimise the ground-state geometry of the molecule using dispersion-corrected ω-B97XD functional using aug-cc-pVDZ basis sets, from which frontier molecular orbitals were studied. This study gave a myriad of information about the electronic properties and descriptors that are well enough to predict the bioactivity of the molecule. Electronic excitations between different energy levels, resulting from the interaction between the electrons and electromagnetic radiation, were analysed using time-dependent density functional theory with CAM-B3LYP functional. Numerous parameters like Fukui, ALIE and MESP provided an ample amount of information about the reactivity preferences of the molecule. Molecular docking studies predicted the biological activity of the molecule and its possible use as an anti-depressant. As it was found to show biological activity, its liquid-state behaviour in different solvents was mapped using molecular dynamics simulations.

Aim of this work is to investigate the catalytic efficiency of silver nanoparticles loaded poly(N-isopropylacrylamide-co-acrylic acid)[Ag-P(NAA)] microgel system towards degradation of an organic d...

Present investigation deals with an in depth study of three compounds including 4-(4-chlorophenyl)-8-methyl-2-oxo- 1,2,5,6,7,8-hexahydroquinoline-3-carbonitrile (1), 4-(4-bromophenyl)-8-methyl-2-oxo-1,2,3,4,4a,5,6,7-octahydroquinoline-3- carbonitrile (2) and 8-methyl-2-oxo-4-(thiophen-2-yl)-1,2,5,6,7,8-hexahydroquinoline-3-carbonitrile (3) with respect to their structural, electronic, optical and charge transport properties. The ground and excited states geometries were optimized by density functional theory (DFT) and time dependent DFT, respectively. To rationalize the adopted methodology, the calculated geometrical parameters at ground state were compared with the experimental crystal structures. Several quantum chemical insights including the analysis of frontier molecular orbitals (FMOs), total/partial density of states (T/PDOS), molecular electrostatic potentials (MEP), local and global reactivity descriptors revealed that the studied compounds would be efficient multifunctional materials. The absorption wavelengths as well as their major transitions were thoroughly studied at TD-B3LYP/6-31G** level of theory. The smaller hole reorganization energies indicate that all these compounds might show better hole transport tendency. The anionic geometry relaxation of compound 2 is larger than the cationic form which leads to higher electron reorganization energy revealing the reduction of electron charge transport as compared to the hole.

Present study reports metabolites profiling, antioxidant, and antidiabetic effects of Cuscuta reflexa grown on Casearia tomentosa. The UHPLC-QTOF-MS/MS method was used to characterize phytochemicals in most potent extract. Thirteen bioactive compounds/metabolites including (2S)-3-(β-D-galactopyranosyloxy)-2-(hexanoyloxy)propyl nonanoate, 4-O-β-D-glucosyl-4-coumaric acid, isorhamnetin-3-O-glucoside, 7-(α-D-glucopyranosyloxy)-2,3,4,5,6-pentahydroxyheptanoic acid, 13S-hydroxyoctadecadienoic acid, astragaloside derivative, salicylic acid, oleanolic acid, citric acid, pinellic acid, quinic acid, caffeic acid derivative and caffeic acid-3-glucoside were detected in 80% hydroethanolic (HE) extract. Among different extracts (aqueous, 20–80% HE and pure ethanolic), 80% HE extract showed maximum TPC (186.19 ± 2.15 mg GAE/g DE) and TFC (106.50 ± 1.68 mg RE/g DE). A strong correlation was observed between TPC, TFC, DPPH radical scavenging (IC50 = 60.64 ± 1.74 µg/mL) and TAP activity (235.96 ± 1.33 mg AAE/g DE) of 80% HE extract among others. The same extract also depicted highest α-amylase and α-glucosidase enzyme inhibition with IC50 of 71.84 ± 1.06 and 57.25 ± 1.40 µg/mL, respectively. Molecular docking was performed to explore possible role of identified phytochemicals. Binding affinity data as well as interaction patterns have revealed possible interaction of the identified bioactives against α-glucosidase and α-amylase. Moreover, intra-molecular charge transfer, energies of the FMOs, HOMO-LUMO-Egaps, MEP and IP were also explained. The present findings suggested that, C. reflexa is a promising natural antioxidant and antidiabetic agent, thus supporting the use of this plant for designing related functional foods and nutra-pharmaceuticals.

A planar small molecule acceptor (IDTT-BO-MN) with 6,12-dihydro-dithieno[2,3-d:2′,3′-d']-s-indaceno[1,2-b:5,6-b']dithiophene (IDTT) as a central core, bis(alkoxy)-substituted benzene ring as conformational control moieties and malononitrile as end-capping units was designed and synthesized. Non-covalent interactions successfully controlled the rotation to make planar backbone. When IDTT-BO-MN was paired with cheapest polymer donor (P3HT), it achieved 5.75% power conversion efficiency and 9.06 × 10−4 cm2V–1S−1 electron mobility. A detailed quantum chemical analysis was performed to understand the electronic and structural behavior of synthesized acceptor. Non-covalent interactions were also studied through the analysis of partial atomic charges and binding energy between participating atoms. Transition dipole moment was calculated that can be simple descriptor for the short circuit current (Jsc). Molecular Packing behavior was also examined and intermolecular binding energy was calculated.

One of the most frequent ways to widen the adsorption range of carbon nitride (CN) is to add a well-known photosensitizer into its basic structure. So far, such attachments have been accomplished by using weak van der Waals forces. However, using strong covalent bonding to attach such photosensitizer with CN is yet to be determined. Here, for the first time, we covalently bonded porphyrin (5,10,15,20-tetrakis(4-(2,4-diamino-1,3,5-triazinyl) phenyl)-Porphyrin (TDP)), a renowned photosensitizer, effectively with CN by thermally balanced molecular strategy. A photoreaction system was set up for the deoxygenated conversion of CO2 to CO under visible light, where cobalt acted as a redox controller to speed up the charge transportation, while CN-TDP worked as a CO2 activating photocatalyst. The subsequent photocatalyst has a broader absorbance range, a greater specific surface area, and intramolecular organic connections that help to decrease the electron-hole pairs’ recombination rate. Furthermore, the average weight ratio between urea and TDP was well-tuned, resulting in a fantastic CO2 photoconversion for CN-TDP7.0 compared to the blank sample. This substantial increase in photocatalytic activity predicts a significant shift in CN’s specific surface area, band gap, chemical composition, and structure, as well as the efficient separation of photogenerated charge carriers from the ground state (HOMO) to the excited state (LUMO), making it a top candidate for CO2 photoreduction. At the same time, this approach paves the path for the bottom-up fabrication of carbon nitride nanosheets.

Optoelectronic and charge transfer properties of three ferrocene derivatives 4-(4-methoxybenzyl)-1-(1-ferrocenylethyl)thio-semicarbazone (1), 4-(2-fluorobenzyl)-1-(1-ferrocenylethyl)thiosemicarbazone (2) and 4-(3,4-dimethylphenyl)-1-(1-ferrocenylethyl)thiosemicarbazone (3) were probed by first-principles study. Density functional theory (DFT) was carried out to elucidate the structural and electronic properties. The B3LYP/6-31G**(LANL2DZ) level was adopted to shed light on the structural parameters and frontier molecular orbitals. The computed geometrical parameters are rationale to the X-ray crystallographic data. The intra-molecular charge transfer from ligand to metal was perceived in ferrocene derivatives. The absorption and emission spectra were computed employing time domain TD-B3LYP/6-31G** (LANL2DZ) level. The hole and electron transfer integrals were estimated to figure out the charge transfer nature in particular ferrocene derivatives. The larger electron transfer integral values are anticipating that these studied Compounds 1–3 might be better electron transfer materials. Moreover, the effect of electron activating groups (–CH3 and –OCH3) and electron deactivating group (-F) was studied on the transfer integrals, structural and electro-optical properties.

Polymer microgels loaded with inorganic nanoparticles have gained much attention as catalytic systems for reduction of toxic chemicals. Enhanced catalytic properties of hybrid microgels are related to the stimuli responsive nature of microgels and extraordinary stability of nanoparticles within network of polymer microgels. Catalytic properties of hybrid microgels can be tuned very easily by slight variation in environmental conditions. Herein we have reviewed catalytic reduction of toxic chemicals such as nitroarenes and organic dyes in the presence of appropriate hybrid microgel catalytic systems under different operating conditions of reaction. Recent advancements in catalytic behavior of hybrid microgels with special emphasis on their ability to catalytically degrade various toxic chemicals has been presented in this review.

This study has been performed to understand the effect of donor strength on photovoltaic performance of Dye-sensitized Solar Cells (DSSCs). For this purpose, Density Functional Theory (DFT) and time domain DFT calculations were carried out. The results reveal that triphenylamine based Dye 2 and carbazole based Dye 4 with di-substituted donor moieties showed red shifted absorption wavelengths, higher oscillator strength and improved electron injection leading to the larger short-circuit photocurrent density (JSC). It is expected that these dyes might show larger open-circuit photovoltage (VOC) as well. These results disclose that di-substitution of the donor moiety would be an efficient strategy to enhance JSC and VOC for better light to power conversion efficiency in DSSCs.

In the current study, the 2,6-diphenyl-4-(3,4,5-trimethoxyphenyl)pyridine (compound 1) has been investigated as proficient material for optoelectronic and nonlinear optical (NLO) applications. In order to highlight the potential at both solid-state (bulk) and molecular levels, different electronic and optical parameters were investigated. The optical and electronic parameters such as refractive index, reflectivity, dielectric function, extinction coefficient, conductivity, electronic band structure, density of states (DOS) of newly reported trimethoxy-phenylpyridine at bulk (solid-state) level have been studied. The band gap is found to be 2.817 eV, which revealed the photon absorption competency has been improved in compound 1 due to narrow band gap and has the capability of containing the absorbed energy. Other calculated optoelectronic properties also revealed that the compound 1 might be better for semiconductor applications. Additionally, the geometric parameters, polarizability (isotropic and anisotropic) and third-order NLO polarizability have been computed at molecular level. For compound 1, its isotropic and anisotropic values are found to be 63.41 × 10−24 esu and 46.22 × 10−24 esu, respectively. The calculated γ amplitude for studied material has been computed as 187.53 × 10−36 esu that is about 25 times bigger than that of the γ amplitude for pNA (a prototype NLO molecule). The third order NLO response for compound 1 has been further tuned through the designing of its further derivatives in the form of compounds 1a, 1b and 1c. Thus, the present study highlights the important optoelectronic and NLO properties of compound 1 and its derivatives.

A novel series of 2-(3-methyl-1,6-diphenyl-1H-pyrazolo[3,4-b]pyridin-4-yl)-5-aryl-1,3,4-oxadiazoles (4a–4h) has been synthesized from corresponding hydrazones (3a–3h) and evaluated their antiplatelet aggregation effect induced by arachidonic acid and collagen. Spectral data and elemental evaluation were used to confirm the structure of the compounds while molecular docking against cyclooxygenase 1 and 2 (COX1 & COX2) and quantitative structure-activity relationship (QSAR) were performed in describing their antiplatelet potential. All synthesized compound exhibited more than 50% platelet aggregation inhibition against both arachidonic acid and collagen. Antiplatelet activities results showed that 4b and 4f compounds have highest % inhibition against arachidonic acid. High Egap and ionization potential values showed that the compound 4d, 4e and 4f were supposed to be more active and good electron donor while 4b, 4c, 4d, 4e, 4g and 4h might be more active due to more electrophilic sites. Interaction with more than one residues in the binding pocket of COX-1 in comparison with aspirin and ligand efficacy (LE) consequences showed that compounds have excellent action potential for COX-1. Computational evaluations are in good agreement with antiplatelet activities of the compounds. All compounds might be promising antiplatelet agents especially 4b, 4f and helpful in the synthesis of new drugs for the treatment of cardiovascular diseases (CVDs).

Multifunctional pyrazole derivative, i.e. 3-amino-1-(5-hydroxy-3-methyl-1H-pyrazol-4-yl)-1H-benzo[f]chromene-2-carbonitrile (PBCC) has been synthesized and characterized. To shed light on various properties of interests, the ground state geometry was optimized by adopting Density Functional Theory (PBE/TZ2P). The effect of different functionals on the absorption wavelengths was studied by using Time-Domain DFT (TDDFT), e.g. GGA functional PBE, hybrid functionals B3LYP and PBE0, rang separated functionals CAM-B3LYP, LCY-PBE and CAMY-B3LYP, Dispersion Corrections PBE-D3 and B3LYP-D3. Among all these functionals PBE and PBE-D3 were found to be good choices which reproduced the absorption spectra of the PBCC. With the aim to enhance the electro-optical, charge transfer and photovoltaic properties, five new derivatives were designed by di-substituting the –F, –Cl, –Br, –COOH and –CN at benzochromene moiety. The electron injection barrier, band gap alignment and related calculated photovoltaic parameters revealed that PBCC and its newly designed derivatives would be proficient to be used in photovoltaic devices. These compounds can be used as donor materials in dye-sensitized solar cells (DSSCs) with favorable type-II band alignment. Moreover, PBCC and most of its derivatives might also be good choice as efficient acceptors with poly(dithieno[3,2-b:2,3-d]pyrrole thiophene) (PDTPr-T) and donor materials with Phenyl-C61-butyric acid methyl ester (PC61BM) in organic solar cells.

Novel smart polystyrene-poly(N-isopropylmethacrylamide-acrylic acid) [PSt@p(NIPMAM-Aac] core/shell gel particles were prepared by two step precipitation polymerization method and used as adsorbent for removal of heavy metal ions such as Pb(II), Cu(II), Cd(II) and Cr(III) from aqueous medium. The adsorption capacity of gel particles for Pb(II), Cu(II), Cd(II) and Cr(III) ions was found as 555.6, 526.3, 476.2 and 434.8 mg/g, respectively. Adsorption process was also studied under different adsorption conditions such as adsorbent dose, metal ions concentration, agitation time, pH and temperature. Adsorption isotherms study was performed for heavy metal ions removal under optimum adsorption conditions. Langmuir and Freundlich adsorption isotherms were employed to evaluate the mechanism of adsorption process. Kinetic study showed the adsorption process followed pseudo second order kinetics. Thermodynamic study enlightens the nature of adsorption process on the basis of thermodynamic parameters such as standard Gibbs energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°). Fourier transform infrared (FTIR) spectroscopy was used to elucidate the characteristics of gel and metal ions loaded gel particles. pH sensitivity and size of gel particles were evaluated by dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. Recoverability and reusability of gel particles for Pb(II) ions removal were also studied to investigate the repeated usage of our reported adsorbent for removal of pollutants from aqueous medium.

Methylene blue (MB) (3,7-bis (dimethylamino)-phenothiazin-5-ium chloride) is a harmful pollutant and has been long been known for its detrimental effects on human health. Over the recent years, many strategies including reduction, oxidation, biological and photochemical degradation have been reported for converting this harmful dye into commercially useful products. Among the aforementioned strategies, the nanocatalytic reduction of MB into its reduced counterpart, i.e. leucomethylene blue, is considered more preferable because it has been reported to have numerous applications in various industrial fields in the academic literature. The reduction of MB is the kinetically unfavorable reaction. Henceforth, various nanocatalytic systems utilizing different kinds of stabilization mediums have reportedly been used for speeding up this particular reaction. This article attempts to not only describe the fundamental properties of the reduction reaction of MB but also present the classification of the recently reported nanocatalytic assemblies on the basis of the utilized supporting medium. Various techniques used for the characterization of nanocatalytic systems reported for the reduction of MB have been summarized in this review. The thermodynamics, kinetics and mechanistic studies of this nanocatalytic reaction have also been narrated here. This critical review has been written comprehensively to abridge the recent research progress in the assemblage of nanocatalytic systems used for the reduction of MB and to propose some new ideas for further development in this area.

The low cost, highly stable and earth abundant furan-based small molecules have been recognized to be prospective and innovative organic semiconductor materials (OSMs) for optoelectronic applications. In this article, we explore various optoelectronic properties of conjugated isomers containing bifuran (TFFT) and bithiophene (FTTF) by employing the density functional theory (DFT) based ultrasoft pseudopotential approach. Our investigations specify the TFFT as a wide and direct bandgap semiconductor with bandgap value of 2.00 eV. Whereas, the bandgap of FTTF is found to be reduced by 0.239 eV in comparison with TFFT owing towards the effect from p-orbitals of carbon and sulfur atoms present at the center of molecular crystal structure. The reduction in the energy and the density of states (DOS) for the compounds in current study endorsed that bandgap could be tuned to any desired value for optoelectronic applications through derivatives designing. Moreover, the achieved outcomes for optoelectronic parameters like dielectric function, conductivity, refractive index, reflectivity, extinction coefficient and energy loss function validates their suitability to use them in electro-optical devices.

In this report, DFT and TDDFT calculations used to explain the noticeable difference in the power conversion efficiencies (PCEs) of three reported triphenylamine-based organic dyes with mono-, di-, and tri-cyanoacrylic acid units as anchoring groups, and thiophene unit as π-bridges used as potential dyes in dye-sensitized solar cell applications. These dyes were showed the superiority of the multi-anchoring systems over the mono-anchoring system. The light was shed on the effect of various functionals, e.g., B3LYP, CAM-B3LYP, ωB 97 XD , M06, PBE0 and BHandHLYP on absorption spectra. The CAM-B3LYP functional was depicted the best among numerous adopted functionals which reproduced the experimental absorption data. The geometries, electronic structures and UV-Vis absorption spectra of the isolated dyes and their adsorbed dye@TiO2 complexes were calculated. The associated physical parameters that control the effectiveness of the cell, such as the light harvesting efficiency ( L H E ), hole and electron reorganization energies ( λ h o l e , and λ e l e ), and the driving force for electron injection ( Δ G i n j ) and dye regeneration ( Δ G r e g ) were computed and analyzed in order to determine their contributions to the open-circuit photovoltage ( V o c ) or the short-circuit photocurrent density ( J s c ), and correlate the structure with property. Also, charge transfer descriptors, such as the charge transfer distance ( D C T ), the amount of charge transferred ( q C T ), and dipole moment ( μ C T ) were investigated. The results reveal that the increasing of anchoring groups made significant influence on the PCE of the cells. The effect of mono-, di-, and tri-substituted anchored cyanoacrylic acid group(s) on the triphenylamine-TiO2 complexes has been explored on the frontier molecular orbitals, binding energies and absorption wavelengths. Among all the studied derivatives, electron injection energy barrier for TPA3T3A has been found the smallest which revealed that electron injection in this compound might be superior to other counterparts. Low-lying lowest unoccupied molecular orbital of TPA3T3A would favor it to stabilize thermodynamically. Moreover, TPA3T3A@TiO2 cluster was observed the most stable adsorption complex especially anchoring of TPA3T3A sensitizer at TiO2 cluster from B-side. Comprehensible intramolecular charge transfer has been observed from occupied to unoccupied molecular orbitals. The red shift in the absorption spectra has been perceived by increasing the number of anchoring groups, i.e., cyanoacrylic acid. The type-II band gap alignment between triphenylamine-based organic sensitizers and TiO2 is revealing that photovoltaic efficiency in these studied derivatives would be enhanced. Our quantum chemical analysis explored that these TPA derivatives especially tri-anchored dye would be proficient to be used in photovoltaic devices which would enhance the solar cell efficiency.

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

In this work, poly(N-isopropylmethacrylamide-co-acrylic acid) [p(NIPMAM-co-AAc)] microgels were synthesized by using precipitation polymerization method. Silver nanoparticles (AgNPs) were uniformly dispersed inside the sieves of the engineered microgels by in situ reduction method. Both microgels and hybrid microgels were characterized by Transmission Electron Microscopy (TEM), Ultraviolet-Visible (UV–Vis) spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy. The average diameter of the fabricated AgNPs was found to be 15 nm. The catalytic reduction of 2-Nitroaniline (2-NA) was used as model reaction to investigate the catalytic activity of the hybrid microgels. The value of apparent rate constant (kapp) for catalytic reduction of 2-NA was determined using pseudo first order kinetic model spectrophotometrically under various conditions of reaction to explore the mechanism of catalysis. The kinetic data reveals that catalytic reduction of 2-NA occurs according to Langmuir-Hinshelwood mechanism. The comparison of present study with previous literature makes our system a facile, efficient and stable catalyst for rapid and economical reduction of 2-NA in aqueous medium.

The methanolic extract along its various fractions Abutilon pakistanicum were analyzed to find total phenolic, flavonoids contents followed by antioxidant and α-glucosidase inhibitions of isolated pure constituents. The total content of phenolics and flavonoids was consistently higher in CH2Cl2 (54.89 and 56.06 mg/g extract respectively) compared with n-hexane, ethyl acetate, n-butanol and H2O portions (ranging between 37.81–54.89 and 38.11–56.06 mg/g extract). In order to determine active biological ingredients from CH2Cl2 subportions, extensive advanced chrotapographic separation methods resulted isolation of new flavonoid glycosides namely abutilins C-D (1–2). The structures of these constituents were interpreted by spectroscopic data including FAB-MS, ESI-MS, 1D and 2D-NMR experiments. Both flavonoid (1–2) were evaluated against antioxidant and α-glucosidase inhibitory assay. The antioxidant potential of dichloromethane extract and abutilins C-D (1–2) were determined using DPPH and nitric oxide radial scavenging assays. The abutilins C displayed significant inhibition, with IC50 values 41.66 (DPPH), 39.04 (NOS) µg/mL, using positive control ascorbic acid and quercetin respectively. Inhibitory effects of flavonoids against enzyme α-glucosidase were also investigated and abutilins C showed significant activity with IC50 values 8.27 µg/mL compared with positive control ascarbose (IC50, 5.92 µg/mL). Abutilins C can serve dual inhibitors as antioxidant agent and to treat α-glucosidase associated diseases. Phytochemicals geometries i.e ground state were optimized by density functional theory (DFT) B3LYP/TZ2P to understand the electronic properties of the studied compounds. The ground state geometries of abutilin_C, abutilin_D and reference compounds were optimized by DFT then various electronic properties were explored. Moreover, we have also investigated the global molecular descriptors, molecular electrostatic potential, Hirshfeld analysis and molecular docking by quantum chemical calculations.

With the goal to tune charge transport and electronic properties of 4,6-di(thiophen-2-yl)pyrimidine (DTP) structure, seven novel V-shaped organic semiconductor compounds were designed by nitrogen doping, oligocenes π-bridge incorporations and push-pull strategy. Primarily, 4,6-bis-thiazol-2-yl-pyrimidine (1) was designed by nitrogen atoms doping in DTP. Then push-pull system named 1DA was designed by substituting –N(CH3)2 at R1 and R2, while –CF3 at R3 and R4 positions of 1. Moreover, various semiconducting materials (2DA-6DA) with tuned properties were designed from 1DA by fusing benzene, naphthalene, anthracene, tetracene and pentacene at both ends. The density functional theory (DFT) and time-dependent DFT were adopted for optimizing the ground and excited state structures, correspondingly. We investigated frontier molecular orbitals, photo-stability, electron injection, electron affinity (EA), ionization energies (IE) and reorganization energies. The push-pull and π-bridge elongation strategies ominously raise EA while diminish IE values, which may lead to decrease the electron and hole injection obstruction. Besides, donors–acceptors and oligocenes at both ends meaningfully drop the electron reorganization energy values as compared to normally used n-type material, i.e., tris(8-hydroxyquinolinato)aluminium (mer-Alq3). These results revealed that newly designed materials 4DA-6DA would be proficient to be used in n-type semiconductor devices.

By condensing ethylene-1,2-diamine with different aldehydes such as benzaldehyde, 4-chloroacetophenone and 2-chlorobenzaldeyhde within 1:2 molar ratio, resulted new series of Schiff base ligands (L1)-(L3) containing bidentate nitrogen atom. Their metal complexes were synthesized by coordinating the ligands with transition metals as Co(II), Cu(II), Ni(II) and Zn(II) and exhibited octahedral geometry. Their characterization was done with the help of spectral, physical and analytical analysis. Spectral and elemental analysis of all bidentate ligands and their corresponding 3d-metal chelates was consistent with their proposed structures, signifying the high purity of these compounds. For in-vitro studies, these metal complexes along their ligands were screened against the six bacterial strains; Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus and Streptococcus faecalis. Six fungal strains; Aspergillus niger, Trichophyton mentogrophytes, Epidermophyton floccosum, Trichophyton schoenleinii, Microscopum canis and Fusarium culmorum were used to study antifungal activity of the compounds. Bioactivity results exhibited that metal complexes showed higher antimicrobial potential as compared with their corresponding ligands. The enhanced activity resulted due to chelation that decreases the polarity of metal ions by complexing with bidentate ligands.

Aims: The aim of the present research was to synthesize glycoluril derivative 2,4-Bis(4- cyanobenzyl)glycoluril through a convergent scheme. Background: For this purpose, Sandmeyer reaction procedure was employed for the synthesis of said compound. The structure of the pure compound was confirmed by using different spectroscopic techniques, such as 1HNMR, 13C-NMR and (HR-MS) Mass spectrometry. Objective: Convergent synthesis of 2,4-BIS (4-CYANOBENZYL)GLYCOLURIL USING SANDMEYER REACTION and urease inhibition study. Methods: The structure of the pure compound was confirmed by using different spectroscopic techniques such as 1H-NMR, 13C-NMR and (HR-MS) Mass spectrometry. The electronic properties of the newly synthesized compound and thiourea were determined by using density functional theory. Results: Furthermore, the compound was evaluated against urease enzyme and was found to be potent inhibitors with an IC50 value of 11.5 ± 1.50 μM when compared with standard inhibitor thiourea (IC50 = 21.0 ± 1.90 μM). The compound may serve as a lead compound to synthesize new cyano-based bambusuril in the future with enhanced biological properties. Conclusion: We have synthesized a new glycoluril derivative 2,4-Bis(4-cyanobenzyl)glycoluril by the sandmeyer reaction. It has been obtained in the form of light yellowish powder in good yield (96%). Glycoluril based macrocycles have been used in various fields; starting from the 2,4-Bis(4-nitrobenzyl)glycoluril (already reported compound), which has undergone reduction (CH3OH,Pt/C) , diazotization (NaNO2/HCl), cyanation (CuCl/KCN), respectively in order to synthesize the desired new glycoluril derivative. The obtained product will be used as a building block for the synthesis of the cyano based bambusuril marcocycle in the future. The yield of the obtained product has been monitored by using different amounts of cyanating reagent, but the best results are shown by the use of 4 mmol of CuCl/KCN. KCN with CuCl assisted the conversion of diazo group into the cyano group with enhanced yield when used in excess amount. It acts as a catalyst. The solubility characteristic of 2,4-Bis(4-cyanobenzyl)glycoluril has also been determined in different organic solvents. 1H NMR technique proved to be very helpful for the structure determination of our desired product. Benzylic protons give signals at 7.5 ppm and 7.8 ppm, respectively. The downfield peaks confirm the presence of CN group near the benzylic protons. Methine protons show a signal at 5.2 ppm, which ensures the basic skeleton of glycoluril. Ureidyl protons also confirm the synthesis of the heterocyclic 2,4-Bis(4-cyanobenzyl)glycoluril compound. The negative and positive electrostatic potential sites, molecular descriptors, and charge density distribution of frontier molecular orbitals are revealing that 4a with promising sites for electrophilic and nucleophilic attacks would result to enhance the urease inhibition, which is in good agreement with the experimental data.

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Two new ferrocene derivatives N-(2-hydroxy-5-methylphenyl) ferrocylideneamine (Fe1) and N-(2-hydroxy-5-chlorophenyl) ferrocylideneamine (Fe2) have been synthesized to study the effect on electronic, optical and charge transfer properties while changing the electron donating group with electron withdrawing group. The synthesized compounds were characterized by different spectroscopic (FTIR, UV–Vis, $$^{\mathrm {1}}\hbox {H NMR}$$ , $$^{\mathrm {13}}\hbox {C NMR}$$ ) and spectrometric (EI) techniques. The geometries for ground and excited states were optimized by density functional theory (DFT/B3lyp/6-31G**, LANL2DZ) and time-dependent DFT (TD-B3lyp/6-31G**, LANL2DZ) levels, respectively. The absorption, fluorescence and phosphorescence spectra were estimated using TD-B3LYP and TD-wB97XD functionals and 6-31G** basis set for C, H, N, O and LANL2DZ for Fe atoms in dichloromethane.

A novel aggregation induced emission (AIE) active anthracene based dihydroquinazolinone derivative (probe 1) has been synthesized and characterized by means of spectroscopic methods. The photophysical properties of this probe have been investigated in solvents of different polarity display that fluorescence states are of intramolecular charge transfer (ICT) character. Probe 1 show clear AIE behavior in water/THF mixture on reaching water fraction 95%. The AIE behavior of probe 1 have been exploited for the detection of metal ions in aqueous solution which reveals high selectivity and sensitivity towards Cu2+ ions by colorimetrically and function as a chemosensor in a remarkable turn-off fluorescence manner. Further, the experimental results were investigated by computational means by optimizing the ground state geometries of probe 1 and probe 1-Cu complex using density functional theory (DFT) at B3LYP/6-31G∗∗ and B3LYP/6-31G∗∗(LANL2DZ) levels of theory. Intra-molecular charge transfer was observed in probe 1 while ligand to metal charge transfer (LMCT) for probe 1-Cu complex.

Poly(N-isopropylmethacrylamide-acrylic acid) [pniM-Ac] microgel particles were synthesized by surfactant free radical precipitation polymerization method. Microgel particles were used as adsorbent for the removal of toxic dyes such as Congo red (CR) (anionic), methylene blue (MB) (cationic) and Rhodamine B (Rh-B) (cationic) from aqueous medium at ambient temperature. Due to presence of carboxylate groups inside the polymer chains of microgel particles, uptake of cationic dyes such as MB and Rh-B was high as compared to anionic dye CR at low temperature and high pH of the medium. But at high temperature, microgel particles were shrunken and their hydrophobicity was increased. Under such conditions, uptake of anionic dye CR was high due to increased hydrophobic interaction between polymer chains of microgel particles and dye molecules. Effect of dye concentration, adsorbent dose, pH of the medium and agitation time on the percentage removal of dyes was also investigated and their optimum values were determined. Langmuir isotherm model best explained the adsorption of CR, MB and Rh-B on microgel particles. Pseudo second order has well explained the kinetics of adsorption of all dyes on microgel system as compared to other kinetic models as reflected by the values of regression coefficients (R2). Mechanism of adsorption of all dyes on microgel particles was explained by intra-particle diffusion model. Microgel particles also showed high capacity to extract toxic dyes simultaneously from aqueous medium as compared to their individual adsorption. Pure and dye loaded microgel particles were analyzed by UV–visible (UV–vis) spectroscopy and Fourier transform infrared (FTIR) spectrometry. Size and morphology of microgel particles were investigated by transmission electron microscopy (TEM).

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

In this work, very first attempt has been made to investigate the electronic, spectroscopic and nonlinear optical properties of l-threoninium picrate (LTHP) molecule by exploiting vital computational methods such as HF, B3LYP and range-separated functionals (CAM-B3LYP and LC-BLYP) with 6-31G* basis set. The calculated values of IR and Raman vibrational frequencies were found to be in a good agreement with experimental results. Time-dependent density functional theory has been applied to calculate the electronic and photophysical properties such as excitation energy, dipole moment and frontier molecular orbital (FMO) energies of LTHP. The excitation energy value calculated by CAM-B3LYP is at ~ 351 nm that in close harmony with experimental value (i.e., 356 nm). Total/partial DOS was determined using GGA/BLYP. The values of μtot, αtot, Δα, β0 and βtot were estimated and discussed. The μtot and βtot are found to be 3 and 51 times higher than urea molecule, respectively. The FMOs, molecular electrostatic potential and global reactivity descriptors were also calculated and discussed. All these results suggest that the LTHP would be a good candidate for optoelectronic applications.

A novel pyrazolyl chromene derivative (Probe 1) displaying aggregation induced emission (AIE) properties that capable of sensing of multiple metal ions has been designed and synthesized. The multi analyte probe exhibits selective sensing for Cu2+ and Ni2+ ions via fluorescence turn-off mechanism and ratiometric selectivity for Hg2+ ions in aqueous media. The extent of binding of the probe with sensitive metal ions has been demonstrated. The experimental results were further investigated by computational means by optimizing the ground state geometries of Probe 1 and its various metal complexes for Probe 1-Ni, Probe 1-Hg and Probe 1-Cu using density functional theory (DFT) at B3LYP/6-31+g(d,p) (LANL2DZ) level. On the basis of binding energies, the stability of metal complexes has been studied. In Probe 1-Ni and Probe 1-Cu complexes, charge transfer has been observed from Probe 1 to metal ions revealing ligand to metal charge transfer (LMCT) while in Probe1-Hg complex LMCT as well as intra-molecular charge tranfer (ICT) within Probe 1.

In present investigation, we present designing and characterization of coumarin appended chalcone hybrids using a dual approach consisting of experimental and computational techniques. For the first time, the parent compound 2 ((E)-2-(3-(2,4-dimethoxyphenyl)acryloyl)-3H-benzo[f]chromen-3-one) is successfully synthesized in our lab. The compound 2 is characterized experimentally as well as quantum computational techniques. The results of absorption and emission spectra are compared with those of computationally calculated spectra. A good agreement is found among the experimental and calculated spectra of compound 2. The experimental absorption spectra show maximum absorption and emission peaks at 392 and 461 nm, which are found to be in agreement with their experimental absorption and emission peaks at 393 and 501 nm, respectively. Additionally, we perform analysis of its nonlinear optical (NLO) properties by calculating its second-(β) and third-order nonlinear polarizabilities. The compound 2 shows reasonably good NLO response with its β and amplitudes mounting to 120.23 × 10−30 esu and 677.12 × 10−36 esu, respectively. These β and amplitudes of compound 2 are ∼6 and ∼20 times larger than those of para-nitroaniline (PNA) at BMK/6-311G** level of theory. Based on above structure-property relationship, we also check the effect of substitution of donor groups in the form of further four derivatives i.e. 2a, 2b, 2c and 2d. Interestingly, among these derivatives, the derivative 2d shows a robust NLO response with its β and amplitudes as large as 218.84 × 10−30 esu and 1515 × 10−36 esu, respectively. The present investigation not only reports the first synthesis of compound 2 but also explores the potential of compound 2 and its derivatives as efficient NLO-phores.

Congo red is highly toxic and carcinogenic anionic dye. Its removal from aqueous medium by chemical reduction method using sodium borohydride as reducing agent in the presence of various nano-catalytic systems has been widely reported in literature during last ten years. This review article focuses on recent research of designing of various metal nanoparticles catalysts reported for catalytic reduction of Congo red by sodium borohydride (NaBH4). Different nano-catalytic systems used for reduction of Congo red and their division on the basis of nature of metal nanoparticles and composition of supporting materials has been described critically. Advantages and disadvantages of different nano-catalysts used for reduction of Congo red and their capability to reduce Congo red present in industrial wastewater has been elaborated. An overview of different analytical techniques used for characterization of nano-catalytic systems reported for reduction of Congo red dye has been provided. Mechanism of chemical reduction of Congo red in the presence of nano-catalysts has been described critically with the help of recent literature.

Due to the unique structures of helicenes, we aim to probe their prospective as proficient optoelectronic and charge transfer materials. With the intention to shed light on both at the molecular and bulk levels various properties of interest have been studied. The optical (refractive indices, reflectivity, conductivity, absorption, dielectric constant and extinction coefficient) and electronic properties (total/partial density of states (T/PDOS) of some recently synthesized diquaternary salts of 4,4′-bipyridine helical viologens, i.e., 5,10-dimethyl-5,10-diaza[5]helicene bis-tetrafluoroborate 12+ (Compound1) and 3,8-dimethyl-3,8-diaza[5]helicene bis-tetrafluoroborate 22+ (Compound2) at the bulk level in solid-state have been reflected. The balanced values of hole and electron electronic coupling (Vh and Ve) for compound1 disclose that it might be good ambipolar material. For Compound2 Ve is greater than Vh enlightening that it might be good electron transfer contender. Furthermore, the electronic, photophysical (absorption, fluorescence, phosphorescence) and charge transfer properties (ionization potential (IP), electron affinity (EA) and hole/electron reorganization energy (λ(h)/(e)) of their bipyridine precursors (Compound3 and Compound4) as well as redox partners of Compound1 and Compound2 which are neutral forms of 12+ and 22+ named Compound5 and Compound6, respectively have been explored. The band gap, DOS, dielectric function, conductivity and refractive indices, IP, EA and λ(h)/(e) values revealed that these diaza[5]helicenes would be good contenders to be used in semiconductor devices. The dielectric functions also revealed that Compounds 1 and 2 retain energy holding ability which these systems absorb. It is also expected that absorption capability of photons would be enhanced in studied compounds especially Compounds 5 and 6 having narrow band gaps.

Various photovoltaic parameters, i.e., electron injection (ΔGinject.), electronic coupling constants (|VRP|), light harvesting efficiencies (LHE), band alignment and electronic properties of five chalcone derivatives were studied by density functional theory (DFT) and time domain. The light was also shed on the effect of different electron donating groups and their strength intensity on the electronic and charge transfer properties. The balanced hole and electron reorganization energies for Comp 4 showed that it might have better ambipolar charge transfer in nature. The strong electron donating group(s) usually enhance(s) the ΔGinject. and |VRP| of chalcones as -N(CH3)2 > OCH3 > OH. Additionally, ΔGinject. and |VRP| of various substituted chalcone derivatives have been observed as trimethoxy > dimethoxy > monomethoxy. The greater electron donating ability of substituents is also favorable for the staggered band alignment. The superior ΔGinject. of all the studied chalcones than of the referenced compounds disclosed that the prior compounds would be proficient photovoltaic materials.

This study describes the adsorption of Cu (II), Co (II) and Ni (II) ions from wastewater on Vigna radiata husk biomass. The ability of adsorbent to capture the metal ions has been found to be in the order of Ni (II)>Co (II) and Cu (II) depending upon the size and nature of metal ions to be adsorbed. It has been observed that percentage removal of Cu (II), Co (II) and Ni (II) ions increases with increase of adsorbent dosage, contact time and pH of the medium but up to a certain extent. Maximum adsorption capacity (qmax) for Cu (II), Co (II) and Ni (II) ions has been found to be 11.05, 15.04 and 19.88 mg/g, respectively, under optimum conditions of adsorbent dosage, contact time and pH of the medium. Langmuir model best fits the adsorption process with R2 value approaches to unity for all metal ions as compared to other models because adsorption sites are seemed to be equivalent and only monolayer adsorption may occur as a result of binding of metal ion with a functional moiety of adsorbent. Pseudo second order kinetic model best interprets the adsorption process of Cu (II), Co (II) and Ni (II) ions. Thermodynamic parameters such as negative value of Gibbs energy (∆G°) gives information about feasibility and spontaneity of the process. Adsorption process was found to be endothermic for Cu (II) ions while exothermic for Co (II) and Ni (II) ions as signified by the value of enthalpy change (∆H°). Husk biomass was recycled three times for removal of Ni (II) from aqueous medium to investigate its recoverability and reusability. Moreover V. radiata husk biomass has a potential to extract Cu (II) and Ni (II) from electroplating wastewater to overcome the industrial waste water pollution.

Poly(N-isopropylacrylamide-acrylamide-methacrylic acid) [p(NIPa-AAm-Ma)] polymer microgels were prepared by free radical precipitation polymerization method. AgNPs were fabricated in the sieves of polymer network by chemical reduction using AgNO3 salt as a precursor of silver ions. Various techniques like dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier transform infrared microscopy (FTIR), and UV-Visible spectroscopy were used for characterization of pure and composite microgels. The diameter of AgNPs fabricated in polymeric network was found to be in the range of 10-15 nm. Stimuli responsive behavior of hybrid microgels was same as that of pure microgels. Catalytic efficiency of the hybrid microgels was investigated by reducing 4-Nitroaniline (4-NA) into 4-Aminoaniline (4-AA) using NaBH4 as reducing agent under different conditions of temperature of the medium, concentration of reducing agent, 4-Nitroaniline and hybrid microgels to explore the catalysis process. Kinetic and thermodynamic aspects of reduction of 4-Nitroaniline in the presence of catalyst were also discussed on the basis of values of Arrhenius and Eyring parameters like pre-exponential factor, activation energy, enthalpy of activation and entropy of activation. Catalytic activity of the hybrid microgels was found to be thermally tunable in the temperature range of 25-70 oC. The value of rate constant (k app ) for reduction of 4-NA was minimum at 55 °C, which can be attributed to volume phase transition of the hybrid microgels.

Large size single crystals of Diiodo-bis(carbamide)-zinc(II) [ZnI2. 2[CO(NH2)2] were grown successfully for the first time by slow evaporation techniques at room temperature within the evaporation time of two weeks. The single phase and high crystalline nature of the grown crystals was confirmed by X-ray diffraction analysis. Quantum chemically the geometrical parameters were found in good correlation with experimental values calculated at B3LYP/6-31G* (LANL2DZ), B2LYPD/6-31G* (LANL2DZ), M062X/6-31G* (LANL2DZ) and MP2/6-31G* (LANL2DZ) level of theories. Additionally, the experimental vibrational modes also have shown a good agreement with calculated ones. The optical transparency and band gap were calculated and found to be ∼80% and 4.706 eV, respectively. The calculated value of HOMO-LUMO gap was found in correlation with experimental energy gap. The electronic properties were investigated by shedding light on the frontier molecular orbitals, partial density of states (PDOS), and total density of states (TDOS). The mechanical and dielectric studies show that the grown crystals possess quite good mechanical strength and dielectric constant. The dielectric loss revealed that the grown crystal contains low defects. The total ac electrical conductivity was increased with frequency and the frequency components confirm the sudden hoping mechanism in the grown crystal.

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 ( β tot ) 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 synthesis and characterisation of mononuclear Fe complexes were carried out by using bipyridine (Compound 1) at ambient conditions. Additionally, three more derivatives were designed by substituting the central Fe metal with Zn, Cr, and Ru (Compound 2, Compound 3, and Compound 4), respectively. The ground state geometry calculations were carried out by using density functional theory (DFT) at B3LYP/6-31G** (LANL2DZ) level of theory. We shed light on the frontier molecular orbitals, electronic properties, photovoltaic parameters, and structure–property relationship. The open-circuit voltage is a promising parameter that considerably affects the photovoltaic performance; thus, we have estimated its value by considering the complexes as donors whereas TiO2 and/or Si were used as acceptors. The solar cell performance behaviour was also studied by shedding light on the band alignment and energy level offset.

Core–shell microgels made of non-responsive polystyrene core and responsive poly(N-isopropylacrylamide) shell show exceptional properties as compared to homogenous microgels prepared by conventiona...

Effort is done to design high-performance small molecule electron acceptors for organic solar cells. Herein, we have designed four acceptor molecules with different donor moiety (triphenylamine, carbazole, indoline and coumarin), thiazolothiazole as π-spacer and cyanoacrylic acid as acceptor. The structure–property relationship was studied then the effect of structure modification on the electronic and optical properties of these acceptors was determined systematically. All acceptor molecules were tested against two donors viz. poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly(dithieno[3,2-b:2,3-d]pyrrole thiophene) (PDTPr-T). These newly designed compounds displayed high open-circuit voltage (eVOC) values compared to phenyl-C61-butyric acid methyl ester (PCBM). In the case of PDTPr-T donor, all acceptor molecules showed balanced properties. For P3HT as donor, all designed acceptors showed low energetic driving force (ΔE) to overcome exciton binding energy.

Recently, syntheses and quantum chemical insights in the structures and properties of crystalline organic compounds have attracted significant attention of the scientific community. In the current work we report the synthesis of two arylsulfonylated 2-amino-6-methylpyrimidin derivatives, A and B. X-ray diffraction technique confirmed the structures of both compounds. The single-crystal analysis showed the presence of various non-covalent interactions that are responsible for their structural stabilities. Theoretical calculations of A and B were performed at the B3LYP/6–311++G(d,p) level. The calculated structures of both compounds were found to be in good agreement with the experimentally reported structural parameters. Frontier molecular orbital (FMO) analysis showed that employing different moieties to bind with the 2-amino-6-methylpyrimidin-4-ol group causes certain changes to the FMOs energies and energy gaps, thus affecting the stability, reactivity, and other properties of the resulting compounds. The Natural Bond Order (NBO) analysis showed high stabilization energies within the molecules of both compounds. The calculated global reactivity parameters (GRP) confirmed noticeable stability of both compounds, showing the compound B to be more stable than the compound A.

Two new anthracene derivatives donor–π–acceptor (Compound 1) and acceptor–π–acceptor (Compound 2) have been designed with the aim to understand the effect of donor and acceptor on the electronic, optical and charge transfer properties of sensitizers and sensitizers@TiO2 cluster. The electron donating group (–OH) and acceptor (–COOH) have been substituted at periphery and the effect was studied thoroughly. The ground state geometries of both the compounds were optimized by using density functional theory (DFT) at B3LYP/6-31G**, CAM-B3LYP/6-31G** LC-BLYP/6-31G**, BHandHLYP/6-31G** and PBE1PBE/6-31G** levels of theory. Moreover, ground state geometries of sensitizers@TiO2 cluster were optimized by adopting the same methods along with LANL2DZ pseudopotential for Ti while 6-31G** basis set for all other atoms. The electro-optical properties and charge transfer nature of dye adsorbed at TiO2 cluster were also systematically investigated. The absorption spectra of anthracene derivatives before and after adsorption at TiO2 cluster were limelighted by adopting time dependent DFT.

Chronic exposure of supraphysiologic glucose concentration to cells and tissues resulted in glucose toxicity which causes oxidative stress. Antioxidants have promising effect in suppressing the oxidative stress in the pathogenesis of diabetes mellitus (DM). Condensation of 2,5-dihydroxyacetophenone with different nitrobenzaldehydes was used to synthesize antioxidant nitro substituted chalcones along with nitro substituted flavanones in one step protocol. The compounds were characterized by IR, 1H NMR and 13C NMR and then screened for their in vitro antioxidant and in vivo antihyperglycemic activities. Postulated structures of the synthesized compounds were in agreement with their spectral data. The results indicated that the novel compound (2E)-1-(2,5-Dihydroxyphenyl)-3-(2-nitrophenyl) prop-2-en-1-one (2a) was potent antioxidant because of its lower IC50 value compared with trolox and ascorbic acid. Compound 2a also exhibited excellent antihyperglycemic activity in diabetic rats while the compound (E)-1-(2,5-Dihydroxyphenyl)-3-(4-nitrophenyl)prop-2-one (2c) suppressed the hyperglycemia more effectively in normal rats. The radical scavenging activity behavior was elucidated on the basis of hydrogen atom transfer and one-electron transfer mechanisms by density functional theory (DFT). The compound 2a showed the smallest ionization potential and bond dissociation enthalpy. Experimental and computational investigations concluded that compound 2a might be an effective antihyperglycemic agent because of its antioxidative nature and smallest ionization potential.