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Carbon nitride-based 2D materials, such as C3N3 and C3N5, and their role as an interlayer in perovskite solar cells to stabilize NiOx hole selectivity are investigated.

Functionalized chiral indole derivatives are privileged and versatile organic frameworks encountered in numerous pharmaceutically active agents and biologically active natural products. The catalytic asymmetric Friedel-Crafts reaction of indoles, catalyzed by chiral metal complexes or chiral organocatalysts, is one of the most powerful and atom-economical approaches to access optically active indole derivatives. Consequently, a wide range of electrophilic partners including α,β-unsaturated ketones, esters, amides, imines, β,γ-unsaturated α-keto- and α-ketiminoesters, ketimines, nitroalkenes, and many others have been successfully employed to achieve a plethora of functionalized chiral indole moieties. In particular, strategies for C-H functionalization in the phenyl of indoles require incorporation of a directing or blocking group in the phenyl or azole ring of indole. The discovery of chiral catalysts which can control enantiodiscrimination has gained a great deal of attention in recent years. This review will provide an updated account on the application of the asymmetric Friedel-Crafts reaction of indoles in the synthesis of diverse chiral indole derivatives, covering the timeframe from 2011 to today.

Two-dimensional van der Waals layered materials display strong Coulomb interactions, which in turn give rise to large exciton binding energies. Tuning the interface is the basis of devices including optoelectrical, and their delineation is of paramount importance. The developed 2D-carbon nitrides, display graphene-like atomic structures, and the variation in synthetic protocols impact their properties. Engineering the interface with carbon nitride at hole transport layers and perovskite, can eliminate defective charge build-up and suppress the charge carrier recombination rate to induce accelerated photo-induced charge transfer. The fabricated solar cells with L-C3N4 or g-C3N4 interface layers gave an improved performance with boosted open-circuit voltage and fill factor. Our interface layers avoid the direct contact of NiOx with perovskite, overcoming the possible instability of the active layer via iodide oxidation and deprotonation of cationic amines. The carbon nitride-based 2D materials will serve as an effective interfacial layer for long-term reliability in photovoltaics.

The intramolecular hydrogen bonding in the series of 4,6-dihaloresorcinols (with halogen atoms being F, Cl, Br, or I) is believed to play a noticeable role in determining the structural and electronic aspects. All theoretical levels employed in this work suggested that the intramolecular O–H…X-C bonding greatly stabilizes the anti (A) configuration that is at least 5 kcal/mol more stable than the syn (S) form, where such an interaction is absent. Vibrational spectroscopic examination of the OH stretching and bending modes suggested that the dibromo derivative encounters a relatively greater extent of intramolecular hydrogen bonding interaction compared to the corresponding molecules, which is in agreement with the ab initio MP4(SDQ) results. The A ↔ AS ↔ S interconversion barriers were predicted to be in the range of 5–10 kcal/mol, with the difluoro derivative corresponding to the smallest energy barriers in the series in the gas phase. The order of the frontier molecular orbitals and electrostatic potential maps showed a consistent correlation with the size and mass down the halogen group. The calculated infrared and Raman wavenumbers were compared with the experimentally observed ones to assist systematic assignments of the vibrational modes. Molecular docking analysis suggested that the difluoro derivative shall be a potent halo-substituted resorcinol candidate in the treatment of specific types of skin inflammation.

Herein, a library of novel pyridone derivatives 1-34 was designed, synthesized, and evaluated for α-amylase and α-glucosidase inhibitory as well as antioxidant activities. Pyridone derivatives 1-34 were synthesized via a one-pot multi-component reaction of variously substituted aromatic aldehydes, acetophenone, ethyl cyanoacetate, and ammonium acetate in absolute ethanol. Synthetic compounds 1-34 were structurally characterized by different spectroscopic techniques. Most of the tested compounds showed more promising inhibition potential than the standard acarbose (IC

Monitoring of pollutant and toxic substances is essential for cleaner environment and healthy life. Sensing of various environmental contaminants and biomolecules such as heavy metals, pharmaceutics, toxic gases, volatile organic compounds, food toxins, and pathogens is of high importance to guaranty the good health and sustainable environment to community. In recent years, graphitic carbon nitride (g-CN) has drawn a significant amount of interest as a sensor due to its large surface area and unique electrochemical properties, low bandgap energy, high thermal and chemical stability, facile synthesis, nontoxicity, and electron rich property. Furthermore, the binary and ternary nanocomposites of graphitic carbon nitride further enhance their performance as a sensor making it a cost effective, fast, and reliable gadget for the purpose, and opens a wide area of research. Numerous reviews addressing a variety of applications including photocatalytic energy conversion, photoelectrochemical detection, and hydrogen evolution of graphitic carbon nitride have been documented to date. But a lesser attention has been devoted to the mechanistic approaches towards sensing of variety of pollutants concerned with environmental and biological aspects. Herein, we present the sensing features of graphitic carbon nitride towards the detection of various analytes including toxic heavy metals, pharmaceuticals, phenolic compounds, nitroaromatic compounds, volatile organic molecules, toxic gases, and foodborne pathogens. This review will undoubtedly provide future insights for researchers working in the field of sensors, allowing them to investigate the intriguing graphitic carbon nitride material as a sensing platform that is comparable to several other nanomaterials documented in the literature. Therefore, we hope that this study could reveal some intriguing sensing properties of graphitic carbon nitride, which may help researchers better understand how it interacts with contaminants of environmental and biological concern. Graphitic carbon nitride Nanosheets as Promising Analytical Tool for Environmental and Biological Monitoring of Hazardous Substances.

Covalent organic frameworks (COFs) are a promising class of porous crystalline materials made up of covalently connected and periodically protracted network topologies through organic linkers. The tailorability of organic linker and intrinsic structures endow COFs with a tunable porosity and structure, low density, facilely-tailored functionality, and large surface area, attracting increasing amount of interests in variety of research areas of membrane separations. COF-based membranes have spawned a slew of new research projects, ranging from fabrication methodologies to separation applications. Herein, we tried to emphasis the major developments in the synthetic approaches of COFs based membranes for a variety of separation applications such as, separation of gaseous mixtures, water treatment as well as separation of isomeric and chiral organic compounds. The proposed methods for fabricating COF-based continuous membranes and columns for real world applications are also thoroughly explored. Finally, a viewpoint on the future directions and remaining challenges for COF research in the area of separation is provided.

The title compounds, 8-{1-[3-(cyclo­pent-1-en-1-yl)benz­yl]piperidin-4-yl}-2-meth­oxy­quinoline and 8-{4-[3-(cyclo­pent-1-en-1-yl)benz­yl]piperazin-1-yl}-2-meth­oxy­quinoline differ only in the nature of the central six-membered ring: piperidine in the first and piperazine in the second. They are isoelectronic (CH cf. N) and isotypic. The major contribution to the inter­molecular inter­actions in the crystals is from dispersion forces (E dis), reflecting the absence of classical hydrogen bonds., The title compounds, 8-{1-[3-(cyclo­pent-1-en-1-yl)benz­yl]piperidin-4-yl}-2-meth­oxy­quinoline, C27H30N2O (I), and 8-{4-[3-(cyclo­pent-1-en-1-yl)benz­yl]piperazin-1-yl}-2-meth­oxy­quinoline, C26H29N3O (II), differ only in the nature of the central six-membered ring: piperidine in I and piperazine in II. They are isoelectronic (CH cf. N) and isotypic; they both crystallize in the triclinic space group P with very similar unit-cell parameters. Both mol­ecules have a curved shape and very similar conformations. In the biaryl group, the phenyl ring is inclined to the cyclo­pentene mean plane (r.m.s. deviations = 0.089 Å for I and 0.082 Å for II) by 15.83 (9) and 13.82 (6)° in I and II, respectively, and by 67.68 (6) and 69.47 (10)°, respectively, to the mean plane of the quinoline moiety (r.m.s. deviations = 0.034 Å for I and 0.038 Å for II). The piperazine ring in I and the piperidine ring in II have chair conformations. In the crystals of both compounds, mol­ecules are linked by C—H⋯π inter­actions, forming chains in I and ribbons in II, both propagating along the b-axis direction. The principal contributions to the overall Hirshfeld surfaces involve H⋯H contacts at 67.5 and 65.9% for I and II, respectively. The major contribution to the inter­molecular inter­actions in the crystals is from dispersion forces (E dis), reflecting the absence of classical hydrogen bonds.

Development of materials with promising nonlinear optical (NLO) properties is getting attention of both theoretical and experimental communities in fundamental and applied research. In present quantum chemical calculations, potential use of viscoelastic surfactants for NLO properties and associated applications has been discussed. Density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations at B3LYP level of theory and 6–311 + G(d, p) basis set have been performed to evaluate the electronic properties, photophysical characteristics, ionization potential (I), electron affinity (A), electronegativity (X), chemical potential (μ), global hardness (η), global softness (S), global electrophilicity (ω), frontier molecular orbital (FMO), natural bond orbital (NBO) analysis, linear and NLO properties or first hyperpolarizability (β) of N-(3-((3-hydrosulfonylpropyl)dimethyl-l4-azaneyl)propyl)-hydroxy- decanamidehydrate based four representative compounds/surfactants as system 1, system 2, system 3 and system 4. The FMO analysis confirmed the successful migration of charge transfer among the molecules. The NBO analysis has confirmed that the presence of non-covalent interactions (NCIs) and hyper-conjugative interactions (HCIs) are pivotal cause for the stability of the studied systems (1–4). The NLO analysis has also shown that the investigated viscoelastic surfactants hold significant NLO properties (752.28–758.53 a.u) which are better than standard molecule recommended for the NLO activity of said viscoelastic surfactants. We hope that this computational insight may provide new ways for the utilization of viscoelastic surfactants as NLO material for optoelectronic applications. Exploring the NLO behavior of N-(3-((3-hydrosulfonylpropyl)dimethyl-l4-azaneyl)propyl)-hydroxy-decanamidehydrate based four novel viscoelastic surfactants. The insight may provide new ways for the utilization of viscoelastic surfactants as NLO material for optoelectronic applications.

The past two decades have witnessed remarkable growth of asymmetric organocatalysis, which is now a firmly established synthetic tool, serving as a powerful platform for the production of chiral molecules. Ring structures are ubiquitous in organic compounds, and, in the context of natural product synthesis, strategic construction of ring motifs is often crucial, fundamentally impacting the eventual fate of the whole synthetic plan. In this review, we provide a comprehensive and updated summary of asymmetric organocatalytic annulation reactions; in particular, the application of these annulation strategies in natural product synthesis will be highlighted.

The oxa-Michael reaction (OMR) offers the most effective and straightforward route to the synthesis of a wide range of 5- and 6-membered oxygen-containing heterocycles including tetrahydropyrans, tetrahydrofurans, 1,4 dioxanes, isoxazolidines, isoxazolines, γ-lactones and related γ-butenolides. These molecular frameworks are frequently featured in numerous biologically active substances. Moreover, the emergence of organocatalytic asymmetric OMR has empowered access to a variety of diverse oxygen-containing heterocycles in a highly enantio- and/or diastereoselective fashion. This review provides an updated account on the recent advances and applications of OMR in the synthesis 5- and 6-membered monocyclic oxo-heterocycles published in the literature since 2013 to date.

The future challenges associated with the shortage of fossil fuels and their current environmental impacts intrigued the researchers to look for alternative ways of generating green energy. Solar-driven water splitting into oxygen and hydrogen is one of those advanced strategies. Researchers have studied various semiconductor materials to achieve potential results. However, it encountered multiple challenges such as high cost, low photostability and efficiency, and required multistep modifications. The conjugated polymers (CPs) have emerged as promising alternatives for conventional inorganic semiconductors. The CPs offer low cost, sufficient light absorption efficiency, excellent photo and chemical stability, and molecular optoelectronic tunable characteristics. Furthermore, organic CPs also present higher flexibility to tune the basic framework of the backbone of the polymers, amendments in the sidechain to incorporate desired functionalities, and much-needed porosity to serve better for photocatalytic applications. This review article summarizes the recent advancements made in visible-light-driven water splitting covering the aspects of synthetic strategies and experimental parameters employed for water splitting reactions with special emphasis on conjugated polymers such as linear CPs, planarized CPs, graphitic carbon nitride (g-C

Scaffold varied dihydropyrimidone derivatives 1–20 were evaluated for their selective urease inhibitory kinetics potential. Compounds 1, 2, 3, 4, 5, 6, and 12 were found to be the most promising urease inhibitors and showed the inhibition (Ki values) within the range of 9.9 ± 0.5 to 18.3 ± 0.4 µM. Lineweaver–Burk plot, Dixon plot and their secondary replots confirm that all these molecules have followed competitive mode of inhibition. Docking arrangements (MOE) revealed that all the ligands bind in the active site and therefore compete with substrate urea. Molecular docking studies of all compounds have confirmed the binding interactions of various ligands with the amino acid residues as well as Ni atoms of active site. Furthermore, these compounds 1–20 were also tested for their cytotoxicity against human neutrophils and plants and were found to be non-toxic.

Herein, we report novel macromolecular prodrugs (MPDs) of flurbiprofen (FLB) onto a cellulose ether, hydroxypropylcellulose (HPC). The FLB was activated with a powerful acylation reagent carbonyldiimadazole (CDI) in N,N′ dimethylacetamide (DMAc) solvent at room temperature. Imidazolide of FLB generated in situ reacts at 80 °C for 24 h with pre-dissolved HPC to prepare HPC-FLB conjugates. The resultant MPDs of FLB showed moderate to high degree of substitution (DS: 0.35–1.3) with good yield (70–82%). Structures were thoroughly characterized using FTIR, UV and NMR spectroscopic analyses. The pharmacokinetic studies showed that the t1/2 and tmax values of FLB from HPC-FLB conjugate were increased substantially as compare to standard FLB indicates enhanced bioavailability of drug after conjugate formation. Remarked anti-inflammatory activity of the HPC-FLB conjugate was also observed.

Zinc plays a key role in many physiological processes and has implications for the environment. Consequently, detection of chelatable zinc ion (Zn2+ ) has attracted widespread interest from the research community. Lanthanide-based luminescent probes offer particular advantages, such as high water solubility, long luminescence lifetimes and a large Stokes' shift, over common organic dye-based fluorescent sensors. Here, we report the synthesis of terbium and europium complex-based probes, Tb-1 and Eu-1, for sensitive and selective detection of Zn2+ in water. These probes featured the incorporation of bis(2-pyridylmethyl)]amine (DPA) receptor for Zn2+ chelation and the 1,4,7-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecane (DO3A) ring to chelate lanthanide (Ln3+ ). Tb-1 and Eu-1 displayed high selectivity for Zn2+ ions over a wide range of competing ions, with limits of detection of 0.50 ± 0.1 μM and 1.5 ± 0.01 μM, respectively. Density functional theory simulations were in good agreement with experimental observations, displaying high Zn2+ selectivity compared with most competing ions. In the competing ions experiments, the luminescence response of Tb-1 and Eu-1 was moderately quenched by some ions such as Cu2+ , this was linked to the comparable binding abilities of these ions for the receptor of the probe.

Polysaccharides are beneficially used as drug carriers via prodrug formation and offer a mechanism for better effectiveness and delivery of the drug. The unique geometry of hydroxypropylcellulose (HPC), a polysaccharide, allows the attachment of drug molecules with a higher degree of substitution because the hydroxyls groups are projected outside the HPC chains. Therefore HPC-Naproxen conjugates, i.e., macromolecular prodrugs, were synthesized using a powerful acylation reagent carbonyldiimadazole (CDI) in N,N' dimethylacetamide (DMAc) solvent. The reactions were carried out at 80 °C under stirring for 24 h and inert environment. This reaction strategy appeared efficient to obtain a high degree of drug substitution (DS = 0.88–1.40) on the polymer parent chain as calculated by UV–visible spectrophotometry after hydrolysis of the samples. The method provides high efficacy as product yields were high (77–81%). Macromolecular prodrugs (MPDs) with different DS of naproxen designed were found soluble in organic solvents.

The optoelectrical and magnetic characteristics of naturally existing iron-based nanostructures, especially hematite and magnetite nanoparticles (H-NPs and M-NPs), gained significant research interest in various applications, recently. The main purpose of this Review is to provide an overview of the utilization of H-NPs and M-NPs in various environmental remediation. Iron-based NPs are extensively explored to generate green energy from environmental friendly processes such as water splitting and CO

1,5-naphthyridine-based conjugated polymers (P1 and P2) were synthesized and extensively characterized by 1H NMR, thermogravimetric analysis (TGA), FT-IR. These polymers were employed as co-sensitizers in DSSCs sensitized with Ru (II) based N3 dye. In comparison to the N3 sensitized device, the P1 and P2 co-sensitized solar cells demonstrated enhanced open circuit voltage, (VOC) of 825 and 788 mV and better fill factor (FF) of 59 and 58%, respectively. The co-sensitization of P1 and P2 with N3 increased the overall efficiencies to 5.88% and 6.21%, respectively, as compared to 5.58% for N3 sensitizer alone. The fabricated device based on N3 co-sensitized with P2 displayed higher charge recombination resistances as compared to the devices based on N3 alone or N3 co-sensitized with P1. The conjugated polymers are believed to enhance light harvesting ability and reduce the charged recombination in the co-sensitized solar cells.

Herein, we report the synthesis and inhibitory potential of indazole (Methyl 1H-indazole-4-carboxylate) derivatives (1–13) against α-amylase and α-glucosidase enzymes. The described derivatives demonstrated good inhibitory potential with IC50 values, ranging between 15.04 ± 0.05 to 76.70 ± 0.06 µM ± SEM for α-amylase and 16.99 ± 0.19 to 77.97 ± 0.19 µM ± SEM for α-glucosidase, respectively. In particular, compounds (8–10 and 12) displayed significant inhibitory activities against both the screened enzymes, with their inhibitory potential comparable to the standard acarbose (12.98 ± 0.03 and 12.79 ± 0.17 µM ± SEM, respectively). Additionally, the influence of different substituents on enzyme inhibition activities was assessed to study the structure activity relationships. Molecular docking simulations were performed to rationalize the binding of derivatives/compounds with enzymes. All the synthesized derivatives (1–13) were characterized with the aid of spectroscopic instruments such as 1H-NMR, 13C-NMR, HR-MS, elemental analysis and FTIR. Communicated by Ramaswamy H. Sarma

The localized surface plasmon resonance (LSPR) excitations are critical towards achieving sizable spectral enhancements of the Raman scattered light. Herein, the synthesis of palladium-based highly reduced graphene oxide (Pd-HRG) with LSPR properties as an effective surface-enhanced Raman scattering (SERS) substrate and its utility in the highly sensitive detection of procaine are reported. The concentration detection of procaine samples was optimized by applying a set of pre-concentration parameters. The Pd-HRG nanocomposite showed a remarkable LSPR response with a Raman enhancement factor of 8.7 × 10

The increasing resistance of infectious microbial organisms to the existing arsenal of antibiotic drugs is on the rise. There is a growing demand for the new antibiotics that are cost effective and easily available to the common people. In search of new antimicrobial entities, this report deals with the in vitro antimicrobial activities of the crude extracts of leaves of Ehretia Serrata. The methanolic extract and its sub-fractions namely n-hexane, chloroform, ethyl acetate, n-butanol and residual water fraction were screened against a range of 30 different bacterial strains and their zones of inhibition (ZI) and minimum inhibitory concentration (MIC) were subsequently evaluated. Methanolic extract has shown activity against all the tested microorganisms such as Azospirillum lipoferum, Escherichia coli, Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Enterococcus sp. with ZOI ranged from 10.3 to 29.0 mm. Moreover, the MIC values of methanolic extract and its sub-fractions against the tested bacteria ranged from 0.8 to 5.1 mg/mL. GC–MS analysis of sub-fractions revealed the presence of mono (2-ethylexyl) 1,2-benzenedicarboxylate, diisooctyl-1,2-benzenedicarboxylate, 3,5-dehydro-6-methoxypivalate-cholest-22-ene-21-ol, and 3,5-bis (1,1-dimethylethyl)-4-hydroxybenzene-propanoic acid. This is the first report on the in vitro antimicrobial activities of leaves of E. Serrata. Keywords: Antimicrobial activity, Ehretia serrata, Boraginacae, GC–MS analysis, Phytochemical studies

A novel hyper cross-linked, 3,5-diacrylamidobenzoic acid based resin (APEADA) has been synthesized for the highly efficient removal of Congo red (CR) and Rhodamine B (RhB) from aqueous solution. The synthesized resin was extensively characterized by FT-IR, FESEM, PXRD, EDX, BET analysis, TGA and solid state 13C (CP-MAS) NMR. APEADA exhibits thermal stability (≈ 200 °C) and a considerable surface area (64.78 m2 g−1), as suggested by Thermogravimetric Analysis (TGA) and Brunauer-Emmett-Teller (BET) analysis, respectively. The experimental data of dyes adsorption onto resin was examined by a variety of isotherm models wherein Langmuir and Temkin models were found to be the best fit for explaining the adsorption of both RhB (R2 = 0.9899) and CR (R2 = 0.9919). The resin can efficiently remove CR (92.03%) at pH 8.14 and moderately adsorb RhB (45.3%) at pH 5.01 and exhibits maximum adsorption capacity (Qmax) for CR (280.0 mg g−1) and RhB (23.28 mg g−1) at 318.6 K. The thermodynamic analysis of the data revealed that the adsorption processes were exothermic and spontaneous. Moreover, APEADA showed efficient removal efficiency (80.13%) for dyes in simulated effluents which warrants its utility and effectiveness in industrial waste water treatment.

A novel epibromohydrin modified crosslinked polyamine resin (EBPAR) was synthesized for highly efficient removal of Methyl orange (MO) and Eriochrome Black T (EBT) from aqueous solution. EBPAR has been characterized extensively by FTIR, XPS, TGA, XRD and FESEM methods. The resin can efficiently remove MO (> 99%) at pH range of 4–6 and EBT (> 97%) at pH 3. The experimental data of dyes adsorption onto resin was examined by a variety of adsorption models including pseudo-first and second order kinetic models, Langmuir, Temkin, Freundlich, Dubinin–Radushkevich, intra-particle diffusion and film diffusion models. Furthermore, the effect of pH, dosage, initial dye concentration and temperature on the adsorption was also investigated. Experimental results revealed that the adsorption of EBT is mainly controlled by film diffusion (xi = 14.5 mg g − 1) as compared to MO where intra-particle diffusion (R2 = 0.9995) is the rate limiting step. Adsorption interactions of dyes onto EBPAR were investigated using Field Emission Scanning Electron Microscope (FESEM) and X-ray diffraction (XRD) analysis.