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Two-dimensional covalent organic frameworks (2D COFs) are a class of crystalline polymers with a design controllable platform that may be developed into a new type of metal-free photocatalyst. The exploration of new frameworks is, however, critical for further progress in this emerging field. To realize their full potential in practical light harvesting applications, the fabrication of a film type photocatalyst is equally essential. Here, we report the successful development of a triazine based covalent organic framework (2D CTF) as an inexpensive and highly efficient visible light active flexible film photocatalyst for solar fuel production from CO2. For this research work, the condensation polymerization between cyanuric chloride and perylene diimide has been exploited for the first time as a new synthetic approach to the construction of 2D CTFs. The visible light-harvesting capacity, suitable band gap and highly ordered π electron channels contribute to the excellent performance of the film photocatalyst. The current study is a benchmark example of COF based photocatalysts for solar fuel production from CO2 and is expected to trigger further interest in potential solar energy conversion applications such as wearable devices. [ABSTRACT FROM AUTHOR]

The successful development of a photocatalyst/biocatalyst integrated system that carries out selective methanol production from CO2 is reported herein. The fine-tuned system was derived from a judicious combination of graphene-based visible light active photocatalyst (CCG-IP) and sequentially coupled enzymes. The covalent attachment of isatin-porphyrin (IP) chromophore to chemically converted graphene (CCG) afforded newly developed CCG-IP photocatalyst for this research endeavor. The current work represents a new benchmark for carrying out highly selective methanol formation from CO2 in an environmentally benign manner. [ABSTRACT FROM AUTHOR]

The consumption of carbon dioxide (CO 2) for direct solar fuel productions and synthesis of fine solar chemicals are gaining leading significance due to the shortage of fossil-fuel and global warming worldwide. Therefore, herein, we report the synthesis and development of solar light harvesting bamboo - shape magnesium tetraphenyl porphyrin based framework (Mg-TPPBF) photocatalyst. The development of Mg-TPPBF photocatalyst-biocatalyst bonded system as a solar light harvesting photocatalyst functions in a extremely efficient manner, increasing to high regeneration of NADH (73.9%), followed by its utilization in exclusive amount of formic acid (HCOOH) production (197.2 μmol) from CO 2. The Mg-TPPBF photocatalyst also enables in consecutive C-S/C-N bonds formation with high yield (~96–99%) and selectivity (~97–99%) under solar light with excellent reusability. The current research work highlights the enlargement and application of Mg-TPPBF photocatalyst for direct solar fuel production from CO 2 and fine solar chemical synthesis. • Atmospheric CO 2 level enhancement cause serious environmental problems. • Mg-TPPBF−F ate DH coupled artificial photosynthetic system reduces CO 2 into HCOOH. • Mg-TPPBF photocatalyst catalyzed C-S/C-N bonds formation under solar light. • The photocatalytic products are useful in agrochemical & pharmacological actions. [ABSTRACT FROM AUTHOR]

[Display omitted] • The structural and electronic property explains that the cation Li+ attraction towards ether oxygen of PEO based on Hard-Soft Acid Base Principle. • Reduction in crystalline nature of PEO is observed after addition of plasticiser PEG. • The reduce in the forbidden gap with the addition of PEG in polymer-metal complex justifies the increase in the ionic conductivity. Quantum chemistry-based codes and methods provide valuable computational tools to study the atomic and molecular structure of any system. This paper provides insights into the electronic and structural properties of polyethylene oxide (PEO) and polyethylene glycol (PEG) based solid polymer electrolyte incorporated with lithium iodide as ion-conducting species using first principle method. PEO shows insulator characteristics with a broad bandgap of 5.2 eV which decreased significantly to 3.19 eV in PEO-PEG-LiI. The wide forbidden energy band gap of PEO-PEG-LiI concludes that conductivity in polymer electrolytes is predominantly ionic rather than electronic. The presence of hydrogen bonding between PEG and PEO shows their amazing compatibility. Hirschfield population analysis (HPA) quantify the interactions involved within the structure and explains the interaction of Li-ion with ether group of PEO. Overlapping of wavefunctions of C, O and H atoms in polymers proves the existence of partial ionic and partial covalent bonding among them. [ABSTRACT FROM AUTHOR]

The utilization of CO2 for production of solar fuels/chemicals is gaining increasing importance due to worldwide fossil-fuel shortage and global warming. As a means to achieve this, we herein report on the synthesis and development of a graphene-based visible light active photocatalyst (CCG-BODIPY) which is chemically converted graphene (CCG) covalently bonded to a light harvesting BODIPY molecule (1-picolylamine-2-aminophenyl-3-oxy-phenyl-4,4'-difluoro -1,3,5,7-tetramethyl-2,6-diethyl-4-bora-3a,4a-diaza-s -indacene-triazine). The photocatalyst-biocatalyst coupled system developed using CCG-BODIPY as photocatalyst functions in a highly efficient manner, leading to high NADH regeneration (54.02 ± 0.61%), followed by its consumption in exclusive formic acid production (144.2 ± 1.8 µmol) from CO2. The present research endeavour highlights the development and application of a graphene based photocatalyst for direct solar fuel formation from carbon dioxide. [ABSTRACT FROM AUTHOR]

The innovation of a highly efficient and inexpensive graphene oxide-based photocatalyst is a challenging task for selective solar chemical regeneration/coenzyme such as nicotinamide adenine dinucleotide (NADH). Herein, we have designed lemon-juice derived highly efficient S-GQD/GO composite as a photocatalyst for regeneration of NADH under solar light. The rational design of a highly efficient photocatalytic system through the orientation of S-GQD on graphene oxide as solar light harvesting photocatalyst is explored for the first time for NADH regeneration. This highly solar light active S-GQD/GO composite photocatalyst upon integration with the NAD+ is used for highly regioselective regeneration of coenzyme (76.36%). The present work provides the benchmark instances of graphene oxide-based material as a photocatalyst for selective regeneration of NADH under solar light and opens a new door for green synthesis. [ABSTRACT FROM AUTHOR]

Abstract: The endogenous cation in peroxidases may contribute to the type of heme coordination. Here a series of ferric and ferrous derivatives of wild-type Leishmania major peroxidase (LmP) and of engineered K+ site mutants of LmP, lacking potassium cation binding site, has been examined by electronic absorption spectroscopy at 25°C. Using UV–visible spectrophotometry, we show that the removal of K+ binding site causes substantial changes in spin states of both the ferric and ferrous forms. The spectral changes are interpreted to be, most likely, due to the formation of a bis-histidine coordination structure in both the ferric and ferrous oxidation states at neutral pH 7.0. Stopped flow spectrophotometric techniques revealed that characteristics of Compound I were not observed in the K+ site double mutants in the presence of H2O2. Similarly electron donor oxidation rate was two orders less for the K+ site double mutants compared to the wild type. These data show that K+ functions in preserving the protein structure in the heme surroundings as well as the spin state of the heme iron, in favor of the enzymatically active form of LmP. [Copyright &y& Elsevier]

The photocatalyst-enzyme coupled system for artificial photosynthesis process is one of the most promising methods of solar energy conversion for the synthesis of organic chemicals or fuel. Here we report the synthesis of a novel graphene-based visible light active photocatalyst which covalently bonded the chromophore, such as multianthraquinone substituted porphyrin with the chemically converted graphene as a photocatalyst of the artificial photosynthesis system for an efficient photosynthetic production of formic acid from CO2. The results not only show a benchmark example of the graphene-based material used as a photocatalyst in general artificial photosynthesis but also the benchmark example of the selective production system of solar chemicals/solar fuel directly from CO2. [ABSTRACT FROM AUTHOR]

C60‐based polymeric systems have been constantly anticipated for sustainable solar energy conversion. Reported, herein is a C60 polymer film as visible light active photocatalyst for efficient and selective reduction of CO2 for the first time. The C60 polymer photocatalyst is synthesized via covalent coupling of C60 monomer units consisting of tetra substituted C60‐pyrene conjugates through spacer groups. The synthesized C60 polymer photocatalyst possesses an extended network of well‐defined repeating monomer units with good stability and visible light‐induced photocatalytic activity. The enhanced visible light harvesting ability of C60 polymer photocatalyst reasonably yields it with higher catalytic ability than its monomer unit. The C60 polymer film photocatalyst upon coupling with the biocatalyst carries out highly selective visible light driven reduction of CO2 to HCOOH (239.46 μmol). The tandem way of incorporating C60 into visible light active polymeric films for continuous use may be highly rewarding for their extended photocatalytic activity for solar fuel production from CO2. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48536. [ABSTRACT FROM AUTHOR]

The generation of a low HOMO-LUMO energy gap makes organic polymer-based composites an important class of materials with outstanding catalytic efficiency. The present work describes the simple and direct synthesis of an excellent photocatalyst, PC (C26H16NO7S)n via doping of erythrosine-B dye on sulfone infused poly(2-amino thiophenol) assembly (PA, (C6H4NO2S)n). The O 1 s spectrum displays peaks at 531.8 eV and 533.3 eV, representing the O=C and O–C groups of the in-situ generated fluorescein loaded on PA surface. Through absorption study (Tauc's plot), the optical band gap (Eg) for polymer PA (2.9 eV) and photocatalyst PC (2.1 eV) has been calculated. Further, due to the efficient absorbance in the range of 400–600 nm with a low optical band gap, the applicability of the catalyst, PC has been checked in photocatalytic C–H activation in thiophene, and the generation of C–C bond with p-nitro aryldiazonium salt. [ABSTRACT FROM AUTHOR]

The visible light-assisted photocatalysis approach allows more sustainable and atom-economical C–H bond arylation processes. The polymer-based photocatalysts are an attractive choice because of their variable design and development feasibility as well as effective catalytic applications. In the present work, by following the basic principles of green chemistry, we have chosen an environmentally friendly and biologically suitable chemical i.e. Erythrosine B as a unit molecule for the generation of photocatalyst EP (C20H8O5S4). The generation of EP has been performed via a one-pot solvothermal reaction of Erythrosine B with sulfur powder. The structural analysis of the EP evidence the generation of an interesting example 2D-polymeric assembly where disulfide (–S–S–) units are acting as linkers and show high thermal stability up to 800 °C (39.9% left as a residue). The low optical band gap of 2.08 eV and electrochemical band gap of 2.09 eV favors its catalytic applicability. The catalytic investigation reveals excellent applicability of EP in C–H arylation (yield 98.5% & selectivity 99%). [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) have emerged as a promising light-harvesting module for artificial photosynthesis and photovoltaics. For efficient generation of free charge carriers, the donor–acceptor (D-A) conjugation has been adopted for two-dimensional (2D) COFs recently. In the 2D D-A COFs, photoexcitation would generate a polaron pair, which is a precursor to free charge carriers and has lower binding energy than an exciton. Although the character of the primary excitation species is a key factor in determining optoelectronic properties of a material, excited-state dynamics leading to the creation of a polaron pair have not been investigated yet. Here, we investigate the dynamics of photogenerated charge carriers in 2D D-A COFs by combining femtosecond optical spectroscopy and non-adiabatic molecular dynamics simulation. From this investigation, we elucidate that the polaron pair is formed through ultrafast intra-layer hole transfer coupled with coherent vibrations of the 2D lattice, suggesting a mechanism of phonon-assisted charge transfer. The donor–acceptor (D-A) conjugation has been adopted for two-dimensional (2D) covalent organic frameworks (COFs) for efficient generation of free charge carriers. Here, the authors investigate the dynamics of photogenerated charge carriers in 2D D-A COFs by combining femtosecond optical spectroscopy and non-adiabatic molecular dynamics simulation. [ABSTRACT FROM AUTHOR]

Our growing energy demands must be met by a sustainable supply with reduced carbon intensity. One of the most exciting prospects to realize this goal is the photocatalyst-biocatalyst integrated artificial photosynthesis system which affords solar fuel/chemicals in high selectivity from CO2. Graphene based photocatalysts are highly suitable for the system, but their industrial scale use requires immobilization for improved separation and recovery of the photocatalyst. Therefore for practical purposes, design and fabrication of film type graphene photocatalyst with higher solar energy conversion efficiency is an absolute necessity. As a means to achieve this, we report herein the successful development of a new type of flexible graphene film photocatalyst that leads to >225% rise in visible light harvesting efficiency of the resultant photocatalyst-biocatalyst integrated artificial photosynthesis system for highly selective solar fuel production from CO2 compared to conventional spin coated graphene film photocatalyst. It is an important step towards the design of a new pool of graphene film based photocatalysts for artificial photosynthesis of solar fuels from CO2. [ABSTRACT FROM AUTHOR]

Melanoma and nonmelanoma skin cancers are among the most prevalent and most lethal forms of skin cancers. To identify new lead compounds with potential anticancer properties for further optimization, in vitro assays combined with in‐silico target fishing and docking have been used to identify and further map out the antiproliferative and potential mode of action of molecules from a small library of compounds previously prepared in our laboratory. From screening these compounds in vitro against A375, SK‐MEL‐28, A431, and SCC‐12 skin cancer cell lines, 35 displayed antiproliferative activities at the micromolar level, with the majority being primarily potent against the A431 and SCC‐12 squamous carcinoma cell lines. The most active compounds 11 (A431: IC50 = 5.0 μM, SCC‐12: IC50 = 2.9 μM, SKMEL‐28: IC50 = 4.9 μM, A375: IC50 = 6.7 μM) and 13 (A431: IC50 = 5.0 μM, SCC‐12: IC50 = 3.3 μM, SKMEL‐28: IC50 = 13.8 μM, A375: IC50 = 17.1 μM), significantly and dose‐dependently induced apoptosis of SCC‐12 and SK‐MEL‐28 cells, as evidenced by the suppression of Bcl‐2 and upregulation of Bax, cleaved caspase‐3, caspase‐9, and PARP protein expression levels. Both agents significantly reduced scratch wound healing, colony formation, and expression levels of deregulated cancer molecular targets including RSK/Akt/ERK1/2 and S6K1. In silico target prediction and docking studies using the SwissTargetPrediction web‐based tool suggested that CDK8, CLK4, nuclear receptor ROR, tyrosine protein‐kinase Fyn/LCK, ROCK1/2, and PARP, all of which are dysregulated in skin cancers, might be prospective targets for the two most active compounds. Further validation of these targets by western blot analyses, revealed that ROCK/Fyn and its associated Hedgehog (Hh) pathways were downregulated or modulated by the two lead compounds. In aggregate, these results provide a strong framework for further validation of the observed activities and the development of a more comprehensive structure–activity relationship through the preparation and biological evaluation of analogs. [ABSTRACT FROM AUTHOR]

Abstract: The front cover artwork for issue 9/2018 is provided by Prof. Jin‐Ook Baeg's artificial photosynthesis research group from Korea Research Institute of Chemical Technology (KRICT), Republic of Korea. The image shows a light harvesting 3D aromatic polymer (3DAP) derived from triptycene that can efficiently and selectively convert CO2 to formic acid. See the Full Paper itself at https://doi.org/10.1002/cctc.201701730. [ABSTRACT FROM AUTHOR]

Abstract: The front cover artwork for issue 9/2018 is provided by Prof. Jin‐Ook Baeg's artificial photosynthesis research group from Korea Research Institute of Chemical Technology (KRICT), Republic of Korea. The image shows a light harvesting 3D aromatic polymer (3DAP) derived from triptycene that can efficiently and selectively convert CO2 to formic acid. See the Full Paper itself at https://doi.org/10.1002/cctc.201701730. [ABSTRACT FROM AUTHOR]

The Cover shows the exclusive production of formic acid from CO2 using a carbon nanodots‐silica hybrid photocatalyst system.In their Full Paper, R. K. Yadav et al. report a new carbon nanodots‐silica hybrid material (CNDSH) as a highly active photocatalyst for the photocatalytic‐biocatalytic coupled selective solar fuel production system from CO2. The CNDSH photocatalyst was obtained by a facile and ecofriendly reverse microemulsion method with a nonionic surfactant. This work would serve as a benchmark example of a carbon nanodots‐silica hybrid photocatalyst system for solar fuel production and is expected to trigger further interest in the development of efficient and ecofriendly solar CO2 reduction systems. [ABSTRACT FROM AUTHOR]

The dysregulated phosphatidylinositol-3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) signaling pathway has been implicated in various immune-mediated inflammatory and hyperproliferative dermatoses such as acne, atopic dermatitis, alopecia, psoriasis, wounds, and vitiligo, and is associated with poor treatment outcomes. Improved comprehension of the consequences of the dysregulated PI3K/Akt/mTOR pathway in patients with inflammatory dermatoses has resulted in the development of novel therapeutic approaches. Nonetheless, more studies are necessary to validate the regulatory role of this pathway and to create more effective preventive and treatment methods for a wide range of inflammatory skin diseases. Several studies have revealed that certain natural products and synthetic compounds can obstruct the expression/activity of PI3K/Akt/mTOR, underscoring their potential in managing common and persistent skin inflammatory disorders. This review summarizes recent advances in understanding the role of the activated PI3K/Akt/mTOR pathway and associated components in immune-mediated inflammatory dermatoses and discusses the potential of bioactive natural products, synthetic scaffolds, and biologic agents in their prevention and treatment. However, further research is necessary to validate the regulatory role of this pathway and develop more effective therapies for inflammatory skin disorders. [ABSTRACT FROM AUTHOR]

Biological wastewater treatment is mostly used in many industries to treat industrial influents. Treated water is consisting of an extremely high concentration of pathogenic microorganisms. Present work demonstrate the treatment of biologically treated sugar industry wastewater (BTSWW) using a low-frequency ultrasound (US). BTWSS consists of Enterobacter, Salmonella, and Escherichia Coli with a total coliform concentration of 2500 ± 300 CFU/mL. Experiments were performed using the individual effect of US, H2O2, and O3 and the combined effect of US with H2O2, O3, and H2O2 + O3. The complete removal of total coliform was obtained for the synergy effect of US with H2O2 and O3. The performance of the process was analyzed based on pseudo-first-order kinetic rate constant and synergy coefficient. The pseudo-first-order kinetic rate constant was 21.6 and 22.3 × 10–2 min−1 with a synergy coefficient of 2 and 1.9 for a combined effect of US with H2O2 and O3, respectively. Another advantage of the synergy of US and O3 was lower requirement of the initial dose of H2O2 (2.1 mM/L). The operational cost of the process was found to be $ 1.5 × 10–2 /MLD. Highlights: • Complete microbial disinfection achieved in 20 min. • The pseudo-first-order kinetic rate constant: 22.3 × 10–3 min−1 and synergy coefficient: 2 for US + O3. • The operational cost of $ 1.5 × 10–2 /MLD for US + O3 [ABSTRACT FROM AUTHOR]

Organic transformations play a vital role in enhancing the scope of pharmaceuticals through the design and development of small bioactive molecules. The facile synthesis of these molecules is more feasible in the presence of catalysts. Nowadays, photocatalysts are quickly replacing the earlier ones due to their eco-friendlier nature and by following the rules of green chemistry. Herein, we are proposing the design and development of a covalent organic framework TBP-SE through the loading of erythrosine B on sulfone-conjugated 2-D pyrene assembly (TBP-S). TBP-SE is a highly crystalline (65.9%) COF with good photostability and fast charge separation (band gap, 2.1 eV). In the photocatalytic study, the TBP-SE is observed as a promising heterogeneous catalyst for efficient cyclization of thioamide to 1,2,4-thiadiazole in high yield (96.5%) along with promising recyclability (5 times). [ABSTRACT FROM AUTHOR]

Natural water quality is continuously diminishing with human intervention and poses a major threat to the ecosystem. The present work investigated the treatment of contaminated lake water using a 40 kHz frequency cavitational reactor. The total colony count present in raw water was 1,300 ± 150 CFU with initial chemical oxygen demand (COD) of 100 ± 30 mg/L. The synergy of cavitation with a catalyst (titanium dioxide [TiO2]) and ozonation was studied. The comparative performance was analyzed by comparing individual and synergic effects. The combined effects of a catalyst with cavitation have shown the maximum removal of the microbial count and COD. Techno-economic feasibility analysis confirmed that the synergy of a catalyst with cavitation results in the maximum reduction in microbial count and COD. The percentage removal of coliform such as Enterobacter, Salmonella, and Escherichia coli (catalyst concentration: 25.0 μM/L and treatment time: 20 min) was 90.8, 92.6, and 100, respectively, with COD removal of 71.6%. Enhanced results may be obtained due to an increase in the cavitational effect in the presence of a solid catalyst. The synergy of cavitation with TiO2 enhanced the microbial removal rate by 45.8% compared to the individual effect. Investigation confirms that synergy effects produced from ultrasound and catalyst were highly beneficial for reducing microbial count from raw water with a substantial COD reduction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bioactivities of 3d-metal complexes of Schiff bases of NO, N 2 O & NO 2 donor sets. • Bioactivities of 3d-metal complexes of Schiff bases of N 2 O 2 & NO 3 donor sets. • Bioactivities of 3d-metal complexes of Schiff base of N 4 O, N 2 O 3 & N 3 O 2 donors sets. • Bioactivities of 3d-metal complexes of Schiff bases of N 4 O 2 & N 2 O 4 donor sets. • Bioactivities of 3d-metal complexes of Schiff bases of N 2 O 5 & N 4 O 3 donor sets. Schiff base ligands have received attention due to their versatile coordination abilities and potential applications in medicinal and biological fields. This investigation offers an in-depth summary of the current advancements in comprehending the diverse biological impacts demonstrated by 3d-metal complexes of N, O-donor multidentate Schiff base ligands derived from salicylaldehyde and its derivatives. The coordination of these ligands with 3d-metal ions results in the formation of stable complexes. The increasing interest in the creation and production of compounds involving 3d-metals with biologically active ligands has led to significant advances in the field of coordination chemistry. The investigations incorporate a range of biological aspects, including anticancer, antifungal, antibacterial, antioxidant, antiproliferative, cytotoxic and SOD activities. The metal complexes exhibit enhanced biological activities compared to their parent ligands, attributed to the coordination of the metal ion and the resulting structural modifications. Furthermore, the manuscript discusses the structure–activity relationships that have been established to understand the underlying mechanisms of biological activities of these complexes. Molecular docking studies and spectroscopic techniques have been employed to elucidate the binding interactions between the metal complexes and relevant biomolecules, shedding light on their potential mode of action. These multifaceted complexes, with diverse biological properties, hold promise as valuable candidates in medicinal chemistry and biological research. [ABSTRACT FROM AUTHOR]

Numerous reports have shown that mitochondrial dysfunctions play a major role in apoptosis of Leishmania parasites, but the endoplasmic reticulum (ER) stress-induced apoptosis in Leishmania remains largely unknown. In this study, we investigate ER stress-induced apoptotic pathways in Leishmania major using tunicamycin as an ER stress inducer. ER stress activates the expression of ER-localized chaperone protein BIP/GRP78 (binding protein/identical to the 78-kDa glucose-regulated protein) with concomitant generation of intracellular reactive oxygen species. Upon exposure to ER stress, the elevation of cytosolic Ca2+ level is observed due to release of Ca2+ from internal stores. Increase in cytosolic Ca2+ causes mitochondrial membrane potential depolarization and ATP loss as ablation of Ca2+ by blocking voltage-gated cation channels with verapamil preserves mitochondrial membrane potential and cellular ATP content. Furthermore, ER stress-induced reactive oxygen species (ROS)-dependent release of cytochrome c and endonuclease G from mitochondria to cytosol and subsequent translocation of endonuclease G to nucleus are observed. Inhibition of caspase-like proteases with the caspase inhibitor benzyloxycarbonyl-VAD-fluoromethyl ketone or metacaspase inhibitor antipain does not prevent nuclear DNA fragmentation and phosphatidylserine exposure. Conversely, significant protection in tunicamycin-induced DNA degradation and phosphatidylserme exposure was achieved by either pretreatment of antioxidants (N-acetyl-L-cysteine, GSH, and L-cysteine), chemical chaperone (4-phenylbutyric acid), or addition of Ca2+ chelator (1,2-bis(2-aminophenoxy)ethane-N,JV,N,N-tetraacetic acidacetoxymethyl ester). Taken together, these data strongly demonstrate that ER stress-induced apoptosis in L. major is dependent on ROS and Ca2+-induced mitochondrial toxicity but independent of caspase-like proteases. [ABSTRACT FROM AUTHOR]

The alkylating as well as alkoxylating behavior of dialkyl sulfites are well presented in the literature. In the present work dialkyl sulphites behavior has been investigated towards EOSIN Y (tetrabrominated fluorescein). The products of the reactions (dialkylated eosin Y) reveal that alkylation takes place at the both active sites (at hydroxyl and carboxyl functionalities) in a single step through sulphur-centred Arbuzov type rearrangement. Density functional theory (DFT) has been used as a tool to analyze the role of the halogen groups present at the periphery of the xanthene moiety in alkylation at hydroxyl and carboxy positions of EOSIN Y. Furthermore, in photo-physical study, it was observed that compound C acts as a superoxide sensor specifically with the detection limit 63μM. Its anti-microbial activity was checked against the E. coli and S-aureus using the agar well diffusion assay and, it was observed that it could be used as better antimicrobial agent. [ABSTRACT FROM AUTHOR]

• Two-dimensional flexible covalent porphyrin framework (2D CPF) was synthesized. • The 2D CPF photocatalyst deposited on the thin film facilitates the C H bond activation. • The 2D CPF shows the high yield and selectivity of product in the C H bond activation. Photocatalysis is one of the most promising ways for the production of organic chemicals with renewable energy source. For the development of cost-effective and metal-free catalysts, two-dimensional covalent organic framework (COF) has been emerged as a photocatalyst. Here, we report the synthetic method of two-dimensional covalent porphyrin framework (2D CPF) and the fabrication procedure of highly active flexible film. 2D CPF were constructed from tetrakis-(4-amino-phenyl)-porphyrin (TAPP) and tetrakis-(4-nitro-phenyl)-porphyrin (TNPP) monomers through the poly-condensation reaction and the resultant composite showed the superb harvesting ability of solar light, the suitable optical band-gap, and the highly ordered π-electron channels which facilitates efficient charge migrations. The 2D CPF photocatalyst deposited on the thin film was readily applicable to light-induced activation of C H bond between p -position of substituted aryl diazonium salts and heteroarenes, and exhibited the high selectivity (~99%) as well as high production yield. Our results show an experimental benchmark for the use of flexible COF film as a highly practical and efficient solar light responsive photocatalyst for the selective C H bond formation in between substituted aryl diazonium salts and heteroarenes derivatives. [ABSTRACT FROM AUTHOR]

[Display omitted] • Use of non-toxic/least toxic chemicals. • Generation of least studied ester-linked covalent organic polymer. • Crystalline nanosheet generation (average crystallite size = 43.5 nm, crystallinity = 90.5 %). • Excellent photocatalytic activity with high selectivity for C-H activation and C-C bond formation reaction. Among all polymeric materials, the chemistry of covalent organic polymers has been the least covered in the field of photocatalysis due to the rare availability of design and synthetic protocols. In the present work, we have come up with an efficient design of a one-dimensional Covalent Organic polymer (COP) (S-COP) through the ester-linked co-polymerization of Erythrosine B with 2,2′-Dithiodibenzoic acid (2,2′-DDB). The COP was synthesized via the facile one-pot solvothermal method. The XRD data analysis favors high crystalline nanoscale polymeric sheet generation (S-COP , 90.5 % & 43.5 nm). The HOMO-LUMO calculation through an electrochemical study as well as Tauc's plot showed 2.1 eV band gap. In this order, S-COP , a metal-free polymeric material was observed as an effective photocatalyst in the solar-driven photocatalytic reaction of heteroarenes with aryl diazonium salts via direct C-H arylation (High yield (∼98 %), and high selectivity (∼98 %)). [ABSTRACT FROM AUTHOR]

Various non-linear and linear properties of Sb-doped Ge-Se-Te glasses for optoelectronic applications are investigated in present paper. The variation of refractive index with respect to wavelength is shown in Figure. • Investigations of Glass forming ability of Ge-Se-Te-Sb glasses. • Anomalous behavior of linear and non-linear properties was revealed. • Highest thermal stability was found in (Ge 11.5 Se 67.5 Te 12.5) 70 Sb 30. • Largest non-linearity was found in (Ge 11.5 Se 67.5 Te 12.5) 90 Sb 10. Various non-linear and linear properties of Sb-doped Ge-Se-Te glasses for optoelectronic applications are investigated in present paper. The linear refractive index of prepared samples was obtained by reflectance spectra. Wemple – Di Domenico (WDD) single oscillator model was used for determination of refractive index dispersion and it was also used for extrapolating static refractive index. Optical conductivity and dielectric constants were obtained using linear refractive index, absorption and extinction coefficients. Volume energy (VELF) and surface energy loss (SELF) were also obtained for prepared samples. Nonlinear response of system under investigations are determined by different empirical and semi-empirical formula developed by different researchers. Nonlinear response of refractive index was investigated by the formula proposed by Fournier and Snitzer. The third order susceptibility of the prepared samples were investigated by Tichy and Ticha formulation. Different optical parameters and thermal parameters are investigated for their behavioral change by Sb addition. [ABSTRACT FROM AUTHOR]

Mimicking natural photosynthesis is a promising way to produce fine chemicals, yet there is a need for efficient catalysts. Here, we synthesized a photocatalyst made of self-assembled graphitic carbon nitride/sulfur/cobalt (III) tetraphenyl porphyrin, and we used this photocatalyst for production of the l-glutamate amino acid in 93.6% yield. Regeneration of the 1,4-dihydronicotinamide adenine dinucleotide cofactor under visible light reached 88.3%. [ABSTRACT FROM AUTHOR]

The selective production of fine chemicals using inexpensive solar light continues to be a challenge. As a means to achieve this we report herein the synthesis and development of a perylene-based solar-light-driven photocatalyst (PDA–DAA) obtained by the covalent bonding of perylene tetracarboxylic dianhydride (PDA) with a 2,6-diamino-anthraquinone (DAA) molecule. The photocatalyst/biocatalyst coupled system developed using PDA–DAA as a photocatalyst functions in a highly efficient manner, leading to high NADH regeneration (80.12%), followed by its consumption in exclusive production of l-glutamate (94.16%) from α-ketoglutarate. The present research highlights the development and application of the PDA–DAA photocatalyst for direct formation of l-glutamate under solar light. [ABSTRACT FROM AUTHOR]