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Coordination polymers are a sub-class of coordination complexes that possess unique opto-electronic properties and hence can be utilized for a wide range of applications such as sensing and photocatalysis. Herein, four new coordination polymers (CPs) with formula [Mn2(HL)(NMP)(H2O)2]n (1), [Mn2(HL)(DMA)2(H2O)·2DMA]n (2), [Mn(H3L)(H2O)2]n (3) and [Mn(H3L)(H2O)(4,4′-bipy)]n (4) (H5L = 3,5-bis(3,4-dicarboxyphenoxy) benzoic acid and NMP = N-methyl pyrrolidone) were synthesized under hydrothermal conditions and characterized. The single-crystal X-ray analysis revealed a distorted octahedral geometry around Mn(II) in these CPs and that they form an extended hydrogen bonding and π⋯π stacking interaction-assisted network. Thermogravimetric studies revealed that the CPs, 1, 2, 3 and 4, have variable thermal stability in the range of 82–194 °C. All four complexes exhibited optical semiconducting behavior and hence were used as photocatalysts for the photodecomposition of antibiotics, including chloramphenicol (CAP), nitrofurazone (NFZ), ornidazole (ODZ), oxytetracycline (OXY) and sulfamethoxazole (SMT). Among the CPs, CP 2 exhibited an impressive 91.93% degradation of NFZ within 60 min. The plausible photocatalytic mechanism was explained with the assistance of Hirshfeld surface analysis. [ABSTRACT FROM AUTHOR]

We have reported the synthesis of JC-La2CoO4 magnetic nanoparticles from Jatropha Curcas L. leaf extract in aqueous medium and potential application study in catalytic & Single Molecule Magnets (SMMs). Several techniques were used to investigate the structural, morphological, and elemental composition, particle size, optical properties, catalytic and magnetic properties by XRD, FTIR, SEM, EDAX, XPS, UV–visible and squid magnetic measurement. It was found that the crystallite sizes and grain sizes of JC-La2CoO4 NPs were 11.3 ± 1 and 24.1 ± 1 nm respectively and surface morphology of the nanoparticles looks spherical shape with good surface area. The band gap of JC-La2CoO4 was found to be 4.95 eV indicates good semiconductor in nature. XPS studies shows that La and Co present in + 3 and + 2 oxidation state respectively and suggest the composition formula is La2CoO4 with satisfied all the valency of metal ions. The photocatalytic efficiency of La2CoO4 shows good result against methylene blue (MB) compared to other dyes like MO, NO, RhB in presence of sunlight with rate constant 56.73 × 10–3 min-1 and completely degraded within 115 mints. The importance of JC-La2CoO4 has magnetic properties with antiferromagnetic coupling and SMMs properties with nature. [ABSTRACT FROM AUTHOR]

In the present study, an eco-friendly method was reported for the green synthesis of silver nanoparticles (AgNPs) using Sonchus arvensis (SA) leaf extract. Phytochemical analysis of plant extract revealed the presence of flavonoids, tannins, glycosides, and alkaloids, which might be used as a potential capping, reducing, and stabilizing agent in the process. SA-AgNPs were found to be stable with no evidence of agglomeration after one week. UV-vis spectroscopy showed a salient SPR peak of Ag0 at 440 nm, and the calculated bandgap (3.2 eV) explained the semiconducting behaviour of the NPs. The FT-IR spectra elucidated the functional groups of SA extract attached with Ag0. TEM and XRD revealed the spherical shape of SA-AgNPs with an average particle and crystalline size of 25 ± 5 and 16 ± 1 nm, respectively. A colorimetric method was employed for the quick detection of heavy metals in aqueous medium using SA-AgNPs. The obtained NPs were found to be highly selective and sensitive to Fe3+ and Hg2+ metal ions at a detection limit of 10−3 M and thereby act as noble solid bio-sensors. SA-AgNPs showed strong catalytic efficiency against methylene blue compared to other dyes in the presence of sunlight and completely degraded the dye within 1 hour. This catalytic efficiency was observed to be due to the lower bandgap value (3.2 eV) of SA-AgNPs. [ABSTRACT FROM AUTHOR]

Nanosized iron niobate (FeNbO4) powder with 35-60 nm average particle size has been synthesized through pyrolysis of precursor solution containing iron nitrate, niobium tartarate, and triethanolamine (TEA). The compressed powder exhibits maximum sensitivity to H2 at 250°C and liquefied petroleum gas (LPG) and NH3 at 300°C. The incorporation of platinum (1 wt %) into the nanosized FeNbO4 by impregnation method reduces the operating temperature along with response time and recovery time for sensing H2, LPG, and NH3. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy studies, energy dispersive X-ray analysis, and Brunauer—Emmett—Teller (BET) surface area measurements have been used for characterization of both the compositions produced after heat-treatment at 850°C. Both samples exhibit orthorhombic structure with crystallite sizes, average particle sizes, and specific surface areas 20-24 nm, 35-60 nm, and 48-51 m2/g, respectively, determined from XRD, TEM studies, and BET surface area measurements. [ABSTRACT FROM AUTHOR]

A novel zinc‐based metal–organic framework (Zn‐MOF), designated as [Zn3(L)(bpyp)2(HCOO)3·2DMF·H2O] (1), was synthesized using 2,5‐bis(pyrid‐4‐yl)pyridine (bpyp), 1,3,5‐benzenetricarboxylic acid (H3L), and Zn(CH3COO)2·2H2O in a DMF solution. Single‐crystal X‐ray diffraction analysis revealed that MOF 1 crystallizes in the monoclinic system with a C2/c space group, featuring a (3,5)‐connected binodal network. The structural integrity and characteristics of MOF 1 were confirmed by Fourier transform infrared (FT‐IR), thermal gravimetric analysis (TGA), powder X‐ray diffraction (PXRD), and Brunauer–Emmett–Teller (BET) analyses, showing type IV isotherms indicative of microporous structures. The photocatalytic efficiency of MOF 1 was evaluated for the degradation of various antibiotics under UV light, with nitrofurantoin (NFT) demonstrating the highest degradation rate of 83.9% at an optimal concentration of 40 ppm and catalyst loading of 5 mg. The degradation process followed a pseudo‐first‐order kinetic model with a rate constant of 0.02492 min−1. Radical trapping experiments identified superoxide radicals (O2˙−) and holes (h+) as the predominant reactive species, while hydroxyl radicals (˙OH) played a negligible role. Reusability tests over four cycles confirmed the stability and durability of MOF 1, with consistent photocatalytic performance and unchanged structural morphology as evidenced by PXRD and SEM analyses. The proposed mechanism involves photoinduced electron–hole pair generation, with subsequent formation of reactive oxygen species (ROS) facilitating NFT degradation. This study highlights MOF 1 as a promising photocatalyst for environmental remediation, specifically for the efficient degradation of pharmaceutical contaminants in aquatic systems, providing insights into its structural properties, photocatalytic activity, and underlying degradation mechanisms. [ABSTRACT FROM AUTHOR]

Hedychium coronarium (Hc) (commonly known as Gulbakawali) leaf extract was used for the stable and sustainable green synthesis of silver nanoparticles (Hc-AgNPs), which were biodegradable and non-toxic. Hedychium coronarium leaf extract was used as a reducing agent to stabilize the Hc-AgNPs by converting Ag + to Ag 0 without adding any capping agent. It demonstrated stability for up to six months, and no agglomeration was observed. The Hc-AgNPs were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), ultraviolet-visible spectrophotometry, and fluorescence spectroscopy analysis. The UV-visible spectrum supported the formation of stable Hc-AgNPs by displaying a strong surface plasmon resonance (SPR) peak at 440 nm. FT-IR spectra showed the functional groups present in the leaf extract of Hedychium coronarium , which was the primary source of secondary metabolites attached to Ag 0 . XRD analysis revealed a distinct 2 θ peak of Hc-AgNPs at 38.15°, indicating a face-centred cubic structure with a crystallite size of 22.6 ± 1 nm at the (111) plane. Moreover, TEM demonstrated the spherical morphology of the Hc-AgNPs with an average particle size of 22.42 ± 1 nm. The photophysical characteristics of the Hc-AgNPs, as highlighted by their UV-vis and fluorescence characteristics, revealed their semiconducting nature with an impressive band gap ( E g ) value of 3.78 eV. Fascinatingly, the fluorescence activity of Hc-AgNPs at 504 nm showed a broad emission band corresponding to the absorption band at 251 nm. We performed the selective colorimetric sensing of Sn 2+ metal ions using Hc-AgNPs, which demonstrated a detection limit of 10 -3 M, suggesting their potential as very good solid biosensors. Interestingly, the Hc-AgNPs showed antifungal activity, which has not been reported before. Specifically, the results showed that the Hc-AgNPs had a higher fungitoxicity effect against Aspergillus flavus (59.58 ± 3.68) than against Fusarium oxysporum (57.93 ± 4.18). The antibacterial activity of the Hc-AgNPs was evaluated against three Gram-negative phytopathogenic bacteria: Xanthomonas oryzae ( X. oryzae ), Ralstonia solanacearum ( R. solanacearum ), and Erwinia carotovora ( E. carotovora ), showing effective inhibition zones of 16.33 ± 0.57, 15.33 ± 0.57, and 14.33 ± 0.57 mm, respectively. These results indicate that the Hc-AgNPs could inhibit these phytopathogenic bacteria with varying degrees of effectiveness in the order of X. oryzae > R. solanacearum > E. carotovora ., Competing Interests: The authors declare no conflict of financial interest., (This journal is © The Royal Society of Chemistry.)

Nowadays, environmentally friendly, low-cost-effective, and sustainable electrocatalysts used widely for hydrogen and oxygen evolution reactions have come into the limelight as a new research topic for scientists. This study highlights the preparation of two unique and symmetrical dinuclear Cu (II) and Mn (III) bifunctional catalysts by a facile simple slow evaporation and diffusion route. [C 32 H 24 Cu 2 F 4 N 4 O 4 ] (1) and [C 32 H 24 Mn 2 F 4 N 4 O 4 ] (2) both have monoclinic ( C 2/ c (15)) crystal systems, with oxidation states +2 and +3, respectively. Prominent SPR peaks at 372 and 412 nm indicate an M-L charge transfer transition in both complexes. The synthesized electrocatalysts display exceptional catalytic activity for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Complex 1 exhibits enhanced hydrogen generation in 0.5 M H 2 SO 4 with a small overpotential of 216 mV at -10 mA cm -2 along with a significantly lower Tafel value of 97 mV/dec compared to Complex 2 . Moreover, Complex 1 is highly active for the OER in 1 M KOH with a small Tafel slope of 103 mV/dec and a low overpotential of 340 mV to acquire 10 mA cm -2 current density, compared to Complex 2 . Complex 1 and Complex 2 remain stable up to 20 h in acidic electrolyte and up to 36 h and 20 h in the basic electrolyte, respectively.

Novel metal-like cerium- and zirconium-doped ZnO photocatalysts were prepared herein with various proportions of molar ratios via a cost-effective co-precipitation method. The effects of novel metal doping on the photocatalytic activity of ZnO were studied. Various techniques were used to investigate the structural, morphological, and elemental composition, particle size, optical properties, and catalytic activity of the synthesized photocatalysts. It was found that the crystallite size and particle size of the nano alloy oxides were 15.12 ± 1 and 5 ± 1 nm, respectively, and the surface morphology of the nanoparticles indicated a satisfactory surface area. Among all synthesized nanocomposites, Ce x Zr x Zn x O 5 ( x = 1) [CZ 1 Z 2 -A] exhibited satisfactory photo-oxidation activity against naphthol orange (NO) under sunlight with a rate constant of 57.5 × 10 -3 min -1 . The effects of pH, inorganic salts, dye concentrations, and catalytic dosage on NO degradation were studied. A probable mechanistic pathway for the degradation of NO in the presence of CZ 1 Z 2 -A was proposed, and studies of sacrificial agents indicated that superoxide radical anion (O 2 ˙ - ) was the main accountable active species in NO degradation. In addition, CZ 1 Z 2 -A exhibited excellent recyclability potential, and XRD studies revealed that there was no change in the crystal structure before or after degradation, which indicated its high stability. The intriguing finding was that Ce- and Zr-doped ZnO did not exhibit satisfactory catalytic performance in the photo-oxidation of NO. However, the composite formula of Ce x Zr x Zn x O 5 ( x = 1) with a 1 : 1 : 1 ratio of metal ions offered excellent catalytic activity., Competing Interests: The authors declare no financial conflicts of interest., (This journal is © The Royal Society of Chemistry.)

In this work, we report the redox properties in organic catalytic transformation and antibacterial activity of novel Cu x Ag x Zn 1-2 x O nanocomposites. Cu- and Ag-doped ZnO [Cu x Ag x Zn 1-2 x O ( x = 0.1)] (CAZ), Cu-doped ZnO [Cu x Zn 1- x O ( x = 0.1)] (CZ), and Ag-doped ZnO [Ag x Zn 1- x O ( x = 0.1)] (AZ) were prepared via a chemical co-precipitation method. The synthesized nanocomposites were characterized using different spectroscopic techniques. The catalytic activity of CAZ, CZ, and AZ was examined for the reduction of 4-nitrophenol (4-NP) and 4-nitroaniline (4-NA) in the presence of NaBH 4 in an aqueous medium. The photocatalytic oxidation efficiency of these catalysts was also observed against naphthol orange (NO) under ultraviolet light. It was found that the catalytic reduction and oxidation efficiency of CAZ is higher than that of CZ and AZ in 4-NP/4-NA and NO in a water solvent, respectively. The antibacterial property of CAZ was also studied against Gram-positive and Gram-negative bacteria by agar well diffusion and the minimum inhibitory concentration methods. It was found that CAZ shows better antimicrobial activity compared to its parental Cu(NO 3 ) 2 ·3H 2 O, AgNO 3 , and ZnO. Therefore, the incorporation of Cu and Ag into ZnO increases its catalytic and antimicrobial activity remarkably. Fourier-transform infrared and X-ray diffraction (XRD) studies of CAZ indicate the incorporation of Cu and Ag into the lattice of ZnO. The phase structure of CAZ was wurtzite hexagonal, and the average crystallite size was 93 ± 1 nm measured from XRD. The average grain size and particle size of CAZ were found to be 200 and 100 ± 5 nm originating from SEM and transmission electron microscopy studies, respectively. The optical energy band gap of CAZ is 3.15 eV, which supports the excellent photocatalyst under UV light. CAZ also exhibits good agreement for photoluminescence properties with a high intensity peak at 571 nm, indicating surface oxygen vacancies and defects which might be responsible for higher photocatalytic activity compared to others. The nanocomposite shows excellent reusability without any significant loss of activity., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Schiff base ligand N,N'-bis( o -vanillinidene) ethylenediamine ( o -VEDH 2 ) has been employed to synthesize new [Co II Co IV ( o -VED)(OAc) 2 (μ 2 -OAc)(OMe)]•MeOH ( 1 ) and [ Co 2 IV ( o -VED) 2 (en) 2 (NCCH 3 )(OCH 3 )][La(NO 3 ) 6 ]( NO 3 - )•2MeOH•MeCN•H 2 O ( 2 ) metal-organic frameworks (MOFs) that have interesting single molecule magnets (SMMs) property. The synthesized complexes are characterized by single crystal X-ray diffraction, fourier transform infrared spectroscopy (FTIR), UV-visible spectroscopy, and squid magnetic measurement. Single crystal X-ray data show that both complexes crystallize in the monoclinic crystal system with P 2 1 / c (14) and P 2 1 / n (14) space groups and generate unique MOF-like structures. Overall, both the metal centers of 1 form octahedral geometry with a butterfly core structure. Variable temperature ( T ) and field ( H ) solid-state direct-current (dc) and alternative current (ac) magnetic susceptibility measurements were performed on both the complexes over 1.8 to 300 K, which exhibited a ground state spins (S) of 4 and 5 of complexes 1 and 2 , respectively. The AC out-phase and in-phase properties of complexes show SMMs. Other properties such as optical, sensing, and DNA-binding interactions were also investigated by the complexes. Complexes 1 and 2 have energy band gaps of 3.7 and 3.03 eV indicating semiconductor properties. Simultaneously, complex 1 was found to sense H 2 O 2 with a rate constant ( k ) = 1.59 × 10 -4 s -1 , whereas complex 2 was found to bind with calf-thymus-DNA by intercalation mode with binding constant ( K b ) of 1.22 × 10 5 M -1 ., (Copyright © 2020 Ghosh, Jana and Ghorai.)

A novel bimetallic and reusable Y 2 ZnO 4 nanocatalyst was synthesized by a simple coprecipitation method. The prepared nanocatalyst exhibited dual catalytic activity and was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). The average crystallite and grain sizes were found to be 17 ± 1 and 10 ± 2 nm, respectively. On the one hand, the catalytic activity of the nanocatalyst was studied for the Knoevenagel condensation reaction of aromatic aldehydes with active methylene compounds, such as ethyl cyanoacetate and malononitrile, under microwave irradiation and solvent-free conditions. On the other hand, the nanoparticles also showed faster photocatalytic activity against methyl orange (MO) compared to other dyes. The nanocatalyst was easily recoverable by a simple filtration method and was recycled without any significant loss of catalytic activity. The advantages of this nanocatalyst were a simple workup procedure, high reaction yields, solvent-free conditions, reusability, and a short reaction time under green reaction conditions., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

O-Vanillin and ethylenediamine were used for the synthesis of N , N '-bis(O-vanillinidene)ethylenediamine (O-VEDH 2 ) Schiff base ligand, which was characterized by UV-visible and 1 H NMR spectroscopy. The Schiff base ligand O-VEDH 2 has been employed to synthesize novel [C 18 H 22 FeN 2 O 6 ]NO 3 ( 1 ) and C 18 H 16 CuN 2 O 5 ( 2 ) complexes by the simple slow evaporation method. The single crystals were characterized by X-ray crystallography, as well as Fourier-transform infrared and UV-visible spectroscopy techniques. Complexes 1 and 2 crystallize in monoclinic and orthorhombic space groups with P 121/ n 1 (14) and Pnma (62) point groups, respectively, and both show metal-organic frameworks like structures. Complexes 1 and 2 have optical band gaps of 4.1 and 2.9 eV, respectively, indicating their semiconducting properties. The dye degradation activity and H 2 O 2 sensing of the complexes 1 and 2 were determined in different conditions. The photocatalytic test was performed in the presence of sunlight, methylene blue (MB), and complexes 1 and 2 . An interesting result was obtained that complex 2 has degradation ability against MB and the rate constant ( K ) is 5.46 × 10 -5 s -1 , whereas complex 1 has H 2 O 2 sensing properties. Both complexes are bound to Calf-thymus DNA by intercalation binding mode, and binding constants ( K b ) of complexes 1 and 2 are 3.77 × 10 3 and 1.49 × 10 4 M -1 , respectively., Competing Interests: The authors declare no competing financial interest., (Copyright © 2019 American Chemical Society.)