Design, One-Step Highly Selective Synthesis and Enhancing Insecticidal Activity and Photo-Self-Degradation of Phenylpyrazole Esterified Derivatives as GABA and nACh Receptor Inhibitors.

In the pursuit of novel insecticides with high activity and a unique mode of action on the GABA receptor, a series of phenylpyrazole esterified derivatives (PEs) were synthesized using an improved Pinner reaction with high selectivity. Lewis acid catalysis was employed in a one-step solvent-thermal method to convert the cyano group of fipronil into an ester unit. FeCl3 was found to exhibit the highest selectivity for PEs synthesis, yielding PEs at 96.4%, with the byproduct being phenylpyrazole amide (PE0) at 2.1%. Initial biological assays indicated superior insecticidal activity of the target compounds against Plutella xylostella and Mythimna separata compared to fipronil. Particularly, the smaller and shorter ester units, PE3, PE5, and PE8, demonstrated 2-2.5 times higher insecticidal activity against P. xylostella than fipronil. The higher activity of ester units compared to amide and acylhydrazone units can be attributed to the enhanced lipid solubility of PEs. Additionally, it may be due to the impact of PEs on the neurotransmitter nACh or the coordination of calcium and chloride ions with the ester's -C═O and -O- bonds, blocking the chloride ion channel. Hydrophobic parameters were confirmed by reversed-phase high-performance liquid chromatography (HPLC), indicating the enhanced lipophilicity conferred by the ester units of PEs. Molecular docking and CoMFA analysis preliminarily validated the strong interactions and structure-activity relationships between PEs and the GABA receptor and nACh receptor in P. xylostella. Furthermore, under simulated natural sunlight, PEs exhibited photodegradation capabilities, transforming back into fipronil parent fragments and enhancing their insecticidal activity. Moreover, PEs displayed excellent fluorescent properties, enabling self-detection of residues. These research findings provide new insights and directions for the development of efficient pesticides, with potential wide applications in the fields of medicine and biosensors.

Structural Diversity Design, Four Nucleation Methods Growth and Mechanism of 3D Hollow Box TiO2 Nanocrystals with a Temperature-Controlled High (001) Crystal Facets Exposure Ratio.

Three-dimensional (3D) hollow box TiO2 nanocrystals with structural diversity have been designed and grown by four nucleation methods, including the acid dissolution denucleation method with Fe2O3 as heterogeneous nucleation, the topological phase transition method, the sonic solvothermal method, and the air atmosphere sintering method with TiOF2 as homogeneous nucleation. Through full morphology analysis and structural characterization, reasonable growth mechanisms of 3D hollow box TiO2 nanocrystals were proposed, including nucleation dissolution, Oswald ripening, and hydrolysis reactions. It was found that the high energy (001) crystal facets exposure ratio was closely correlated with reaction temperature of four nucleation-methods, which even reached 92% for the first time. Under simulated sunlight irradiation, their hydrogen production performance and photocatalytic degradation efficiency on model dye molecules rhodamine B (RhB) and methylene blue (MB) were evaluated, and as-prepared hollow box TiO2 nanocrystals prepared by the sonic solvothermal method exhibited the best photocatalytic performance, with a hydrogen production rate of 93.88 µmol/g/h. Within 70 min, the photocatalytic degradation rates of RhB and MB reached 96.59 and 75.25%, respectively, which were 5.74 and 5.54 times that of P25. Their properties are closely connected with the orderly cubic and hierarchy configuration structure of hollow box TiO2 nanocrystals, which have a high exposure ratio of (001) facet controlled by reaction temperatures, thereby greatly improving the photocatalytic activity. This study provides a classic reference for improving the properties of hollow box TiO2 nanocrystals through structural diversity design and various methods of nanocrystal growth.

Design and One-Pot Ultrasound Synthesis of Inorganic Base-Promoted Fluorescent Ligand-Gated Ion Channel Fused Arylpyrazole Sulfonamide Skeletons to Enhance Phloem Mobility and Insecticidal Activity as GABA and nACh Receptors Inhibitors.

Ligand-gated ion channels are essential in living organisms, and sulfonamides have antibacterial effects and can be readily coordinated with metal ions with good biological activity. A series of fluorescent ligand-gated ion channel fused arylpyrazole sulfonamide skeletons (APSnM) were synthesized based on a one-pot ultrasound strategy promoted by an inorganic base. APSnM had a high fluorescence quantum yield and a large Stokes shift in ethanol solvent. The ligand bonded ions took on a different color from the ligand and can be used as a probe to detect their own residue on plant surfaces. Their hydrophobic parameters and the fluorescence distribution in Chinese cabbage leaves indicated that APSnM significantly increased the phloem mobility of the plant. The insecticidal activity of APS3Na was higher (LC50 = 7.2423 µg/mL) than that of fipronil (15.2312 µg/mL) against Plutella xylostella, and the mechanism of high insecticidal activity of APS3Na was simulated by molecular docking, which confirmed its strong interactions with the GABA and nACh receptors of Plutella xylostella. Analysis of the crystal structure of these ligand-gated ion channels further confirmed the consistency of their structure and biological activity.

One pot solvothermal synthesis of novel fluorescent phloem-mobile phenylpyrazole amide pesticides fused olefin moieties to enhance insecticidal bioactivities and photodegradation properties.

In order to find a novel type of fluorescent phloem-mobile insecticides, a facile one-pot solvothermal strategy via fipronil addition-elimination substitution reaction with the corresponding acyl chloride derivatives has been employed to construct series of phenylpyrazole amide derivatives (PAs) fused olefin moieties in high yields. The investigation for insecticidal bioactivities of PAs against 3rd instar larvae of Plutella xylostella exhibited better activities than that of fipronil, which can be elucidated by enhanced phloem mobility and calcium ions' coordination with amide N-C=O, CC double bonds and chloride ions, extended conjugate moieties and decreasing steric hindrance of the stereoscopic structure. The introduction of amide units conferred phloem mobility to PAs, which was evaluated by the hydrophobic parameters determined with reversed-phase HPLC through the chromatographic capacity factor. By introducing conjugate moieties and organic chromophore into phenylpyrazole parent structure to increase their conjugation degree and light absorption abilities, PAs exhibited good photodegradation properties. The relationships between extended conjugate moieties of parent structure, electronegativity of substituted groups and photodegradation properties have been discussed. The olefin units connected to PAs caused electronic absorption and fluorescent wavelengths bathochromic shifted. Under simulated solar irradiation, PAs can be reconverted into fipronil parent fragments by photodegradation, thereby enhancing their insecticidal activity. The fluorescent quantum yields of PAs were almost 4 times that of fipronil, which also laid a foundation for the natural degradation and fluorescence detection of insecticide residues.

A Facile One-Pot Synthesis of Biomimetic Photocatalyst Zn(II)-Porphyrin-Sensitized 3D TiO2 Hollow Nanoboxes and Synergistically Enhanced Visible-Light Degradation.

A serials of biomimetic photocatalyst zinc(II) meso-tetra(4-carboxyphenyl)porphyrinato (ZnTCP)-sensitized 3D hierarchical TiO2 hollow nanoboxes (TiO2-HNBs) assembled by six ordered nanosheets with dominant {001} facets exposure (ZnTCP@TiO2-HNBs) have been successfully synthesized by a facile one-pot solvothermal method via a topological transformation process with TiOF2 as template. Infrared spectra (IR), UV-vis spectroscopy, and X-ray photoelectron spectroscopy (XPS) confirmed that ZnTCP played a decisive role in constructing 3D hollow nanoboxes through the formation of ester bond combined to TiO2-HNBs, which also provided a transferring photo excited electrons bridge to sensitize TiO2-HNBs for enhancing visible-light response. Due to the superior sensitization and biomimetic activity of ZnTCP, the photodegradation rate of rhodamine B (RhB) of as-prepared ZnTCP@TiO2-HNBs with ZnTCP/TiOF2 mass ratio of 2% (T-2p) improves 3.6 times compared to that of TiO2-HNBs with a degradation yield of 99% for 2 h under simulated sunlight irradiation (> 420 nm). The enhanced photodegradation ability was attributed to synergistic visible photocatalytic mechanism of biomimetic catalyst, which can not only produce hydroxyl radical (•OH) and superoxide radical (•O2-) coming from the excitation process of ZnTCP sensitized TiO2-HNBs, but also generate singlet oxygen (1O2) that was only provided by biomimetic enzyme porphyrins. Furthermore, the photocatalyst showed good recycling stability and dispersibility after five rounds, ascribed to ZnTCP strong chemical bonding to the support TiO2-HNBs. By means of electrochemical cyclic voltammetry analysis, the effect of central zinc ions and parent porphyrin rings on the redox property of biomimetic catalyst was studied.

One-step topological preparation of carbon doped and coated TiO2 hollow nanocubes for synergistically enhanced visible photodegradation activity.

Various three-dimensional TiO2 hollow structures have attracted strong scientific and technological attention due to their excellent properties. 3D hierarchical TiO2 hollow nanocubes (TiO2-HNBs) are not good candidates for industrial photocatalytic applications due to their large energy gap which is only activated by UV light. Herein, visible-light-responsive carbon doped and coated TiO2-HNBs (C@TiO2-HNBs) with a dominant exposure of {001} facets have been prepared via a template-engaged topotactic transformation process using facile one-step solvothermal treatment and a solution containing ethanol, glucose and TiOF2. The effects of reaction time and glucose/TiOF2 mass ratio on the structure and performance of C@TiO2-HNBs were systematically studied. We found that glucose played an important role in providing H2O during the topological transformation from self-templated TiOF2 cubes into 3D hierarchical TiO2 hollow nanocubes versus dehydration reactions, where its main function was as a carbon source. Coated carbon was deposited predominantly on the surface as sp2 graphitic carbon in extended p conjugated graphite-like environments, and doped carbon mainly replaced Ti atoms in the surface lattice to form a carbonate structure. The results were confirmed using TEM SEM, EDS, XRD, FT-IR, XPS and Raman spectroscopic studies. The C@TiO2-HNBs achieved greatly improved RhB photodegradation activity under visible light irradiation. The catalyst prepared with glucose/TiOF2 at a mass ratio of 0.15 (T24-0.15) showed the highest photodegradation rate of 96% in 40 min, which is 7.0 times higher than those of the TiO2-HNBs and P25. This new synthetic approach proposes a novel way to construct carbon hybridized 3D hierarchical TiO2 hollow nanocubes by combining two modification methods, "element doped" and "surface sensitized", at the same time.

Rhodium-Catalyzed Stereoselective Intramolecular [5 + 2] Cycloaddition of 3-Acyloxy 1,4-Enyne and Alkene.

The first rhodium-catalyzed intramolecular [5 + 2] cycloaddition of 3-acyloxy 1,4-enyne and alkene was developed. The cycloaddition is highly diastereoselective in most cases. Various cis-fused bicyclo[5.3.0]decadienes were prepared stereoselectively. The chirality in the propargylic ester starting materials could be transferred to the bicyclic products with high efficiency. Electron-deficient phosphine ligand greatly facilitated the cycloaddition. Up to three new stereogenic centers could be generated. The resulting diene in the products could be hydrolyzed to enones, which allowed the introduction of more functional groups to the seven-membered ring.

The role of endophytic fungal individuals and communities in the decomposition of Pinus massoniana needle litter.

The role of fungal endophytes (FEs) as "pioneer" decomposers has recently been recognized; however, the extent to which FEs contribute to litter loss is less well understood. The genetic and enzymatic bases of FE-mediated decomposition have also rarely been addressed. The effects of populations and individuals (with an emphasis on two dominant Lophodermium taxa) of FEs on needle-litter decomposition were assessed for Pinus massoniana, a ubiquitous pine in southern China. Data from in vivo (microcosm) experiments indicated that the percentage of litter-mass loss triggered by FEs was linearly correlated with incubation time and approached 60% after seven months. In vitro decomposition tests also confirmed that endophytic Lophodermium isolates caused 14-22% mass loss within two months. Qualitative analysis of exoenzymes (cellulase and laccase, important for lignocellulose degradation) revealed that almost all of the Lophodermium isolates showed moderate or strong positive reactions. Furthermore, partial sequences of ß-glucosidase (glycoside hydrolase family 3, GH3), laccase, and cellobiohydrolase (GH7) genes were amplified from Lophodermium isolates as "functional markers" to evaluate their potential for lignocellulolytic activity. Three different genes were detected, suggesting a flexible and delicate decomposition system rich in FEs. Our work highlights the possibility that the saprophytism and endophytism of FEs may be prerequisites to initiating rapid decomposition and thus may be key in Fes' contribution to litter decomposition, at least in the early stage. Potential indicators of the presence of core fungal decomposers are also briefly discussed.

Effect of ester on rhodium-catalyzed intermolecular [5+2] cycloaddition of 3-acyloxy-1,4-enynes and alkynes.

We systematically examined the effect of different esters on the rhodium-catalyzed intermolecular [5+2] cycloaddition of 3-acyloxy-1,4-enynes and alkynes with a concomitant 1,2-acyloxy migration. Significant rate acceleration was observed for benzoate substrates bearing an electron-donating substituent. The cycloaddition can now be conducted under much more practical conditions for most terminal alkynes.

Synthesis and electronic absorption and fluorescence of 2-arylbenzothiazole derivatives.

A series of new 2-arylbenzothiazoles have been prepared in high yields by Jacobson's cyclization condensation of 2-aminobenzenethiol with benzoyl chloride or benzaldehyde derivatives under three different routes. These compounds have been fully characterized by EA, IR, NMR and MS. The electronic absorption and fluorescence of these compounds have been systematically investigated for the first time. The relationships between their photophysical properties and structures have been discussed. The alteration of absorption and emission wavelengths can be elucidated by Hammett's substituent constants.

Novel, highly efficient blue-emitting heteroleptic iridium(III) complexes based on fluorinated 1,3,4-oxadiazole: tuning to blue by dithiolate ancillary ligands.

Novel blue-emitting phosphorescent iridium(III) complexes with fluorinated 1,3,4-oxadiazole derivatives as cyclometalated ligands and dithiolates as ancillary ligands have been synthesized and fully characterized; highly efficient OLEDs have been achieved using these complexes in the light-blue to blue-emitting region.

Di-mu-chloro-bis[bis[2,5-bis(4-methoxyphenyl)-1,3,4-oxadiazole-kappa2C2',N]iridium(III)] dichloromethane disolvate.

In the title compound, [Ir2(C16H13N2O3)4Cl2].2CH2Cl2, the two Ir atoms, 3.7075 (6) angstroms apart, are bridged by two Cl atoms which straddle a twofold axis of rotation through the two Ir atoms. Each Ir centre resides in a distorted octahedral environment completed by two chelating 2,5-bis(4-methoxyphenyl)-1,3,4-oxadiazole ligands, with trans-N-N and cis-C-C dispositions. In the stacking structure, there are two types of hydrogen bonds, involving the methoxy substituent, an N atom of the oxadiazole ring and the dichloromethane solvent molecules.