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Picric acid is known as one of the most dangerous explosive materials and it has become one of the main pollutants in soil and, inter alia, groundwater. To date, many organic or inorganic probes have been reported to detect picric acid, especially in organic solvent systems. Nonetheless, the detection and adsorption of trace (sub-ppm or ppb level) picric acid in aqueous media remain challenging. Herein, we describe the facile synthesis of a tetraphenylethylene-based superphane cage via [6 + 2] condensation of dialdehyde and hexakis-amine, followed by a NaBH4–mediated reduction. This purely covalent organic cage was found able to show aggregation enhanced emission in a mixture of tetrahydrofuran and water (1:9, v/v), which can be utilised as a probe for detection of picric acid with ultrahigh sensitivity (as low as 0.9 ppb) and selectivity (against other tested nitroaromatic compounds). More importantly, this new superphane cage can serve as a new nonporous amorphous superadsorbent (NAS) material for adsorption of picric acid with an exceptional maximum uptake capability of 454 mg g−1. It also proved able to eliminate trace picric acid from aqueous media with up to 99% removal efficiency, meeting the discharge standard (<1.0 ppb). As such, we believe that this study offers new insight into the design and synthesis of NAS-based advanced materials for sensitive and selective detection and adsorption of trace pollutants from complex aqueous wastes. [ABSTRACT FROM AUTHOR]

Carbon xerogel was prepared by a sol–gel technique by mixing formaldehyde with dissolved resorcinol in acetone solution using picric acid as a catalyst, followed by pyrolysis treatment at the desired temperature. X-ray diffraction analysis revealed that the obtained product has an amorphous phase, with an average grain size of approximately 2 nm. Scanning electron microscopy showed the existence of a mesoporous structure in the resorcinol–formaldehyde (RF) matrix with a pore size of about 50 nm. The electrical measurements carried out on our material showed interesting results. In fact, DC conductivity indicated that the xerogel is transformed from an insulating phase to a carbon-conducting phase under the pyrolysis temperature effect. The current–voltage (I–V) characteristics of the sample prepared at 650°C show different regions—an ohmic region at low applied voltages and a negative differential resistance (NDR) region at higher voltages, with the NDR phase appearing above a threshold voltage. Also, a hysteresis effect depending on the synthesis and measurement parameters was observed. The observed behaviors are explained in terms of the filament formation phenomenon and the Joule heating effect. These interesting behaviors are promising for threshold switching and neuromorphic computing applications. [ABSTRACT FROM AUTHOR]

The combination of an optical probe and single-drop direct immersion microextraction (DI-SDME-OP) was used for the preconcentration and subsequent spectrophotometric determination of rhodamine 6G (Rh6G). The developed method is based on the formation of an ionic associate between Rh6G and picric acid at pH 3.0 and its extraction with amyl acetate. A microdrop of the organic phase was stably placed in the hole of an optical probe immersed in the sample solution. The absorbance of the extraction phase was monitored at 534 nm. The proposed method combines in a single step several stages of the analytical procedure, such as pre-concentration, phase separation, transfer of the extraction phase to the instrument and online measurement. The sensitivity of the proposed approach is not inferior to existing microextraction methods involving the combination of liquid-phase or solid-phase extraction with spectrophotometry or HPLC with a UV-Vis detector. The evaluation of the greenness of the developed method carried out by the AGREE method (0.58 points) showed that it outperforms other similar existing techniques using this parameter. The calibration plot for the determination of Rh6G by the DI-SDME-OP method was linear over the range of 10–500 nM with a correlation coefficient of 0.9956. The limit of detection was 3.4 nM. The accuracy and applicability of the method were evaluated by the determination of Rh6G in natural waters and lipstick. [ABSTRACT FROM AUTHOR]

A novel tellurium (Te) containing fluorophore, 1 and its nickel (2) and copper (3) containing metal organic complex (MOC) have been synthesized to exploit their structural and optical properties and to deploy these molecules as fluorescent probes for the selective and sensitive detection of picric acid (PA) over other commonly available nitro‐explosives. Furthermore, density functional theory (DFT) and single crystal X‐ray diffraction (SCXRD) techniques revealed the inclusion of "soft" Tellurium (Te) and "hard" Nitrogen (N), Oxygen (O) atoms in the molecular frameworks. Owing to the presence of electron rich "N" and "O" atoms along with "Te" in the molecular framework, 1 could efficiently and selectively sense PA with more than 80 % fluorescence quenching efficiency in organic medium and having detection limit of 4.60 μM. The selective detection of PA compared to other nitro‐explosives follows a multi‐mechanism based "turn‐off" sensing which includes photo‐induced electron transfer (PET), electrostatic (π‐π stacking and π‐anion/cation) interaction, intermolecular hydrogen bonding and inner filter effect (IFE). The test strip study also establishes the sensitivity of 1 for detection of PA. [ABSTRACT FROM AUTHOR]

Synthesis of a highly fluorescent binuclear ZnII-metallacycle (1) based on a novel Schiff base (H2L) viz. 2,7-dimethylacridine-3,6-diyl-bis(azaneylylidene)-bis(methaneylylidene)-bis(3-diethylaminophenol) is described and characterized through various spectral (FT-IR, 1H-NMR and HRMS) methods followed by structural authentication of 1 by single crystal X-ray diffraction analysis. The ZnII-metallacycle 1 is strategically incorporated with four –N(C2H5)2 groups, which enables it to exhibit excellent selectivity towards picric acid (PA) among other nitro aromatic compounds (NACs) in the form of fluorescence quenching (71%). The vital role of –N(C2H5)2 is substantiated by performing UV-vis, fluorescence, and 1H-NMR spectral and DFT studies on 1 with all NACs and comparing it with a model complex 2, which lacks the –N(C2H5)2 group. Studies revealed that the quenching involved a static and dynamic mechanism with a quenching constant (KSV) of 3.44 × 104 M and LOD of 7.62 × 10−8 M. The static pathway involved the formation of a H-bonded ground state ion pair complex of 1 and PA [1-(C2H5)2N–H+⋯O−–picrate] and the dynamic quenching is attributed to energy transfer from the excited state of 1 to the ground state of PA facilitating polar–polar resonance between them. Conclusively, 1 has been demonstrated as a significant probe, which can be employed for naked eye detection of PA in solid and liquid phases. [ABSTRACT FROM AUTHOR]

Based on the electron-deficient property of picric acid (PA), two neutral Ir(III) complexes 1 and 2 modified with the electron-rich carbazolyl groups were synthesized and characterized. Both 1 and 2 exhibit aggregation-induced phosphorescence emission (AIPE) properties in THF/H2O. Among them, 2 is extremely sensitive for detecting PA with a limit of detection of 0.15 μM in THF/H2O. Furthermore, the selectivity for PA is significantly higher compared to other analytes, enabling the efficient detection of PA in four common water samples. The density functional theory calculations and the spectroscopic results confirm that the sensing mechanism is photo-induced electron transfer (PET). [ABSTRACT FROM AUTHOR]

2-Pyrazoline containing benzothiazole ring 2-[1-(1,3-benzothiazol-2-yl)-5-(4-methoxyphenyl)-4,5-dihydro-1H-pyrazol-3-yl]phenol (BP) have been synthesized for the effective identification of picric acid over other competing nitro compounds using fluorescence technique. The pyrazoline BP showed quenching efficiency as high as 82% comparative to other nitro aromatics. The limit of detection and limit of quantification were found to be 1.1 μM and 3.3 μM. The possible mechanism with the quenched PA detection efficiency was based on fluorescence energy transfer and photoinduced electron transfer. Moreover, the observed results were supported by the optimized structures of the compounds using the DFT/B3LYP/6-311G/LanL2DZ method. Eventually, the pyrazoline derivative BP was further utilized for natural water samples, showing recoveries in the 87.62–101.09% and RSD was less than 3%. [ABSTRACT FROM AUTHOR]

Introducing conjugated Mesoporous Perylene and triphenylamine based Triazine oligomers (M-TPI and D-TPI) for N2 adsorption and fluorescence detection of explosive materials such as Picric acid. This has been synthesized from perylene 3,4,9,10-tetracarboxylic dianhydride with mono and di amino triazine and triphenylamine based compound using a simple polycondensation route. These oligomers are well analysed towards FT-IR, Solid-state NMR (CP-MAS), and HRMS technique. These oligomers have shown good thermal stability up to 280 ˚C from TGA analysis. The mesoporous of these oligomers was recognized from BET N2 adsorption/desorption measurements and showed pore size and volume increased from 1.3 to 2 nm and 0.002–0.08 cm3/g before and after pyrolysis. Photophysical properties (UV–Vis and Fluorescence) reveal that absorption at 350 nm and emission at 513 nm and 505 nm. The optical band gap was found to be 1.7 eV and 1.6 eV and it was well correlated with DFT data. These oligomers dealt with polar solvents and observed a Bathochromic shift of fluorescence emission. In-depth studies of oligomers with various solvent fractions (THF/Water), luminescence intensity was increased leading to aggregation-induced enhanced emission (AIEE), and specifically 60–70% fractioned oligomers showed enormous emission. Further analysis from FE-SEM studies showed that the particles are well aggregated, and the size was measured in the range of 0.67–2.6 µm. AIEE helped to detect explosives (particularly picric acid) and the LOD determined as 1.48 × 10–6 M and 1.196 × 10–7 for M-TPI and D-TPI oligomers. These oligomers underwent practical application on real-water samples, demonstrating excellent recovery rates. These results highlight their efficacy for explosive applications, indicating their potential for significant real-world impact. Hence, the synthesized oligomers are well deserved for gas adsorption and explosive applications. [ABSTRACT FROM AUTHOR]

Abstract In recent years, using nanomaterials based on multi-wall carbon nanotubes (MWCNT) through the activation of peroxymonosulfate (PMS) has attracted more attention to the degradation of organic pollutants. This research presented a new route for the synthesis of MWCNT/CoMn2O4 nanocomposite for the degradation of picric acid using advanced oxidation processes (AOPs). Firstly, CoMn2O4 nanoparticles were prepared and then loaded on MWCNT using ultrasonic waves. The results of various analyzes confirmed the successful loading of nanoparticles on carbon nanotubes. As the degradation process proceeds through oxidation processes, the high electronic conductivity of MWCNT and the active sites of Mn and Co in the nanocomposite play an essential role in activating PMS to generate reactive oxygen species (ROS). An investigation of the reaction mechanism in different conditions showed that the highest speed of picric acid decomposition in the presence of nanocomposite (98%) was in 47 min. However, the scavenger test showed that HO· and SO4 ·− radicals are more important in the degradation process. Meanwhile, the results showed that removing picric acid using MWCNT/CoMn2O4 was more effective than CoMn2O4 alone and confirmed the interaction effect of MWCNT nanotubes with AB2O4 nanocatalyst.

Two isostructural rare earth metal–organic frameworks, namely [Re2(BBTC)(DMF)5Cl2]·2DMF·H2O [BBTC4– = 1,1'-butadiynebenzene-3,3',5,5'-tetracarboxylate, Re = Y (1) and Ho (2)], have been prepared via solvothermal reaction. Single crystal X − ray analyses reveal that complexes 1 and 2 both crystallize in the P21/m space group. Topological analyses suggest that these frameworks possess the same two–dimensional (2D) (4,4)-connected networks. Notably, the emission spectrum reveals the fluorescence of complex 1 is mainly from the ligands to ligands charge transfer transition. Further investigation indicates that complex 1 can act as a fluorescent sensor for highly sensitive and selective detection of Fe3+ and 2,4,6-trinitrophenol (TNP) in MeCN solution, the quenching constants (Ksv) are 1.45 × 105 M−1 for Fe3+ and 4.08 × 104 M−1 for TNP, with the detection limit (LOD) of 0.12 µM for Fe3+ and 0.52 µM for TNP. Furthermore, the possible sensing mechanisms of complex 1 as bifunctional sensors have been studied based on experiments. Two isostructural rare earth metal–organic frameworks based on 1, 1'−butadiynebenzene−3, 3', 5, 5'−tetracarboxylate ligand were synthesized and structurally characterized in detail, and complex 1 is promising bifunctional luminescent probe for highly sensitive and selective sensing Fe3+ ions and TNP through luminescence quenching effect, complex 1 also exhibits good recyclability for detecting Fe3+ ions and TNP. The quenching mechanisms were studied as well. [ABSTRACT FROM AUTHOR]

In recent years, using nanomaterials based on multi-wall carbon nanotubes (MWCNT) through the activation of peroxymonosulfate (PMS) has attracted more attention to the degradation of organic pollutants. This research presented a new route for the synthesis of MWCNT/CoMn2O4 nanocomposite for the degradation of picric acid using advanced oxidation processes (AOPs). Firstly, CoMn2O4 nanoparticles were prepared and then loaded on MWCNT using ultrasonic waves. The results of various analyzes confirmed the successful loading of nanoparticles on carbon nanotubes. As the degradation process proceeds through oxidation processes, the high electronic conductivity of MWCNT and the active sites of Mn and Co in the nanocomposite play an essential role in activating PMS to generate reactive oxygen species (ROS). An investigation of the reaction mechanism in different conditions showed that the highest speed of picric acid decomposition in the presence of nanocomposite (98%) was in 47 min. However, the scavenger test showed that HO· and SO4·− radicals are more important in the degradation process. Meanwhile, the results showed that removing picric acid using MWCNT/CoMn2O4 was more effective than CoMn2O4 alone and confirmed the interaction effect of MWCNT nanotubes with AB2O4 nanocatalyst. [ABSTRACT FROM AUTHOR]

In this work, we introduced a simple aggregation-induced emission enhancement (AIEE) sensor (PHCS) which can selectively detect and discriminate three environmentally and biologically imperative heavy metal ions (Cu2+, Co2+ and Hg2+) and a hazard class 1 categorized nitro-explosive picric acid (PA) in differential media. By virtue of its weak fluorescence attributes in pure organic medium owing to the synergistic operation of multiple photophysical quenching mechanisms, the molecular probe showcased highly selective 'TURN ON' fluorogenic response towards hazardous Hg2+ with a limit of detection (LOD) as low as 97 nM. Comprehensive investigation of binding mechanism throws light on the cumulative effect of probe-metal complexation induced chelation enhanced fluorescence (CHEF) effect and subsequent AIEE activation within the formed probe-metal adducts. Noteworthily, the probe (PHCS) can be readily used in real water samples for the quantitative determination of Hg2+ in a wide concentration range. In addition, the probe displayed modest colorimetric recognition performances to selectively detect and discriminate two essential heavy metal ions (Cu2+ and Co2+) with a LOD of 96 nM and 65 nM for Cu2+ and Co2+ respectively, in semi-aqueous medium. Intriguingly, based on high photoluminescence efficiency, the AIEE active nano-aggregated PHCS displayed a remarkable propensity to be used as a selective and ultra-sensitive 'TURN-OFF' fluorogenic chemosensor towards PA with LOD of 34.4 ppb in aqueous medium. Finally, we specifically shed light on the interaction of PHCS hydrosol towards PA using some unprecedented techniques, which helped uncover new photophysical insights of probe-explosive molecule interaction. We shed light on novel photophysical insights toward unique multifunctional sensory aptitude of a simple aggregation-induced emission enhancement active organic functional molecule in differential media, enabling ultra-sensitive discriminative detection of toxic heavy metal ions and explosive molecule simultaneously. [ABSTRACT FROM AUTHOR]

We present the synthesis of a new oxacalix[4]arene system, DMANSOC, wherein two 5-(dimethylamino)-1-naphthalene sulfonamide subunits are attached to the lower rims of the basic oxacalix[4]arene platform. Extensive spectrophotometric studies were conducted to investigate the selectivity and sensitivity of DMANSOC towards nitroaromatic explosives. Detailed analysis of spectrophotometric data, utilizing techniques such as Stern-Volmer, Benesi-Hildebrand, Job's plot, and interference study, unequivocally demonstrated the effectiveness of DMANSOC as a highly efficient fluorescent sensor for 2,4,6-trinitrophenol explosive (TNP) detection in an aqueous medium. The sensor exhibited a linear concentration range of 7.5 μM to 50 μM, with a low detection limit of 4.64 μM and a high binding affinity of 2.45 × 104 M towards TNP. Furthermore, the efficiency of the sensor in environmental samples contaminated with TNP was evaluated, yielding excellent recovery rates. Complementary DFT calculations and molecular dynamics simulations were performed to elucidate the mechanism behind the selective fluorescence quenching of DMANSOC in the presence of TNP. [ABSTRACT FROM AUTHOR]

A fluorescent sensor, 5-((2-hydroxynaphthalen-1-yl)methyleneamino)benzene-1,3-dicarboxylic acid (coded as SB), containing both π-π interacting sites (such as π-electron-rich moieties) and hydrogen bonding (H-bonding) interacting sites (such as highly acidic protons) has been developed via high yield reflux method. It was characterized by the various analytical techniques such as Fourier transform-infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1 H-NMR), thermogravimetric analysis (TGA), field emission scanning electron microscope (Fe-SEM), elemental mapping, and UV − visible spectroscopy etc. The spectral response of the as-synthesized SB sensor has been investigated for various nitro explosives (NEs). It has been found that the SB sensor selectively and sensitive sense highly toxic 2,4,6-trinitrophenol (TNP) via the "turn-off" quenching response. Its limit of detection for TNP was calculated to be 30 ppb. Spectral overlap, detailed mechanistic studies for their mode of action, and density functional theory (DFT) calculations reveals that photo-induced electron transfer process (PET), fluorescence energy transfers process (FRET), and electrostatic interactions (i.e. H-bonding) are the key factors for the turn-off response of SB towards TNP. Notably, the synthesis of the sensor is cost-effective, energy efficient, and economic. [ABSTRACT FROM AUTHOR]

A triazole-bridged anthracene-sugar derivative 1 was designed and synthesized in one step. The sensing ability of 1 towards picric acid over other nitroaromatic compounds was established by absorbance and fluorescence spectroscopy in a water−acetonitrile medium (3 : 2, v/v). Furthermore, compound 1 could recognize Au(III) ions in 100% water among different metal species and anions. In the presence of picric acid, the receptor's fluorescence quenches within a minute. The Stern–Volmer quenching constants for picric acid and Au(III) ions were observed to be 1.59 × 105 and 1.8 × 105 M–1, respectively. Spectroscopic studies and density functional theory calculations supported the formation of the non-emissive charge transfer complex 1-picric acid after the interaction between 1 and picric acid. The probe showed a 1 : 1 binding mode for picric acid and Au(III) ions. The detection limits of 1 for picric acid and Au(III) were calculated to be 0.09 and 0.094 µM, respectively. Furthermore, receptor 1 has been effectively utilized to sense picric acid in river, pond, and tap water samples. Interestingly, it was found that the quenching process of 1 with picric acid is totally opposite to quenching with Au(III). [ABSTRACT FROM AUTHOR]

Aggregation-induced emission (AIE) active compounds have attracted tremendous interest due to their unique properties of restriction of intramolecular rotations, which leads to the generation of luminescence in these compounds. Here we have successfully developed a novel AIE active fluorescent probe H2L [(E)-2,4-dibromo-6-(((5-chloropyridin-2-yl)imino)methyl)phenol] with Al(III), Fe(III), and aqueous and gas phase picric acid detection ability. UV, fluorescence, and DLS studies are implemented to give solid proof of the AIE active behavior of the probe. Optical, SEM, and TEM images clearly prove the morphological adaptability of the probe through structural alterations with the variation of water percentage. It shows AIE active behavior in DMSO–H2O (3 : 7 v/v) solutions. One remarkable and noteworthy observation is that the ligand's morphology and emission intensity are altered by the presence of water with varying percentages (10–70%) when the AIE activity is taken into account. This results in the appearance of two distinct optical color changes and emission intensity changes within the 10–70% water percentage range. The probe becomes emissive in the solid state due to the intermolecular H-bonding and keto–enol tautomerism. Interestingly in 9 : 1 (v/v) DMSO–H2O solvent H2L can selectively detect Al(III) through turn-on fluorescence. In the AIE active medium, it can selectively detect Fe(III) and picric acid by turning off fluorescence. The ESIPT process in the solid state leads to molecular aggregation, resulting in the generation of strong luminescence in the probe, and impressively the solid state fluorescence is used to detect picric acid in the vapor phase. The LOD values are determined as 6.02 × 10−9 (M) for Al(III), 7.5 × 10−9 (M) for Fe(III) and 6 × 10−8 (M) for picric acid. During Al(III) sensing the ESIPT off and "CHEF" on mechanisms jointly operate leading to emission enhancement, whereas during Fe(III) sensing and picric acid sensing the destruction of the aggregation state is mainly responsible for the reduction of emission intensity of the probe. Impressively the probe can detect picric acid in the solid state also. The Job plot analysis of the UV spectral data and the mass spectral analysis support the 1 : 1 stoichiometry complexation between the probe and the analytes. Moreover, the proposed analytical system with its clear AIEE mechanism demonstrates a promising prospect for on-site practical applications. Finally, the probe's ability to detect and quantify Al(III) in the market-available drug samples has been checked. [ABSTRACT FROM AUTHOR]

Fuchsine acid serves as a supramolecular dye in Masson's trichrome stain, finding extensive applications in histology. It is also utilized with picric acid in Van Gieson's method to reveal red collagen fibers and in Masson's trichrome to highlight smooth muscle in contrast to collagen. Beyond these applications, it plays a crucial role in electronic fields and photonic devices as an organic semiconductor. Therefore, investigating and predicting the complex molecular structure of fuchsine acid becomes essential, serving as the foundation for understanding its physicochemical features. This article employs topological modeling, specifically a connection number edge partition, to explore the supramolecular nature of fuchsine acid. Closed formulae for key degree-based molecular descriptors are derived, aiming to illuminate the effectiveness of these descriptors for QSAR and QSPR analyses. The 2D structure of fuchsine graph with connection numbers [ABSTRACT FROM AUTHOR]

Sorghum is considered a fifth major cereal, widely used as a multipurpose crop worldwide. The use of sorghum as a major forage crop is limited due to cyanogenic glycoside dhurrin in the vegetative shoot tissues. This cyanogenic glycoside is harmful to livestock when fed as fodder. The present study selected three sorghum genotypes for estimating hydrogen cyanide potential (HCNp) in vegetative tissues under well-watered (WW) conditions. The HCNp concentration varied from genotype to genotype and ranged from 364 to 512 ppm. The HCNp estimation was observed more in ICSR 14001 with 511 ppm, followed by ICSV 93046 (443 ppm) and CSH 24 MF (364 ppm). A significant difference was noticed between the genotypes. Sequence information of dhurrin biosynthesis pathway genes was retrieved and characterized using different bioinformatic tools. The gene expression analysis of dhurrin biosynthesis pathway genes showed different expression patterns, with the highest in ICSV 93046 and less in ICSR 14001 and CSH 24 MF. Genes CYP79A1, CYP71E1 and UGT85B1 showed a 2.5- to 4 fold increase in ICSV 93046 and no significant expression in ICSR 14001 and CSH 24 MF. The genotype CSH 24 MF observed a 1.5-fold increase in CYP79A1 gene expression, and the other genes observed no significant increase. This study assisted in identifying the contrasting genotypes inducing HCNp and the key genes of the dhurrin pathway producing hydrogen cyanide (HCN) under WW conditions, which can be used as potential candidates for gene editing, providing safe feed for the livestock. [ABSTRACT FROM AUTHOR]

Promising charge transfer (CT) complexes were prepared to be used as: solid conducting electrolytes for batteries voltaic cells, biosensors, biochips, diagnostic applications and the electronic devices. Charge transfer (CT) complexes generated between electron Schiff bases donor of Aryl 2-azomethine dibenzothiophene-Schiff base, 1,3-dinitrobenzene (A1), 2,4-dinitrophenol (A2) and picric acid (A3) as-acceptors have been studied using spectroscopic kinetic investigations. The reactions of the donor and the acceptor compounds were followed at different temperatures (20, 30, 40 and 50 °C) and in the range of time between 0 and 55 min. The rate of formation of the product (k) and the molar extinction coefficient (ε) has been calculated and discussed. The activation energy (Ea) has been calculated from the first-order kinetic equation. The thermal dehydration and decomposition of these complexes were studied kinetically using the integral method applying the Coats–Redfern, Ozawa and composite methods. These donor–acceptor charge transfer complexes have a promising antimicrobial activity comparable to the corresponding schiff base compound. TGA-DTA and DSC studies were also carried out to check the stability of CT complex, and activation energy (Ea) has been calculated. These donor–acceptor charge transfer complexes and the attributed of N, O and S atoms have a promising antimicrobial activity that suggested the applications of this class of compounds in pharmaceutical and medical applications. The antibacterial and antifungal activities of the synthesized charge transfer complexes were screened against and fungi (Candida) bacterial species (Escherichia coli and Staphylococcus aureus). The activity data show that the CT complexes have a promising biological activity comparable to the Schiff base compound against bacterial and fungal species. These CT complexes comparable to the corresponding schiff base compound have semiconducting and piezoelectric properties electronic conductivity. The piezoelectric polarization is induced due to the reorientation of the polar groups and its dipoles. The phase transition on heating the complexes reflects the dielectric nature due to the defect and the transport properties. [ABSTRACT FROM AUTHOR]

Mentha arvensis L. var. 'kosi', occasionally recognized as corn mint or field mint, belongs to the Lamiaceae family and is widely grown in temperate climates throughout Europe, western and central Asia, as well as North America for its medicinal significance (Aflatuni et al, 2005). The essential oil extracted from the mint plant reveals a rich assortment of secondary metabolites. Among these compounds are menthol, menthone, menthyl acetate, neomenthol, á-pinene, â-pinene, piperitone, limonene, tannins, and flavonoids. The recognition and analysis of these constituents contribute to a thorough understanding of the intricate chemical composition inherent in mint plant essential oil (Akram et al, 2011). The plant has long been utilized in Indian medicine to alleviate stomach problems, fevers, and headaches. The influence of phenolic compounds on antimicrobial, antibacterial and antioxidant activities, germination and early development of herbaceous woodland plants, and seed germination has sparked considerable attention. Menthol, obtained from the essential oil of the mint plant, is credited with therapeutic properties that effectively combat skin allergies. Additionally, it demonstrates diuretic properties and serves as an antiseptic and carminative agent. The authors observed that the stimulating effects of salicylic acid, methyl jasmonate and similar phenolic compounds can be used to increase the content present in the essential oil and medicinal and pharmacological values of the plants of the Lamiaceae family. This idea led us to try the other phenolic compounds' foliar application to various species of mint with an expectation to increase the quality of these plants. The present study had the goal to evaluate if the exogenous foliar application of different phenolic compounds (phenol, catechol, pyrogallol, picric acid and salicylic acid) at concentration of 1.0 mM can optimize the physiological, biochemical activities and essential oil production in 120-day-old mint plants. Growth and physiological, biochemical, and total essential oil content assessments inclusive of menthol, menthone, menthyl acetate indicated that 1.0 mM concentration of pyrogallol and salicylic acid were most potent at eliciting a general stimulation of mint metabolism. Overall, the findings demonstrate that salicylic acid and pyrogallol stimulate mint physiology and open up new avenues for biotechnological application on additional plant species with agronomic promise. [ABSTRACT FROM AUTHOR]

A chromone‐coupled adenine‐based fluorogenic chemosensor (BD1) has been introduced for cascade detection of Zn2+ and HSO4−ions or Zn2+ and picric acid (PA) based on the fluorescence 'OFF‐ON‐OFF' mechanism. A momentous fluorescence improvement has been observed due to the accumulation of Zn2+ ions in the BD1 solution because of the formation of the Zn2+ chelated BD1 complex. A cyan color fluorescence enhancement is visible under the exposure of a 365 nm UV lamp, which is also manifested in the CIE diagram. The detection limit of our developed sensor BD1 and Zn2+−BD1 complex towards the identification of Zn2+ and HSO4− ions are in the nM and μM range, respectively, in the solution phase. Among the several explosive nitroaromatic compounds (NACs), only PA quenches the fluorescence of the Zn2+ chelated BD1 complex, and the nature of quenching is both static and dynamic. A paper strips‐based test kit experiment is performed for on‐spot identification of Zn2+ ions and PA. Based on these chemically encoded inputs and the fluorescence intensity as optical output, we have constructed an INHIBIT molecular logic circuit. The present report evokes a new approach for the development of new chemosensors from bioinspired materials such as adenine, a purine nucleobase. [ABSTRACT FROM AUTHOR]

In this work we report two zinc(II) complexes, namely {[Zn(L)(dca)](0.5CH3OH)}n (1) and [Zn2(L)2(N3)2] (2), (where HL = 1-((2-pyridylmethyl)iminomethyl)-2-naphthol, dca = dicyanoamide anion) that have been structurally characterized by spectroscopic technique and X-ray single crystal diffraction. Structural analysis showed for complex 1 an undulated polymer with Zn(L) units connected by bridging dca anions, while 2 is a dinuclear complex where the azide anions are monodentate and end-on coordinated. The emission properties of both complexes have been studied in various organic solvents, and among them, nitrobenzene attracts attention due to its significant quenched effect. The synthesized complexes were tested as fluorescence-based sensors for nitroaromatic analytes (nitrobenzene, 4-nitrotoluene, 2,4-dinitrophenol, p-nitrophenol, 1,3-dinitrobenzene, 2-nitrotoluene, 4-nitrobenzaldehyde, and picric acid) and results showed that complexes 1 and 2 exhibit a selective response in particular towards picric acid (PA). The fluorescence sensor mechanisms have been explained according to photoinduced electron transfer (PET) mechanism and resonance energy transfer (RET). [ABSTRACT FROM AUTHOR]

Nitrophenols has become a significant threat to the ecosystem and the health of the human beings. Photocatalytic degradation is considered to be the utmost competent approach for the amputation of nitroaromatic pollutants. In this research, 2-nitrophenol (MNP), 2,4-dinitrophenols (DNP), and 2,4,6-trinitrophenol or picric acid (PA) are taken for the degradation studies using the photo-Fenton catalyst of synthesized TiO2 nanoparticle modified with biopolymer containing organic and inorganic functionalities. The morphological study reveals the uniformly distributed TiO2 nanoparticles (15 nm) surfaces are encapsulated by the active site-rich chitosan-ligand-copper complex facilitating more absorption and enhancing the photocatalytic activity toward the target molecules. The UV spectra confirm the predominant shifting of absorption peak in the range 305–310 nm which results due to the formation of TiO2-CBGCu nanocomposites. The zeta potential of the synthesized nanocomposites TiO2-CBGCu 5%, TiO2-CBGCu 10%, and TiO2-CBGCu 20% are − 12, − 20, and − 29 mV which reveals that the value increases with the increase in CBGCu content which in turn signifies the more stability in aqueous solution. Amid the prepared nanocomposites, TiO2-CBGCu 10% demonstrates the imperative catalytic performances toward MNP, DNP, and PA pollutants along with the Fenton's reagent at pH 3.0 under visible light and solar light. It shows effective degradation for strong acid PA within 18 min in visible light compared to MNP and DNP due to the presence of more active sites in the synthesized nanocomposites. This work has created awareness about the multifunctional catalyst and the effectiveness of the same has opened a new passage to eliminate nitrophenols from the agonized environment. [ABSTRACT FROM AUTHOR]

Nitroaromatic compounds, recognized as principal organic pollutants, are a grieving concern now a days. Herein, we report the use of tungsten disulfide/reduced graphene oxide (WS2/rGO) composites as new catalysts for the reduction of picric acid by NaBH4 in aqueous media. Unlike the conventional methods, the required WS2 nanosheets were prepared via mechanical grinding devoid of using large volumes of solvents. For assessing the effect of composition towards the catalysis, we have prepared WS2/rGO composites with 1:1, 1:2 and 2:1 weight ratios and WS2/GO with 1:1 weight ratio, followed by characterization using Fourier transform infrared, X-ray diffraction, scanning electron microscopy and UV–visible spectroscopy. Among the composites, WS2/rGO (1:1) exhibits superior catalytic properties than WS2/GO (1:1) due to the high electron relay of rGO. In the presence of WS2/rGO as a catalyst, a 96% reduction of picric acid was achieved within 10 min. Experimental data indicate the existence of a synergistic phenomenon involving both adsorption of the analyte onto the catalyst surface and its subsequent chemical reduction which attributes to the fact of enhanced catalytic behavior. The reduction reaction follows pseudo-first-order kinetics, with a rate constant K = 3.1 × 10–1 min−1 which is about tenfold higher than that of using the composite WS2/GO, rGO and WS2. The reusability of the catalyst is good as the catalytic efficiency does not significantly decrease after 10 catalytic cycles. [ABSTRACT FROM AUTHOR]

An efficient and short synthesis of fused dihydroisoquinolines, diaryl substituted pyridine derivatives in good to high yields has been established by using an environmentally safe, solvent‐metal‐oxidant‐free tandem approach. In this article, we discuss how the electrocyclic reaction is more pronounced in the solid phase in the presence of urea, whereas the typical aza‐Michael addition is more prominent in presence of arylamine in the solution phase for 3‐(2‐formylcycloalkenyl)acrylic ester derivative substrates. The wide range of substrates and urea‐promoted neat synthesis made our approach more significant in medical and also analytical science. Moreover, an isoquinoline alkaloid decumbenine B analogue has been synthesized by using our newly developed neat methodology. We have also investigated the photophysical properties of the synthesized fused dihydroisoquinoline derivatives. One of the synthesized molecules was used as a sensor for the selective detection of toxic picric acid. Therefore, the effective neat synthesis and molecular sensing applications of these compounds made our approach more exciting in the field of heterocyclic chemistry. [ABSTRACT FROM AUTHOR]

Three phases (α, β, and γ) of manganese dioxide (MnO2) are successfully stabilized in a single entity for the first time. For this purpose, Citrullus colocynthis (bitter apple) extract is used as a natural surfactant in green synthesis. MnO2 nanoparticles were synthesized in the presence and absence of plant extracts under the same conditions. The morphology of both products is analysed by SEM and STEM to understand the role of plant extract in controlling the morphology of particles. The crystallinity and composition are analysed by XRD and confirmed that the product is composed of multiple phases α, β, and γ. The reduction of dyes and nitroarenes is studied using MnO2 nanoparticles (green and chemical products) as catalysts. The apparent rate constant, a percentage reduction, time reduction and reduced concentration compare the activities of both catalysts. After comparative data analysis, the catalytic reduction of picric acid is found fastest among all the substrates. All the results are analysed based on structure, functional group and affinity towards catalysts. [ABSTRACT FROM AUTHOR]

High levels of unconjugated bilirubin (UB) in serum lead to asymptomatic and neonatal jaundice and brain dysfunctions. Herein, we have reported the detection of UB at as low as 1 μM in an aqueous alkaline medium using a Zn(II) complex. The specificity of the complex has been validated by the HPLC in the concentration window 6–90 μM, which is rare. The sensory response of the probe at physiological pH against nitro explosives developed it as an instant‐acting fluorosensor for picric acid (PA) and 2,4‐dinitrophenol (2,4‐DNP). Spectroscopic titration provided a binding constant of 4×105 M−1 with PA. The naked eye detection was found to be 15 μM. The solid‐state photoluminescent nature of the complex enabled it for PA sensing in the solid phase. Interestingly, the probe remained fluorescent in various volatile and non‐volatile organic solvents. As a result, it can also detect PA and 2,4‐DNP in a wide range of common organic media. NMR studies revealed the coordination of PA, 2,4‐DNP, and UB to the Zn(II) center of the probe, which is responsible for the observed quenching of the probe with the analytes. [ABSTRACT FROM AUTHOR]

In this paper, a new three-dimensional network coordination polymer {[Co(TPTC)(HBPDPE)2·2H2O]·3H2O}n [[[(1:1′:4′,1″-terphenyl)-3,3″,5,5″-tetracarboxylic cobalt (II)] dipyridine dihydrate] trihydrate] (Complex 1) was generated under solvothermal synthesis by rigid conjugated ligand H4TPTC ([1:1′:4′,1″-terphengl]-3,3″,5,5″-tetracarboxylic), V-shaped BPDPE (4,4′-bis (pyridyl) diphenyl ether) and Co(II) ion. In complex 1, the neighboring Co(II) ions are linked by deprotonated TPTC4- to achieve a 1D zigzag chain [Co(TPTC)(HBPDPE)2]n, then the adjacent [Co(TPTC)(HBPDPE)2]n chains linked each other by various H-bondings to extend the structure from 1D chain to 3D network. Complex 1 has excellent fluorescence sensing performance and exhibits high sensitivity and selectivity for detecting 2,4,6-trinitrophenol (TNP), the quenching constant Ksv is up to 2.08 × 105 M−1 along with the correlation coefficient R2 of 0.993. Furthermore, the quench mechanisms of this Co-MOF as a sensor to detect nitro- aromatic explosives were studied as well. A new three-dimensional coordination polymer {[Co(TPTC)(HBPDPE)2·2H2O]·3H2O}n (1), constructed by 1D zigzag chains and H-bondings interactions, was synthesized under solvothermal condition by a rigid conjugated ligand H4TPTC ([1:1′:4′,1″-terphengl]-3,3″,5,5″-tetracarboxylic), BPDPE (4,4′-bis (pyridyl) diphenyl) and Co(II) ion. Complex 1 has excellent fluorescence sensing performance for detecting Nitroaromatic explosive (NAE) 2,4,6-trinitrophenol (TNP), the quenching constant Ksv is up to 2.08 × 105 M−1, and the quenching mechanism was studied as well. [ABSTRACT FROM AUTHOR]

Resorcinol–formaldehyde-based organic xerogel was prepared by sol–gel method using picric acid as a catalyst. Following thermal treatment in an inert atmosphere at high temperatures, the sample exhibited three-dimensional hopping conduction behaviors within a temperature range of 80–300 K, displaying typical semiconductor properties. Based on additional literature data, the authors inferred a potential interdependence between mobility and conductivity, characterized by a universal empirical relationship of the form μ (cm2/Vs) ∝ σ0.76 (S/cm). Equivalent circuits were proposed to accurately fit the experimental data, with impedance measurements facilitating the identification of the equivalent circuit and its fundamental parameters. This approach allowed for the estimation of grain and grain-boundary contributions. The outcomes present very promising prospects for various technological applications in the advancement of negatronic devices and power electronic technology components. [ABSTRACT FROM AUTHOR]

3,5‐Difluoro‐2,4,6‐trinitrophenol (DFTNP) was designed as energetic compounds, based on the "NO2FNO2" strategy. Its structure was fully characterized by IR, NMR, elemental analysis, and single‐crystal X‐ray diffraction. Physico‐chemical characterization of this compound was investigated based on several theoretical techniques. The result indicated that DFTNP is less sensitive to external stimuli, with a thermal sensitivity of 213 °C, impact and friction sensitivity of 15 J and 240 N. It also shows particularly high density (ρ=1.949 g cm−3) and detonation performance (D=8440 m s−1, P=32.60 GPa), which far exceeds the performance of picric acid. Its crystal packing and the intermolecular interaction of DFTNP play an important role inreducing localized heating. In addition, this compound also has great potential for building ionic salts, and its ammonium salt performance exhibits better performance. Good performance not only highlight this compound as a suitable replacement for picric acid, but also suggests that "NO2FNO2" may be a good choice in designing energetic compounds. [ABSTRACT FROM AUTHOR]

The aims of this study were to investigate the potential of utilising molecularly imprinted polycarbazole layers to detect highly toxic picric acid (PA) and to provide information about their performance. Quantum chemical calculations showed that strong interactions occur between PA and carbazole (bond energy of approximately 31 kJ/mol), consistent with the theoretical requirements for effective molecular imprinting. The performance of the sensors, however, was found to be highly limited, with the observed imprinting factor values for polycarbazole (PCz) layers being 1.77 and 0.95 for layers deposited on Pt and glassy carbon (GC) electrodes, respectively. Moreover, the molecularly imprinted polymer (MIP) layers showed worse performance than unmodified Pt or GC electrodes, for which the lowest limit of detection (LOD) values were determined (LOD values of 0.09 mM and 0.26 mM, respectively, for bare Pt and MIP PCz/Pt, as well as values of 0.11 mM and 0.57 mM for bare GC and MIP PCz/GC). The MIP layers also showed limited selectivity and susceptibility to interfering agents. An initial hypothesis on the reasons for such performance was postulated based on the common properties of conjugated polymers. [ABSTRACT FROM AUTHOR]

The development of high‐intensity fluorescent materials is always the focuses and forefront projects because of their important applications in displays, sensing and detection fields. In recent years, the detection of explosives has attracted increasing attention due to security and counterterrorism issues. Herein, two diphenyl−anthracene (DPA) derivatives were designed and synthesized by introducing strong electron withdrawing fluorine atoms and cyano‐groups to DPA, which exhibited strong fluorescence both in the solution and solid phase with the absolute quantum yields up to 70.4 % and 45.9 % respectively. The detection behavior of nitroaromatic explosives such as picric acid (PA), 2,4,6‐trinitrotoluene (TNT) and 3‐Nitropropionic acid (3‐NP) also shows good sensitivity with the quenching constant as high as 6.3×104 L mol−1. Theoretical calculation demonstrates that the fluorescence quenching behavior of the two DPA derivatives is caused by the behavior of photoinduced electron transfer (PET) and the resonance energy transfer (RET) studies explained the higher sensitivity and selectivity of both compounds towards PA than other nitro‐containing explosives. Furthermore, the strong solid‐state fluorescence of the DPA derivatives also shows excellent advantages in enhancing latent fingerprint recognition. [ABSTRACT FROM AUTHOR]

Nitrogen-doped carbon dots (N-CDs) possess outstanding photostability and interesting physicochemical and photochemical properties. Herein, we present cyan-emitting N-CDs that were fabricated through the treatment of salicylic acid with ethylene diamine using a simple microwave-assisted method. It was observed that the reaction produced N-CDs that strongly emitted cyan light with a quantum yield (QY) of 33%. The N-CDs were examined with the assistance of HR-TEM, XPS, XRD, FTIR, PL, and UV measurements. Due to the fluorescence enrichment effect caused by the N atoms in carbon dots, these N-CDs can be used as a fluorescent material for the detection of nitro-explosives and toxic metal cations. The addition of picric acid resulted in splendid quenching of the N-CDs, with a limit of detection (LOD) value of approximately 82.9 nM that was ascribed to the Förster resonance energy transfer between the N-CDs and the nitro-aromatics. Furthermore, the powerful coordination between oxygen-rich moieties and N-CDs for the detection of Fe3+ and Hg2+ cations induced fluorescence quenching through photo-induced electron transfer and the inner-filter effect pathway, leading to the effective recognition of metal ions. The sensor probe exhibited a wide-ranging linear response with an LOD of approximately 30 nM for Fe3+ and 160 nM for Hg2+ ions. Thus, the as-prepared N-CDs can function as a fluorescence sensor, a secure portable information device, and a paper-based probe for detection in biological systems. [ABSTRACT FROM AUTHOR]

It is challenging to explore novel-structure lanthanide coordination polymers (Ln-CPs) for sensing environmental pollutants. Herein, we designed and synthesized an organic bridging linker 3-(carboxymethoxy)-1-(carboxymethyl) pyrazole-4-carboxylic acid (H3ccpc), and then successfully prepared and characterized a novel Ln-CP, namely [Tb2(ccpc)2(H2O)6]·1.5H2O (ccpcTb). Structural analysis indicates that ccpcTb exhibits a two-dimensional structure, in which Tb ions are in an eight-coordinated environment. The photoluminescence performance of ccpcTb was discussed in detail. The ccpcTb displays bright green luminescence and behaves as a multi-responsive luminescent sensor toward Fe3+ ions, Cr2O72− ions and 2,4,6-trinitrophenol with high selectivity and low detection limits. Furthermore, the possible luminescence sensing mechanisms have been addressed in detail. The luminescence quenching mechanism of sensing Fe3+ and Cr2O72− is attributed to the energy competitive absorption, while that of sensing TNP is due to the synergistic effect of energy competitive absorption and photo-induced electron transfer. [ABSTRACT FROM AUTHOR]

During World War I, an enormous amount of chemical and conventional munitions was fired. Many of these munitions did not explode and are still recovered in the soil of the regions where the war raged for several years. After the war, many of the remaining munitions were dumped in the sea as an easy way of removal. These unexploded and dumped munitions are still present so many years after the end of the war. The explosive material inside the munitions is more than 100 years old now. Samples were collected from some of these old munitions. These samples have been analyzed to determine their composition. The explosives typically used in World War I (TNT, DNT, DNB and picric acid) have been identified. It has been shown that the aged samples still contain their energy. They have not become more sensitive to friction or impact. For one the samples, it has been shown that it is still cap-sensitive and detonates normally. These results are important for any risk assessment involving old munitions. [ABSTRACT FROM AUTHOR]

Explosives such as tetryl and picric acid, which were common in the past, now have lost their combat relevance. However, they are often used for peaceful purposes individually and in combination with other trinitroaromatic compounds (e.g., trinitrotoluene). As a result of their use, environmental pollution occurs, followed by intoxication of plants, animals, and people. Cases of explosive poisoning during their production are also described. The symptoms of poisoning include both of general disorders and specific phenomena such as skin staining, impaired physiological efficiency of NADPh-dependent enzymes, genotoxicity, and immunotoxicity. Previous scientific studies established a trend toward the development of chemical-analytical probes. Various options for the sensor surface of the device and methods for detecting compounds are considered. To determine the explosives, ion mobility spectrometry is widely used, which is very rare for the chemicaltoxicological analysis of other groups of compounds. Simultaneously, methods commonly used in the analysis of narcotic and psychotropic substances (gas chromatography/ combination of high-performance liquid chromatography and mass spectrometry methods) are also applicable to determine trinitroaromatic explosives. However, the presence of nitro groups in their structure complicates such an analysis. This problem can be resolved by injecting cold samples directly to the column. Despite the availability of various developed techniques and methods, the possibility of their application to study biological matrices remains insufficient. Therefore, further studies of the chemicaltoxicological nature should be conducted to establish the optimal conditions for extracting the substances in question, the parameters of instrumental analysis, and the possibility of storing samples and for solving other problems of forensic medical examination.

Here, yellow fluorescent sulphur-doped carbon dots (S-CDs) with high quantum yield (QY) of ~27.9% were synthesised from m-cresol purple by a fast and low-cost one-step hydrothermal method without other reagents. The surface morphology, functional groups and optical properties of S-CDs were characterised by high-resolution transmission electron microscope (HRTEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectrum and ultraviolet visible (UV-vis) absorption. The fluorescence intensity of S-CDs can be specifically and stably quenched by picric acid (PA) through inner filtration effect (IFE). The linearity between fluorescent intensity and PA concentration was used for developing a fluorescent probe with detecting range of 0–259.0 μM and a detection limit as low as 14.6 nM. We developed the method by applying S-CDs to determine PA in lake water with recoveries in the range of 93.0–103.7%, which verified the feasibility of this probe in practical analysis. In addition, due to the low toxicity and good biocompatibility, S-CDs can be applied to biological imaging. [ABSTRACT FROM AUTHOR]

Unusual diastereomeric C1,C2,C3-functionalized carba[3]ferrocenophanes with two stereogenic centres have been obtained using a ring closing reaction, based upon double/two-fold 1,4-Michael addition under solid support conditions. The [3]ferrocenophanes are the first known structures among the class of saturated tri-functionalized carba[3]ferrocenophanes. One meso-type (1S,2s,3R) and two enantiomeric (1S,3S and 1R,3R) [3]ferrocenophanes have been identified and characterized. A mechanism has been proposed to understand the possible mode of nucleophilic attack that led to the unusual stereoisomeric tri-functionalized ferrocenophanes. The heterocycle functionalized ferrocenophanes with three pyridyl chains oriented in different directions have been used as antennas to explore the sensing of picric acid selectively at the ppb level. [ABSTRACT FROM AUTHOR]

The sensor 4‐(9H‐carbazol‐9‐yl)‐N,N‐dimethylbenzenamine, CNDMA a green fluorescent ligand developed for selective sensing of picric acid in DMSO/H2O (1 : 9) over different other nitroaromatic compounds. The sensing mechanism involves emission quenching significantly in the presence of picric acid with a color change from green to non‐fluorescent yellow. The sensing process drives through electrostatic and Hydrogen bonding interaction with formation of an Electron Donor‐Acceptor complex. In addition, inner filter effect also play role on the fluorescence quenching. The fluorescence quenching is a mixed‐type of both static and dynamic quenching process. The binding nature was figured out using the 1H NMR and FTIR titration studies. In addition the sensor showed good quenching efficiency and quenching constant with a lowest detection limit (LOD) of 5.09×10−8 M (R=0.99964) at 358 nm. Test strip experiment is demonstrated to understand the practical feasibility of the sensor. [ABSTRACT FROM AUTHOR]

Nitroaromatic compounds are extremely explosive materials that pose a national security risk and raise environmental concerns. The design and development of sensitive and selective compounds for explosive materials are highly desirable. 'Aggregation-Induced Emission' (AIE) active materials are best suited for sensing purposes because of their sensitivity, fast detection time, and easy operation. By rationally incorporating substituents on the cyclometalated (C^N) ligand, four different AIE active iridium(III) based monocyclometalated complexes with the general formula [Ir(PPh3)2(H)(Cl)(C^N)] were synthesized. The phenyl ring of the phenyl pyridine cyclometalated portion of an iridium(III) complex was substituted with the right substituents to adjust the FMO levels thus, leading to appropriate alignment of the energy levels. Each of the resulting complexes displayed a significant property known as 'Aggregation-Induced Phosphorescent Emission' (AIPE). The complexes were subjected to structural characterization, electrochemical analysis, and photophysical property studies. The synthesized complexes were employed for the detection of aromatic nitro explosive compounds such as trinitrophenol (TNP) and trinitrotoluene (TNT) in the aqueous phase with a high degree of sensitivity. The sensing capabilities of each complex were assessed for these nitro explosive compounds and compared to those of the unsubstituted iridium(III) complex (M). Notably, the best limits of detection for TNP and TNT have been achieved with iridium(III) complexes [M1 (489 pM) and M3 (3.6 nM)] within the literature reported until now. For detecting picric acid with M1, FRET was found to be the potential mechanism, and for TNT, PET was found to be the cause of emission quenching by M3. Furthermore, for low-cost detection, filter paper-based sensing was also found effective for each complex. Real-field sensing of PA in soil samples was also performed. [ABSTRACT FROM AUTHOR]

We employed a solvothermal and thermal pyrolysis approach to prepare a heterojunction of oxide perovskite (Bi2MoO6) dispersed on polymeric carbon nitride (PCN) sheets. The introduction of Bi2MoO6 particles onto the PCN sheets improved the light absorption characteristics of the Bi2MoO6/PCN heterojunction. The as synthesized Bi2MoO6/PCN heterojunction exhibited a larger surface area of 24 m² g-1, compared to the individual Bi2MoO6 (18 m² g-1) and PCN (7 m² g-1), respectively. This enhanced surface area provided newer catalytic sites for the heterojunction. The resulting heterojunction was employed as a photocatalyst for the reduction of a series of toxic mono, di, and tri-nitrophenols, namely 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, and 2,4,6-trinitrophenol, into industrially important amino phenols. By utilizing visible light irradiation and NaBH4 as a reducing agent, the Bi2MoO6/PCN photocatalyst demonstrated accelerated reduction kinetics compared to the individual catalysts. This enhanced performance was attributed to the larger surface area and suppressed charge carrier recombination of the Bi2MoO6/PCN heterojunction, which facilitated efficient photoreduction. Overall, this study sheds light on the promising application of oxide perovskite/PCN heterojunction systems in photocatalytic reduction reactions, offering a viable solution for mitigating emerging pollutants. [ABSTRACT FROM AUTHOR]

Luminescent materials have garnered significant research interest due to their potential applications in optoelectronics, sensing, and medical diagnostics. Within this context, tetra-coordinated organoboron complexes have emerged as promising luminescent materials due to their enhanced stabilities, high electron affinities, and tuneable fluorescence properties. Herein, we report the synthesis, structure, and photophysical properties of two different types of N,O-chelated tetra-aryl pyrazole-based organoboron compounds. We also investigated the aggregation-induced enhanced emission properties of the synthesized complexes and further demonstrated their utility for picric acid sensing. The absorption and emission behaviours of these compounds reveal that the position of boron chelation plays a crucial role in determining their photophysical properties as well as their sensing behaviour. [ABSTRACT FROM AUTHOR]

This study reports the synthesis of cofacial organic cage molecules containing aggregation‐induced emissive (AIE) luminogens (AIEgens) through four‐fold Cu(I)‐catalyzed azide–alkyne cycloaddition (CuAAC) "click" reactions. The shorter AIEgen, tetraphenylethylene (TPE), afforded two orientational isomers (TPE‐CC‐1A and TPE‐CC‐1B). The longer AIEgen, tetrabiphenylethylene (TBPE), afforded a single isomer (TBPE‐CC‐2). The click reaction employed is irreversible, yet it yielded remarkable four‐fold click products above 40 %. The phenyl rings around the ethylene core generate propeller‐shaped chirality owing to their orientation, which influences the chirality of the resulting cages. The shorter cages are a mixture of PP/MM isomers, while the longer ones are a mixture of PM/MP isomers, as evidenced by their x‐ray structures. The newly synthesized cage molecules are emissive even in dilute solutions (THF) and exhibit enhanced AIE upon the addition of water. The aggregated cage molecules in aqueous solution exhibit turn‐off emission sensing of nitroaromatic explosives, with selectivity to picric acid in the 25–38 nanomolar detection range. [ABSTRACT FROM AUTHOR]