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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]

A potassium 4-(ethoxycarbonyl)phenyldithiocarbamate, (4-etphdtc), and 6-ethoxybenzothiazol)-dithiocarbamate, (6-etbedtc), ligands have been isolated and four metal dithiocarbamate complexes of the type [M(4-etphdtc)2] and [M(6-etbedtc)2] (M = Zn, Cd;) were synthesized and characterized by elemental analysis and spectroscopic techniques (FT-IR,1H and13C{1H}-NMR, HRMS, UV–vis). Thermogravimetric studies of all four complexes were performed and the final product of the thermal decomposition was metal sulfides. The theoretical study with density functional theory (DFT) has been utilized to optimize the structures of the complexes for HOMO–LUMO energy calculation. Non-bonding orbitals (NBO) analysis was performed to determine the numerous hyper-conjugative interactions responsible for the stability of the compound. In addition, Molecular Electrostatic Potential (MEP) analysis was conducted to identify the compounds' electron-rich, electron-poor, reactive sites, and bonding characteristics. The Electron Localization Function (ELF), and AIM Charges are also calculated. In vitro cytotoxicity, the complexes were examined against cervical cancer cells (HeLa) to assess their reactivity. Molecular docking studies were conducted to confirm the biological activity by simulating the binding orientation and affinity of the ligands and their complexes against VEGFR-2 kinase, The investigated ligands interact with the binding site as; hydrophilic (Lys868, Glu885, His1026, Cys1045, and Asp1046) and hydrophobic (Val889 and Leu889) for 4-etphdtc; hydrophilic (Lys868, Glu885, Cys1045, and Asp1046) and hydrophobic (Val889, Leu889, Leu1035, and Phe1047) for 6-etphdtc. The calculated binding free energy values for Zn(4-etphdtc)2 and Zn(6-etphdtc)2complexes are – 9.700 kcal/mol, – 10.003 kcal/mol, respectively. [ABSTRACT FROM AUTHOR]

Zinc and cadmium pollutants cause a significant environmental effect that cannot be ignored. Due to their considerable amount in an aqueous environment, industries are seeking suitable adsorbents that are environmentally friendly and inexpensive for removing metals from wastewater before disposing of them in surface waters. This research employed original MXene (MX) and chitosan-modified MXene (CSMX) to extract zinc (Zn(II)) and cadmium (Cd(II)) metal ions from water-based solutions. The composite material produced was analyzed using techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET). The effects of contact duration, pH of the solution, and initial concentration of metal ions on the adsorption process of Zn(II) and Cd(II) onto both MX and CSMX composites were investigated. MX and prepared CSMX composite presented a high adsorption capacity for both studied heavy metals, which were 91.55 and 73.82 mg/g for Zn(II) and Cd(II) onto MX, 106.84 and 93.07 mg/g for Cd(II) and Zn(II) onto CSMX composite, respectively. Furthermore, the maximum competitive adsorption capacities for Zn(II) onto MX and CSMX composites are 77.29 and 93.47 mg/g, and for are Cd(II) 60.30 and 79.66 mg/g, respectively. Hence, the removal capacities for both single and competitive metal ions were superior to CSMX composite. However, the adsorption capacities after five successive regeneration sequences were only dropped by 13.2% for Zn(II) and 17.4% for Cd(II) onto the CSMX composite compared to the first cycle. These results confirm that both metals could be efficiently terminated from wastewater, which makes the prepared CSMX composite a favorable candidate adsorbent in practical applications. [ABSTRACT FROM AUTHOR]

Zinc and cadmium pollutants cause a significant environmental effect that cannot be ignored. Due to their considerable amount in an aqueous environment, industries are seeking suitable adsorbents that are environmentally friendly and inexpensive for removing metals from wastewater before disposing of them in surface waters. This research employed original MXene (MX) and chitosan-modified MXene (CSMX) to extract zinc (Zn(II)) and cadmium (Cd(II)) metal ions from water-based solutions. The composite material produced was analyzed using techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET). The effects of contact duration, pH of the solution, and initial concentration of metal ions on the adsorption process of Zn(II) and Cd(II) onto both MX and CSMX composites were investigated. MX and prepared CSMX composite presented a high adsorption capacity for both studied heavy metals, which were 91.55 and 73.82 mg/g for Zn(II) and Cd(II) onto MX, 106.84 and 93.07 mg/g for Cd(II) and Zn(II) onto CSMX composite, respectively. Furthermore, the maximum competitive adsorption capacities for Zn(II) onto MX and CSMX composites are 77.29 and 93.47 mg/g, and for are Cd(II) 60.30 and 79.66 mg/g, respectively. Hence, the removal capacities for both single and competitive metal ions were superior to CSMX composite. However, the adsorption capacities after five successive regeneration sequences were only dropped by 13.2% for Zn(II) and 17.4% for Cd(II) onto the CSMX composite compared to the first cycle. These results confirm that both metals could be efficiently terminated from wastewater, which makes the prepared CSMX composite a favorable candidate adsorbent in practical applications.

The [ZnL(ONO2)2] 1 and [ZnL(NCS)2] 2 complexes were synthesized using self-assembly of the s-triazine tridentate ligand (L) with Zn(NO3)2·6H2O and Zn(ClO4)2·6H2O/NH4SCN, respectively. The Zn(II) is further coordinated by two nitrate and two isothiocyanate groups as monodentate ligands in 1 and 2, respectively. Both complexes have distorted square pyramidal coordination environments where the extent of distortion is found to be greater in 2 (τ5 = 0.41) than in 1 (τ5 = 0.28). Hirshfeld calculations explored the significant C···O, C···C, N···H, and O···H contacts in the molecular packing of both complexes. The energy framework analysis gave the total interaction energies of −317.8 and −353.5 kJ/mol for a single molecule in a 3.8 Å cluster of 1 and 2, respectively. The total energy diagrams exhibited a strong resemblance to the dispersion energy frameworks in both complexes. NBO charge analysis predicted the charges of the Zn(II) in complexes 1 and 2 to be 1.217 and 1.145 e, respectively. The electronic configuration of Zn1 is predicted to be [core] 4S0.32 3d9.98 4p0.45 4d0.02 5p0.01 for 1 and [core] 4S0.34 3d9.97 4p0.53 4d0.02 for 2. The increased occupancy of the valence orbitals is attributed to the donor→acceptor interactions from the ligand groups to Zn(II). The Zn(II) complexes were examined for their cytotoxic and antimicrobial activities. Both 1 and 2 have good cytotoxic efficiency towards HCT-116 and A-549 cancerous cell lines. We found that 1 is more active (IC50 = 29.53 ± 1.24 and 35.55 ± 1.69 µg/mL) than 2 (IC50 = 41.25 ± 2.91 and 55.05 ± 2.87 µg/mL) against both cell lines. Also, the selectivity indices for the Zn(II) complexes are higher than one, indicating their suitability for use as anticancer agents. In addition, both complexes have broad-spectrum antimicrobial activity (IC50 = 78–625 μg/mL) where the best result is found for 2 against P. vulgaris (IC50 = 78 μg/mL). Its antibacterial activity is found to be good compared to gentamycin (5 μg/mL) as a positive control against this microbe. [ABSTRACT FROM AUTHOR]

Based on phenanthroline derivate ligand and Zn(ii), two novel coordination polymers, namely [Zn(L)(hta)]n (1) and {[Zn2(L)2(dhb)2]·H2O}n (2) (L = 2-(2,6-dichlorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline, H2hta = heptanedioic acid, and H2dhb = 3,5-dinitro-2-hydroxybenzoic acid), have been synthesized under the hydrothermal condition. For 1, each hta anion bridges two Zn(ii) atoms in a tridentate mode to shape into a chain structure and through different π–π stacking interactions to form a three-dimensional supramolecular structure. The L ligand of 2 connects two neighbouring Zn(ii) atoms to give a 1D chain, which is further extended into the 2D supramolecular layer.

Background. The increasing pollution of natural waters by heavy metals has become a major problem in recent years, so their determination requires separation and pre-concentration techniques. Purpose. Development of a hybrid, sensitive sorption-spectrophotometric method for determining the Zn(II) ion using a polyethylene polyamine polyacrylonitrile (PPF-1) matrix immobilized in alizarin red C. Methodology. Research was carried out using a spectrophotometer, diffuse reflectance spectroscopy, IR spectroscopy and methods of mathematical statistics. Originality. For the first time, alizarin red C (AKS) was immobilized on a modified PPF-1 and a new matrix was used for the effective determination of Zn(II) Findings. The sensitivity of Zn(II) determination by selective immobilized ACS was maximum at 522 nm. The optimal pH for determining Zn(II) is 5.0 at room temperature. The linear range was found to be 6.5-40 mg/L, the detection limit was 0.6 mg/L, and the adsorption percentage was about 97%. [ABSTRACT FROM AUTHOR]

In this article, we present a sensitive and efficient method for the separation and determination of Zinc (II) and Magnesium (II) ions using a combination of liquid ion exchange and cloud point extraction (CPE). The process includes converting these ions into metal ion complexes by using EDTA at pH 10. These complexes are then bound electrostatically with Brilliant Green (BG) to form ion pair association complexes, which are subsequently transferred into a cloud point layer. The study involved optimizing the extraction conditions, including the EDTA concentration, temperature, heating duration, and surfactant volume. The concentration of EDTA for achieving higher extraction efficiency is 1×10-4 M in the presence of 100 μg of Zn(II) and Mg(II) per 10 mL of aqueous solution using 1×10-4 M of BG. The solutions should be heated at 85°C for Zn(II) and 80°C for Mg(II) for 20 minutes. The optimal volume of surfactants is 0.5 mL of Triton X-100 for Zn(II) and 0.6 mL for Mg(II). The study also includes an analysis of the impact of electrolytes and interferences and the spectrophotometric identification of Zn(II) and Mg(II) in various samples. [ABSTRACT FROM AUTHOR]

In the present study the behavior of Cu(II) and Zn(II) complexes with ethylenediamine and 2,2′:6′,2′′ terpyridine in an aqueous environment was studied by classical MD simulations. Special attention was paid to the effect of Cu2+ for Zn2+ substitution on complex water surroundings and mobility. The replacement of a metal ion affects the structure of the complex water environment only in the vicinity of its location. However, it changes such a characteristic as the lifetime of a water molecule in the first coordination shell of a metal which can significantly affect the mobility of the complex. Moreover, the degree of influence on translational and rotational mobility can be different. [ABSTRACT FROM AUTHOR]

Combined heavy metal contamination in soil is a common phenomenon. Biochar amendment into the soil is considered to be an alternative for immobilization remediation of soil contaminated with heavy metals due to its adsorption and alkalization. However, much attention has been paid to the adsorption and immobilization of single heavy metals by biochar. In this paper, the competitive adsorption of Cd(II) and Zn(II) on biochar derived from cotton straw and pig manure at 500°C (BCS500 and BPM500), loess and biochar-loess mixtures were investigated using the batch equilibrium method. The results showed that the adsorption capacities of biochars, loess, and biochar-loess mixtures to Cd(II) and Zn(II) in the mixed Cd-Zn systems increased with the increase of initial metal concentrations of Cd(II) and Zn(II). The adsorptive capacities of BCS500 and BPM500 to Cd(II) in mixed Cd-Zn system were 33% and 35% less than those in the single Cd(II)systems, while the adsorptive capacities to Zn(II) were 62% and 56% less than those in the single Zn(II) systems. The adsorptive capacities of loess to Cd(II) and Zn(II) in mixed Cd-Zn systems were 29% and 55% less than those in the single metal systems. The adsorptive capacities of loess-BCS500 (LBCS) and loess-BPM500 (LBPM) to Cd(II) in mixed Cd-Zn system were 40% and 38% less than those in the single Cd(II) systems, while the adsorptive capacities to Zn(II) were 63% and 60% less than those in the single Zn(II)systems. Moreover, the competitive adsorptive capacity of Cd(II) is greater than that of Zn(II). It can be seen that when heavy metal pollution with similar nature of multiple elements exists in soil, the amount of adsorbent should be increased to resist the possible weakened adsorption caused by competitive adsorption in order to guarantee an effective absorption treatment. [ABSTRACT FROM AUTHOR]

The modified clinoptilolite was used to mitigate Cu(II) and Zn(II) in acid mine drainage. This study explored integrating the cationic surfactant HDTMA-Br and the cation Mg(II) into clinoptilolite. The added HDTMA-Br concentration is designed to give a value with constant cation exchange capacity (k×CEC). The modified clinoptilolite using Mg(II) ions gives a higher volume and pore diameter of modified zeolite than natural clinoptilolite. However, the addition of HDTMA-Br can cover the surface of natural clinoptilolite, causing a decrease in pore volume and diameter and the adsorbent surface area. The addition of HDTMA-Br at level 1 of CEC (HDCL-1) led to an increase in the adsorption capacity of zeolite towards Cu(II) and Zn(II). According to the Langmuir model, the modified zeolite HDCL-1 exhibited the highest adsorption capacity, reaching 15.16 mg/g for Cu(II) and 15.51 mg/g for Zn(II). The findings suggest that Cu(II) and Zn(II) adsorption may involve an ion exchange mechanism. The use of HDCL-1 as an adsorbent at an initial pH of 5 can remove Cu(II) and Zn(II) ions by 100% and 75.5%, respectively in AMD model solutions that contain a ratio of Cu(II):Zn(II) = 1:1. HDCL-1 composite selectivity is better at absorbing Cu(II) metal ions than in absorbing Zn(II) ions. Continuous adsorption is carried out in a fixed bed adsorber column with a diameter of 1.25 cm. The concentration of Cu(II) coming out of the fixed bed column follows Thomas's model, and it is obtained that there is an increase in HDCL-1 saturation time from 0.2 h to 20.5 h if the adsorbent height is increased from 2 cm to 2.5 cm.

Abstract Background The increasing prevalence of the Galvanized and dry battery industries has led to a rise in zinc proportions in landfills, posing environmental risks. This study explores the potential of bentonite, renowned for its metal adsorption capability, as a landfill barrier material. Methods Adsorption characteristics of Zn(II) in natural bentonite and Shanghai clay were investigated. Various factors affecting Zn(II) adsorption, including pH, Na ion strength, contact time, initial Zn(II) concentration, and adsorption temperature, were analyzed through batch-type adsorption tests. Results The change in pH and Na strength demonstrates no significant impact on the adsorption of Zn(II) onto bentonite, highlighting the strong selectivity of bentonite for Zn(II). Conversely, the equilibrium adsorption capacity of Zn(II) onto clay increases with rising pH or decreasing ion strength. The Zn(II) adsorption onto bentonite is well-described by the pseudo-second-order, intra-particle diffusion, and Elovih models, each achieving an R2 value exceeding 0.9. While both physical and chemical adsorption coexist in Zn(II) adsorption onto bentonite or clay, the primary determinant of the adsorption rate is chemical adsorption. The adsorption onto bentonite is spontaneous, whereas onto clay it is not. The mechanism involves van der Waals forces, ion exchange, and chemical actions such as inner-sphere complexation for Zn(II) adsorption onto both bentonite and clay.

Background: The increasing prevalence of the Galvanized and dry battery industries has led to a rise in zinc proportions in landfills, posing environmental risks. This study explores the potential of bentonite, renowned for its metal adsorption capability, as a landfill barrier material. Methods: Adsorption characteristics of Zn(II) in natural bentonite and Shanghai clay were investigated. Various factors affecting Zn(II) adsorption, including pH, Na ion strength, contact time, initial Zn(II) concentration, and adsorption temperature, were analyzed through batch-type adsorption tests. Results: The change in pH and Na strength demonstrates no significant impact on the adsorption of Zn(II) onto bentonite, highlighting the strong selectivity of bentonite for Zn(II). Conversely, the equilibrium adsorption capacity of Zn(II) onto clay increases with rising pH or decreasing ion strength. The Zn(II) adsorption onto bentonite is well-described by the pseudo-second-order, intra-particle diffusion, and Elovih models, each achieving an R2 value exceeding 0.9. While both physical and chemical adsorption coexist in Zn(II) adsorption onto bentonite or clay, the primary determinant of the adsorption rate is chemical adsorption. The adsorption onto bentonite is spontaneous, whereas onto clay it is not. The mechanism involves van der Waals forces, ion exchange, and chemical actions such as inner-sphere complexation for Zn(II) adsorption onto both bentonite and clay. [ABSTRACT FROM AUTHOR]

The [ZnL(ONO2)2] 1 and [ZnL(NCS)2] 2 complexes were synthesized using self-assembly of the s-triazine tridentate ligand (L) with Zn(NO3)2·6H2O and Zn(ClO4)2·6H2O/NH4SCN, respectively. The Zn(II) is further coordinated by two nitrate and two isothiocyanate groups as monodentate ligands in 1 and 2, respectively. Both complexes have distorted square pyramidal coordination environments where the extent of distortion is found to be greater in 2 (τ5 = 0.41) than in 1 (τ5 = 0.28). Hirshfeld calculations explored the significant C···O, C···C, N···H, and O···H contacts in the molecular packing of both complexes. The energy framework analysis gave the total interaction energies of −317.8 and −353.5 kJ/mol for a single molecule in a 3.8 Å cluster of 1 and 2, respectively. The total energy diagrams exhibited a strong resemblance to the dispersion energy frameworks in both complexes. NBO charge analysis predicted the charges of the Zn(II) in complexes 1 and 2 to be 1.217 and 1.145 e, respectively. The electronic configuration of Zn1 is predicted to be [core] 4S0.32 3d9.98 4p0.45 4d0.02 5p0.01 for 1 and [core] 4S0.34 3d9.97 4p0.53 4d0.02 for 2. The increased occupancy of the valence orbitals is attributed to the donor→acceptor interactions from the ligand groups to Zn(II). The Zn(II) complexes were examined for their cytotoxic and antimicrobial activities. Both 1 and 2 have good cytotoxic efficiency towards HCT-116 and A-549 cancerous cell lines. We found that 1 is more active (IC50 = 29.53 ± 1.24 and 35.55 ± 1.69 µg/mL) than 2 (IC50 = 41.25 ± 2.91 and 55.05 ± 2.87 µg/mL) against both cell lines. Also, the selectivity indices for the Zn(II) complexes are higher than one, indicating their suitability for use as anticancer agents. In addition, both complexes have broad-spectrum antimicrobial activity (IC50 = 78–625 μg/mL) where the best result is found for 2 against P. vulgaris (IC50 = 78 μg/mL). Its antibacterial activity is found to be good compared to gentamycin (5 μg/mL) as a positive control against this microbe.

The synthesis and X-ray crystal structure analyses of the azido complex [Zn(N3)(Arg)2](N3)·3H2O, where Arg is L-arginine, were presented. The molecular structure of the complex was further studied using FT-IR spectra as well as atoms in molecules (AIM) theory. An analysis of the crystal data indicated monoclinic crystal system and P21 space group with a = 13.0283(5) Å, b = 15.2032(7) Å, c = 13.3633(6) Å, β = 114.3580(10)°, V = 2411.28(18) Å3, and Z = 4. Two of the [Zn(N3)(Arg)2](N3)·3H2O formulae represent the asymmetric unit of this complex where the geometric parameters of both units are slightly different. In [Zn(N3)(Arg)2](N3)·3H2O, the central Zn(II) ion is penta-coordinated with two Arg molecules as a bidentate ligand and one terminally coordinated azide ion. Each of the two Arg molecules are located trans to one another and coordinated with the Zn(II) via the N and O atoms of the amino and carboxylate groups, respectively. Hence, Zn(II) is five-coordinated and has a distorted square pyramidal coordination geometry. The supramolecular structure of the [Zn(N3)(Arg)2](N3)·3H2O complex was inspected using the Hirshfeld analysis. The O···H (26.6–28.4%), H···H (32.3–35.3%), and N···H (30.4–34.0%) contacts are the most significant interactions in the crystal structure of the [Zn(N3)(Arg)2](N3)·3H2O complex. The Zn–N, and Zn–O bonds have slight covalent interactions based on the AIM study. [ABSTRACT FROM AUTHOR]

This study aims to investigate the process and mechanism of adsorption of Zn(II) and Pb(II) by river sediments under hydrodynamic conditions. Surface sediments were collected from the Ganjiang River in Nanchang, China, and the adsorption characteristics of heavy metals Zn(II) and Pb(II) under different hydrodynamic conditions were simulated using the particle entrainment simulator. The results showed that under different hydrodynamic conditions, the adsorption equilibrium of Zn(II) and Pb(II) can be reached within 6h, and the adsorption amount of Pb(II) by the sediment was significantly higher than that of Zn(II). Pseudo-second-order dynamics and the Elovich model can better describe the kinetics of adsorption in both metals (R2 > 0.90). The Langmuir model and Freundlich model could better simulate the adsorption isotherms of Zn(II) and Pb(II) on sediments, which revealed that the adsorption spots are heterogeneous. According to the △G and −F results the adsorption of Zn(II) and Pb(II) is mainly physical adsorption. Furthermore, there are certain differences in the adsorption of heavy metals Zn(II) and Pb(II) by sediments at different pH, where the adsorption amount of Zn(II) increases with the increase of pH, but Pb(II) is not sensitive to the change of pH. HIGHLIGHTS Pseudo-second-order kinetics and Elovich models could better describe the kinetic process of adsorption of both metals.; Langmuir and Freundlich models could better simulate the adsorption isotherms of Zn(II) and Pb(II) on sediments.; The adsorption rate of Zn(II) and Pb(II) on sediments increased with increasing shear stress.;

A new thiosemicarbazide-naphthalene-based fluorescent chemosensor FNC ((2-(furan-2-carbonyl)-N-(naphthalen-1-yl)hydrazine-1-carbothioamide)) for Zn2+ was synthesized and identified. FNC was applied to selectively detect Zn2+ with fluorescent turn-on response. The detection limit was determined to be 1.93 µM, which is much below the WHO standard (76.5 µM). The detecting mechanism of FNC to Zn2+ was revealed to bind FNC to Zn2+ in the proportion of 1: 1 by Job plot, ESI-mass and 1H NMR titrations. DFT and TD-DFT calculations were performed for FNC and FNC-Zn2+, which provide insight into structural, electronic and photophysical properties. [ABSTRACT FROM AUTHOR]

Using density functional theory (DFT) B3PW91/TZVP, M06/TZVP, and OPBE/TZVP chemistry models and the Gaussian09 program, a quantum-chemical calculation of geometric and thermodynamic parameters of Ni(II), Cu(II), and Zn(II) macrotetracyclic chelates, with (NNNN)-coordination of ligand donor centers arising during template synthesis between the indicated ions of 3d elements, thiocarbohydrazide H2N–HN–C(=S)–NH–NH2 and diacetyl Me–C(=O)–C(=O)–Me, in gelatin-immobilized matrix implants was performed. The key bond lengths and bond angles in these coordination compounds are provided, and it is noted that in all these complexes the MN4 chelate sites, the grouping of N4 atoms bonded to the M atom, and the five-membered and six-membered metal chelate rings are practically coplanar. NBO analysis of these compounds was carried out, on the basis of which it was shown that all these complexes, in full accordance with theoretical expectations, are low-spin complexes. The standard thermodynamic characteristics of the template reactions for the formation of the above complexes are also presented. Good agreement between the data obtained using the above DFT levels is noted. [ABSTRACT FROM AUTHOR]

A D-π-A type compound (L) was synthesized by condensation of 2.2':6'.2"-terpyr- idine-4'-carboaldehyde with 4-Amino-N. N-diphenylaniline. The structure of L was determined by X-ray single crystal diffraction. Compound L is capable of intramolecular charge transfer (ICT). Terpyridine group acts as the Zn(II) recognition group due to its strong coordination ability. Upon the coordination with Zn(II), its electron-withdrawing capacity became stronger, and the energy required to generate ICT was reduced. Hence the fluorescence was significantly enhanced and red-shifted. The complexation ratio of L with Zn(II) in the detection system was confirmed to be 2: 1 by electrospray ionization mass spectrometry.Job's Plot and fluorescence titration. The formed Zn(II) complex exhibits aggregation-induced emission (AIE) property in THF/H2O. Therefore, based on ICT coupled with AIE, compound L can be used to detect Zn(II) in aqueous media. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Nanchang University (Engineering & Technology) is the property of Nanchang University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The efficient removal of organic contaminants from wastewater is, nowadays, a prominent area of study due to its biological as well as environmental significance. Antibiotics are now found in wastewater because of their high use, which has become a source of aquatic pollution. These antibiotics have dangerous implications for people's health. Hence, effective pharmaceutical removal from wastewater and contaminated water bodies, especially the removal of antibiotics, is of major interest to global research organizations. This is why it is necessary to investigate this class of toxic material in wastewater discharge. We synthesized three different coordination polymers (CPs) in the presence of various assistant carboxylate linkers, namely, [Zn(Hbtc)(dip)]n (1), [Zn4(1,2-bdc)4(dip)4]n (2), and [Zn(1,4-bdc)(dip)]n (3) (3,5-di(1H-imidazol-1-yl)pyridine = dip, 1,3,5-benzenetricarboxylic acid = H3btc, 1,2-benzenedicarboxylic acid = 1,2-H2bdc, and 1,4-benzendicarboxylic acid = 1,4-bdc). These CPs were characterized by using different techniques, including single-crystal X-ray diffraction. The structural studies demonstrated that in 2, there are four Zn(II) centers and both centers are in different coordination environments (Zn2 has distorted tetrahedral geometry, whereas Zn1, Zn3, and Zn4 have square pyramidal geometry). Hirshfeld surfaces analysis revealed that different types of intermolecular interactions (C⋯C, H⋯C, H⋯H, O⋯C, N⋯H, and O⋯H) are present in the synthesized CPs. We examined the different antibiotics, such as metronidazole (MDZ), nitrofurazone (NFZ), dimetridazole (DTZ), sulfasalazine(SLA), and oxytetracycline (OXY), degradation behaviors of the synthesized CPs, which showed remarkable degradation efficiency. 1 showed photocatalytic behavior toward the NFZ antibiotic in an aqueous media. This study also showed that these catalysts are stable and reusable under mild conditions. [ABSTRACT FROM AUTHOR]

Recrystallization of [Zn(malt)2(H2O)1.5] (malt = maltolato(-1), C6H5O3) from a concentrated aqueous solution acidified with HCl to pH 3.0 yielded colorless crystals of [Zn(Hmalt)2Cl2] (Hmalt = neutral maltol, C6H6O3). The Zn(II) site exhibits distorted tetrahedral coordination through bonding to two chloride ligands and to two neutral maltol ligands, each bonding through the ketonic oxygen. [Zn(Hmalt)2Cl2] is a unique example of a neutral monodentate coordination by the maltol ligand. A view of the tetrahedral [Zn(Hmalt)2Cl2] (Hmalt = neutral maltol, C6H6O3). [ABSTRACT FROM AUTHOR]

Two new Zn(ii) coordination complexes [Zn(L)(dna)(H2O)] (1) and [Zn(L)(glu)]2·H2O (2) (L = 2-(4-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline, H2dna = 3,5-dinitrosalicylic acid, H2glu = glutaric acid) have been hydrothermally synthesized and characterized by single crystal X-ray diffraction, elemental analysis, fluorescence spectrum, and infrared spectroscopy. For complex 1, the dna2− anion adopts μ 1 -η 1 :η 1 chelating bidentate mode to coordinate with one Zn(ii) atom and π–π stacking interactions are formed between the L ligands. For complex 2, glu2− anions connect Zn(ii) atoms to form a wavy two-dimensional layer, and the L ligands are attached on two sides of the two-dimensional layer.

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A Schiff base, 3-Hydroxy-4-(3-hydroxy benzylidene amino) benzoic acid was synthesized from the corresponding starting ketone, 3-Hydroxy benzaldehyde and amine, 3-hydroxy 4-amino benzoic acid by condensation reaction. Further, the metal complexes of the Schiff base with Ni(II) and Zn(II) were synthesized. These Schiff base and its Ni(II) and Zn(II) metal complexes were characterized by spectral techniques like FT-IR, ¹H NMR and 13C NMR spectroscopy. The synthesized compounds were evaluated for their antibacterial activity against Gram positive and negative bacteria like Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The anti-fungal activities were also studied for Candida albicans, Candida parapsilosis. The Zn(II) metal complex exhibited the good antibacterial and antifungal activity among the all prepared compounds. [ABSTRACT FROM AUTHOR]

A metallomesogen based on an Zn(II) coordination complex was employed as precursor to obtain a complex matrix nanoplatform for the fabrication of a high-performance electrochemical hybrid sensor. Three representative paste electrodes, which differ by the weight ratio between Zn(II) metallomesogen and carbon nanotubes (CNT), i.e., PE_01, PE_02 and PE_03, were obtained by mixing the materials in different amounts. The composition with the largest amount of CNT with respect to Zn complex, i.e., PE_03, gives the best electrochemical signal for uric acid detection by cyclic voltammetry in an alkaline medium. The amphiphilic structure of the Zn(II) coordination complex likely induces a regular separation between the metal centers favoring the redox system through their reduction, followed by stripping, and is characterized by enhanced electrocatalytic activity towards uric acid oxidation. The comparative detection of uric acid between the PE_03 paste electrode and the commercial zinc electrode demonstrated the superiority of the former, and its great potential for the development of advanced electrochemical detection of uric acid. Advanced electrochemical techniques, such as differential-pulsed voltammetry (DPV) and square-wave voltammetry (SWV), allowed for the highly sensitive detection of uric acid in aqueous alkaline solutions. In addition, a good and fast amperometric signal for uric acid detection was achieved by multiple-pulsed amperometry, which was validated by urine analysis. [ABSTRACT FROM AUTHOR]

Organic nanoparticles of 4 ligands i.e. ONPs of JM-1 , JM-2 , JM-3 and JM-4 are prepared. Among them, ONPs of JM-1 and JM-4 have shown chemosensing towards Zn(II) and Hg(II) respectively. [Display omitted] • Four dipodal ligands JM-1 , JM-2 , JM-3 and JM-4 are synthesized and their ONPs are prepared. • ONPs of JM-1 have shown chemosensing towards Zn(II) ions by PET-off mechanism with LOD of 55.7 nM. • ONPs of JM-4 have shown chemosensing towards Hg(II) ions by PET-off mechanism with LOD of 1.35 µM. Zinc (II) plays a pivotal role in sustaining life processes, whereas Mercury (II) stands out as a significant environmental contaminant. It is imperative to accurately identify these elements to gauge potential imbalances, whether in deficiency or excess, within biological and ecological systems. In this manuscript, four dipodal ligands JM-1 i.e. 1,1′-(2,2′-disulfanediylbis(ethane-2,1-diyl))bis(3-(4-nitrophenyl)urea), JM-2 i.e. 1,1′-(2,2′-disulfanediylbis (ethane-2,1-diyl))bis(3-(4-nitrophenyl)thiourea), JM-3 i.e. 1,1′-(2,2′-disulfanediylbis(ethane-2,1-diyl))bis(3-(naphthalen-1-yl)urea) and JM-4 i.e. 1,1′-(2,2′-disulfanediylbis(ethane-2,1-diyl))bis(3-(naphthalen-1-yl)thiourea) are synthesized and characterized by various spectroscopic methods. In order to minimize the organic solvent, organic nanoparticles (ONPs) (0.01 mM) of these ligands (2 mM) have been fabricated by reprecipitation method. ONPs of JM-1 has shown chemosensing towards Zn(II) with limit of detection upto nanomolar level i.e. 55.7 nM and ONPs of JM-4 had shown chemosensing towards Hg(II) with limit of detection as 1.35 µM while ONPs of JM-3 and JM-2 did not show any kind of chemosensing behavior towards any cation or anion. Both of ONPs of JM-1 and ONPs of JM-4 showed recognition behavior via photoinduced electron transfer (PET)-off phenomenon. ONPs of JM-1 showed 18 fold enhancement in its fluorescence emission intensity when bound to Zn(II) with excellent linearity which was quite stable with respect to time. [ABSTRACT FROM AUTHOR]

[Display omitted] • The SPE was decorated with platinum and nickel microstructures via a simple electrodeposition technique. • The electrochemical detection was performed by CV, DPV, and SWV techniques. • Excellent electro-catalytic activity towards 4-AP, PA, AA and Zn(II) was accomplished. • The proposed sensor has been successfully applied to monitor 4-AP, PA, AA and Zn(II) in pharmaceutical formulations and real human serum samples. • The signal recoveries of the prepared sensor reach to 95.4–109% in real human blood samples and pharmaceutical formulations samples. In this study, we report for the first time, a method for simultaneous detection of paracetamol (PA) and its toxic impurities, 4-aminophenol (4-AP), as well as commonly co-formulated drugs, ascorbic acid and zinc (AA and Zn(II)), using screen-printed electrodes (SPEs) as a sensing platform. To improve the electrochemical performance of the SPEs, these are decorated with platinum and nickel microstructures (Pt–Ni), using a simple electrodeposition technique. The structures and morphologies of the synthesized Pt–Ni/SPE electrode were confirmed by FE–SEM, TEM, EDX, XRD and AFM measurements. Furthermore, electrochemical characterization of the as-prepared sensor was investigated using cyclic voltammetry and electrochemical impedance spectroscopy methods. Under optimum conditions, the content of 4-AP, PA, AA and Zn(II) was quantified using cyclic voltammetry, differential pulse voltammetry and square-wave voltammetry techniques. The designed sensor exploits a dual effect, leveraging the efficiency of Pt for Zn(II) detection and Pt–Ni for the detection of 4-AP, AA, and PA. On one hand the as-prepared Pt–Ni/SPE sensor exhibits a linear response towards 4-AP and PA, ranging from 0.5 to 200 μM for both, with detection limits of 0.33 µM and 0.23 µM (S/N = 3) for 4-AP and PA, respectively. On the other hand, it demonstrates a linear response towards PA, AA, and Zn(II), ranging from 0.01 to 0.8 μM for Zn(II), 10 to 1800 μM for AA, and 0.5 to 200 μM for PA, with detection limits of 0.004 µM, 9.0 µM, and 0.15 µM for Zn(II), AA, and PA, respectively. Crucially, the as-fabricated sensor, with its remarkable reproducibility, recovery, long-term stability, and anti-interference capabilities, effectively quantified 4-AP, PA, Zn(II) and AA in both pharmaceutical formulations and human plasma samples. [ABSTRACT FROM AUTHOR]

Reaction of Zn(II) and Cu(II) bromide and chloride with 2-(aminomethyl)aniline produced a family of 4-, 5- and 6-coordinate complexes. All zinc compounds exhibit monodentate coordination through the aminomethyl group, while the copper complexes exhibit chelation of the 2-(aminomethyl)aniline. [Display omitted] The syntheses and structures of 2-(aminomethyl)aniline (2-AMAn) complexes of CuX 2 and ZnX 2 (X = Cl, Br) are reported: [(2-AMAn)ZnCl 2 ] (1), [(2-AMAn)ZnBr 2 ] (2), [(2-AMAn) 2 ZnCl 2 ] (3), [(2-AMAn) 2 ZnBr 2 ] (4), [(2-AMAn) 2 CuCl]Cl (5) and [(2-AMAn) 2 Cu(H 2 O) 2 ]Br 2 (6). Compounds 1 and 2 are isomorphous and crystallize in the monoclinic space group Ia with two coordinated halide ions and one chelating 2-AMAn ligand. Compounds 3 and 4 are also isomorphous and crystallize in the monoclinic space group P 2 1 / n with two monodentate 2-AMAn ligands and two coordinated halide ions. All four Zn(II) complexes are slightly distorted tetrahedral in geometry. The Cu(II) complexes are structurally distinct from the Zn(II) complexes. 5 crystallizes in the monoclinic space group P 2 1 / n and is strongly distorted square pyramidal in geometry with two chelating 2-AMAn ligands, one coordinated chloride ion and one dissociated chloride ion. The bromide compound, 6 , crystallizes in the monoclinic space group P 2 1 / c , also with two chelating 2-AMAn ligands, but with two coordinated water molecules and both bromide ions dissociated in the lattice. [ABSTRACT FROM AUTHOR]

The emergence of new biotechnologies has increased interest in the study of the impact of environmental contamination on microbial communities, particularly in relation to the potential benefits that stress-adapted microorganisms offer in environmental protection, industrial ecology, and mineral and waste processing. This study aimed to compare the bioaccumulation abilities of recently isolated microscopic fungi belonging to the genera Aspergillus, Phoma, Cystobasidium, Cladosporium and Exophiala. These fungi were isolated from a site contaminated with both toxic metals and organic pollutants. The study monitored the bioaccumulation of selected toxic metal ions (Cu(II), Zn(II), Ni(II), Cr(III), Pb(II)), as well as pH changes, over a 30-day of biomass growth. The medium containing Pb(II) exhibited a statistically significant pH change during the 30-day accumulation period (Mann-Whitney U Test, p < 0.05). These findings provide valuable insights for the potential industrial application of microscopic fungi in bioaccumulation processes.

The synthesis and X-ray crystal structure analyses of the azido complex [Zn(N3)(Arg)2](N3)·3H2O, where Arg is L-arginine, were presented. The molecular structure of the complex was further studied using FT-IR spectra as well as atoms in molecules (AIM) theory. An analysis of the crystal data indicated monoclinic crystal system and P21 space group with a = 13.0283(5) Å, b = 15.2032(7) Å, c = 13.3633(6) Å, β = 114.3580(10)°, V = 2411.28(18) Å3, and Z = 4. Two of the [Zn(N3)(Arg)2](N3)·3H2O formulae represent the asymmetric unit of this complex where the geometric parameters of both units are slightly different. In [Zn(N3)(Arg)2](N3)·3H2O, the central Zn(II) ion is penta-coordinated with two Arg molecules as a bidentate ligand and one terminally coordinated azide ion. Each of the two Arg molecules are located trans to one another and coordinated with the Zn(II) via the N and O atoms of the amino and carboxylate groups, respectively. Hence, Zn(II) is five-coordinated and has a distorted square pyramidal coordination geometry. The supramolecular structure of the [Zn(N3)(Arg)2](N3)·3H2O complex was inspected using the Hirshfeld analysis. The O···H (26.6–28.4%), H···H (32.3–35.3%), and N···H (30.4–34.0%) contacts are the most significant interactions in the crystal structure of the [Zn(N3)(Arg)2](N3)·3H2O complex. The Zn–N, and Zn–O bonds have slight covalent interactions based on the AIM study.

The inorganic mineral content in biochar influences the adsorption of Zn(II) metal ions. Metal ion adsorption on mineral rich rice straw biochar is influenced upon washing. Rice straw slow pyrolysis biochar BC1-3, respectively, prepared at 400, 500, and 600 °C, were leached under Toxicity Characteristic Leaching Procedure (TCLP) and Synthetic Precipitation Leaching Procedure (SPLP) conditions to furnish BT1-3 and BS1-3, respectively. The Zn(II) adsorption studies were carried out for pH and dose optimization, initial concentration, isotherm fit, and kinetic studies. The Zn(II) adsorption by B(C/S/T)1–3 showed Langmuir and Freundlich isotherm, with pseudo-second-order kinetics at optimum pH 5 and dose 1 g/L. The adsorption of Zn(II) followed the trend BC3(qm 47 mg/g) > BC2 > BC1 > BS2 > BS1 > BS3 > BT2 > BT1 > BT3 (qm 3.5 mg/g), i.e., metal ion adsorption decreased with extent of leaching. The Zn(II) adsorption on biochar involved precipitation as dominant factor for metal ion adsorption on the biochars followed by ion exchange and proton exchange. The precipitation of Zn(II) ions in case of BC1-3 is attributed to the pH of biochar, which increases with proportion of minerals to organic content in biochar. In case of biochar BS1-3 and BT1-3, ion exchange and proton exchange mechanisms driven by demineralization are responsible for Zn(II) adsorption. The adsorption mechanism for Zn(II) on biochar is supported by XPS, solid state NMR studies. [ABSTRACT FROM AUTHOR]

A new complex of Zn(II), with 5-chloro-2-methylbenzoxazole ligand (L), has been synthesized by the reaction of zinc dichloride with the ligand (L= C8H6ClNO) in ethanol solution: dichloridobis(5-chloro-2-methyl-1,3-benzoxazole)- zinc(II), C16H12Cl4N2O2Zn. The synthesized complex has been fully characterized by elemental analysis, molar conductivity, FT-IR, UV-Vis, and single-crystal X-ray diffraction (XRD). The XRD analysis reveals that the complex has a 1:2 metal-to-ligand ratio. The zinc(II) complex has a distorted tetrahedral geometry with two coordinated nitrogen atoms from the ligand. Density Functional Theory (DFT) calculations were performed at the B3LYP level of theory using the LANL2DZ basis set for metal complex and the 6-31G(d) basis set for non-metal elements to determine the optimum geometry structure of the complex, and the calculated HOMO and LUMO orbital energies were presented. A natural bond orbital (NBO) analysis was carried out on the molecules to analyze the atomic charge distribution before and after the complexation of the ligand. The Hirshfeld surface mapped over dnorm, shape index, and curvature exhibited strong H... Cl/Cl...H and H...H intermolecular interactions as the principal contributors to crystal packing. [ABSTRACT FROM AUTHOR]

In this study, we have synthesized two zinc(II)-based metal-organic frameworks (MOFs) designated as [Zn(4-nvp)(bdc)]·(MeOH) (1) and [Zn2(4-nvp)2(bpdc)2]·(DMF) (2) [4-nvp = 4-(1-Naphthylvinyl) pyridine, H2bdc = 1,4-benzendicarboxylic acid and H2bpdc = 4,4'-biphenyldicarboxylic acid]. Single-crystal X-ray diffraction (SCXRD) of both compounds unveiled an interesting paddle-wheel [Zn2(O2C-C)4] secondary building unit composed of dinuclear Zn (II) centers and four dicarboxylate groups with a (4,4) square grid topology. These SBUs are interconnected giving rise to an infinite 2D layer architecture. Notably, the grid structure is composed of MeOH molecules in compound 1 and DMF molecules in compound 2, both of them arranged in a free lattice. In both compounds, 3D supramolecular architecture is ultimately formed through the stacking of 2D layers. Since the length of the bpdc ligand is higher than that of the bdc ligand, the solvent-accessible void volume is comparatively higher for compound 2. To corroborate all non-bonded interactions, Hirshfeld analysis was carried out for synthesized compounds. DNA binding application was extensively investigated through docking study. Results indicated that the synthesized compounds have strong affinities towards DNA via DNA groove binding. Henceforth, the synthesized compounds 1 and 2 would open the door for their potential applications as particular protein binders and bioactive substances., (© 2024 Wiley‐VCH GmbH.)

In this study, L-methionine and nano-Fe3O4 were encapsulated and cured on sodium alginate by the ionic cross-linking method to form magnetic composite gel spheres (SML) as an adsorbent for the removal of Zn(II) from water. The influence of adsorbent dosages, pH, reaction time, and initial ion concentration on the ability of the gel spheres to adsorb Zn(II) was investigated, and the adsorption mechanism was identified. The experimental results showed that under the optimum conditions (pH = 5, t = 60 min, dosage of SML is 0.7 g·L−1), the maximum amount of Zn(II) adsorbed by the adsorbent gel spheres reached 86.84 mgˑg−1. The reaction process of this adsorbent fits well with the Langmuir and pseudo-second-order kinetic models and is a heat absorption reaction. The adsorbent would preferentially adsorb Pb(II), and the adsorption efficiency of Zn(II) decreased when the concentration of interfering ions increased in the coexistence system. Further mechanistic research showed that this magnetic composite adsorbent is a mesoporous material with superior adsorption performance, and the amino and carboxyl groups on it react with Zn(II) via ligand chelation; the ion exchange effect of Ca(II) also plays a role. The adsorption amount of Zn(II) was maintained at a higher level after 5 cycles, and the loss of Fe was approximately 0.2%. In summary, SML, which is environmentally friendly, efficient, and recyclable, is an ideal adsorbent for Zn(II) removal. [ABSTRACT FROM AUTHOR]

The rational design of heterometallic compounds bearing s-block metal ions have been a difficult task for chemists owing to their lack of preferential geometries. However, some strategies, such as the design of coordinating pockets with different sizes and/or donor atoms, have offered great results. In this work, this strategy has been tested using Ca(II) as an s-block metal ion and a compound previously obtained by our group with the formula [Zn3(μ-ACA)6(4-phpy)2], which contains tetrahedral N,O- and octahedral O-coordinating pockets as a model structure. From this work, the corresponding heterometallic compound with the formula [Zn2Ca(μ-ACA)6(4-phpy)2]·EtOH (1) has been successfully synthesized, and fully characterized, and its crystal structure has been elucidated. Furthermore, we have compiled all the crystal structures containing [Zn2M] pinwheel secondary building units (SBUs), where M stands for an s-block metal ion, and the observed tendencies, as well as the promising applications as template SBUs for the preparation of 1D–3D coordination polymers, have been discussed. Finally, solid-state UV-Vis and photoluminescence have been recorded and compared with the homometallic [Zn3(μ-ACA)6(4-phpy)2] compound. [ABSTRACT FROM AUTHOR]

In this study, a batch sorption study approach was combined with an instrumental analytical approach of atomic absorption spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) for the sorption of copper and zinc ions from aqueous solution on zeolites. Both copper and zinc are biogenic elements; nevertheless, many industrial processes produce an excessive amount, which is why their efficient removal from water must be studied. Two types of zeolites, Zeolite Micro 20 (Z-M20) and Zeolite Micro 50 (Z-M50), were used. The results showed that the maximum sorption capacities for removal of Cu and Zn were 1.06 for CuSO4, 42.35 for Cu(NO3)2, 1.15 for ZnSO4 and 2.29 for Zn(NO3)2 adsorption onto Z-M20 and 0.45 for CuSO4, 1.67 for Cu(NO3)2, 0.39 for ZnSO4 and 1.51 for Zn(NO3)2 adsorption onto Z-M50. The maximum sorption capacities are higher for sulfates and the sorbent with smaller particle size. The sorption capacities of Cu and Zn for corresponding anion and particle size differ only up to 5–15%. Using XRD and XPS analyses before and after the sorption process, it was found that the content of both Cu and Zn in the surface layer and the bulk are the same for sorption onto sorbent with smaller particle size, but are higher in the surface layer than in the bulk for sorption onto sorbent with larger particle size. One of the main findings of this study is that a zeolite with smaller particles takes Cu and Zn by the whole particle, while with bigger particles, Cu and Zn concentrate in the surface of the particle. The results of the study may be used as an indicator for sorption efficiency of the studied zeolites for their application in the treatment of copper and zinc contaminated effluents. [ABSTRACT FROM AUTHOR]

2,4-bis (3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (BPMT) pincer ligand was used to synthesize the new [Zn(BPMT)(NCS)2] (1) and [Zn(BPMT)(Br)2] (2) complexes by a reaction with Zn(NO3)2·6H2O in the presence of either KSCN or KBr, respectively. The structure of complex 1 has been exclusively confirmed using single crystal X-ray diffraction. In this neutral heteroleptic complex, the BPMT is a pincer chelate coordinating the Zn(II) ion via three interactions with the two pyrazole moieties and the s-triazine core. Hence, BPMT is a tridentate NNN-chelate. The coordination environment of Zn(II) is completed by two strong interactions with two terminal SCN− ions via the N-atom. Hence, the Zn(II) is penta-coordinated with a distorted square pyramidal coordination geometry. Hirshfeld analysis indicated the predominance of H...H, H...C and N...H intermolecular interactions. Additionally, the S...H, S...C and S...N contacts are the most significant. The free ligand has no or weak antimicrobial, antioxidant and anticancer activities while the studied Zn(II) complexes showed interesting biological activity. Complex 1 has excellent antibacterial activity against B. subtilis (2.4 μg/mL) and P. vulgaris (4.8 μg/mL) compared to Gentamycin (4.8 μg/mL). Additionally, complex 1 (78.09 ± 4.23 µg/mL) has better antioxidant activity than 2 (365.60 ± 20.89 µg/mL). In addition, complex 1 (43.86 ± 3.12 µg/mL) and 2 (30.23 ± 1.26 µg/mL) have 8 and 12 times the anticancer activity of the free BPMT ligand (372.79 ± 13.64 µg/mL). [ABSTRACT FROM AUTHOR]

Using density functional theory (DFT) B3PW91/TZVP, M06/TZVP, and OPBE/TZVP chemistry models and the Gaussian09 program, a quantum-chemical calculation of geometric and thermodynamic parameters of Ni(II), Cu(II), and Zn(II) macrotetracyclic chelates, with (NNNN)-coordination of ligand donor centers arising during template synthesis between the indicated ions of 3d elements, thiocarbohydrazide H2N–HN–C(=S)–NH–NH2 and diacetyl Me–C(=O)–C(=O)–Me, in gelatin-immobilized matrix implants was performed. The key bond lengths and bond angles in these coordination compounds are provided, and it is noted that in all these complexes the MN4 chelate sites, the grouping of N4 atoms bonded to the M atom, and the five-membered and six-membered metal chelate rings are practically coplanar. NBO analysis of these compounds was carried out, on the basis of which it was shown that all these complexes, in full accordance with theoretical expectations, are low-spin complexes. The standard thermodynamic characteristics of the template reactions for the formation of the above complexes are also presented. Good agreement between the data obtained using the above DFT levels is noted.

• Two new coordination polymers were synthesized and characterized. • 1 and 2 display high chemical stability. • 1 and 2 are the first CPs for the detecting Hg2+ and PEF. • The turn-off mechanisms were investigated in detail. Detection of heavy ions and antibiotics employing fuorescent sensing techniques has been one of the most active research fields in chemistry. Based on 1,3-bis(2-ethylbenzimidazol-1-ylmethyl)benzene (L) and 2,5-dichloroterephthalic acid (H 2 DCTP) mixed ligands, two new coordination polymers [Cd 2 L(DCTP) 2 ·H 2 O] n (1) and [ZnL(DCTP)] n (2) were synthesized by changing the metal ions under solvothermal conditions. 1 expresses a double-layer V-shaped 1D chain, which further extended into a 2D supramolecular network through classic O–H⋯O hydrogen bonding interactions. 2 features a 2D 4-connected sql layer. The two CPs perform high thermal and pH stability. 1 and 2 are the first CPs to detect Hg2+ ions and pefloxacin by fluorescence quenching with low detection limits and superior recyclability. Two robust metal coordination polymers can be acted as sensitive dual-responsive sensors for Hg2+ ions and pefloxacin in water with excellent selectivity and recyclability. The quenching mechanism of two coordination polymers were investigated in detail. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, fluorescent gold nanoclusters (AuNCs) conjugated with pyridoxal-5-phosphate (PLP) were synthesized, characterized, and used for Zn2+ fluorescence turn-on sensing. PLP was conjugated over the surface of papain-stabilized fluorescent gold nanoclusters (pap-AuNCs; λex = 380 nm, λem = 670 nm) by forming imine linkage. Due to this modification, the red color emitting pap-AuNCs changed to orange color emitting nanoclusters PLP_pap-AuNCs. The nano-assembly PLP_pap-AuNCs detect Zn2+ selectively by showing a notable fluorescence enhancement at 477 nm. Zn2+ detection with PLP_pap-AuNCs was quick and easy, with an estimated detection limit of 0.14 µM. Further, paper strips and cotton buds coated with PLP_pap-AuNCs were developed for affordable on-site visual detection of Zn2+. Finally, the detection of Zn2+ in actual environmental water samples served as validation of the usefulness of PLP_pap-AuNCs. [ABSTRACT FROM AUTHOR]

Pyrene-naphthaldehyde derivative PNY was synthesized and employed for the cascade fluorescent 'On-Off' detection of Zn2+ and H 2 P O 4 -. [Display omitted] • A pyrene-naphthaldehyde based Schiff base PNY was synthesized and characterized. • PNY was employed for cascade fluorescent 'Off-On-Off' detection of Zn2+ and phosphate ions. • PNY showed a distinct fluorescence enhancement at 450 nm for Zn2+ due to the formation of a pyrene excimer. • The in-situ formed PNY-Zn2+ complex gets decomplex upon the addition of phosphate ions. • PNY and PNY-Zn2+ were explored to quantify Zn2+ and phosphate ions in real samples. There is growing research on developing fluorescent chemosensors that can detect multiple analytes. Herein, a pyrene-naphthaldehyde based Schiff base PNY was synthesized, characterized, and employed for the cascade fluorescent 'Off-On-Off' detection of Zn2+ and phosphate ions. The interaction of PNY with Zn2+ led to a distinct fluorescence enhancement at 450 nm, and the fluorescent color of PNY was changed from blue to cyan-blue due to the complexation-induced formation of a pyrene excimer. PNY, as a fluorescent turn-on sensor can be employed to detect Zn2+ down to 2.20 × 10−7 M. Subsequently, the in-situ formed PNY-Zn2+ complex gets decomplex upon the addition of phosphate ion among other tested anions with a detection limit of 3.42 × 10−7 M. With the addition of phosphate ion, fluorescence intensity of PNY-Zn2+ at 450 nm was quenched with the concomitant formation of an emission peak at around 396 nm. The excimer-monomer mechanism was used to explain the sensing ability of PNY. Further, to complement the phosphate ion selectivity, the ability of PNY-Zn2+ to detect adenosine triphosphate (ATP) was explored. At last, the analytical novelty of PNY and PNY-Zn2+ was explored by quantifying Zn2+ and phosphate ions in real environmental and biological samples. [ABSTRACT FROM AUTHOR]

The efficient removal of organic contaminants from wastewater is, nowadays, a prominent area of study due to its biological as well as environmental significance. Antibiotics are now found in wastewater because of their high use, which has become a source of aquatic pollution. These antibiotics have dangerous implications for people’s health. Hence, effective pharmaceutical removal from wastewater and contaminated water bodies, especially the removal of antibiotics, is of major interest to global research organizations. This is why it is necessary to investigate this class of toxic material in wastewater discharge. We synthesized three different coordination polymers (CPs) in the presence of various assistant carboxylate linkers, namely, [Zn(Hbtc)(dip)]n (1), [Zn4(1,2-bdc)4(dip)4]n (2), and [Zn(1,4-bdc)(dip)]n (3) (3,5-di(1H-imidazol-1-yl)pyridine = dip, 1,3,5-benzenetricarboxylic acid = H3btc, 1,2-benzenedicarboxylic acid = 1,2-H2bdc, and 1,4-benzendicarboxylic acid = 1,4-bdc). These CPs were characterized by using different techniques, including single-crystal X-ray diffraction. The structural studies demonstrated that in 2, there are four Zn(II) centers and both centers are in different coordination environments (Zn2 has distorted tetrahedral geometry, whereas Zn1, Zn3, and Zn4 have square pyramidal geometry). Hirshfeld surfaces analysis revealed that different types of intermolecular interactions (C⋯C, H⋯C, H⋯H, O⋯C, N⋯H, and O⋯H) are present in the synthesized CPs. We examined the different antibiotics, such as metronidazole (MDZ), nitrofurazone (NFZ), dimetridazole (DTZ), sulfasalazine(SLA), and oxytetracycline (OXY), degradation behaviors of the synthesized CPs, which showed remarkable degradation efficiency. 1 showed photocatalytic behavior toward the NFZ antibiotic in an aqueous media. This study also showed that these catalysts are stable and reusable under mild conditions.