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ABSTRACT The 3,5‐diaryl‐1,2,4‐oxadiazole scaffolds 2 and 3 were synthesized and used as ligands to obtain three novel Ag(I) complexes 4–6. The structure of the Ag(I) complexes 4–6 has been confirmed by single crystal X‐ray diffraction. Complex 4 has the dinuclear formula [Ag(2)(NO3)]2. 5 and 6 are monomeric complexes having the formula [Ag(3)2(NO3)] and [Ag(3)2]ClO4, respectively. In vitro, trypsin, ALDH2, and iNOS inhibition activities were assessed for the free ligands and their Ag(I) complexes. Interestingly, Ag(I) complexes 4–6 revealed more prominent trypsin inhibitory activity than the ligands 2 and 3. The oxadiazole derivative 3 and its Ag(I) complex (6) showed significant ALDH2 inhibition (45% and 55%, respectively). Complex 6 (IC50 = 35.61 μM) surpassed its 1,2,4‐oxadiazole ligand 3 (IC50 = 88 μM) and evidenced the most prominent ALDH2 inhibitory activity. The oxadiazole derivative 3 and its corresponding Ag(I) complexes 5 and 6 showed significant iNOS inhibition (77.77%, 84.12%, and 84.15%, respectively). With IC50 values of 18.13, 18.15, and 13.96 μM, respectively, complex 6 is the most potent against iNOS, surpassing the reference standard. [ABSTRACT FROM AUTHOR]

Untreated or inadequately treated silver−containing wastewater may pose adverse effects on hu−man health and the ecological environment. Currently, significant progress has been made in the treatment of Ag(I) in wastewater using adsorption methods, with adsorbents playing a pivotal role in this process. This paper provides a systematic review of various adsorbents for the recovery and treatment of Ag(I) in wastewater, including MOFs, COFs, transition metal sulfides, metal oxides, biomass materials, and other polymeric materials. The adsorption mechanisms of these materials for Ag(I) are elaborated upon, along with the challenges currently faced. Furthermore, insights into optimizing adsorbents and developing novel adsorbents are proposed in this study. [ABSTRACT FROM AUTHOR]

Fe nanoparticle-functionalized ordered mesoporous carbon (Fe0/OMC) was synthesized using triblock copolymers as templates and through solvent evaporation self-assembly, followed by a carbothermal reduction. Fe0/OMC had three microstructures of two-dimensional hexagonal (space group, p6mm, Fe0/OMC-1), body centered cubic (Im3̄m, Fe0/OMC-2), and face centered cubic (Fm3̄m, Fe0/OMC-3) which were controlled by simply adjusting the template. All Fe0/OMC displayed paramagnetic characteristics, with a maximum saturation magnetization of 50.1 emu·g−1. This high magnetization is advantageous for the swift extraction of the adsorbent from the solution following the adsorption process. Fe0/OMC was used as an adsorbent for the removal of silver ions (Ag(i)) from aqueous solutions, and the adsorption capacity of Fe0/OMC-1 was enhanced by the functionalization of Fe0. Adsorption property of Fe0/OMC-1 was significantly higher than that of Fe0/OMC-2 and Fe0/OMC-3, indicating that the long and straight ordered pore channels were more favorable for adsorption, and the adsorption capacity of Ag(i) on Fe0/OMC-1 was 233 mg·g−1. The adsorption process exhibited conformity with both the pseudo-second-order kinetic model and the Freundlich model, suggesting that the dominant mechanism of adsorption involved multilayer adsorption on heterogeneous surfaces.

The pollution of silver ion (Ag(i)) has become a serious environmental threat and hazard to ecosystem and human health. Thus, the nanoscale zero valent iron (nZVI)-doped polypyrrole-based carbon nanotube (nZVI/CNT) composites were synthesized by a facile method to remove Ag(i) from wastewater due to the toxicity and scarcity nature of Ag(i). In this process, Fe3+ initiated the self-assembly of polypyrrole tubes in the presence of methyl orange, while it also served as an iron source generated nZVI/CNTs by carbothermal reduction method. The nZVI/CNT composites exhibited a homogeneous tubular structure, and the nZVI formed were uniformly dispersed in the nZVI/CNT composites. The nZVI/CNT composites were used as an adsorbent for the removal of Ag(i) and showed a higher adsorption capacity compared to nZVI and CNTs, with a maximum adsorption capacity of 522.41 mg g−1. Ag(i) was adsorbed on nZVI/CNT composites by ion exchange and chelation, where Ag(i) was reduced to non-toxic Ag due to the redox reaction among pyrrolic-N, nZVI, and Ag(i). The adsorption process of Ag(i) on nZVI/CNT composites was dominated by monolayer adsorption. According to our results, nZVI/CNT composites can be used as economical treatment for wastewater containing Ag(i).

This study examines the use of coffee dregs waste as biosorbents of Cu(II) and Ag(I). Coffee dregs waste still contains a high level of carbon and cellulose for biosorbents production. The production process was started with charcoal activation using H3PO4. The batch method was applied by variations of contact time, the mass of the biosorbent, and the initial concentration of metal ions. The results showed that Cu(II) and Ag(I) were optimally adsorbed at pH 6 and 4, respectively. The amount of adsorbed metal ions increased with adsorption contact time. The adsorption process of both metal ions reaches stability within 60 min and the optimum biosorbent mass is 1 g. Isothermal adsorption studies show that Cu(II) adsorption tends to follow Langmuir isotherm with an adsorption energy of 31.42 kJ/mol and Ag(I) adsorption follows Freundlich isotherms with an adsorption energy of 27.74 kJ/mol. Based on the results, the interaction between metal ions and adsorbents is a chemical adsorption process and coffee dregs charcoal has the potential to adsorb Cu(II) and Ag(I) metal ions.

The synthesis of a substituted diimine with a bipydirine-type backbone, (3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine, L) and its coordination towards Cu(I) and Ag(I) is studied in the presence of diphosphine ligand bis(diphenylphosphino)methane, dppm. The metal complexes are characterized by IR, 1H, and 13C NMR and single crystal X ray diffraction studies. They are dinuclear, as they are held by diphosphine bridges between the tetrahedral metal centers, forming eight-membered ring with the participation of the bridging diphosphinomethane ligands. Within each ring, the planar orientations of M2P2 and of all four P atoms are realized. Solid state excitation spectra are dominated by metal-to-ligand charge transfer bands (MLCT), while geometry relaxation permits only low-intensity emission for the copper compound.

A new Ag(I) adduct was synthesized by the reaction of 4-amino-4H-1,2,4-triazole (L) with AgNO3. Its chemical structure was approved to be [Ag2(L)2(NO3)]n(NO3)n utilizing elemental analysis, FTIR spectra, and single crystal X-ray diffraction (SC-XRD). According to SC-XRD, there are two independent silver atoms which are coordinated differently depending on whether the nitrate anion is coordinated or not. The coordination geometry of Ag1 is a slightly bent configuration while Ag2 has a distorted tetrahedral structure. The 4-amino-4H-1,2,4-triazole ligand and one of the nitrate groups adopt bridging mode, which connects the crystallographically independent Ag1 and Ag2 atoms resulting in the formation of two-dimensional coordination polymer. Hirshfeld surface analysis displays that the intermolecular O···H (34.0%), Ag···N (10.6%), H···H (10.4%), Ag···O (9.3%), and N···H (9.0%) contacts are the most abundant interactions. Regarding anticancer activity, the [Ag2(L)2(NO3)]n(NO3)n demonstrates stronger cytotoxic efficacy against lung (IC50 = 3.50 ± 0.37 µg/mL) and breast (IC50 = 2.98 ± 0.26 µg/mL) carcinoma cell lines than the anticancer medication cis-platin. The [Ag2(L)2(NO3)]n(NO3)n complex showed interesting antibacterial and antifungal activities compared to the free components (AgNO3 and 4-amino-4H-1,2,4-triazole). The investigated silver(I) complex exhibits remarkable antibacterial activity against E. coli (MIC = 6.1 µg/mL) that may be on par with Gentamycin (MIC = 4.8 µg/mL). As a result, the newly synthesized Ag(I) complex could be suggested for anticancer and antibacterial treatments. [ABSTRACT FROM AUTHOR]

The [Ag(3ADMT)(NO3)]n complex was synthesized by the self-assembly of 3-amino-5,6-dimethyl-1,2,4-triazine (3ADMT) and AgNO3. Its molecular structure was analyzed utilizing FTIR spectra, elemental analysis, and single crystal X-ray diffraction (SC-XRD). There is one crystallographically independent Ag atom, which is tetra-coordinated by two nitrogen atoms from two 3ADMT and two oxygen atoms from two nitrate anions where all ligand groups are acting as connectors between the Ag1 sites. The geometry around the Ag(I) center is a distorted tetrahedron with a AgN2O2 coordination sphere augmented by strong argentophilic interactions between Ag atoms, which assist the aggregation of the complex units in a wavy-like and coplanar pattern to form a one-dimensional polymeric chain. The O...H (37.2%) and N...H (18.8%) intermolecular interactions contributed significantly to the molecular packing based on Hirshfeld surface analysis. The [Ag(3ADMT)(NO3)]n complex demonstrates promising cytotoxicity against lung (IC50 = 2.96 ± 0.31 μg/mL) and breast (IC50 = 1.97 ± 0.18 μg/mL) carcinoma. This remarkable cytotoxicity exceeds those of 3ADMT, AgNO3, and the anticancer medication cis-platin towards the tested cancer cell lines. In addition, the complex has a wide-spectrum antimicrobial action where the high antibacterial potency of the [Ag(3ADMT)(NO3)]n complex against P. vulgaris (MIC = 6.1 µg/mL) and B. subtilis (MIC = 17.2 µg/mL) could be comparable to the commonly used drug Gentamycin (MIC = 4.8 µg/mL). These results confirm that the components of the [Ag(3ADMT)(NO3)]n complex work together synergistically, forming a powerful multifunctional agent that could be exploited as an effective antimicrobial and anticancer agent. [ABSTRACT FROM AUTHOR]

The synthesis of a substituted diimine with a bipydirine-type backbone, (3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine, L) and its coordination towards Cu(I) and Ag(I) is studied in the presence of diphosphine ligand bis(diphenylphosphino)methane, dppm. The metal complexes are characterized by IR, 1H, and 13C NMR and single crystal X ray diffraction studies. They are dinuclear, as they are held by diphosphine bridges between the tetrahedral metal centers, forming eight-membered ring with the participation of the bridging diphosphinomethane ligands. Within each ring, the planar orientations of M2P2 and of all four P atoms are realized. Solid state excitation spectra are dominated by metal-to-ligand charge transfer bands (MLCT), while geometry relaxation permits only low-intensity emission for the copper compound. [ABSTRACT FROM AUTHOR]

Untreated or inadequately treated silver−containing wastewater may pose adverse effects on hu−man health and the ecological environment. Currently, significant progress has been made in the treatment of Ag(I) in wastewater using adsorption methods, with adsorbents playing a pivotal role in this process. This paper provides a systematic review of various adsorbents for the recovery and treatment of Ag(I) in wastewater, including MOFs, COFs, transition metal sulfides, metal oxides, biomass materials, and other polymeric materials. The adsorption mechanisms of these materials for Ag(I) are elaborated upon, along with the challenges currently faced. Furthermore, insights into optimizing adsorbents and developing novel adsorbents are proposed in this study.

The present work reports the synthesis of new N4-donor compounds carrying p-xylyl spacers in their structure. Different Schiff base aliphatic N-donors were obtained synthetically and subsequently evaluated for their ability to interact with two models of nucleic acids: calf-thymus DNA (CT-DNA) and the RNA from yeast Saccharomyces cerevisiae (herein simply indicated as RNA). In more detail, by condensing p-xylylenediamine and a series of aldehydes, we obtained the following Schiff base ligands: 2-thiazolecarboxaldehyde (L1), pyridine-2-carboxaldehyde (L2), 5-methylisoxazole-3-carboxaldehyde (L3), 1-methyl-2-imidazolecarboxaldehyde (L4), and quinoline-2-carboxaldehyde (L5). The structural characterisation of the ligands L1-L5 (X-ray, 1H NMR, 13C NMR, elemental analysis) and of the coordination polymers {[CuL1]PF6}n (herein referred to as Polymer1) and {[AgL1]BF4}n, (herein referred to as Polymer2, X-ray, 1H NMR, ESI-MS) is herein described in detail. The single crystal X-ray structures of complexes Polymer1 and Polymer2 were also investigated, leading to the description of one-dimensional coordination polymers. The spectroscopic and in silico evaluation of the most promising compounds as DNA and RNA binders, as well as the study of the influence of the 1D supramolecular polymers Polymer1 and Polymer2 on the proliferation of Escherichia coli bacteria, were performed in view of their nucleic acid-modulating and antimicrobial applications. Spectroscopic measurements (UV–Vis) combined with molecular docking calculations suggest that the thiazolecarboxaldehyde derivative L1 is able to bind CT-DNA with a mechanism different from intercalation involving the thiazole ring in the molecular recognition and shows a binding affinity with DNA higher than RNA. Finally, Polymer2 was shown to slow down the proliferation of bacteria much more effectively than the free Ag(I) salt. [ABSTRACT FROM AUTHOR]

A new Ag(I) adduct was synthesized by the reaction of 4-amino-4H-1,2,4-triazole (L) with AgNO3. Its chemical structure was approved to be [Ag2(L)2(NO3)]n(NO3)n utilizing elemental analysis, FTIR spectra, and single crystal X-ray diffraction (SC-XRD). According to SC-XRD, there are two independent silver atoms which are coordinated differently depending on whether the nitrate anion is coordinated or not. The coordination geometry of Ag1 is a slightly bent configuration while Ag2 has a distorted tetrahedral structure. The 4-amino-4H-1,2,4-triazole ligand and one of the nitrate groups adopt bridging mode, which connects the crystallographically independent Ag1 and Ag2 atoms resulting in the formation of two-dimensional coordination polymer. Hirshfeld surface analysis displays that the intermolecular O···H (34.0%), Ag···N (10.6%), H···H (10.4%), Ag···O (9.3%), and N···H (9.0%) contacts are the most abundant interactions. Regarding anticancer activity, the [Ag2(L)2(NO3)]n(NO3)n demonstrates stronger cytotoxic efficacy against lung (IC50 = 3.50 ± 0.37 µg/mL) and breast (IC50 = 2.98 ± 0.26 µg/mL) carcinoma cell lines than the anticancer medication cis-platin. The [Ag2(L)2(NO3)]n(NO3)n complex showed interesting antibacterial and antifungal activities compared to the free components (AgNO3 and 4-amino-4H-1,2,4-triazole). The investigated silver(I) complex exhibits remarkable antibacterial activity against E. coli (MIC = 6.1 µg/mL) that may be on par with Gentamycin (MIC = 4.8 µg/mL). As a result, the newly synthesized Ag(I) complex could be suggested for anticancer and antibacterial treatments.

A new Ag(I)-azine complex of the formula [Ag(La)]2(ClO4)2.1/2(Lb) was synthesized and characterized using elemental analysis, FTIR, XPS and single-crystal X-ray diffraction. The [Ag(La)]2(ClO4)2.1/2(Lb) complex was obtained via Ag(I)-mediated hydrolysis of 2-(((1-(pyridin-2-yl)ethylidene)hydrazineylidene)methyl)phenol (L) with AgClO4 leading to the formation of the azines (1E,2E)-1,2-bis(1-(pyridin-2-yl)ethylidene)hydrazine (La) and 2,2'-((1E,1'E)-hydrazine-1,2-diylidene bis(methanylylidene)) diphenol (Lb). The former underwent complexation with AgClO4, while the latter was co-crystallized with the resulting Ag(I) complex, leading to the complex formula [Ag(La)]2(ClO4)2.1/2(Lb). In this complex, the azine La is acting as a bridged bidentate chelate connecting the two Ag(I) sites, leading to a tetra-coordinated Ag(I) with a distorted square planar coordination environment. Hirshfeld analysis indicated the importance of the H...H (38.4%), O...H (17.9%), H...C (13.2%), C...C (9.0%) and N...H (8.9%) interactions in the molecular packing. The antimicrobial, antioxidant and cytotoxic activities of the [Ag(La)]2(ClO4)2.1/2(Lb) complex were examined and compared with those of [Ag(La)]2(ClO4)2. The former was found to have lower bioactivity than the latter, which shed light on the lowering of biological actions as a consequence of the incorporation of the azine Lb within the Ag(I) complex. In other words, lowering the %Ag decreases the biological actions. The [Ag(La)]2(ClO4)2.1/2(Lb) complex (ΜIC = 39 μg/mL) has higher activity against the fungus A. fumigatus than the control Ketoconazole (ΜIC =156 μg/mL). This complex also has good cytotoxic activity against colon carcinoma and weak antioxidant activity. [ABSTRACT FROM AUTHOR]

The [Ag(3ADMT)(NO3)]n complex was synthesized by the self-assembly of 3-amino-5,6-dimethyl-1,2,4-triazine (3ADMT) and AgNO3. Its molecular structure was analyzed utilizing FTIR spectra, elemental analysis, and single crystal X-ray diffraction (SC-XRD). There is one crystallographically independent Ag atom, which is tetra-coordinated by two nitrogen atoms from two 3ADMT and two oxygen atoms from two nitrate anions where all ligand groups are acting as connectors between the Ag1 sites. The geometry around the Ag(I) center is a distorted tetrahedron with a AgN2O2 coordination sphere augmented by strong argentophilic interactions between Ag atoms, which assist the aggregation of the complex units in a wavy-like and coplanar pattern to form a one-dimensional polymeric chain. The O...H (37.2%) and N...H (18.8%) intermolecular interactions contributed significantly to the molecular packing based on Hirshfeld surface analysis. The [Ag(3ADMT)(NO3)]n complex demonstrates promising cytotoxicity against lung (IC50 = 2.96 ± 0.31 μg/mL) and breast (IC50 = 1.97 ± 0.18 μg/mL) carcinoma. This remarkable cytotoxicity exceeds those of 3ADMT, AgNO3, and the anticancer medication cis-platin towards the tested cancer cell lines. In addition, the complex has a wide-spectrum antimicrobial action where the high antibacterial potency of the [Ag(3ADMT)(NO3)]n complex against P. vulgaris (MIC = 6.1 µg/mL) and B. subtilis (MIC = 17.2 µg/mL) could be comparable to the commonly used drug Gentamycin (MIC = 4.8 µg/mL). These results confirm that the components of the [Ag(3ADMT)(NO3)]n complex work together synergistically, forming a powerful multifunctional agent that could be exploited as an effective antimicrobial and anticancer agent.

In pH 4.4∼4.6 weakly acidic media, erythrosine (Ery) can react with Ag(I) to form hydrophobic ion-association complex, which can further aggregate to form nanoparticles with an average particle size of about 45 nm under the action of water phase extrusion and van der Waals force. As a result, it could lead to a decrease of absorbance, a significant enhancement of resonance Rayleigh scattering (RRS) and the appearance of a new emission spectrum. Based on these Phenomena, two new methods (spectrophotometry and RRS) were established for the determination of trace Ag(I). The detection limits for Ag(I) by spectrophotometry and RRS are 9.74 and 0.12 ng/ml, respectively. In this paper, we have investigated the formation of nanoparticles, the optimum reaction conditions, the influence factors, explored the reason for enhancement of the scattering intensity and the effect of coexisting substance. This research shows that RRS method not only has good selectivity and high sensitivity, but also is simple and rapid. Analyzing of actual samples and standard samples, the determination result of this method is consistent with that of standard methods (Flame atomic absorption spectroscopy). Thus the method had potential feasibility to analysis for Ag(I) in the environmental water samples, pharmaceutical, and food industries.

Organic ligand containing the imidazole heterocycle [N-methyl-N′-propyltrimethoxysilylimidazolium chloride] immobilizing on the surface of ordered mesoporous silica (SBA-15) can be chelated with different metal ions such as Ag(I), Au(III), and Pd(II). This functionalized SBA-IL showed an exceptional selectivity for removing precious metal ions from an aqueous solution through batch techniques. Moreover, these precious metals could be desorbed from this functionalized SBA through simple acid treatment [HCl (0.5 M) for Au(III) and Pd(II) and HNO3 (0.5 M) for Ag(I)] and quantified by flame atomic absorption spectrometry. The adsorption kinetics was investigated for Ag(I), Au(III), and Pd(II), which adsorption kinetics fit a pseudo-second-order rate equation. The experimental data were analyzed by Langmuir and Freundlich isotherm models which the adsorption isotherm plots confirm the Langmuir model, demonstrating that the adsorption process is the uniform monolayer adsorption. Furthermore, the recovery experiments showed that the maximum adsorption capacity was 250, 130, and 263 mg/g for Ag(I), Au(III), and Pd(II), respectively in pH = 4 at 25 ℃. Herein, the prepared SBA-IL is based on imidazolium chloride and also used for rapid removal of precious metals such as Au(III), Ag(I), and Pd(II) ions extracted and quantified by FAAS. Moreover, the adsorption kinetic and isotherm models were also studied. The recovery experiments showed a high adsorption capacity. [ABSTRACT FROM AUTHOR]

Electronic waste (e-waste) has been confirmed containing some precious metals such as gold and silver. Mangosteen peel waste as eco-friendly adsorbent has been studied to recover Au(III) and Ag(I) successfully. Recovery was started through adsorbent preparation, consisting of soxhlet extraction and maceration. About 100 mg of adsorbent was dispersed into Au(III) and Ag(I) solutions in various pH conditions (2–6). The result proves that the optimum adsorptions of Au(III) and Ag(I) are at pH 2 and pH 6, respectively. Au(III) adsorption follows the isotherm model of Langmuir with a maximum capacity of 0.580 mmol/g (114.27 mg/g). Ag(I) adsorption follows the isotherm model of Freundlich with a maximum capacity of 0.511 mmol/g (55.10 mg/g).

The present work reports the synthesis of new N4-donor compounds carrying p-xylyl spacers in their structure. Different Schiff base aliphatic N-donors were obtained synthetically and subsequently evaluated for their ability to interact with two models of nucleic acids: calf-thymus DNA (CT-DNA) and the RNA from yeast Saccharomyces cerevisiae (herein simply indicated as RNA). In more detail, by condensing p-xylylenediamine and a series of aldehydes, we obtained the following Schiff base ligands: 2-thiazolecarboxaldehyde (L1), pyridine-2-carboxaldehyde (L2), 5-methylisoxazole-3-carboxaldehyde (L3), 1-methyl-2-imidazolecarboxaldehyde (L4), and quinoline-2-carboxaldehyde (L5). The structural characterisation of the ligands L1-L5 (X-ray, 1H NMR, 13C NMR, elemental analysis) and of the coordination polymers {[CuL1]PF6}n (herein referred to as Polymer1) and {[AgL1]BF4}n, (herein referred to as Polymer2, X-ray, 1H NMR, ESI-MS) is herein described in detail. The single crystal X-ray structures of complexes Polymer1 and Polymer2 were also investigated, leading to the description of one-dimensional coordination polymers. The spectroscopic and in silico evaluation of the most promising compounds as DNA and RNA binders, as well as the study of the influence of the 1D supramolecular polymers Polymer1 and Polymer2 on the proliferation of Escherichia coli bacteria, were performed in view of their nucleic acid-modulating and antimicrobial applications. Spectroscopic measurements (UV–Vis) combined with molecular docking calculations suggest that the thiazolecarboxaldehyde derivative L1 is able to bind CT-DNA with a mechanism different from intercalation involving the thiazole ring in the molecular recognition and shows a binding affinity with DNA higher than RNA. Finally, Polymer2 was shown to slow down the proliferation of bacteria much more effectively than the free Ag(I) salt.

A new Ag(I)-azine complex of the formula [Ag(La)]2(ClO4)2.1/2(Lb) was synthesized and characterized using elemental analysis, FTIR, XPS and single-crystal X-ray diffraction. The [Ag(La)]2(ClO4)2.1/2(Lb) complex was obtained via Ag(I)-mediated hydrolysis of 2-(((1-(pyridin-2-yl)ethylidene)hydrazineylidene)methyl)phenol (L) with AgClO4 leading to the formation of the azines (1E,2E)-1,2-bis(1-(pyridin-2-yl)ethylidene)hydrazine (La) and 2,2’-((1E,1’E)-hydrazine-1,2-diylidene bis(methanylylidene)) diphenol (Lb). The former underwent complexation with AgClO4, while the latter was co-crystallized with the resulting Ag(I) complex, leading to the complex formula [Ag(La)]2(ClO4)2.1/2(Lb). In this complex, the azine La is acting as a bridged bidentate chelate connecting the two Ag(I) sites, leading to a tetra-coordinated Ag(I) with a distorted square planar coordination environment. Hirshfeld analysis indicated the importance of the H…H (38.4%), O…H (17.9%), H…C (13.2%), C…C (9.0%) and N…H (8.9%) interactions in the molecular packing. The antimicrobial, antioxidant and cytotoxic activities of the [Ag(La)]2(ClO4)2.1/2(Lb) complex were examined and compared with those of [Ag(La)]2(ClO4)2. The former was found to have lower bioactivity than the latter, which shed light on the lowering of biological actions as a consequence of the incorporation of the azine Lb within the Ag(I) complex. In other words, lowering the %Ag decreases the biological actions. The [Ag(La)]2(ClO4)2.1/2(Lb) complex (ΜIC = 39 μg/mL) has higher activity against the fungus A. fumigatus than the control Ketoconazole (ΜIC =156 μg/mL). This complex also has good cytotoxic activity against colon carcinoma and weak antioxidant activity.

A novel Schiff base 4-{(E)-[(3-methyl-5-sulphanyl-4H-1,2,4-triazol-4-yl)imino]methyl}benzaldehyde (MSTB) and its complexes with Ag(I), Hg(II), Cu(II), Ni(II) and Co(II) have been prepared. MSTB is prepared by the condensation reaction between triazole and terephthaldehyde. In complexes, MSTB molecules are found to link with the metal ion, through thiolsulphur after deprotonation and the nitrogen of the azomethine group. The composition of the complexes are found to be ML where M =Ag, ML2 where M=Zn, Hg and ML2(H2O)2 where M= Co, Ni. Linear polymeric structure is proposed for Ag(I) complex, tetrahedral structure is proposed for Zn(II) and Hg(II) complexes and octahedral structure is proposed for Co(II) and Ni(II) complexes. [ABSTRACT FROM AUTHOR]

In this study, 2-aminothiazole, (2AT), was polymerized with benzoyl peroxide in 1,4-dioxane solution, and adsorption efficiencies of poly(2-aminothiazole), P-2AT, for the Ag(I) ions to remove from the aqueous solutions were investigated. Adsorption experiments were studied at different pH, contact time and initial Ag(I) ion concentration in a batch system. The optimal pH for Ag(I) adsorption onto P-2AT was found to be 5.0, and the maximum adsorption capacity was determined to be 336.98 mg/g for 1200 mg/L Ag(I) solution at 90 min. P-2AT adsorbents were followed up by recycling in multiple adsorption cycles. The results showed that adsorbent can be used several times. Ag(I) ion adsorption performance of the P-2AT was investigated in conjunction with Cu(II) and Zn(II) ions. The selectivity series of ions were found as Ag(I) > Cu(II) > Zn(II). According to the experimental data, the adsorption reaction fitted the pseudo-second-degree kinetic model and the Langmuir isotherm equation. [ABSTRACT FROM AUTHOR]

Silver ions discharged from various industries, are potentially toxic to living organisms at low concentrations, thus, there is an increasing need for development of an eco-friendly and cost-effective approach for its bioremediation. Filamentous fungi especially, Fusarium solani displayed a strong resistance to copper and cadmium ions as revealed from our previous study (El-Sayed 2014), however, the mechanisms of silver resistance by this fungus has not been resolved yet. Thus, this study was an extension to our previous work, to elucidate the mechanism of silver ions resistance and biotransformation by F. solani. The growth, bioaccumulation, thiol, total antioxidant, malondialdehyde (MDA), hydrogen peroxide (H2O2) contents and polyphenol oxidase (PPO) and catalase (CAT) activities of F. solani in response to silver ions were determined. Production and bioaccumulation of silver nanoparticles was characterized by UV-visible spectroscopy, TEM, and X-ray powder diffraction (XRD). The ultrastructural changes of F. solani induced by Ag(I) was examined by TEM and SEM. Production of oxalic acid by F. solani was increased by about 343.8% in response to 400 mg/l Ag(I), compared to control cultures (without silver ions) as revealed from HPLC analysis. The maximum biosorption levels by the native and alkali-treated biomass were carried out at pH 5.0, initial metal concentration 200 mg/l, biomass 0.5 g/l, temperature 35 °C, and contact time 1 h (native biomass) and 3 h (alkali-treated biomass). Fourier transform infrared spectroscopy (FTIR) results revealed that the main functional groups involved on this mycoremediation were C–S stretching, C=O C=N, C – H bending, C–N stretching and N–H bending. EDX spectra indicated the involvement of fungal cellular sulfur and phosphorus compounds in Ag(I) binding.

An efficient route is proposed to synthesize magnetic nitrogen-doped mesoporous carbon (Fe3O4/NMC) composites. The nitrogen-doped mesoporous carbon (NMC) material was prepared using a melamine–formaldehyde resin as nitrogen and carbon source and fumed silica as a template via a template method, and Fe3O4 nanoparticles were introduced via an in situ formation method. The effects of the loading amount of Fe3O4 on the morphology, structure, magnetic properties and adsorption performance of the Fe3O4/NMC composites were investigated. Fe3O4 nanoparticles dispersed well on the surface and inside the NMC, and the Fe3O4/NMC remained a mesoporous structure. Fe3O4/NMC exhibited superparamagnetic behavior, and the maximum saturation magnetization was 30.1 emu/g. Fe3O4/NMC had a decreased specific surface area and pore volume compared to NMC, but the Fe3O4/NMC composites still showed excellent adsorption capacity for Ag(I), reaching 71.9 mg/g. The adsorption efficiency of Fe3O4/NMC remained at 90.3% of the initial removal capability after five cycles, which demonstrated the potential large-scale industrial applications of these composites. Magnetic nitrogen-doped mesoporous carbon (Fe3O4/NMC) composites were prepared by a template method and in situ formation method. Fe3O4/NMC was used as adsorbent to removal Ag(I) from aqueous solution. Fe3O4/NMC showed excellent adsorption capacity for Ag(I). The Ag(I) was chelated by –NH-/–NH2 groups to chelate ligand and reduced by free –NH2 to Ag0, respectively. [ABSTRACT FROM AUTHOR]

The polymeric resins containing diethylenetriamine, tetraethylenepentamine, 2-(diethylamino)ethanol, 1-methylimidazole, and 1,2-dimethylimidazole ligands have been synthesized from vinylbenzyl chloride-divinylbenzene copolymers and used in the removal of Ag(I) from chloride solution. The best Ag(I) sorption was reached in the case of 1-methylimidazole resin. Resins retain their capacity towards Ag(I) in five consecutive sorption/desorption cycles. The resins with imidazole ligands were highly selective for Ag(I) from synthetic chloride solution and they did not sorb chloride complexes of Cu(II). Additionally, the recovery of Ag(I) was tested from real chloride solution coming from leaching of the copper concentrate from Lubin Concentrator (KGHM Polska Miedź S.A.). [ABSTRACT FROM AUTHOR]

[Display omitted] • A New spectrophotometry and fluorescence quenching methods have been developed for the determination of Ag(I). • The method is high sensitivity, good selectivity, high accuracy and simple operation. • The coordination position of Ag(I) to EY have been confirmed. Ag(I) and Eosin Y (EY) can interact directly under weakly acidic conditions to form a sparingly soluble ionic association which results in absorbance reduction and fluorescence quenching of EY. New spectrophotometry and fluorescence quenching methods have been developed for the determination of Ag(I) within the ionic association of EY-Ag, with detection limits of 0.17 µM and 2.2 nM, respectively. The fluorescence quenching method offers high sensitivity, good selectivity, high accuracy, and ease of operation, making it suitable for the analysis of silver ions in surface water samples and wastewater samples as well as Ag(I) standard samples. Through the analysis of the absorption spectrum, density functional theory (DFT) theoretical calculations and Nuclear Magnetic Resonance (NMR) spectroscopy, it was found that under weakly acidic conditions, the Ag(I) coordinates with the carboxyl functional group of EY, forming a 1:1 sparingly soluble ionic association that induces static fluorescence quenching. [ABSTRACT FROM AUTHOR]

A pH-sensitive polyethersulfone (PES) membrane was prepared with the aid of newly synthesized Ag(I) coordination polymer (Ag(I)-CP) particles. Indicating obvious adsorptive property toward dyes, the Ag(I)-based metalorganic framework (MOF) was selected to be used as an additive to improve the dye selectivity of PES membranes for both cationic and anionic dyes. The performance examination and characterization of prepared membranes indicated the influence of Ag(I)-CP in PES membrane improvement. The effect of feed pH approved the membrane response to pH changes in dye removal results. By adjusting feed pH based on pH pzc of Ag(I)-CP, it is possible to remove both anionic and cationic dyes (97% of acid orange 7 (AO) & and 100% of methylene blue (MB)) from the effluent along with an enhanced permeated flux. The results offered a synergism in embedding Ag(I)-CP in PES membrane in dye removal efficiency. The additive particles can be applied with their natural size (200–300 nm) without severe influence on the uniformity of the membrane morphology if the optimum Ag(I)-CP content is considered. • A pH-sensitive polyethersulfone mixed matrix membrane was prepared. • The Ag(I)-CP MOF was embedded into the membrane matrix. • Prepared membranes highly removed cationic and anionic dyes from water. • The membrane morphology changes controlled by filler optimum content. [ABSTRACT FROM AUTHOR]

Pemakaian obat dan sediaannya secara intensif, selain memberikan keuntungan dalam pelayanan kesehatan juga memiliki efek sekunder yaitu akumulasi limbah yang tidak diinginkan. Akumulasi zat antibiotik seperti amoksisilin di perairan dapat menyebabkan resistensi. Di lingkungan, limbah amoksisilin dapat bersama-sama dengan limbah anorganik seperti ion Ag(I). Kajian tentang fotodegradasi dilakukan dengan menggabungkan cahaya ultraviolet dan partikel semikonduktor sebagai fotokatalis. Hal tersebut dilakukan untuk mengetahui pengaruh penyinaran, keberadaan ion Ag(I), dan kondisi optimum terhadap efektivitas fotodegradasi amoksisilin yang dikatalisis TiO2dengan kehadiran ion Ag(I). Proses fotodegradasi amoksisilin dilakukan dalam suatu reaktor tertutup dilengkapi dengan satu set alat pengaduk magnetik dan lampu UV. Hasil kemudian dianalisis dengan Spektrofotometer UV untuk mengetahui konsentrasi amoksisilin sisa dan Spektrofotometer Serapan Atom (SSA) untuk mengetahui konsentrasi ion Ag(I) sisa. Hasil penelitian menunjukkan bahwa amoksisilin yang terdegradasi meningkat dengan semakin lamanya waktu penyinaran karena lamanya kontak antara fotokatalis TiO2 dengan cahaya dan kontak antara amoksisilin dengan radikal •OH. Keberadaan ion Ag(I) meningkatkan hasil fotodegradasi amoksisilin karena rekombinasi radikal •OH yang berasal dari spesies hole dengan elektron tereksitasi dapat dicegah. Efektivitas fotodegradasi amoksisilin terjadi pada waktu penyinaran 90 menit, larutan amoksisilin 200 mg/L sebanyak 25 mL dengan penambahan ion Ag(I) 40 mg/L sebanyak 25 mL, dan TiO2 sebagai katalis sebanyak 20 mg. Pada kondisi tersebut fotodegradasi amoksisilin sebesar 32,40 % dan persen ion Ag(I) yang tereduksi sebesar 70,40 %.

Abstract In order to manage and utilize a large amount of wasted apple pomace, the magnetic biochar was prepared through pyrolysis of apple pomace at 600 °C in nitrogen environment, followed by immersion aging in Fe(II)/Fe(III) aqueous solution. The characterization of the resulting magnetic biochar, herein called the M600APB, showed that the saturation magnetization value and the Brunauer-Emmett-Teller (BET) specific surface area of M600APB were 9.52 emu/g and 102.18 m2/g, respectively. The batch adsorption showed that M600APB could preferentially enrich the low concentration of Ag(I) with the maximum adsorption capacity of 818.4 mg/g in an Ag(I)-Pb(II)-Cu(II)-Ni(II)-Zn(II) aqueous system at ambient temperature. The column adsorption experiments indicated that M600APB could effectively enrich and separate Ag(I) from the same aqueous mixture. The presumable mechanism of Ag(I) adsorption on M600APB involves intra-particle diffusion, coordination, ion exchange and reduction. This study provided an effective approach to both utilize wasted apple pomace and enrich the low concentration of Ag(I) in a sustainable way. Graphical abstract Unlabelled Image Highlights • M600APB was prepared by pyrolyzing ample pomace and aging in Fe2+/Fe3+ solution. • M600APB could enrich Ag(I) from effluents in both batch and column modes. • Sorption of Ag(I) on M600APB was considerably governed by intra-particle diffusion. • M600APB could be regenerated and cyclically reused. [ABSTRACT FROM AUTHOR]

Thiourea-functionalized silica gel (HO-SG-GPTS-TS and HE-SG-GPTS-TS) were synthesized by homogeneous and heterogeneous methods, respectively. The feasibility of the as-prepared adsorbents for the remove of Ag(I) from aqueous solution was systemically studied under different solution pH, contact time, temperature, and initial Ag(I) concentration. The adsorption capacity is found to depend on the solution pH and the maximum adsorption capacity is achieved at pH 6. Adsorption kinetic indicates the adsorption can reach equilibrium within 180 min. The adsorption follows pseudo-second order model and is controlled by film diffusion process. Adsorption isotherm shows that the adsorption capacity increases with the increase of initial Ag(I) concentration and temperature. The adsorption isotherm is suitable to be simulated by Langmuir model and is proceeded by chemical mechanism. Thermodynamic parameters suggest the adsorption is a spontaneous, endothermic, and entropy increased process. Density functional theory calculation reveals that the formation of chelates with Ag(I) by S and hydroxyl O atoms dominate the adsorption, and S atom is the main contributor. [ABSTRACT FROM AUTHOR]

A series of fifteen silver (I) quinoline complexes Q1–Q15 have been synthesized and studied for their biological activities. Q1–Q15 were synthesized from the reactions of quinolinyl Schiff base derivatives L1–L5 (obtained by condensing 2-quinolinecarboxaldehyde with various aniline derivatives) with AgNO3, AgClO4 and AgCF3SO3. Q1–Q15 were characterized by various spectroscopic techniques and the structures of [Ag(L1)2]NO3Q1, [Ag(L1)2]ClO4Q6, [Ag(L2)2]ClO4Q7, [Ag(L2)2]CF3SO3Q12 and [Ag(L4)2]CF3SO3Q14 were unequivocally determined by single crystal X-ray diffraction analysis. In vitro antimicrobial tests against Gram-positive and Gram-negative bacteria revealed the influence of structure and anion on the complexes′ moderate to excellent antibacterial activity. In vitro antioxidant activities of the complexes showed their good radical scavenging activity in ferric reducing antioxidant power (FRAP). Complexes with the fluorine substituent or the thiophene or benzothiazole moieties are more potent with IC50 between 0.95 and 2.22 mg/mL than the standard used, ascorbic acid (2.68 mg/mL). The compounds showed a strong binding affinity with calf thymus-DNA via an intercalation mode and protein through a static quenching mechanism. Cytotoxicity activity was examined against three carcinoma cell lines (HELA, MDA-MB231, and SHSY5Y). [Ag(L2)2]ClO4Q7 with a benzothiazole moiety and [Ag(L4)2]ClO4Q9 with a methyl substituent had excellent cytotoxicity against HELA cells.

• Five new coordination polymers (CPs) have been constructed by using 1-(4-carboxybenzyl)−1H-pyrazole-3,5-dicarboxylic acid (H 3 L) as an organic ligand. • Five compounds show various structures because of different metal ions, various coordination modes of H 3 L and the addition of the neutral ligand. • The luminescent properties of compounds 1 – 5 have been studied in detail. Five new coordination polymers (CPs), namely {Pb 1.5 (L)} (1), {Pb 3 (L) 2 (2,2′-bpy) · 2·5H 2 O} (2), {[P b (HL)(phen)] · H 2 O} (3), {Ag 2 (HL)} (4) and {Ag(H 2 L)(phen)} (5), have been constructed by using 1-(4-carboxybenzyl)-1H-pyrazole-3,5-dicarboxylic acid (H 3 L) as an organic ligand. Compound 1 reveals a three-dimensional (3D) (4,6,7)-connected framework with the point symbol of {410·65}{46} 2 {48·613} 2. Compound 2 exhibits a novel (3,6)-connected 3D framework based on a trinuclear Pb(II) cluster with point symbol {42.6} 2 {44.62.88.10}. Compound 3 is a 1D chain that is further assembled into a 3D supramolecular framework by hydrogen-bonds. Compound 4 shows a (3,6)-connected 3D structure based on a tetranuclear Ag(I) cluster with {4·62} 2 {42·610·83} topology. Compound 5 is a 0D structure, and can be further expanded into a 3D supramolecular network by various weak interactions. The solid-state luminescent spectra have been measured at room temperature. The results show that compounds 1–5 exhibit strong luminescent emission in the visible region, and can be tunable by varying excitation wavelengths. Five new luminescent coordination polymers have been synthesized under solvothermal conditions. [Display omitted] [ABSTRACT FROM AUTHOR]

An efficient route is proposed to synthesize a novel three-dimensional (3D) magnetic MXene aerogel (3D MXene/Fe 3 O 4). 3D MXene were synthesized by self-assembly of 2D MXene Ti 3 C 2 T x using ethylenediamine (EDA) as crosslinking inducer, then Fe 3 O 4 was in situ coprecipitation onto 3D MXene. 3D MXene/Fe 3 O 4 was applied as an adsorbent for Ag(I) removal from aqueous solutions. 3D MXene/Fe 3 O 4 exhibits a cross-linked 3D porous network with magnetic Fe 3 O 4 nanoparticles uniformly dispersed on its surface and edges. The maximum adsorption capacity of 3D MXene/Fe 3 O 4 for Ag(I) was 2385 mg g−1. The kinetics and isothermal process during adsorption were described accurately by the pseudo-second-order model and the Freundlich isotherm model, and the adsorption process was driven by chemisorption and multilayer adsorption, where the diffusion mechanism involved surface diffusion and intraparticle diffusion. Furthermore, the 3D MXene/Fe 3 O 4 are recyclable, retaining 71% of the initial removal rate after 5 adsorption/desorption cycles. [Display omitted] • 3D MXene aerogel was formed by EDA induced self-assembly of nanosheets and subsequently Fe 3 O 4 was assembled. • 3D MXene/Fe 3 O 4 exhibits a cross-linked porous network and Fe 3 O 4 uniformly were dispersed on its surface and edges. • 3D MXene/Fe 3 O 4 provides a controllable channel for the transmission of Ag(I), and can quickly be recycled after adsorption. • The adsorption capacity of 3D MXene/Fe 3 O 4 for Ag(I) is 2385 mg.•g−1. [ABSTRACT FROM AUTHOR]

In this work, five Ag(I)-based CPs with luminescent properties have been synthesized under hydrothermal conditions. [Display omitted] • Five Ag(I)-based coordination polymers (CPs) have been synthesized under hydrothermal conditions. • Organic ligand plays a key role in the formation of the final structures. • The luminescent color of compounds 1 – 5 can be tunable by varying excitation wavelengths. In this work, five Ag(I)-based coordination polymers (CPs), namely, [Ag(HL)(H 2 L)] n (1), [Ag(HL)(2,2′-bpy)(H 2 O) 0.5 ] (2), [Ag(HL)(phen)(H 2 O) 0.5 ] (3), {[Ag 2 (HL) 2 (4,4′-bpy)(H 2 O) 2 ]∙H 2 O} (4) and [Ag(HL)(thpy)] n (5), were synthesized under hydrothermal conditions (H 2 L = 1-(3-carboxybenzyl)-1H-pyrazole-4-carboxylic acid, 2,2′-bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline, 4,4′-bpy = 4,4′-bipyridine and thpy = 2-(2-thienyl)pyridine). These coordination polymers were characterized by single-crystal X-ray diffraction, elemental analyses, infrared spectroscopy, thermogravimetric analyses and powder X-ray diffraction. Compound 1 displays a one-dimensional (1D) chain structure which can be further extended into a three-dimensional (3D) supramolecular structure via intermolecular hydrogen bond. In compounds 2 and 3 , the binuclear zero dimensional (0D) units are extended to 3D supramolecular frameworks by intermolecular hydrogen bond and π–π stacking interaction. In compound 4 , the 0D units constructed by HL− anions, 4,4′-bpy and metal ions are expanded to form a two-dimensional (2D) supramolecular network. Compound 5 shows a different 2D supramolecular structure extended from 1D chain by intermolecular hydrogen bond. The results suggest that organic ligand plays a key role in the formation of the final structures. The solid-state luminescent properties of compounds 1 – 5 were studied in detail. The results show that the luminescent color of compounds 1 – 5 can be tunable by varying excitation wavelengths. [ABSTRACT FROM AUTHOR]

An efficient strategy was proposed to fabricate magnetic N-doped mesoporous carbons (Fe0/NMC) via one-pot process. This one-pot strategy involved the synthesis of N-containing porous polymers using amphiphilic triblock copolymer (F127) through self-assembly of melamine formaldehyde resin, and the formation and entrapment of Fe0 nanoparticles by an in-situ carbothermal reduction approach. The surface morphology and the main chemical groups of the developed Fe0/NMC were characterized by various analytical methods such as XRD, FTIR, TGA-DTA, BET, TEM and VSM. Fe0/NMC exhibited a mesoporous structure and Fe0 nanoparticles were dispersed homogeneously on Fe0/NMC, with a saturation magnetization of 134.6 emu/g. As an adsorbent, Fe0/NMC showed an excellent adsorption capacity for Ag (I), reaching 335 mg/g. The adsorption process was consistent with the quasi-secondary kinetic model and Freundlich isothermal adsorption model, which indicated that the adsorption process was multilayer adsorption and the adsorbed element Ag was present on Fe0/NMC in the form of Ag(I) as well as chelates and Ag monomers. It could be believed that Fe0/NMC was a viable adsorption material for Ag(I) and had full-scale applications. [Display omitted] • Fe/NMC was synthesized via one-pot strategy and in-situ carbothermal reduction approach. • The Fe/NMC exhibited excellent magnetic behavior and cycles properties. • The adsorption capacity of Fe/NMC for Ag(I) was determined to be 335 mg/g. [ABSTRACT FROM AUTHOR]

In this study, the adsorption property of 3.0 generations polyamidoamine dendrimer functionalized magnetic graphene oxide (MGO-PAMAM-G3.0) for Ag(I) in aqueous solution was investigated by batch experiments and magnetic separation technology. The adsorption mechanism was studied by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR) and N2 adsorption/desorption isotherm. The effect of the adsorption conditions, such as pH, initial Ag(I) concentration, contact time and temperature on the adsorption property of MGO-PAMAM-G3.0 for Ag(I) was explored. The equilibrium data were analyzed using the Henry, Langmuir, Freundlich and Temkin isotherm models. The pseudo-first-order and pseudo-second-order adsorption kinetic models were employed to fit kinetics experimental data. The results showed that the main adsorption mechanism of MGO-PAMAM-G3.0 for Ag(I) was the formation of N-metal ions chemical complex and Ag(I) was reduced to element Ag in the adsorption process. The solution pH value had a major impact on adsorption Ag(I) with optimal removal observed around pH = 4.0–6.0 and the MGOPAMAM- G3.0 was suitable for the adsorption low concentration Ag(I) from aqueous solution. The experimental data were better fitting of the Langmuir isotherm model and the pseudo-second-order equation, respectively. [ABSTRACT FROM AUTHOR]

Abstract: A new coordination polymer of {[Ag(Qina)(Bpp)]·(H2O)2}n (Qina = 2‐quinolinecarboxylic‐carboxylate, Bpp = 4,4'‐trimethylenedipyridine) is successfully synthesized and the structure is determined using single crystal X‐ray diffraction. The complex is crystallized in the monoclinic system with P21/c space group: Each atom of Ag(I) is chelated by one Qina group, with each Bpp ligand bridging two Ag(I) atoms to form the 1D polymer chains. Furthermore, the 3D supramolecular architecture is a costructure directed via weak stacking interactions of C–H···π and hydrogen bond. The complex shows competitive binding affinities in calf thymus DNA (ct‐DNA) interaction by fluorescence spectroscopy. In addition, the complexes’ cytotoxic activity is explored for two kinds of cancer cell lines (Hela, MCF‐7), indicating an anticancer activity and cytotoxicity. CCDC: 1553426 [ABSTRACT FROM AUTHOR]

In this study, amino-functionalized magnetic graphene oxide (Fe3O4/GO-NH2) nanocomposites were fabricated by one-pot solvothermal method. As-prepared Fe3O4/GO-NH2 nanocomposites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption/desorption isotherm, elemental analysis, and vibrating sample magnetometer (VSM). Adsorption behaviors of Fe3O4/GO-NH2 nanocomposites for Ag(I) in aqueous solution were investigated. Detailed adsorption studies demonstrate that Ag(I) was reduced to silver in the process of the adsorption by Fe3O4/GO-NH2 nanocomposites. The pH value of aqueous solution had a major impact on Ag(I) adsorption. The maximum adsorption capacity of Fe3O4/GO-NH2 nanocomposites for Ag(I) was 114.90 mg/g. The adsorption process of Fe3O4/GO-NH2 nanocomposites for Ag(I) was well described by the pseudo-second-order kinetics model and the Langmuir isotherm model. [ABSTRACT FROM AUTHOR]

[Display omitted] • UiO-66-Rd i-s and UiO-66-Rd p-m adsorbents were designed for capturing Ag(I) from wastewater. • Rhodanine groups were confirmed to be modified outside of UiO-66-Rd p-m and inside of UiO-66-Rd i-s. • UiO-66-Rd p-m exhibited faster kinetic and higher selectivity for Ag(I) capture than UiO-66-Rd i-s. • Enhanced selectivity was dominated by high-exposure rhodanine sites outside of UiO-66-Rd p-m. Highly efficient capturing of silver from wastewater is critical for environmental and economic sustainability but remains significantly challenging to achieve fast kinetics and precise selectivity. Herein, we present two approaches based on rhodanine (Rd)-modified UiO-66 including post-modified ligand exchange for UiO-66-Rd p-m and in-situ solvothermal for UiO-66-Rd i-s. The resultant UiO-66-Rd p-m and UiO-66-Rd i-s perform maximum adsorption capacity of 120 and 109 mg·g−1, respectively, which are both about 6 times higher than pristine UiO-66. Benefitting from high-exposure Rd groups over the surface, UiO-66-Rd p-m exhibits about 3 times faster kinetic adsorption and nearly 15 times higher maximum selectivity coefficient than UiO-66-Rd i-s. Experiment and calculation demonstrate that the excellent performance of Rd-modified UiO-66 is dominantly owing to S chelation in the Rd group. In addition, site energy distributions of the Dubinin-Ashtakhov isotherm model confirm that UiO-66-Rd p-m has more effective sites for Ag(I) adsorption relative to UiO-66-Rd i-s. While a higher density of Rd outside the UiO-66-Rd p-m provides a larger coordination number of S/Ag (1.41) than UiO-66-Rd i-s (0.59), which is attributed to its sufficient exposed active S sites for multidentate coordination of Ag(I), thus significantly enhancing adsorption rate and selectivity. These findings are exploited to shed new insight into the design of adsorbents for the efficient recycling of noble metals from water. [ABSTRACT FROM AUTHOR]

A novel approach for the catalyzed formation of bisindolylmethane derivatives (BIMs) is described. This methodology is the unique example where AgOTf has been successfully used for the activation of aldehydes, giving easy access to a broad range of bisindolyl derivatives with excellent results. Moreover, the simplicity and easy operational methodology using a small amount of commercially available AgOTf (1–3 mol %), one of the lowest catalytic charge used in this process to date, makes this procedure an alternative approach for this interesting and appealing reaction.

The influence of the composition of the methanol-acetonitrile (MeOH-AN) solvent on the solvation of 18-crown-6 ether (18C6) has been studied. Increasing fraction of AN in the binary solvent stabilizes the 18C6 solvation complex by increasing the exothermicity of 18C6 solvation. Analysis of the solvation contributions of the reagents to the enthalpies of complex formation of silver(I) ion with 18C6 in MeOH-AN mixtures has been performed to establish that the decrease in the exothermicity of complex formation in going from MeOH to AN is mostly associated with the solvation contribution of Ag(I). [ABSTRACT FROM AUTHOR]

Three coordination polymers [ZnLCl]( 1), [(AgL·NO)]( 2), [CuL·2NO]( 3) (L = uniconazole) have been synthesised and structurally characterized by element analysis, infrared spectra and X-ray crystal diffraction. Complex 1 is the triclinic system, space group P-1 with a = 8.9407(10) Å, b = 13.2994(15) Å, c = 14.9242(17) Å, α = 93.8180(10)°, β = 99.0250(10)°, γ = 104.7690(10)°, V = 1684.1(3) Å. Complex 2 is the Triclinic system, space group P-1 with a = 8.997(3) Å, b = 16.941(5) Å, c = 24.113(7) Å, α = 89.182(4)°, β = 86.440(4)°, γ = 86.440(4)°, V = 3483.0(19) Å. Complex 3 is the triclinic system, space group P-1 with a = 8.7387(5) Å, b = 13.4087(8) Å, c = 15.4353(9) Å, α = 87.8870(10)°, β = 80.7150(10)°, γ = 71.3930(10)°, V = 1691.42(17) Å. In 1 and 3, Each six-coordinated Zn(II), Cu(II) ions adopts a distorted octahedral geometry. 1 and 3 was linked into a one dimensional chain by intermolecular hydrogen bonds. But in 2, each Ag(I) ion is two-coordinated in a linear mode. Althought there is many intermolecular hydrogen bonds, but the complex is zero dimensional. Graphical Abstract: Three new coordination polymers [ZnLCl]( 1), [(AgL·NO)]( 2), [CuL·2NO]( 3) (L = uniconazole) have been synthesised and structurally characterized by element analysis, infrared spectra and X-ray crystal diffraction. [ABSTRACT FROM AUTHOR]

Treatment of AgNO3 with a tetrazolyl ligand H2L1 afforded a 3-D coordination polymer [Ag2( L1)]n ( 1). The crystal structure was determined by X-ray crystallography and it shows that both Ag1 and Ag2 atoms in the asymmetric unit exhibit distorted tetrahedron geometries, which are modified by Ag⋯Ag interactions. The flexible methylene -CH2- linkage between tetrazolate and phenyl ring effectively reduces the steric strain in the resultant 3D-framework. L1 exhibits an unsual coordination mode in which all nitrogen atoms in the two tetrazolato units are coordinated to the AgI centers. The luminescent property of 1 was also investigated. It exhibits multiple emission bands; the high energy emission band is assigned to the ligand-centered π⋯π transition, while the low energy emission bands are tentatively assigned to ligand-to-metal charge transfer (LMCT) that are modified by Ag⋯Ag interaction. The independence of the chromaticity coordinates of 1 on the excitation wavelength also suggests that it is a potentially useful single-component white-light-emitting material. [ABSTRACT FROM AUTHOR]

State-of-the-art polymeric membranes are faced with significant challenges of overcoming the permeability-rejection trade-off. Herein, the conjugated polymer PEDOT:PSS based multilayered polymer membranes are rationally constructed for silver-containing wastewater treatment. It is noteworthy that Ag(I) ions with hydrated diameters approximately two-fold smaller than the pore size can still be completely rejected while maintaining preferable permeability, and the interception performance of PEDOT:PSS/PDA@PVDF composite membranes remains at 95% after three cycles. Encouragingly, the formation of metallic silver on the membrane is observed during ultrafiltration, where the S binding sites in the thiophene ring and the covalent O in the dioxane ring of PEDOT come into being a synergistic effect on the adsorption and reduction of Ag(I), benefiting for the enhanced rejection performance as well as desirable anti-fouling properties. The integrated adsorptive/reductive polymeric membrane exhibits exceptional potential as a suitable candidate for the next generation wastewater treatment and resource recovery. [Display omitted] • Integrated adsorptive/reductive PEDOT:PSS-based membranes are firstly designed. • Permeability-rejection balance is achieved during membrane separation of Ag(I). • The S sites and the covalent O of PEDOT synergistically promoted Ag(I) rejection. • The membranes exhibited desirable recyclability and anti-fouling properties. [ABSTRACT FROM AUTHOR]

Stereoselective cyclo-addition reactions of azomethine ylides promoted by in situ generated Ag(I)/bisphosphine complexes were studied. Under the optimised conditions, the pyrrolidine products were isolated in up to 84 % yield and with up to 71 % e.e. The effects of various reaction variables on the stereoselectivity were also investigated.

The pollution of Hg(II) and Ag(I) to water system exerts hazardous effect to aquatic ecosystem and public security. Simple strategy for constructing adsorbents to efficient remove them is greatly desired. Thus, a series of thiol and amino groups containing bifunctional polysilsesquioxanes (ASPSS) microspheres with adjustable porous structure and functional group content were synthesized by one-step feasible sol–gel process. The adsorption behavior and mechanism of ASPSS microspheres toward Hg(II) and Ag(I) was thoroughly determined. The maximum adsorption capacity of ASPSS for Hg(II) and Ag(I) are 4.32 and 3.86 mmol·g−1 under 25 ℃. The as-prepared ASPSS microspheres can 100% selectively capture Hg(II) with the coexisting of Mn(II), Co(II), Pb(II), Cd(II), Cu(II), Fe(III). And they can 100% adsorb Ag(I) with the presence of Cd(II), Pb(II), Co(II), Ni(II), and Zn(II). Moreover, the ASPSS microspheres exhibit good removal efficiency for Hg(II) and Ag(I) from simulated industrial wastewater with the coexistence of multiple pollutants. Adsorption mechanism suggests the adsorption for Hg(II) and Ag(I) is the synergistic coordination effect of amino and thiol groups. The excellent adsorption selectivity for Hg(II) and Ag(I) is attributed to the super binding ability of these functional group. ASPSS microspheres also exhibit good regeneration ability and could be reused for removing Hg (II) and Ag(I) from aqueous solution with practical value. [Display omitted] • Bifunctional polysilsesquioxanes microspheres were synthesized by feasible method. • ASPSS microspheres display outstanding adsorption performance for Hg(II) and Ag(I). • Adsorption mechanism was revealed based on experiment and DFT calculation. • The capture for Hg(II) and Ag(I) is the synergistic coordination of amino and thiol groups. [ABSTRACT FROM AUTHOR]

• Ag-NHC metallo-supramolecular architectures were synthesized and characterized by X-ray. • A box or square dinuclear Ag-NHC [2+2] tetracarbene and 1D linear Ag-NHC polymer. • Ag-NHC supramolecular assemblies exhibit inhibitory effects on breast cancer cell growth. Four Ag(I)-N-heterocyclic carbene (Ag-NHC) supramolecular assemblies, viz. Ag 2 (L 1) 2 (PF 6) 2 (L 1 = 2, 5-bis[1-benzenyl-2-ylidene-imidazolium-3-yl)]-pyridine) (5), Ag 2 (L 2) 2 (PF 6) 2 (L 2 = 1, 3-bis[1-benzenyl-2-ylidene-benzimidazolium-3-yl)]-benzene) (6), Ag 2 (L 3) 2 (PF 6) 2 (L 3 = 1, 4-bis[1-(quinolin-8-yl)-2-ylidene-imidazolium-3-yl)]-benzene) (9), and [Ag(L 4)PF 6 ] n (L 4 = 1, 4-bis[1-benzenyl-1, 2, 4-triazolium-4-yl-5-ylidene)]-benzene) (12), were synthesized from silver oxide and the corresponding NHC ligand precursors (3, 4, 8 , and 11). They were characterized by 1H NMR, 13C NMR, ESI–MS, and single-crystal X-ray diffraction (XRD) analysis. X-ray crystallography revealed that the Ag-NHC supramolecular assemblies 5, 6 , and 9 are a box or square dinuclear Ag-NHC [2+2] metallo-macrocyclic supramolecular assemblies, whereas 12 functioned as a one-dimensional (1D) linear Ag-NHC polymer with the link of carbene C NHC –Ag–C NHC bonds. The structural assignments for 5 were further supported by density functional theory (DFT) calculations. The emission band of 12 has a slight blue shift as compared to the precursors NHC compound 11 , owing to the metal–ligand charge transition in 1D linear Ag-NHC polymer. The in vitro cytotoxic activity observed in 5, 6, 9 , and 12 against breast cancer MCF-7 cells indicates that the Ag-NHC supramolecular assembly 9 displayed the best anticancer activity in MCF-7 cells at a concentration of 5 × 10−6 mol/L. All four Ag-NHC supramolecular assemblies had significant inhibitory effects on breast cancer cell growth at a concentration of 5 × 10−5 mol/L. [Display omitted] [ABSTRACT FROM AUTHOR]

In this article, ultrasonic-assisted cloud point extraction (UA-CPE) was used to the preconcentration of trace Ag(I) and Cd(II) in dried nut and vegetable samples. After ion association of Ag(I) and Cd(II) ions with 3, 7- diamino- 2, 8- dimethyl- 5- phenyl- phenaziniumchlorid (Safranin T) in the presence of excess potassium iodide (KI) at pH 6.0, the ternary complexes formed were quantitatively extracted into a micellar phase of poly( ethyleneglycol- mono- p- nonylphenylether) (PONPE 7.5) and then determined by flame atomic absorption spectrometry (FAAS). The matrix effects of possible some interfering ions on the method recovery and tolerance limits were also investigated. Under the optimized reagent conditions, the method was linearly dependent on the analyte concentrations in the range of 0.08-90 and 3-250 μg L with limits of detection of 0.02 and 0.9 μg L for Ag(I) and Cd(II), respectively. The reproducibility as the percent relative standard deviations (RSDs %) (0.5, 5.0, and 25 μg L for Ag(I) and 15, 30, and 100 μg L for Cd(II), n = 6) was lower than 3.6 % for both analytes. The accuracy of the method was controlled by analysis of two certified samples (SRM 1573a Tomato leaves and SRM 1643e Trace elements in waters) as well as recovery studies from spiked samples. It has been observed that the results obtained are in a good agreement with the certified values at confidence interval of 95 %. The method was successfully applied to determination of Ag(I) and Cd(II) in several dried nut and vegetable samples by FAAS after separation/preconcentration with UA-CPE. [ABSTRACT FROM AUTHOR]