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Herein, a straightforward method for rapid access to all-carbon tertrasubstituted alkenes bearing alkyl, aryl and alkynyl groups is established via palladium-catalyzed three-component cross-coupling reaction of internal alkynes, haloalkynes and arylboronic acids. This protocol is characterized by a broad substrate scope and excellent chemo- and regioselectivities. The dual beneficial roles of silver salts in activating haloalkynes and inhibiting bromoalkynylation have been demonstrated by serving as both the Lewis acid and halide scavenger. [ABSTRACT FROM AUTHOR]

The determination of arsenic content in phosphorus pentoxide by atomic fluorescence spectroscopy method was studied, and the acid medium, acidity, reducing agent concentration, pre reducing agent, and masking agent were determined. The results indicate that the method has good linearity in the range of 1.0~50.0 /, ig/L, the correlation coefficient is r>0.999, the detection limit is 0.06 µg/L, quantification limit is 0.21 µg/L. The relative standard deviation (RSD) of the 8 sample analysis results is 1.94%, and the spiked recovery rate are 92.87%~101.30%. The test results show no significant difference from the DDTC silver salt method, and this method is a reliable method for detecting arsenic content in phosphorus pentoxide, because it is more convenient and less reagent used. [ABSTRACT FROM AUTHOR]

Molecular solar thermal systems (MOST) represent an auspicious solution for the storage of solar energy. We report silver salts as a unique class of catalysts, capable of releasing the stored energy from the promising 1,2‐dihydro‐1,2‐azaborinine based MOST system. Mechanistic investigations provided insights into the silver catalyzed thermal backreaction, concurrently unveiling the first crystal structure of a 2‐aza‐3‐borabicyclo[2.2.0]hex‐5‐ene, the Dewar isomer of 1,2‐dihydro‐1,2‐azaborinine. Quantification of activation energies by kinetic experiments has elucidated the advantageous energy change associated with Lewis acid catalysts, a phenomenon corroborated through computational analysis. By means of low temperature NMR spectroscopy, mechanistic insights into the coordination of Ag+ to the 1,2‐dihydro‐1,2‐azaborinine were gained. [ABSTRACT FROM AUTHOR]

The reactivity of carbamoyl radicals, generated in situ from sodium oxamate salts, has been investigated in the context of radical carbofluorination reactions of olefins and α‐fluoroolefins, respectively. Both transformations are catalyzed by silver salts and required the presence of potassium persulfate (K2S2O8) and SelectfluorTM as a radicophilic fluorine source. The reported methods provide a direct access to β‐fluoroamides and β,β‐difluoroamides. [ABSTRACT FROM AUTHOR]

Under ambient temperature conditions, a novel method has been developed for the conversion of aryl bromides to aromatic aldehydes, utilizing DMF (N,N-dimethylformamide) as both the starting material and solvent, in the presence of samarium metal and a trace of silver salts. This research has successfully explored an efficient approach for Barbier-type addition reactions, leading to the establishment of a novel C-C bond. A variety of bromides have been investigated as substrates, and aldehydes are readily obtained in moderate to high yields under mild conditions. The presence of 1 mol% of silver nitrate and potassium iodide is sufficient to catalyze the reaction, with the primary role of potassium iodide being to generate soluble silver iodide in the organic solvent, thereby catalyzing the reaction. The mechanism of the silver(I)-catalyzed process is discussed. [ABSTRACT FROM AUTHOR]

Silver-based metal–organic decomposition inks composed of silver salts, complexing agents and volatile solvents are now the subject of much research due to the simplicity and variability of their preparation, their high stability and their relatively low sintering temperature. The use of this type of ink in inkjet printing allows for improved cost-effective and environmentally friendly technology for the production of electrical devices, including flexible electronics. An approach to producing a silver salt-based reactive ink for jet printing has been developed. The test images were printed with an inkjet printer onto polyimide substrates, and two-stage thermal sintering was carried out at temperatures of 60 °C and 100–180 °C. The structure and electrical properties of the obtained conductive lines were investigated. As a result, under optimal conditions an electrically conductive film with low surface resistance of approximately 3 Ω/square can be formed. [ABSTRACT FROM AUTHOR]

Silver has been shown to improve the antibiotic effects of other drugs against both Gram- positive and -negative bacteria. In this study, we investigated the antibiotic potential of cannabidiol (CBD), cannabichromene (CBC) and cannabigerol (CBG) and their acidic counterparts (CBDA, CBCA, CBGA) against Gram-positive bacteria and further explored the additive or synergistic effects of silver nitrate or silver nanoparticles using 96-well plate growth assays and viability (CFUs- colony-forming units). All six cannabinoids had strong antibiotic effects against MRSA with minimal inhibitory concentrations (MICs) of 2 mg/L for CBG, CBD and CBCA; 4 mg/L for CBGA; and 8 mg/L for CBC and CBDA. Using 96-well checkerboard assays, CBC, CBG and CBGA showed full or partial synergy with silver nitrate; CBC, CBDA and CBGA were fully synergistic with silver nanoparticles against MRSA. Using CFU assays, combinations of CBC, CBGA and CBG with either silver nitrate or silver nanoparticles, all at half or quarter MICs, demonstrated strong, time-dependent inhibition of bacterial growth (silver nitrate) and bactericidal effects (silver nanoparticles). These data will lead to further investigation into possible biomedical applications of specific cannabinoids in combination with silver salts or nanoparticles against drug-resistant Gram-positive bacteria. [ABSTRACT FROM AUTHOR]

This work provides a method for the development of conductive water-based printing inks for gravure, flexography and screen-printing incorporating commercial resins that are already used in the printing industry. The development of the respective conductive materials/pigments is based on the simultaneous (in one step) reduction of silver salts and graphene oxide in the presence of 2,5-diaminobenzenesulfonic acid that is used for the first time as the common in-situ reducing agent for these two reactions. The presence of aminophenylsulfonic derivatives is essential for the reduction procedure and in parallel leads to the enrichment of the graphene surface with aminophenylsulfonic groups that provide a high hydrophilicity to the final materials/pigments. [ABSTRACT FROM AUTHOR]

Objective: To compare the efficacy of table salt with silver nitrate in the treatment of umbilical granuloma presenting to the neonatal unit/paediatric department KTH. Study Design: Randomized Controlled Trial Setting: Neonatal Unit of Khyber Teaching Hospital. Period: November 2019 to November 2022. Methods: A total of 120 patients who presented to the neonatal unit/paediatric department, aged 15-60 days were enrolled in this study via consecutive sampling. Seventy-five patients each, were allocated to two groups, Group A (common salt) and Group B (silver nitrate). Sixteen patients from Group A whereas, in Group B, 17 patients were lost to follow-up. Results: A total of 58 out of the remaining 117 patients were female whereas 59 patients were male. Treatment response was recorded for both groups. The cure rate was greater among Group B (93%) as compared to Group A (88%) but there was no statistically significant difference between Group A and B in treatment response (p= 0.35). Conclusion: Table salt is a cheaper, easily accessible, and safe alternative to topical silver nitrate in the treatment of umbilical granuloma. [ABSTRACT FROM AUTHOR]

The synthesis of binuclear silver(I)-NHC complexes from bis-benzimidazolium salts and silver(I) ions has been carried out via an in-situ deprotonation (NHC = N-heterocyclic carbene). The reaction between 1,3-dibromopropane and two moles of N-substituted alkyl benzimidazole (R = methyl, hexyl, heptyl, octyl, and 4-methyl-benzyl) resulted in the formation of bis-benzimidazolium salts, H2L‧2Br- (1–5). Subsequent reactions of the respective salts with excess Ag2O yielded the formation of bis-NHC binuclear silver(I) complexes with the formula of [Ag2L2]·2PF6 (Ag1-Ag5). All compounds were characterized by 1H and 13C NMR, FTIR, elemental analysis, molar conductivity measurement, melting point analysis, and solubility tests. Single crystal X-ray crystallography data reveals that Ag2 exists as a dinuclear complex with no significant intramolecular argentophilic interactions. Anticancer studies of salts 1-5 and complexes Ag1-Ag5 were carried out by employing breast cancer cell lines (MCF-7). None of the salts showed antiproliferative activity, while all the complexes possessed significant anticancer properties in a dose-dependent manner. The complexes indicate better activity than a positive control except for Ag4. [ABSTRACT FROM AUTHOR]

The possibility of using plasma electron spectroscopy (PLES) as a practical method for the detection and identification of crystalline impurities of salts: silver salts, as well as ammonium salts, used in explosives and dangerous substances is shown. To create a prototype of the PLES detector, relatively simple technical solutions are adopted. The source of excitation of metastable atoms is a short DC glow discharge. For analysis, probe scheme for registering electric current from an auxiliary additional electrode probe is used when scanning the retarding electric potential. As a result of a series of experiments, the possibility of detecting products, cathode sputtering, and decomposition of ammonium and silver salts was shown. In particular, peaks from ammonia, nitrogen oxide, silver, and chlorine were recorded. [ABSTRACT FROM AUTHOR]

Nanoparticles have a wide range of physiochemical properties that can harm many organs, tissues, enzymatic and hormonal activities. Throughout the world, silver nanoparticles (AgNPs) are frequently used in consumer products. The aim of the current study was to synthesize the AgNPs and to investigate their impact on hormones, antioxidant enzymatic activities, and histopathology of the liver of albino mice. The precursor salt silver nitrate and the reducing and capping agent triethylamine were used to synthesize silver nanoparticles. SEM analysis indicated particles ranged between 10–20 nm. The EDX analysis indicated distinct peaks, which illuminated the crystalline, spherical, and face-centred cubic structure of the silver particles being analyzed. Further, the albino model showed that increasing the concentration of AgNPs increased the level of plasma cortisol, T3 and T4. Catalase (CAT), Superoxide Dismutase (SOD), and Glutathione S-Transferase (GST) activities increased at 5 mg/ kg but decreased dramatically at 50 mg/kg, whereas Glutathione (GSH) activities and lipid peroxidation (LPO) levels increased with increasing AgNPs concentration. Furthermore, AgNPs caused neutrophilic and lymphocytic infiltration, central vein damage, and hemorrhage in albino mouse liver at low concentrations (5 mg/kg). High concentrations of AgNPs (50 mg/kg) caused the formation of pknotic nuclei, pyknosis, apoptosis, and vacuolation. The study concluded that AgNPs have dose-dependent toxicity that alters stress hormones, T3 and T4, antioxidant enzymatic activities, and produces some histopathological alterations. [ABSTRACT FROM AUTHOR]

We describe an efficient and versatile method for the direct C−H arylation of xanthines with aryl halides using Pd/P(o‐tolyl)3 as catalyst and Ag2O as an additive. Silver salts have been frequently used as an additive in the Pd‐catalyzed C−H bond activation reactions albeit in excessive amounts (2 to 4 eq.). Herein, we use of a stoichiometric amount (0.1 to 1 eq.) of Ag2O to obtain the optimum yields of C‐8 arylated products. This method exhibits broad substrate scope and enables synthesis of a wide range of xanthine derivatives by variation of aryl component at the C‐8 position. A key advantage of silver additive is that it reduces the catalyst loading and time required for the completion of reactions. Although kinetic experiments show that the inclusion of silver salt accelerates the rate of reaction, catalytic role of silver salt could not be conceived since the C−H bond cleavage is not a rate determining step. Silver salt presumably act as a terminal oxidant in the catalytic cycle and assist the regeneration of Pd catalyst. Moreover, preliminary assessment of biological activities of xanthines demonstrates that the C‐8 arylated xanthines derivatives efficiently inhibit the α‐Synuclein fibrillation, a key factor behind Parkinson's disease. [ABSTRACT FROM AUTHOR]

The synthesis of Cyanobacteria‐mediated nanoparticles has attracted great attention due to its ecofriendly, cost‐effective and biocompatible properties. Silver nanoparticles (AgNPs) are used in different areas such as medicine, household products, disinfectants or food storage. The present study aimed the biosynthesis of AgNPs from Cyanobacterial Chroococcus sp. and their antimicrobial activities on some important pathogen bacterial species. According to the obtained data, optimal conditions for synthesis of AgNPs were extract rate 3 : 1 v/v (cell extract/AgNO3), silver salt concentration 10 mM, pH 7, temperature 60 °C and time 30 minutes. The surface plasmon resonance peak of AgNPs was observed at 420–430 nm, and AgNPs were well‐dispersed spherical with an average size of 11–13 nm in diameter by TEM. SEM‐EDX analysis revealed a strong signal of silver. With FTIR analyzes, shift in the absorption bands after the AgNPs formation was confirmed. X‐ray diffraction analysis exhibited that the AgNPs were cubic crystalline shape. Zeta potential of AgNPs showed ‐ 20 mV. The AgNPs strong showed antibacterial activity on an opportunistic bacterial pathogens of Micococcus luteus, Bacillus subtilis and Pseudomonas aeroginosa. The effective and rapid synthesis of Chroococcus‐mediated AgNPs and their strong antimicrobial effects can create an important potential for their use in biomedical and environmental applications. [ABSTRACT FROM AUTHOR]

This research work presents a "green" strategy of weed valorization for developing silver nanoparticles (AgNPs) with promising interesting applications. Two types of AgNPs were phyto-synthesized using an aqueous leaf extract of the weed Andropogon halepensis L. Phyto-manufacturing of AgNPs was achieved by two bio-reactions, in which the volume ratio of (phyto-extract)/(silver salt solution) was varied. The size and physical stability of Andropogon—AgNPs were evaluated by means of DLS and zeta potential measurements, respectively. The phyto-developed nanoparticles presented good free radicals-scavenging properties (investigated via a chemiluminescence technique) and also urease inhibitory activity (evaluated using the conductometric method). Andropogon—AgNPs could be promising candidates for various bio-applications, such as acting as an antioxidant coating for the development of multifunctional materials. Thus, the Andropogon-derived samples were used to treat spider silk from the spider Pholcus phalangioides, and then, the obtained "green" materials were characterized by spectral (UV-Vis absorption, FTIR ATR, and EDX) and morphological (SEM) analyses. These results could be exploited to design novel bioactive materials with applications in the biomedical field. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus is the Gram-positive, immobile, round-shaped bacterium usually existing on wounds, marine environments, and contaminated food. α-Hemolysin (also called -toxin), a common pore-forming toxin that presents in most S. aureus strains with the ability to penetrate the host cell membrane, leading to osmotic swelling and cell death, appears to be a potential biomarker for detection. Based on a sandwich format, this study developed a lateral flow immunoassay (LFIA) targeting -toxin to detect S. aureus. Silver enhancement method was applied to enhance the test line's signal and, therefore, improve the limit of detection (LOD). This method relies on the accumulation on AuNP surface of silver atoms which come from silver nitrate salt after being reduced by reducing agent. The developed LFIA could detect the target antigen within approximately 20 min with no cross-reactivity. The LOD was increased 10-fold after the silver enhancement, from 105 to 104 CFU/mL of bacteria suspensions. The results indicated that -toxin is a promising target to detect S. aureus. Targeting -toxin not only can be a potential detection approach but also a tool for measuring toxicity. [ABSTRACT FROM AUTHOR]

The structures of five ammonium salt forms of monosulfonated azo dyes, derivatives of 4‐(2‐phenyldiazen‐1‐yl)benzenesulfonate, with the general formula [NH4][O3S(C6H4)NN(C6H3)RR′]·XH2O [R = OH, NH2 or N(C2H4OH)2; R′ = H or OH] are presented. All form simple layered structures with alternating hydrophobic (organic) and hydrophilic (cation, solvent and polar groups) layers. To assess for isostructural behaviour of the ammonium cation with M+ ions, the packing of these structures is compared with literature examples. To aid this comparison, the corresponding structures of four potassium salt forms of the monosulfonated azo dyes are also presented herein. Of the five ammonium salts it is found that three have isostructural equivalents. In two cases this equivalent is a potassium salt form and in one case it is a rubidium salt form. The isostructurality of ion packing and of unit‐cell symmetry and dimensions tolerates cases where the ammonium ions form somewhat different interaction types with coformer species than do the potassium or rubidium ions. No sodium salt forms are found to be isostructural with any ammonium equivalent. However, similarities in the anion packing within a single hydrophobic layer are found for a group that consists of the ammonium and rubidium salt forms of one azo anion species and the sodium and silver salt forms of a different azo species. [ABSTRACT FROM AUTHOR]

Readily accessible, oxygenated 6,6‐dibromobicyclo[3.1.0]hexanes react with isovanillin in the presence of silver salts and an inorganic base to afford ring‐expanded/nucleophilic trapping products of various regio‐ and stereo‐chemical forms. Most such products undergo efficient, intramolecular Mizoroki‐Heck reactions to give the corresponding tetrahydrodibenzofurans. In certain cases, simple variations in the first step of such reaction sequences enables the preparation distinct ring‐expansion products that also cyclise to give tetrahydrodibenzofurans embodying alternative substitution patterns. [ABSTRACT FROM AUTHOR]

Isoxazolopyridines are highly significant for the development of pharmaceuticals and new materials. In continuation of our ongoing research on transformations of 5‐aminoisoxazoles, we report herein a divergent synthesis of two kinds of novel isoxazolo[5,4‐b] pyridines through condensation of 5‐aminoisoxazoles with β,γ‐alkynyl‐α‐imino esters. By using two different silver salts and a phosphoric acid as catalysts, isoxazolo[5,4‐b] pyridine‐α‐carboxylates and isoxazolo[5,4‐b] pyridine‐γ‐carboxylates were constructed as major isomers in moderate to good yields, respectively. The structures of the two kinds of the isoxazolo[5,4‐b] pyridines were confirmed by X‐ray crystal structural analysis. Furthermore, control experiments were conducted to elucidate the reaction mechanism. [ABSTRACT FROM AUTHOR]

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Metals play an important role in the structure and functions of various proteins. The combination of metal ions and peptides have been emerging as an attractive field to create advanced structures and biomaterials. Here, we are reporting the anion‐influenced, silver ion coordinated diverse networks of designed short tripeptide 310‐helices with terminal pyridyl groups. The short peptides adopted classical right‐handed, left‐handed and 310EL‐helical conformations in the presence of different silver salts. The peptides have displayed conformational flexibility to accommodate different sizes and interactions of anions to yield a variety of metal‐coordinated networks. The complexes of metal ions and peptides have shown different porous networks, right‐ and left‐handed helical polymers, transformation of helix into superhelix and 2 : 2 metal‐peptide macrocycles. Further, the metal‐peptide crystals with inherent dipoles of helical peptides gave striking second harmonic generation response. The optical energy upconversion from NIR to red and green light is demonstrated. Overall, we have shown the utilization of short 310‐helices for the construction of diverse metal‐coordinated helical networks and notable non‐linear optical effects. [ABSTRACT FROM AUTHOR]

A discrete liphophilic organotelluroxane macrocycle has been found to catalyse the hydrogen evolution reaction (HER) by proton reduction efficiently. The macrocycle is synthesized via chloride abstraction from bis(p-methoxyphenyl) tellurium dichloride (p-MeOC6H5)2TeCl2 (1) by silver salts AgMX4 (MX4 = BF4−, and ClO4−) resulting in in situ generated di-cationic tetraorganoditelluroxane units; two such units are held together by two weak anions μ2-MX4, bridging to form 12-membered di-cationic macrocycles [((p-MeO-C6H4)2Te)2(μ-O)(μ2-F2BF2)2]2+ (2) and [((p-MeO-C6H4)2Te)2(μ-O)(μ2-O2ClO2)2]2+ (3) stabilized via Te–(μ2-BF4/ClO4), with secondary interactions. The charge is balanced by the presence of two more anions, one above and another below the plane of the macrocycle. Similar reaction at higher temperatures leads to the formation of telluronium salts R3TeX [X = BF4− (4), ClO4− (5)] as a major product. The BF4− anion containing macrocycle and telluronium salt were monitored using 19F NMR. HRMS confirmed the structural stability of all the compounds in the solution state. The organotelluroxane macrocycle 2 has been found to act as an efficient electrocatalyst for proton reduction in an organic medium in the presence of p-toluene sulfonic acid as a protic source. [ABSTRACT FROM AUTHOR]

A set of N-coordinated tellurium(II) compounds containing either C,N-chelating ligands CNR (where CN = 2-(RN＝CH)C6H4, R = tBu or Dipp; Dipp = 2,6-iPr2C6H3) or N,C,N pincer ligands NCNR (where NCN = 2,6-(RN＝CH)2C6H4, R = tBu or Dipp) were synthesized. In the case of C,N-chelated compounds, the reaction of CNDippLi with Te(dtc)2 (where dtc = Et2NCS2) in a 1 : 1 molar ratio smoothly provided the carbamate CNDippTe(dtc) which upon treatment with 2 eq. of HCl provided the chloride CNDippTeCl. In contrast, the analogous conversion of NCNRLi with Te(dtc)2 surprisingly furnished ionic bromides [NCNRTe]Br as a result of the exchange of dtc by Br coming from nBuBr present in the reaction mixture. Furthermore, the reaction of CNDippTeCl or [NCNRTe]Br with silver salts AgX (X = OTf or SbF6) provided the expected tellurenium cations [CNDippTe]SbF6 and [NCNRTe]X. To further increase the Lewis acidity of the central atom, the oxidation of selected compounds with 1 eq. of SO2Cl2 was examined yielding stable compounds [CNtBuTeCl2]X and [NCNtBuTeCl2]X. The oxidation of the Dipp substituted compounds proved to be more challenging and an excess of SO2Cl2 was necessary to obtain the oxidized products [CNDippTeCl2]SbF6 and [NCNDippTeCl2]SbF6, which could solely be characterized in solution. Compounds [CNtBuTeCl2]OTf and [NCNtBuTeCl2]OTf were shown to undergo a controlled hydrolysis to the corresponding telluroxanes. All compounds were studied by multinuclear NMR spectroscopy in solution and for selected compounds solid state 125Te NMR spectroscopy and single-crystal X-ray diffraction analysis were performed. The Lewis acidity of the studied cations was examined by the Gutmann–Beckett method using Et3PO as the probing agent. The Te–N chalcogen bonding situation of selected compounds has also been examined computationally by a set of real-space bonding indicators. [ABSTRACT FROM AUTHOR]

Herein, we report a protocol for the selective δ‐thiolation of aliphatic α‐amino acids catalyzed by a Pd(II)/Ag(I) system. This reaction employs disulfides as thiolating agents and N‐COPy as directing group, providing valuable non‐proteinogenic amino acid derivatives in moderate to good diastereoselectivities and yields. Remarkably, the method is also suitable for the late‐stage functionalization of a dipeptide. Experimental and DFT studies have provided significant insights into the mechanism and underlying factors controlling the selectivity of the process and determining the key role of the silver salt. [ABSTRACT FROM AUTHOR]

Keywords: C-H bond functionalization; fused-ring systems; heteroarenes; homogeneous catalysis; synthetic methods EN C-H bond functionalization fused-ring systems heteroarenes homogeneous catalysis synthetic methods 3526 3534 9 10/19/23 20231102 NES 231102 Graph Pyrazolo[1,5- I a i ]pyrazines are an emerging class of 5,6-fused bicyclic heterocycles that shows huge potential in medicinal chemistry. [22] Nevertheless, the fact that Ag SB 2 sb CO SB 3 sb was more effective than Cs SB 2 sb CO SB 3 sb in the cross-coupling of B 1a b and B 4a b (Table 1) suggested that the silver cation should play a special role. The results showed that both Cs SB 2 sb CO SB 3 sb and Ag SB 2 sb CO SB 3 sb could facilitate H/D exchange of B 1a b at the C7 position. HRMS: I m i / I z i [M + H] SP + sp calcd for C SB 16 sb H SB 13 sb F SB 3 sb N SB 3 sb O SB 3 sb : 352.0909; found: 352.0891. [Extracted from the article]

The antifungal activity of ten new silver salts of pyrrolo[3,4-c]pyrazol-3-ones and pyrazole-3-carboxamides containing sulfamide groups was studied. Data from in vitro studies and computer predictions of their biological activity were compared. The pharmacophores affecting the antifungal activity were identified. The compound with a 4-ethoxyphenyl substituent in the heterocycle 5-position exhibited the most pronounced antifungal effect (including against Candida non-albicans species) that exceeded the activity of the reference drugs by two times and more (MIC50 = 1.0 mg/L, MIC90 = 15.6 mg/L). This gave grounds for further study of the mechanisms of the revealed antimycotic activity. [ABSTRACT FROM AUTHOR]

An asymmetric Michael addition/hydroarylation reaction sequence, catalyzed by a sequential catalytic system consisting of a squaramide and a combination of silver and gold salts, provides a new series of cyclic aza-spirooxindole derivatives in excellent yields (up to 94%) and high diastero- and enantioselectivities (up to 7 : 1 dr, up to >99% ee). Computational study has also been performed. [ABSTRACT FROM AUTHOR]

In ancient, human used silver and silver salts but silver nanoparticles (AgNPs) have recently been found to be accepted as the result of green synthesis. Now a day, silver nanoparticles (AgNPs) have become extremely popular in the field of the sensor due to their remarkable and significant optical, chemical, and electrical properties. In this paper, we have reported the green and reasonably priced synthesis of silver nanoparticles using Acacia confusa leaf extract which acts as both capping as well as reducing agents. The optical sensing and morphology of the as prepared AgNPs were determined using ultraviolet-visible (UV-Visible) and scanning electron microscopy (SEM) analysis. The sensing of Hg2+ ion through colorimetric and optical have been studied by UV-Vis spectroscopy as well as the naked eye. Moreover, the SEM analysis showed that the volume of the extract had no considerable effect on the morphology except for size. The colorimetric and optical sensing study revealed that the as-synthesized AgNPs exhibited a good response with colorimetric and optical sensing activity specifically towards the toxic Hg2+ ion. [ABSTRACT FROM AUTHOR]

A systematic study is currently demonstrated approach for approving the superior role of silver and palladium metallic particles in acting the role of mordant with acquiring the dyed cotton fabrics excellence in color fastness with additional functions of antimicrobial potentiality and UV-protection action. Whereas, samples were dyed with extract of red peanuts skin as natural textile colorant (RPN dye). The represented data revealed that, in absence of mordant, the samples treated with metal precursors prior to dyeing were exhibited with the excellent color strength, color fastness, antimicrobial action and UV-protection action. Color fastness (washing, rubbing and light fastness) was estimated to be in the range of very good–excellent. Sample pretreated with silver salt and dyed in the absence of mordant was graded with excellent UV-protection action (UPF 31.5, UVB T% 2.6% and UVB blocking percent 97.4%). Antimicrobial potency against E. coli, S. aureus and Candida albicans through inhibition zone and the reduction percent was approved to be in the range of excellence (93.01–99.51%) for the samples dyed in absence of mordant and pretreated with either silver or palladium precursors. [ABSTRACT FROM AUTHOR]

The reactions of copper, silver and palladium salts with the homochiral ligands 3,3′-bis[(S,S)-4-isopropyl-2-oxazolyl]-4-chloro-2,2′-bipyridine (L1), 3,3′-bis[(S,S)-4-benzyl-2-oxazolyl]-4-chloro-2,2′-bipyridine (L2) and 2-[(S)-4-isopropyl-2-oxazolyl]quinoline (L3) yield three new chiral complexes: [Cu(L1)Br2] (1), [Ag(L2)(CH3CN)]·(BF4)·(CH3OH)0.17·(H2O)0.08 (2) and [Pd(L3)Cl2]·(CH3COCH3)0.5 (3), which have been characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental and thermogravimetric analyses. The complexes 1–3 display discrete mononuclear structures. Non-linear optical properties of complexes 1–3 were investigated. [ABSTRACT FROM AUTHOR]

A chromatographic system based on in-tube SPME coupled to capillary LC-DAD has been used to study the synthesis of silver nanoparticles using polyphenols in different scenarios: excess of the reducing agent or of the silver salt, addition of the cationic surfactants, and thermal synthesis. The optimized synthesis conditions allowed to quantify the polyphenols used as reducing agents, such as Trolox and chlorogenic acid. Two chromatographic peaks with different absorption spectrum were monitored during the syntheses. Depending on the molar relationship, a linear relation between the area of the chromatographic peaks and the concentration of the silver or polyphenol was established. For stabilization of silver nanoparticles, different cationic surfactants were used allowing to evaluate the role of anion (chloride and bromide) and of the alkyl chain. The proposed methodology can be used to determine chlorogenic acid up to 3 mM with a detection limit of 34 μM at λ= 400 nm. Chlorogenic acid was determined in dietary products with successful results. Precision (RSD=10%) and recovery (97–100%) were also satisfactory. [ABSTRACT FROM AUTHOR]

With the aim of achieving bioorthogonal intracellular catalysis, a library of platinum(II) complexes was synthesized. Their non‐toxicity to living cells was demonstrated and their catalytic activity was evaluated on a cyclization reaction leading to a highly fluorescent coumarin. None of the platinum complexes showed any catalytic activity for coumarin synthesis. Still, we demonstrated that the silver salt AgSbF6 commonly used to 'activate' metal catalysts by removing a chloride is a very efficient catalyst for the studied intramolecular cyclization reaction. [ABSTRACT FROM AUTHOR]

Reported herein is the development of a novel method for activating thioglycosides without a glycosyl halide intermediate. This has been achieved through the use of a silver salt coupled with an acid additive and molecular iodine. The enhanced stereocontrol was achieved via the H‐bond mediated aglycone delivery (HAD) method, and the extended trisaccharide synthesis was achieved via iteration of deprotection and glycosylation steps. [ABSTRACT FROM AUTHOR]

Green nanoparticle (NPs) synthesis is eco-friendly, non-toxic, and the NPs have demonstrated improved biocompatibility for use in healthcare. This study evaluated the biogenic synthesis of AgNPs from the leaves of Cardamine hirsuta L. and their biological properties. The UV-Vis. spectra at 411 nm exhibited a distinct resonance spectrum for C-AgNPs produced from C. hirsuta L. FT-IR analysis exhibited the presence of functional groups of phyto-compounds of C. hirsuta responsible of silver salt reduction and capping agents of C-AgNPs. The microscopic-based study, such as HR-TEM analysis, showed that the particles were uniformly distributed, spherical, and ranged in size from 5.36 to 87.65 nm. EDX analysis confirmed a silver (Ag) content of 36.3% by weight, and XRD analysis exhibited the face-centred cubic (FCC) crystalline nature of C-AgNPs. DLS measured the mean particle size of 76.5 nm. The zeta potential was significant at −27.9 mV, and TGA analysis revealed that C-AgNPs had higher thermal stability. C-AgNPs demonstrated moderate antimicrobial activity against the tested pathogens. In addition, the anti-proliferative activity measured by the MTT assay on the Caco-2 cell line demonstrated decreased cell viability with increasing C-AgNPs dosage, with an IC50 concentration of 49.14 µg/mL. In addition, an Annexin-V/Propidium iodide flow cytometric study was utilized to evaluate the induction of apoptosis in cancer cells. Early and late apoptosis cell populations increased significantly compared to the untreated control. Therefore, green-synthesized C-AgNPs have significant antimicrobial and anti-proliferative abilities, making them intriguing options for future biomedical applications. [ABSTRACT FROM AUTHOR]

Acute oral mucositis (OM) is a painful complication of concurrent chemoradiotherapy (CCRT). This severe adverse symptom may impact on patient's quality of life, lead to malnutrition. Thus, finding more effective methods in OM management is very important. The purpose of this study is to evaluate the efficacy of polyacrylate silver salt/Polyvinylpyrrolidone-based liquid oral gel (named as polyacrylate silver salt oral gel) in improving the symptomatic relief of CCRT-induced oral mucositis and oral dysfunction in neck and head cancer patients. In this study, 24 oral cancer patients underwent CCRT and having OM grade 2 or higher were randomly assigned into the test group and the control group. Both groups followed Multinational Association of Supportive Care in Cancer and International Society of Oral Oncology (MASCC/ISOO) clinical practice guidelines for the management of mucositis, but adding rinsing with 15 g oral gel right after oral hygiene treaded the test group. Clinical OM and oral function were assessed weekly for 4 consecutive weeks till 5–10 days after the completion of radiotherapy. For evaluation, Common Terminology Criteria for Adverse Events (CTCAE) v3.0 was used for collecting the data of OM grade. The results showed that polyacrylate silver salt oral gel had better effect for relieving the oral mucositis. There were statistically significant differences in OM grades (1.59 vs. 2.8, p < 0.0001) between the test group and the control group. Our clinical studies demonstrated that polyacrylate silver salt oral gel is an effective interventional option in terms of rapid mucositis healing. [ABSTRACT FROM AUTHOR]

Antibiotic resistance in bacteria is a major problem worldwide that costs 55 billion USD annually for extended hospitalization, resource utilization, and additional treatment expenditures in the United States. This review examines the roles and forms of silver (e.g., bulk Ag, silver salts (AgNO3), and colloidal Ag) from antiquity to the present, and its eventual incorporation as silver nanoparticles (AgNPs) in numerous antibacterial consumer products and biomedical applications. The AgNP fabrication methods, physicochemical properties, and antibacterial mechanisms in Gram-positive and Gram-negative bacterial models are covered. The emphasis is on the problematic ESKAPE pathogens and the antibiotic-resistant pathogens of the greatest human health concern according to the World Health Organization. This review delineates the differences between each bacterial model, the role of the physicochemical properties of AgNPs in the interaction with pathogens, and the subsequent damage of AgNPs and Ag+ released by AgNPs on structural cellular components. In closing, the processes of antibiotic resistance attainment and how novel AgNP–antibiotic conjugates may synergistically reduce the growth of antibiotic-resistant pathogens are presented in light of promising examples, where antibiotic efficacy alone is decreased. [ABSTRACT FROM AUTHOR]

A catalytic amount of CsI enables dual concurrent activation of poorly reactive perfluoroalkoxide and alkyl halides, especially alkyl chlorides, leading to the formation of diverse perfluoroalkoxylated organic compounds. Installation of perfluoroalkoxy groups by this methodology is cost-effective, circumventing the need for over-stoichiometric cesium or silver salts. This methodology also provides high functional group compatibility and tolerance of sterically hindered substrates. [ABSTRACT FROM AUTHOR]

An approach based on the use of a silver salt with an organic anion based on nicotinonitrile containing a tricyanobutadiene fragment was proposed for the quantitative fluorimetric determination of a number of anions and thiols, including glutathione and cysteine. [ABSTRACT FROM AUTHOR]

Phosphoranides comprising three phosphorus carbon bonds are scarcely represented in the literature. We now utilized tris(pentafluoroethyl)phosphane, P(C2F5)3, and cyanobis(pentafluoroethyl)phosphane, P(C2F5)2(CN), featuring electron withdrawing pentafluoroethyl groups, to synthesize such compounds. Metal fluorides MF (M=Ag, Cs) add to P(C2F5)3 yielding respective M[P(C2F5)3F] salts. Those M[P(C2F5)3F] subsequently suffer a loss of C2F4, furnishing M[P(C2F5)2F2]. The cesium salt decomposes instantaneously when warmed to rt, whereas the silver salt decomposes slowly over several days at rt. Treatment of Ag[P(C2F5)3F] with 2,2'‐bipyridine facilitated the isolation and structural characterization of [Ag(bipy){P(C2F5)3F}]. With P(C2F5)2(CN), AgF reacts under substitution of the cyano group yielding P(C2F5)2F, rather than phosphoranide formation. However, [K(18‐crown‐6)]F adds to P(C2F5)2(CN) furnishing [K(18‐crown‐6)][P(C2F5)2(CN)F]. Its structural characterization was successful, despite its tendency to undergo an exchange of substituents, yielding [K(18‐crown‐6)][P(C2F5)2F2] and presumably [K(18‐crown‐6)][P(C2F5)2(CN)2]. The latter forms an equilibrium with [K(18‐crown‐6)]CN and P(C2F5)2(CN) which lies well on side of the phosphane and cyanide salt. [ABSTRACT FROM AUTHOR]

In our previous study, quaternary fluoroalkyl phosphonium salt with iodine anion (PPICF-13) was synthesized as an antibacterial agent for PC, but it would dye PC to be brown during processing because of the oxidation of the iodine. With the aim to eliminate the dyeing problem, three quaternary fluoroalkyl phosphonium salts (PPCF) with trifluoroacetate (TFA-PPCF-13), tetrafluoroborate (FB-PPCF-13), and trifluoromethanesulfonate (TFMS-PPCF-13) were synthesized in the research described here through anion exchange reactions between PPICF-13 with the relative silver salts. After evaluation of their antibacterial activity and thermal stability, FB-PPCF-13 was chosen to prepare antibacterial PC through injection processing. The influence of FB-PPCF-13 concentration on the mechanical properties, thermodynamic properties, light transmittance, appearance, and antibacterial activity of the antibacterial PC was investigated. The results showed that incorporation of FB-PPCF-13 had no negative influence on the mechanical properties of PC, but could reduce Tg and increase the MFI due to the plasticization effect of FB-PPCF-13. When the concentration of FB-PPCF-13 was 2 wt.% or more, the resulting antibacterial PC could have strong antibacterial activity no matter before or after being aged. Though FB-PPCF-13 reduced the light transmittance of PC, it did not influence the color scheme of dyed PC products. [ABSTRACT FROM AUTHOR]

We have been successfully developed a thick film aluminum-based conductivity (7.329 × 10–8 Ω m) comparable to thick film silver. Core–shell powders were created by coating aluminum powder with silver using a chemical galvanic replacement reaction, which creates a silver shell around the aluminum particles when aluminum powder is mixed with silver salt. This core–shell particles interacts and turns into an alloy. The Al2Ag alloy creates bridging between the particles, resembling a network, which contribute significantly to the thick film's high conductivity. To sustain the particles, nevertheless, by filling the pores and preventing oxidation, glass frit was added. In this work, the impact of the glass frit content is also investigated. The lowest resistivity was reached by adding 3% glass frit and sintering at temperature 600°C. [ABSTRACT FROM AUTHOR]

Propargyl ureas can lead to a range of possible heterocyclic compounds, mainly depending on the employed catalyst. Silver salts are known to promote the N-5-exo-dig cyclization mode to imidazolidinone derivatives. Conversely, a versatile and stereoselective O-5-exo-dig cyclization of propargyl ureas to 2-aminooxazolines by Ag(I) catalysis is here disclosed. Good to excellent yields and complete stereoselectivity of the external double bond have been achieved under milder reaction conditions (50-60 °C). A one-pot protocol starting from the corresponding propargylic amines and isocyanates has been developed as well. N,N'-Dipropargyl ureas underwent a uncommon O-5-exo-dig/N-5-endo-dig double cyclization sequence. Finally, insights into the tautomeric equilibrium of 2-aminooxazoles and on their relative reactivity are provided. [ABSTRACT FROM AUTHOR]

Epithelial integrity and function must be maintained in a dynamic healthy equilibrium, keeping unaltered the oxidative and inflammatory conditions and the microbiome of the cutaneous layers. Beside the skin, other mucous membranes can be injured, such as the nasal and anal ones, because of the contact with the external environment. Here, we detected the effects of RIPACUT®, a combination of Iceland lichen extract, silver salt and sodium hyaluronate that individually act in diverse biological ways. The findings we obtained on keratinocytes, nasal and intestinal epithelial cells reveal that this combination showed a marked antioxidant activity, further assessed by the DPPH assay. Additionally, by analyzing the release of the IL-1β, TNF-α and IL-6 cytokines, we proved the anti-inflammatory effect of RIPACUT®. In both cases, the main preserving action was due to Iceland lichen. We also observed a notable antimicrobial activity mediated by the silver compound. These data suggest that RIPACUT® could signify the basis for an attractive pharmacological approach to maintaining healthy epithelial conditions. Interestingly, this may be extended to the nasal and anal areas where it protects against oxidative, inflammatory and infectious insults. Thus, these outcomes encourage the creation of sprays or creams for which sodium hyaluronate can guarantee a surface film-forming effect. [ABSTRACT FROM AUTHOR]

Our research centers on structural, biological, and electronic properties of N-heterocyclic carbene salts and their silver acetate-based complexes. After theoretical calculations, compounds were synthesized. In the DFT studies, functional of B3LYP was used with the basis set of 6-31++G and LanL2DZ for salts and complexes, respectively. The most stable structures were calculated and non-covalent interactions evaluated. Electronic parameters were checked while calculating their HOMO and LUMO energies so that their biological potential can be evaluated. Density of states were studied to check the electronic densities. Among all compounds, 3 was considered the best with energy gap of 0.121 eV. As all eight compounds have very reasonable HOMO-LUMO energy gaps they were considered feasible to synthesize and have strong biological potentials. Compounds were characterized by FT-IR and NMR spectroscopy. [ABSTRACT FROM AUTHOR]

Facilitated transport membranes containing silver ions have attracted much attention thanks to their high performance in olefin/paraffin separation. However, the poor long-term stability of such membranes remains a drawback that must be overcome to enable their practical use. In this work, silver ions were incorporated as ion complexes in the Pebax®2533 matrix to increase their stability as a function of time. Two complexing agents were evaluated: ammonia and 15-crown-5-ether. Membranes of Pebax®2533/Ag(NH3)2OH and Pebax®2533/[Ag(15-crown-5-ether)]BF4 maintained stable selectivity for more than thirty days of observation without compromising permeability. Although complexation decreases the performance of silver compared to free ions, it significantly increases the long-term performance in ethylene/ethane separation. the complexing agents weaken the intensity and strength of Ag+/ethylene-π complexation, but prevent the reduction of Ag(I) to Ag(0). In long-term single gas permeation tests, the Pebax®2533/Ag(NH3)2OH membrane showed selectivity in the range of 12.3 to 9 for 39 days, while the Pebax®2533/[Ag(15crown-5-ether)]BF4 membrane showed selectivity around 9 for 30 days. Mixed gas permeation studies allowed to identify conditions to maintain the separation performance above the upper bound for more than 40 days, under continuous membranes exposure to mixed gases. Increased stability compared to membranes reported in the literature was achieved. [ABSTRACT FROM AUTHOR]

Saline soil or water can highly affect plant physiological and biochemical responses including general disruption in the nutritional status of plants, osmotic stress, and ion-specific toxicity The rapid development and potential release of engineered nanoparticles (ENPs) have raised considerable concerns due to the unique properties of nanomaterials. Spinach is considered a model plant in hydroponic system production and is of research interest all over the world. In this study, we aim to study the physiological responses of spinach under different concentrations of both silver nanoparticles and salt stress. Spinach seedlings were exposed to 16 treatments asthreesalinity concentrations (4.0, 6.0, and 10.0 dS.m-1),three silver nanoparticles concentrations (20, 40, 60 ppm), nine treatments as combination of salinity and silver nanoparticles and control.Relative water content (RWC), stomatal conductance (gs), chlorophyll content index (CCI),), dry weights (DW), leaf area (LA), and specific leaf area (SLA) of 41 days old spinach seedlings were examined and recorded for 6 weeks. The application of Silver nanoparticles had affected plant growth and altered many plant physiological responses. We concluded that silver nanoparticles might have positive effects on the physiological parameters but only under non-saline stress. However, it negatively impacts plants when it was added under saline conditions. [ABSTRACT FROM AUTHOR]

Cascade reactions provide a straightforward access to many valuable compounds and reduce considerably the number of steps of a synthetic sequence. Among the domino and multicomponent processes that involve alkynes, the cascade reaction between alkynoic acids and C-, N-, O- and S-aminonucleophiles stands out as a particularly powerful tool for the one-pot construction of libraries of nitrogen-containing heterocyclic compounds with scaffold diversity and molecular complexity. This reaction, based on an initial metal-catalyzed cycloisomerization that generates an alkylidene lactone intermediate, was originally catalyzed by gold(I) catalysts, along with silver salts or Brönsted acid additives, but other alternative metal catalysts have emerged in the last decade as well as different reaction media. This review examines the existing literature on the topic of metal-catalyzed cascade reactions of acetylenic acids and dinucleophiles and discusses aspects concerning substrate/catalyst ratio for every catalyst system, nature of the aminonucleophile involved and substrate scope. In addition, alternative solvents are also considered, and an insight into the pathway of the reaction and possible intermediates is also provided. [ABSTRACT FROM AUTHOR]

Silver nanodal was synthesized on orthodontic braces using silver nitrate salts as an electrochemical method. The synthesized Ag nanobranch were characterized by UV-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). Antibacterial microbial performance of Lactobacillus salivarius analyzed with electrochemically synthesized silver nanobranch on orthodontic brackets. The specific antibacterial properties of all the composites showed specific antibacterial effects or antiadherence, independently of the amount of silver nanobranch deposited, likely due to the differences in the bacterial cell wall structures. As a result, the brackets, which are very important for orthodontics, showed a good antibacterial performance with the nanostructures obtained by electrochemically coated with Ag, which is known to have antibacterial properties. [ABSTRACT FROM AUTHOR]

Waveguide–plasmon polaritons sustained in metallic photonic crystal slabs show fascinating properties, such as narrow bandwidth and ultrafast dynamics crucial for biosensing, light emitting, and ultrafast switching. However, the patterning of metallic photonic crystals using electron beam lithography is challenging in terms of high efficiency, large area coverage, and cost control. This paper describes a controllable patterning technique for the fabrication of an Ag grating structure on an indium–tin oxide (ITO) slab that enables strong photon–plasmon interaction to obtain waveguide–plasmon polaritons. The Ag grating consisting of self-assembled silver nanoparticles (NPs) exhibits polarization-independent properties for the excitation of the hybrid waveguide–plasmon mode. The Ag NP grating can also be annealed at high temperature to form a continuous nanoline grating that supports the hybrid waveguide–plasmon mode only under transverse magnetic (TM) polarization. We tuned the morphology and the periodicity of the Ag grating through the concentration of silver salt and the photoresist template, respectively, to manipulate the strong coupling between the plasmon and the waveguide modes of different orders. [ABSTRACT FROM AUTHOR]