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Uniform silver nanoparticles with diameters smaller than 10 nm have been synthesized by the hydrothermal method on micro/nanofibrils of cellulose, which is used as a substrate, in a solution consisting of a water/ethylene glycol (reductant) mixture, a silver salt, poly(vinylpyrrolidone), and silver chloride used as a seed. Cellulose plays the role of an additional mild reductant, which prevents the formed nanoparticles from coalescence and provides the formation of their linear assemblies, in which the density of the nanoparticles and the gaps between them are regulated by varying silver salt concentration in the reaction mixture. Experiments performed with rhodamine 6G dye have shown that the synthesized assemblies of silver nanoparticles exhibit surface-enhanced Raman scattering. The proposed synthesis method may be used for the production of inexpensive sensor elements for surface-enhanced Raman scattering spectroscopy analysis. [ABSTRACT FROM AUTHOR]

Potassium salts of arylmethylidene derivatives of malononitrile trimer were obtained by the reactions of aromatic aldehydes with malononitrile trimer in an aqueous medium under micellar catalysis. The optical properties of the synthesized salts were studied to show they absorb in the range of 313–436 nm, depending on the substituent. Exchange reactions with various metal salts showed that the synthesized derivatives of malononitrile trimer form difficultly soluble compounds with silver salts. [ABSTRACT FROM AUTHOR]

A silver-free amination procedure, here called "complexation", was developed to obtain a class of Pt(II) complexes bearing a payload (such as a diagnostic or a therapeutic moiety). These complexes are crucial intermediates for the efficient development and production of antibody–drug conjugates (ADCs) based on a novel Pt(II)-based linker technology. We termed this metal–organic linker, [ethylenediamineplatinum(II)]2+, "Lx"®. The present, newly developed procedure is a greener alternative for the classically applied activation reaction of Pt-halido complexes with silver salts, followed by amination. The crucial finding is that the leaving ligand of the classical process, chloride, can now be replaced by its higher homologue iodide. This not only decisively improved the manufacturing process of the intermediate, but also was found to be key to a more efficient conjugation procedure, i.e. a subsequent step in which this intermediate is coupled to an antibody. The new process allowed upscaling to be readily realized and the desired intermediate was successfully manufactured on a multigram scale. The obtained Ag-free procedure can be generalized and has a great potential to be applied for other Pt(II) complexes of high importance, such as anti-cancer therapeutics. [ABSTRACT FROM AUTHOR]

An oxidative catalytic vanadium(V) system was developed to access the naturally nonabundant diastereomers of carpanone from the corresponding alkenyl phenol monomer in one pot by tandem oxidation, oxidative coupling, and 4+2 cyclization. This system was applied to the synthesis of two other analogues of carpanone. Mild oxidizing silver salts were used as the terminal oxidant to minimize background oxidation which produces the natural diastereomer of carpanone. Further, the first examples of enantioselective oxidative benzoxanthenone formation are reported. Solvent polarity has a strong effect on enantioselectivity, consistent with a mechanism involving binding of vanadium Schiff base catalysts to the alcoholic moiety of the alkenyl phenols during the cyclization step. [ABSTRACT FROM AUTHOR]

A facile, straightforward, and low-cost method is proposed to synthesize gold@silver@gold core double-shell nanoparticles. The technique is a seed-mediated growth protocol that contains four steps of (1) gold seed synthesis, (2) gold seed growth, (3) silver layer coating through silver salt reduction, and (4) gold layer deposition via gold precursor reduction. The prepared nanoparticles had a narrow size distribution and the average particle size of 28 ± 1 nm. Cysteine was introduced to the nanoparticles solution as a coupling agent to assemble nanoparticles. Aggregation-induced two-photon photoluminescence enhancement of three types assembled nanoparticles, i.e., gold@silver@gold, gold@silver, and gold nanoparticles, was studied. It was observed that the assembled core double-shell nanoparticles presented huge enhancement in two-photon photoluminescence signal in comparison with two other nanoparticles. Moreover, the gold@silver@gold nanoparticle is a stable and biocompatible plasmonic nanosystem. This paper provides a novel candidate for two-photon photoluminescence excitation sensing and imaging for biomedical applications. [ABSTRACT FROM AUTHOR]

This chapter discusses the reactions of 4-phosphorylated 5-hydroxypenta-2,3-dienoates with protected or unprotected hydroxy group involving 5-endo-trig cyclizations. Reactions with electrophiles produce mixtures of the 2,5-dihydro-1,2-oxaphosphole-5-carboxylates and the 5-phosphoryl-furan-2(5H)-ones by competitive electrophilic cyclization due to the neighboring phosphonate (phosphine oxide) and the carboxylate groups participation. 4-Phosphorylated 5-hydroxypenta-2,3-dienoates were smoothly converted into the corresponding 4-phosphoryl-2,5-dihydrofuran-2-carboxylates by using 5 mol% of a silver salt as a catalyst in the 5-endo-trig cycloisomerization reaction. [ABSTRACT FROM AUTHOR]

The isolation of simultaneously low‐coordinate and low‐valent compounds is a timeless challenge for preparative chemists. This work showcases the preparation and full characterization of tri‐coordinate rhodium(‐I) and rhodium(0) complexes as well as a rare rhodium(I) complex. Reduction of [{Rh(μ‐Cl)(IPr)(dvtms)}2] (1, IPr=1,3‐bis(2,6‐diisopropylphenyl)imidazolyl‐2‐ylidene; dvtms=divinyltetramethyldisiloxane) with KC8 gave the trigonal complexes K[Rh(IPr)(dvtms)] and [Rh(IPr)(dvtms)], whereas the cation [Rh(IPr)(dvtms)]+ results from their oxidation or by abstraction of chloride from 1 with silver salts. The paramagnetic Rh0 complex is a unique fully metal‐centered radical with the unpaired electron in the dz2 orbital. The Rh(‐I) complex reacts with PPh3 with replacement of the NHC ligand, and behaves as a nucleophile, which upon reaction with [AuCl(PPh3)] generates the trigonal pyramidal complex [(IPr)(dvtms)Rh‐Au(PPh3)] with a metal–metal bond between two d10 metal centers. [ABSTRACT FROM AUTHOR]

Selective C–H bond alkynylation toward modular access to material and pharmaceutical molecules is of great desire in modern organic synthesis. Disclosed herein is rhodium(III)‐catalyzed selective C–H bond mono‐/bialkynylation of 4‐aryl phthalazin‐1(2H)‐one was developed. The silver salt AgSbF6 are demonstrated to play a vital role in promoting the bialkynylation reactions. The present alkynylation strategy is simple, efficient, and features high functional group tolerance and broad substrate scope under an air atmosphere. Additionally, 6‐aryl pyridazin‐3(2H)‐one scaffold is amenable to the selective monoalkynylation and sequential bialkynylation, respectively. [ABSTRACT FROM AUTHOR]

This work is aimed at obtaining mixed cluster ions of amino acids with copper salts using soft ionization methods. We have shown that amino acid molecules are capable of forming aggregates stabilized by d-metals. In particular, such clusters can form in the presence of silver salts. In the present work, it is revealed that the largest cluster ions can be obtained using the electrospray ionization method. It is found that, upon ionization of amino acids (leucine, alanine, proline, tyrosine, and tryptophan) in the presence of copper salts, cluster associates with a mass of up to 1500 Da are formed. It is also found that the formation of cluster ions strongly depends on the nature of the amino acid and polarity of the charge in the cluster. [ABSTRACT FROM AUTHOR]

Aryl iodides and 2‐(trifluoromethyl)acrylic acid reacted together in ligand‐free Mizoroki‐Heck reaction furnishing a quick and efficient access to highly valuable α‐trifluoromethylacrylic acids. The useful transformation was independent with regard to the electronic nature of the aryl group substituent. A three‐component one‐pot version was also developed to give diverse substituted acrylates. The versatility of α‐trifluoromethylacrylic acids was demonstrated by quick access to 3‐CF3‐coumarins as well as fluorinated analogues of therapeutic or cosmetic agents. Finally, we proposed a catalytic cycle based on the silver carboxylate salt, identified as a key intermediate in the reaction. [ABSTRACT FROM AUTHOR]

An expedient approach to C-glycosylated isoquinolines was established based on the coupling of vinyl isonitriles with tetrafuranos-4-yl and pentapyranos-5-yl radicals generated from oxidative decarboxylation of uronic acids derived from monosaccharides and complex oligosaccharides. This approach enjoyed a broad substrate scope and good functional group tolerance, and afforded structurally diverse C-glycosylated isoquinolines in the presence or absence of silver salts. Deprotection of the coupling products was conducted to yield C-glycosylated isoquinolines with multiple hydroxyl groups. These novel architectures would offer opportunities for investigation of their bioactivities. Structurally novel C-glycosylated isoquinolines have been achieved by treating isonitriles with uronic acids through oxidative radical decarboxylation process. [ABSTRACT FROM AUTHOR]

Following the recent discovery that traditional silver(I) oxide‐promoted glycosidations of glycosyl bromides (Koenigs–Knorr reaction) can be greatly accelerated in the presence of catalytic TMSOTf, reported herein is a dedicated study of all major aspects of this reaction. A thorough investigation of numerous silver salts and careful refinement of the reaction conditions led to an improved mechanistic understanding. This, in turn, led to a significant reduction in the amount of silver salt required for these glycosylations. The progress of this reaction can be monitored by naked eye, and the completion of the reaction can be judged by the disappearance of characteristic dark color of Ag2O. Further evidence on higher reactivity of benzoylated α‐bromides in comparison to that of their benzylated counterparts has been acquired. [ABSTRACT FROM AUTHOR]

Biosynthesis of nanoparticles has gained great attention in moving towards an economic and environmentally friendly process. However, there is a limited number of studies that describe the parameters for tuning the dimension and geometry of nanoparticles in the biosynthesis process. Therefore, in this study, silver nanoparticles were synthesized by varying the synthesis parameters in aqueous extract of Imperata cylindrica. The particles were characterized by visual observation; color changes, UV-visible spectroscopy, dynamic light scattering, field scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. Changing the parameters such as plant extract concentration, silver salt concentration, the temperature of biosynthesis and pH of reaction mixture influence the size and dispersion of the nanoparticles. The optimum parameters for synthesizing silver nanoparticles are 10% of aqueous extract, 10 mM of silver nitrate, pH 5.7 with a reaction temperature of 60°C. The synthesized silver nanoparticles are in spherical with a diameter below 100 nm. [ABSTRACT FROM AUTHOR]

Plant-mediated nanoparticles synthesis is considered as one of the appealing options in bionanoparticles synthesis, however, there is contradictory information about the positive or negative impacts of nanoparticles on plants. Investigating the toxic effects of Ag NPs on model plants, such as onion, can reveal the probability of damage. Thus, the present study was conducted to compare the germination indices and biochemical parameters of edible onion seeds treated with different concentrations of two types of silver nanoparticles (green synthesized and chemical synthesized) to examine the oxidative stress. Based on our results, the interaction between leaf extract and silver salt resulted in a color change from pale yellow to dark brown, the first sign of the AgNPs formation. The green AgNPs treatment improved the onion germination indices. The green AgNPs-exposed seeds displayed a nosignificant reduction in protein content and same protease activity as the control treatment, but chemical AgNPstreated displayed a significant rise of protease and reduction in protein content in concentration more than 0.06 gL-1. In chemical AgNPs-treated seeds both peroxidase and catalase displayed an ascending linear trend and the most activities belonged to chemical AgNPs at 0.05 g L-1 (315.62 and 51.45 µmol min-1g-1 FW, respectively). Both nanoparticle types made an increase in MDA, but green AgNPs did not significantly differ with control treatment. It can be concluded that the green synthesis of nanoparticles is a safe and suitable alternative for chemicalsynthesized metal nanoparticles. [ABSTRACT FROM AUTHOR]

The research work was arranged to check the role of AgNPs and silver ions on callus cells of sugarcane (Saccharum spp. cv CP-77,400). AgNPs were synthesized chemically and characterized by UV-Vis spectra, XRD and SEM. AgNPs and silver ions were applied in various concentrations (0, 20, 40, 60 ppm) to sugarcane calli and the induced stress was characterized by studying various morphological and biochemical parameters. AgNPs and silver ions treatments produced high levels of malondialdehyde, proline, proteins, TP and TF contents. Similarly, CAT, SOD and POX activity was also significant in both treatments. The lower concentration of AgNPs and silver ions (20 ppm) provided maximum intracellular GSH level. This work mainly showed effects of AgNPs and silver ions on sugarcane calli in terms of morphological aberrations and cell membrane damage due to severe oxidative stress and production of enhanced levels of enzymatic and non-enzymatic antioxidants as self-defence to tolerate oxidative stress by scavenging reactive oxygen species. These preliminary findings will provide the way to study ecotoxicity mechanism of the metal ions and NPs in medicine industry and in vitro toxicity research. Furthermore, silver ions alone and their chemically synthesised AgNPs can be used for various biomedical applications in future. [ABSTRACT FROM AUTHOR]

In this paper, humic acid (HA) was used as stabilizer to prepare silver nanoparticles (Ag NPs) by chemically reducing silver salts in water phase, which were employed to produce Ag NPs inks for inkjet printing conductive silver patterns. The obtained silver nanoparticles stabilized with HA (HA-Ag NPs) were all in spherical shape and the particle size was about 7–12 nm. By re-dispersing HA-Ag NPs in ultrapure water, conductive ink with excellent storage stability was prepared, which can be placed at room temperature for 30 days without any precipitation. The as-prepared HA-Ag NPs conductive ink was printed onto photopapers to fabricate conductive silver patterns with a domestic inkjet printer. The resistivity of the printed pattern could reach 135 μΩ cm after printed for 40 layers and sintered at 180 °C for 60 min. In addition, the printed conductive silver patterns could be integrated into a LED device or alarm apparatus, indicating it could be widely used in flexible printing electronics. [ABSTRACT FROM AUTHOR]

Silver nanocrystals made by a chemical reduction of silver salts (AgNO3) by sodium borohydride (NaBH4) were studied using transmission electron microscopy and light scattering simulations. For various AgNO3/NaBH4 molar ratios, the size distributions of the nanocrystals were found to be approximately log-normal. In addition, a linear relation was found between the mean nanocrystal size and the molar ratio. In order to relate the size distribution of Ag nanocrystals of the various molar ratios to the scattering properties of Ag nanocrystals in solar cell devices, light scattering simulations of Ag nanocrystals in Si, SiO2, SiN, and Al2O3 matrices were carried out using MiePlot. These light scattering spectra for the individual nanocrystal sizes were combined into light scattering spectra for the fitted size distributions. The evolution of these scattering spectra with respect to an increasing mean nanocrystal size was then studied. From these findings, it is possible to find the molar ratio for which the corresponding nanocrystal size distribution has maximum scattering at a particular wavelength in the desired matrix. [ABSTRACT FROM AUTHOR]

• The PMB-AZAP/Ag 2 O was first applied to the carboxylative cyclization of propargylic alcohols with CO 2 and achieved high yield (>99 %) and selectivity (>99 %) of the α-alkylidene cyclic carbonates at room temperature and atmospheric pressure. • The reaction mechanism revealed that PMB-AZAP and Ag 2 O formed a silver complex PMB-AZAP-Ag during the reaction, which was a key active species for catalytic carboxylative cyclization. • The PMB-AZAP/Ag 2 O was also applied for the one-pot reaction of propargylic alcohol, CO 2 and CH 3 OH, affording the β-carbonyl carbonate with high yield of 80 %. The utilization of carbon dioxide (CO 2) to synthesize various chemicals is of great importance. Herein, various azaphosphatranes and silver salts were applied to catalyze the carboxylative cyclization of CO 2 and propargylic alcohols to prepare α-methylene cyclic carbonates. The influences of catalyst structures, solvents and reaction parameters on catalytic performance were systematically studied. The combination of tris(4-methoxybenzyl) azaphosphatranes (PMB-AZAP) and Ag 2 O with molar ratio of 0.5:1 gave α-methylene cyclic carbonate in the yield of >99 % at room temperature. Meanwhile, other azaphosphatranes (i -Bu-AZAP, Me-AZAP) gave the product in slightly lower yields. The mechanism exploration revealed that PMB-AZAP and Ag 2 O formed a silver complex PMB-AZAP-Ag during the reaction, which could synergistically catalyze carboxylative cyclization reaction with PMB-AZAP, resulting in a high product yield. In contrast, AgCl or AgNO 3 couldn't react with PMB-AZAP to form silver complexes, and the corresponding catalytic system had no activity. The difference of the catalytic performance indicated that PMB-AZAP-Ag was a key active species for the carboxylative cyclization reaction. The in situ NMR studies concretely demonstrated that PMB-AZAP could activate propargylic alcohols through hydrogen bonding. Furthermore, the catalytic system had good substrate generality. The PMB-AZAP/Ag 2 O was also applied for the one-pot reaction of propargylic alcohol, CO 2 and CH 3 OH, affording the β-carbonyl carbonate with yield of 80 % at CH 3 OH/propargylic alcohols ratio of 20:1. [Display omitted] [ABSTRACT FROM AUTHOR]

• Detail study of (η6-C 6 Me 6)Ru(Cl) 2 (P(OMe) 3) with AgOTf in different solvents. • A comparative study of counterions OTf− and BF 4 −in [(η6-C 6 Me 6)Ru(Cl)(P(OMe) 3) 2 ]X. • Formation of mono-, di- and trinuclear structures with (η6-C 6 Me 6)Ru(P(OMe) 3) moieties. • Complex sequence which undergoes coordinated trimethylphosphite ligands in solution. • A great preference to coordinate adventitious water and labile acetone adducts. An extensive study of the reactions of (η6-C 6 Me 6)Ru(Cl) 2 (P(OMe) 3) (1) with AgOTf in three different deuterated and non-deuterated solvents: chloroform, acetone and nitromethane is described. A series of compounds with the moiety (η6-C 6 Me 6)Ru(P(OMe) 3) is isolated and characterized, along with their crystalline structures. A simple associative step assisted by coordination of the silver cation to two molecules of 1 through the Cl-Ru-Cl bonds affords [{(η6-C 6 Me 6)Ru(Cl) 2 (P(OMe) 3)} 2 (μ-Ag)](OTf) (2), loss of AgCl from 2 gives 1 and (η6-C 6 Me 6)RuCl(OTf)(P(OMe) 3) (3), meanwhile 3 dimerizes to [(η6-C 6 Me 6)Ru(μ-Cl)(P(OMe) 3)] 2 (OTf) 2 (4) which in presence of P(OMe) 3 gives [(η6-C 6 Me 6)RuCl(P(OMe) 3) 2 ](OTf) (11OTf). A comparative study of the influence of the counterions OTf− and BF 4 − was carried out with the analogue [(η6-C 6 Me 6)RuCl(P(OMe) 3) 2 ](BF 4) (11BF4), as well as the corresponding demethylation of the coordinated trimethylphosphite ligands by the classical Michaelis-Arbuzov reactions. The resulting "quasi-chelate" (η6-C 6 Me 6)RuCl(P(O)(OMe) 2)(P(OH)(OMe) 2) (17) where a bridging proton in the phosphinito-phosphinous acid ligands is replaced by BF 2 affords (η6 - C 6 Me 6)RuCl({P(OMe) 2 (O)} 2 BF 2) (18) which contains the chelating structure [Me 2 POBF 2 OPMe 2 ]. The chemistry in solution at room temperature of 1 with AgOTf shows non-selective reactions, as can be determined by multinuclear NMR spectroscopy (1H, 13C{1H}, 31P, 19F). The mixture of products shows a great preference to coordinate water, even when it is in traces, as observed for the formation of [(η6-C 6 Me 6)RuCl(H 2 O)(P(OMe) 3)](OTf) (5), [(η6-C 6 Me 6)Ru(H 2 O)(OTf)(P(OMe) 3)]OTf (6) and [(η6-C 6 Me 6)Ru(H 2 O) 2 (P(OMe) 3)](OTf) 2 (7), being the latter 7 the "sink" product. Also, in presence of anhydrous AgOTf compound 1 can be transformed into the highly hygroscopic (η6-C 6 Me 6)Ru(OTf) 2 (P(OMe) 3) (8) which readily replaces triflate ligands by trace water. Structural characterization by single crystal X-ray diffraction of trinuclear compound 2 , dinuclear 4 and mononuclear 7, 11X (X = OTf, BF4), 18 and nitrile derivatives [(η6-C 6 Me 6)Ru(NCR) 2 (P(OMe) 3)](OTf) 2 (R = Et, 9 ; Me, 10) is discussed. The chemical transformations of AgOTf with (η6-C 6 Me 6)Ru(Cl) 2 (P(OMe) 3) lead to a variety of organoruthenium compounds in a non-selective path. The competition between products depends on the stoichiometry, solvent, and largely on the silver triflate salt, whose hygroscopic capacity favors the coordination of water in several compounds under study. [Display omitted] [ABSTRACT FROM AUTHOR]

Transition metal catalyzed C−H phosphorylation remains an unsolved challenge. Reported methods are generally limited in scope and require stoichiometric silver salts as oxidants. Reported here is an electrochemically driven RhIII‐catalyzed aryl C−H phosphorylation reaction that proceeds through H2 evolution, obviating the need for stoichiometric metal oxidants. The method is compatible with a variety of aryl C−H and P−H coupling partners and particularly useful for synthesizing triarylphosphine oxides from diarylphosphine oxides, which are often difficult coupling partners for transition metal catalyzed C−H phosphorylation reactions. Experimental results suggest that the mechanism responsible for the C−P bond formation involves an oxidation‐induced reductive elimination process. [ABSTRACT FROM AUTHOR]

Here, two series of structurally and electronically varied benzonitrile and coumarin substituted imidazolium (2 – 5) and benzimidazolium (7 – 10) hexafluorophosphate salts and corresponding NHC silver(I) complexes (11 – 18) are reported. Substituents on the coumarin ring are varied with an intention of bringing appropriate electronic changes in the complex, which facilitates the targeted activity. Additionally, the structure of two azolium salts (2 and 7) has been established by SCXRD technique. Extended structure of these salts witnessed a series of hydrogen bonds between the azolium cations and the hexafluorophosphate anions along with moderate π–π stacking interactions operating between the adjacent heterocyclic and/or aromatic rings such as coumarin, (benz)imidazole and benzonitrile phenyl systems. Further, a preliminary antibacterial study of the representative salts and silver complexes against a Gram positive (S. aureus , ATCC 29213) and a Gram negative (E. coli , ATCC 25922) bacteria has been carried out. Both the series of silver complexes demonstrated potent antibacterial activity with a MIC of 8/16 μg/mL against E. coli , while there activity against S. aureus found moderate with a MIC in the range 32–128 μg/mL. Furthermore, the salts evidenced no activity in the working concentration range against tested bacteria, indicating that the activity of the complexes is due to the metal center. Image 1 • Two series of silver complexes possessing coumarin-appended NHC ligands were reported. • Successive N-alkylation is followed to prepare NHC precursors. • Two of the NHC precursors were characterized by SCXRD method. • Complexes displayed good to moderate activity against two bacterial strains. [ABSTRACT FROM AUTHOR]

A new cascade oxidative cyclization reaction of N-Cbz hydrazones with internal alkynes has been explored for the preparation of isoquinoline derivatives using Cp*CoIII-catalyst through C–H and N–N bond functionalization. N-Cbz hydrazones are rarely explored as directing group for redox-neutral [4 + 2] cyclization reaction through the cyclometallation and this catalyst system does not require any external oxidizing agent, as well as, silver or antimony salt. The current efficient approach has been utilized for the synthesis of different isoquinoline derivatives with good regioselectivity and yields. [ABSTRACT FROM AUTHOR]

[3+2]-Cycloaddition of arenediazonium salts with diazo compounds (earlier exemplified only for trimethylsilyldiazomethane and 2,2,2-trifluorodiazoethane) has been developed to include a wide range of readily available α-diazocarbonyl compounds. The resulting 2-aryl-5-acyl-2 H -tetrazoles are of high value in medicinal chemistry. [ABSTRACT FROM AUTHOR]

A new two‐component alkylarylation of N‐benzyl‐N‐(2‐ethynylaryl)amides with α‐bromoalkyl esters using visible light photoredox catalysis promoted by silver salts for producing substituted dibenzazepines is described. Employing α‐bromoalkyl esters to form the alkyl carbon‐centered radicals enables the alkylarylation of alkynes where two carbon‐centered functional groups are introduced across the C≡C bond in a single reaction. [ABSTRACT FROM AUTHOR]

This Essay deals with the fascinating and highly explosive compounds fulminating gold and fulminating silver, which are easily made by treatment of gold dissolved in aqua regia with ammonia, and by reaction of silver oxide or silver salts with ammonia, respectively. Fulminating gold in particular captivated the alchemists in the 16th to 18th centuries. Numerous preparations were described, as well as numerous attempts to make volatile, sublimable or distillable gold, and to use the products so obtained (which were most likely gold chlorides) to make the sought‐after tincture, which would "heal" the "impure" metals and transform them into gold, and equally be a panacea to cure all human illnesses. [ABSTRACT FROM AUTHOR]

A simple and highly efficient room temperature catalytic protocol was developed towards the synthesis of thioesters from thiols and acyl chlorides under solvent-free conditions. Ambient reaction conditions, shorter reaction time, excellent product yields are notable features of this methodology. [ABSTRACT FROM AUTHOR]

The synthesis of two dinuclear ionic complexes with chemical formula [Au(PR 3) 2 ][Au(C ≡ CC 5 H 4 N-4) 2 ] that contain the water soluble phosphines, PR 3 , PTA (1, 3,5-triaza-7-phosphaadamantane, 1) and DAPTA (3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane, 2) is herein described. The differences on their intermolecular reorganization have been analyzed and compared with the previously reported for the neutral complexes [Au(PR 3)(C ≡ CC 5 H 4 N-4)]. It has been evidenced that the reorganization of the ligands giving rise to the dinuclear ionic complexes produces a complete change in the properties giving rise to Au⋯Au intermolecular assemblies. These aurophilic contacts are the responsible for the resulting luminescence which is not displayed for the parent compounds [Au(PR 3) 2 ]Cl and [PPh 4 ][Au(C ≡ CC 5 H 4 N-4) 2 ]. Compounds 1 and 2 were made react with three different silver salts (nitrate, triflate and hexafluorophosphate) giving rise to 1:1 heterometallic assemblies with some changes both on the wavelength and emission intensity. Image 1 • The ionic complexes [Au(PR 3) 2 ][Au(C ≡ CC 5 H 4 N) 2 ] gives rise to aggregates. • X-ray structures evidences the presence of aurophilic contacts. • Absorption, emission and NMR are useful tools for the analysis of aggregation. [ABSTRACT FROM AUTHOR]

A novel catalytic reaction involving terminal alkynes, carbon disulfide, and aziridines has been described. In this transformation, silver-acetylides react with carbon disulfide and aziridines to form 1,4-thiomorpholine molecules in good yields. The optimum conditions developed using silver iodide and (i-Pr)2EtN in DMF at 70°C. [ABSTRACT FROM AUTHOR]

A cobalt‐catalyzed difunctionalization of styrenes with ethers was developed which initiated through α‐C(sp3)−H bond activation of ethers to give the oxyalkylation products. A safe and stable inorganic silver salt was used as the oxidant instead of organic peroxides. The reaction proceeded under simple and mild conditions and exhibited good regioselectivities and functional group tolerance. It provided a method to easily prepare α‐oxyalkyl ketones from readily available substrates. [ABSTRACT FROM AUTHOR]

The complexes Ag(L)n[WCA] (L=P4S3, P4Se3, As4S3, and As4S4; [WCA]=[Al(ORF)4]− and [F{Al(ORF)3}2]−; RF=C(CF3)3; WCA=weakly coordinating anion) were tested for their performance as ligand‐transfer reagents to transfer the poorly soluble nortricyclane cages P4S3, P4Se3, and As4S3 as well as realgar As4S4 to different transition‐metal fragments. As4S4 and As4S3 with the poorest solubility did not yield complexes. However, the more soluble silver‐coordinated P4S3 and P4Se3 cages were transferred to the electron‐poor Fp+ moiety ([CpFe(CO)2]+). Thus, reaction of the silver salt in the presence of the ligand with Fp−Br yielded [Fp−P4S3][Al(ORF)4] (1 a), [Fp−P4S3][F(Al(ORF)3)2] (1 b), and [Fp−P4Se3][Al(ORF)4] (2). Reactions with P4S3 also yielded [FpPPh3−P4S3][Al(ORF)4] (3), a complex with the more electron‐rich monophosphine‐substituted Fp+ analogue [FpPPh3]+ ([CpFe(PPh3)(CO)]+). All complex salts were characterized by single‐crystal XRD, NMR, Raman, and IR spectroscopy. Interestingly, they show characteristic blueshifts of the vibrational modes of the cage, as well as structural contractions of the cages upon coordination to the Fp/FpPPh3 moieties, which oppose the typically observed cage expansions that lead to redshifts in the spectra. Structure, bonding, and thermodynamics were investigated by DFT calculations, which support the observed cage contractions. Its reason is assigned to σ and π donation from the slightly P−P and P−E antibonding P4E3‐cage HOMO (e symmetry) to the metal acceptor fragment. [ABSTRACT FROM AUTHOR]

The complexes Ag(L)n[WCA] (L=P4S3, P4Se3, As4S3, and As4S4; [WCA]=[Al(ORF)4]− and [F{Al(ORF)3}2]−; RF=C(CF3)3; WCA=weakly coordinating anion) were tested for their performance as ligand‐transfer reagents to transfer the poorly soluble nortricyclane cages P4S3, P4Se3, and As4S3 as well as realgar As4S4 to different transition‐metal fragments. As4S4 and As4S3 with the poorest solubility did not yield complexes. However, the more soluble silver‐coordinated P4S3 and P4Se3 cages were transferred to the electron‐poor Fp+ moiety ([CpFe(CO)2]+). Thus, reaction of the silver salt in the presence of the ligand with Fp−Br yielded [Fp−P4S3][Al(ORF)4] (1 a), [Fp−P4S3][F(Al(ORF)3)2] (1 b), and [Fp−P4Se3][Al(ORF)4] (2). Reactions with P4S3 also yielded [FpPPh3−P4S3][Al(ORF)4] (3), a complex with the more electron‐rich monophosphine‐substituted Fp+ analogue [FpPPh3]+ ([CpFe(PPh3)(CO)]+). All complex salts were characterized by single‐crystal XRD, NMR, Raman, and IR spectroscopy. Interestingly, they show characteristic blueshifts of the vibrational modes of the cage, as well as structural contractions of the cages upon coordination to the Fp/FpPPh3 moieties, which oppose the typically observed cage expansions that lead to redshifts in the spectra. Structure, bonding, and thermodynamics were investigated by DFT calculations, which support the observed cage contractions. Its reason is assigned to σ and π donation from the slightly P−P and P−E antibonding P4E3‐cage HOMO (e symmetry) to the metal acceptor fragment. [ABSTRACT FROM AUTHOR]

In an electrochemical cell with electrolyte containing silver or copper salts, the metal deposition takes place on the surface of a transparent electrically conducting coating. Under certain conditions, the metal film becomes specular and the electrochemical cell periodically switches from transparent to mirror state in response to changes in the voltage. The data obtained on electrochemical cells switchable between transparent to mirror states are analyzed. It is noted that the electrolyte properties play the decisive role in characteristics of such devices. Their prototypes with three optical states: transparent‑transient semitransparent‑mirror are realized recently. The modes are achieved in which the mirror state is preserved for a long period (over 2 h) at switched-off voltage (deenergized state). These results allow us to expect that the development of electrochemically switchable glasses-mirrors for windows will soon reach its commercial stage. [ABSTRACT FROM AUTHOR]

A ruthenium‐catalyzed protocol to access conjugate addition or decarboxylative conjugate addition of aromatic acids with maleimides has been developed. The reaction shows interesting chemoselectivity with different substituted benzoic acids. The reaction pathway of C−H alkylation is controlled by the intrinsic property of aromatic acids but not reaction conditions. Under almost the same reaction conditions, carboxyl can act as either a classical directing group or a traceless directing group, thereby generating two kinds of products, i. e. 2‐alkyl substituted benzoic acids and alkyl substituted benzenes. These two reactions proceeded under mild and redox‐neutral conditions in neat water under the atmosphere of air, and could be easily scaled up to grams. The decarboxylative conjugate addition, where carboxyl acts as a traceless directing group, can be realized without the addition of any ligand, silver or copper salt. [ABSTRACT FROM AUTHOR]

The present study evaluated silver nanoparticle (AgNPs) toxicity using biomarkers of oxidative and metabolic stress, immunological impairment and cellular damage in zebrafish (Danio rerio), as well as the optimal dose of vitamin E neutralizing undesirable effects. Fish were fed for ten days and eight study groups were investigated: controls, AgNPs exposure alone (1.5 mg L−1) and combined with three different vitamin E doses (1.5 mg L−1 of AgNPs + vitamin E 100, 200 or 400 mg kg−1 of food), also one positive control group exposed to AgNO 3 alone or combined with the same vitamin E doses. D. rerio exposed to AgNPs alone or combined with the lower vitamin E dose showed overall worse results in comparison with the control groups and the groups combining nanoparticles and 200 or 400 mg kg−1 of food of vitamin E-supplemented diet. AgNPs caused cell impairment by increasing LDH activity and cortisol levels, generated oxidative stress by inhibiting SOD and CAT activity and immunosuppression by inhibiting ACH50 and lysozyme activity. The groups exposed to Ag salt showed the same response-pattern found for the NPs groups, reinforcing that Ag toxicity of AgNPs is mediated by Ag+. In conclusion, although AgNPs are toxic to Danio rerio , vitamin E supplementation at 200 or 400 mg kg−1 can act protectively against its toxic effects. Unlabelled Image • AgNPs and AgNO 3 induced oxidative stress, metabolic and immunological disturbances. • Vitamin E supplementation conferred a protective effect. • The most adequate biomarkers were LDH, CAT and ACH50 activities. [ABSTRACT FROM AUTHOR]

An efficient synthesis of functionalized iminoisoindolinone derivatives has been achieved via a mild electrochemical oxidative C H/N H functionalization/intramolecular annulations with isocyanides in undivided cell equipped with a nickel cathode. • Oxidative C H/N H functionalization by using electricity as oxidant. • Less toxic and earth-abundant cobalt catalyst. • Cheap cathode (Ni) and mild reaction conditions (50 °C Vs 100–170 °C). • The reaction was conducted in an undivided cell. An efficient synthesis of functionalized iminoisoindolinone derivatives has been achieved via a mild electrochemical oxidative C H/N H functionalization/intramolecular annulations with isocyanides in undivided cell equipped with a nickel cathode. In the presence of earth abundant cobalt catalyst, versatile iminoisoindolinone derivatives obtained in good yields and in a sustainable manner by using electricity as an oxidant in place of stoichiometric amount of silver and copper salts. [ABSTRACT FROM AUTHOR]

It was shown that the interaction of silver cations in alkaline aqueous solutions with various kinds of silicates, regardless of their chemical and aggregation state, leads to the formation of an exclusively disilicate form of silver salt. We develop procedures for synthesis of nanostructured weakly ordered nonstoichiometric silver disilicate Ag6 –xHxSi2O7 capable of forming aqueous colloids. We study the micellular structure of colloidal particles in these solutions and demonstrate that permeability of silicic acid layers enveloping nanosized salt cores of these micelles depends on pH. Colloidal silver disilicate is found to exhibit a high catalytic activity in photoinduced oxidation of a broad spectrum of different compounds, which is demonstrated for compounds stable in aqueous solutions such as some organic dies and ferrocyanide complex ([Fe(CN ). [ABSTRACT FROM AUTHOR]

Herein, we report an atom‐efficient, rapid, green, and sustainable approach to synthesize isoquinolines and isoquinolinones using a homogeneous recyclable ruthenium catalyst in PEG Media assisted by microwave energy. Dibenzoylhydrazine was used for C–H/N–N activation reactions for the first time in combination with ketazine as oxidizing directing groups for annulation reactions with internal alkynes. The developed protocol is environmentally benign due to significantly shortened times with an easy extraction method, higher atom economy, external oxidant and silver or antimony salt free conditions, applicability to a gram scale synthesis, use of biodegradable solvent and wide substrate scope with higher product yields. Moreover, it is worth noting that the established methodology allowed reuse of the catalytic system for up to five successive runs with minimal loss in activity. [ABSTRACT FROM AUTHOR]

A one-pot asymmetric Michael addition/Conia-ene reaction sequence, catalyzed by combination of a dipeptide-derived multifunctional quaternary phosphonium salt and Ag 2 CO 3 has been developed, which provides a series of synthetically important chiral methylenecyclopentane derivatives in moderate to excellent yields (up to 97%) and enantioselectivities (up to 93%). Image 1 [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Trans-disubstituted diamido diamine cyclams support cationic zirconium complexes. • (Bn 2 Cyclam)ZrCl 2 reacts with silver salts to form either neutral or cationic species. • (Bn 2 Cyclam)Zr(C 6 F 5) 2 displays a fluxional behaviour in solution. • (Bn 2 Cyclam)ZrCl} 2 (k 2- N,N' -Bn 2 Cyclam) displays one terminal- and one bridging- cyclam. • [(ansa -η5:η5-Cp 2 CMe 2)ZrCl(HBn 2 Cyclam)] is the first mixed cyclam/cyclopentadienyl complex. Abstract (Bn 2 Cyclam)ZrCl 2 reacts with silver salts to form either neutral or cationic species depending on the nature of the counterion. The reaction of (Bn 2 Cyclam)ZrCl 2 with AgCF 3 COO affords (Bn 2 Cyclam)Zr(OCOCF 3) 2 while with AgPF 6 the cationic species [(Bn 2 Cyclam)ZrCl(CH 3 CN)]PF 6 is formed. Cations of formulas [(All 2 Cyclam)ZrX(L)]+ (X = Me, L = CD 2 Cl 2 ; X, L = η2-CH 2 Ph), [(MeAll 2 Cyclam)Zr(η2-CH 2 Ph)]+ and [(Bn 2 Cyclam)Zr(n Bu)(THF)]+ were prepared by abstraction of one alkyl ligand from (R 2 Cyclam)ZrX 2 (R = All, MeAll, Bn; X = Me, CH 2 Ph, n Bu) using B(C 6 F 5) 3 or [PhMe 2 NH][B(C 6 F 5) 4 ]. (Bn 2 Cyclam)Zr(C 6 F 5) 2 was obtained by reaction of (Bn 2 Cyclam)ZrCl 2 with 2 equiv. of MgBrC 6 F 5. The complex (Bn 2 Cyclam)ZrCl} 2 (k 2- N,N' -Bn 2 Cyclam) displaying a cyclam bridging ligand was obtained either from the 1:1 reaction of (Bn 2 Cyclam)ZrCl 2 with LiNiPr 2 and from the reaction of 2 equiv. of (Bn 2 Cyclam)ZrCl 2 with Li 2 (Bn 2 Cyclam).(THF) 2 in THF. The reaction of LiCpC(Me) 2 CpLi with (Bn 2 Cyclam)ZrCl 2 led to the formation of the mixed cyclam/cyclopentadienyl complex [(ansa -η5:η5-Cp 2 CMe 2)ZrCl(HBn 2 Cyclam)]. [ABSTRACT FROM AUTHOR]

Abstract A series of ionic liquids with different cations and anions were synthesized and their performances for the silver catalyzed one-pot A3-coupling reactions were investigated. The selection showed that the combination of AgNO 3 and ionic liquid [TMG][TFA] showed highest catalytic activity. This catalytic system was then utilized for the production a series of propargylamines with satisfactory isolated yields. This reaction system is very simple and easy to be conducted because no inert gases or any other additional solvents, basic additives are needed. This also led to the convenience of the following work-up procedures and the recycle and reutilization for the catalytic system. The ionic liquid was believed to be involved in the catalytic procedure through the interaction with substrates or catalysts as co-catalyst and ligands. Graphical abstract Unlabelled Image Highlights • Synergetic effect of ionic liquid and Ag salt in the catalytic A3 coupling reactions. • Easy operation and work-up procedures. • No necessary of inert gases, basic additives, or any other additional solvents. • Reusable catalytic system. [ABSTRACT FROM AUTHOR]

An efficient method was developed towards the synthesis of alkenylphosphonates from simple olefins and phosphonate diesters. This method was enabled by the use of cheap and commercially available silver salts and TEMPO. This method exhibits of good functional group tolerance, specific (E)‐selectivity for all olefins and vinyl selectivity for aliphatic olefins. A radical mechanism was proposed, and TEMPO was involved in the product formation step. An efficient and novel method was developed towards the synthesis of alkenylphosphonates from simple olefins and phosphonate diesters. This method was enabled by the use of cheap and commercially available silver salts and TEMPO. This method exhibits of good functional group tolerance, specific (E)‐selectivity for all olefins and vinyl‐selectivity for aliphatic olefins. A radical mechanism was proposed, and TEMPO was involved in the product formation step. [ABSTRACT FROM AUTHOR]

It has been shown that monodisperse silver nanoparticles can be obtained in a chitosan solution. The temperature regime, reaction time, and pH of the reaction medium at which monodisperse silver nanoparticles with an average diameter of 65 nm are formed have been selected. The nanoparticles are potentially usable in medicine. Spectral studies have been performed to clarify the character of the interaction between chitosan and a silver salt. It has been found that not only hydroxyl groups of chitosan, but also its free primary amino groups, are involved in the reduction of silver ions and stabilization of formed nanoparticles. [ABSTRACT FROM AUTHOR]

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

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

• One-pot synthesis of a hybrid microsphere with a novel architecture are reported. • Ag@CFR have high antimicrobial activity and low cytotoxicity to mammalian cells. • Ag@CFR can be immobilized onto cotton fabrics via facile pad-dry-cure methods. Silver nanoparticles (Ag NPs) are widely utilized as antibacterial agents, but they are easily agglomerated and have weak adhesion to the substrate, resulting in low stability in the performance of Ag NPs modified antibacterial fabrics. In this work, a one-pot hydrothermal synthesis of silver nanoparticle@catechol formaldehyde resin microspheres (denoted as Ag@CFR) was developed using catechol, hexamethlenetetramine, and silver salts as precursors. When the catechol to silver salt ratio was adjusted to 10:1, monodisperse microspheres were synthesized with the incorporation of Ag NPs both on the surface and within. Ag@CFR could be uniformly dispersed in water, showed very high antimicrobial activity against S. aureus , E. coli , and C. albicans , and had a comparatively low level of cytotoxicity to mammalian cells. Subsequently, Ag@CFR were uniformly deposited and firmly adhered onto the fabric surface using the pad-dry-cure method, resulting in the production of durable antimicrobial cotton fabrics. Ag@CFR-coated fabrics showed very high antimicrobial activities and laundering durability, which presented a high bacteriostatic and fungistatic rate of 99.99% against S. aureus , E. coli , and C. albicans even after 50 laundering cycles. Ag@CFR-coated fabrics maintained good tensile properties, hand feel, and air permeability while presenting superhydrophilicity during the test. This work presents a pioneering attempt to modify fabrics using CFR coatings via a facile method, which is suitable for large-scale production and holds significant potential for widespread applications in various fields. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of benzimidazolium salts and their corresponding Silver(I)- N -Heterocyclic carbene complexes were synthesized and characterized. • Structures of all compounds were characterized by 1H NMR, 13C NMR, and IR spectroscopy, as well as elemental analysis techniques. • Silver(I) NHC complexes were used to investigate the antiproliferation activity against four different cancer cell lines. The study focuses on the synthesis, characterization, and evaluation of silver (I)- N -heterocyclic carbene complexes for their inhibitory effect on cell proliferation. The benzimidazolium salts (3 – 5) and their respective silver complexes (6 – 8) were synthesized and characterized by various techniques including FTIR, NMR and X-ray crystallography. The salts and complexes were then evaluated for their ability to inhibit the proliferation of four different cancer cell lines (EA.hy926, HeLa, MDA-MB-231 and A549). MTT assay demonstrated that the salts and complexes exhibited potent cytotoxicity towards all cancer lines. The study highlights the importance of N -heterocyclic carbene ligands in the development of silver-based drugs with anticancer properties. [ABSTRACT FROM AUTHOR]