Silver Coordination Research Articles

Predictive calculation of the stability constants of silver(I) ion with pyridine and 2,2′-bipyridyl in a solvent environment

In the present study, the stability constants of silver(I) coordination compounds with 2,2′-bipyridyl (bpy, L) in mixed methanol–acetonitrile solvents (MeOH-AN, χAN = 0.0 ÷ 1.0 mol fr.) were determined by the potentiometric method at 25.0 °C. The influence of reagents solvation on the change in stability of [Ag(bpy)]+ and [Ag(bpy)2]+ complexes upon changing the composition of the solvent MeOH→(MeOH-AN) was analyzed. It has been established that the determining factor in the shift of the complex formation equilibrium along the first and second steps of coordination with a change in the composition of the solvent is the contribution from the central ion resolvation. The obtained results and data on the thermodynamics of complex formation reactions of Ag+ with bpy and pyridine (py, L) in a few binary non-aqueous solvents were compared. The possibility of carrying out an estimated calculation of the stability constants of [Ag(L)]+ in non-aqueous solvents was confirmed.

Physicochemical properties, biological chemistry and mechanisms of action of caries-arresting diammine-silver(I) fluoride and silver(I)-fluoride solutions for clinical use: a critical review.

This paper serves as a Part II follow-up of our research investigations performed on the molecular structures of silver(I)-fluoride (SF) and diammine-silver(I) fluoride (SDF) complexes in solution-based commercial products for clinical application, their precise chemical compositions, and their nature in aqueous solution, the latter including rapid fluoride-exchange processes at the silver(I) ion centre monitored by 19F NMR analysis (Part I). Part I of this series also explores the mechanisms of action (MoA) of these complexes, and is therefore largely focused on their chemical reactions with constituents of human saliva, which has access to their sites of application. Such reactions were found to slowly promote the generation of potentially physiologically-active Ag/AgCl nanoparticles from primarily-generated discoloured silver(I) chloride (AgCl) precipitates, a process involving salivary electron-donors such as thiocyanate and L-cysteine. Since this research has shed new light on potential MoAs for these products, in this accompanying report (Part II), we have performed a critical review of scientific literature in order to rationalize our results in relation to current views on these mechanisms for SF and SDF products employed for the successful clinical arrest of dental caries. Following an Introduction to the subject matter ( Section 1), this paper comprises a generalized overview of silver coordination chemistry ( Section 2), which is followed by a section focused on the aqueous solution status and equilibria involved in SF chemistry ( Section 3), the latter including results acquired from an original simulation of the electronic absorption spectra of coloured SF complexes in aqueous solution (Section 3.1). Section 4 then investigates detailed rationales for the biologically-relevant ligand-exchange and redox chemistries, disposition and fates of SF, SDF and silver(I)-nitrate when employed for the treatment of dental caries, with emphasis placed on their therapeutic MoAs. This Section is supported by the provision of valuable information centralized on (1) relevant biomolecular chemistry involved in solution- and solid-state matrices ( Section 4.1); (2) SF and perhaps silver(I)-nitrate as more cost-effective alternatives to SDF therapies ( Section 4.2); and (3) the potential therapeutic benefits and effects offered by silver-based nanoparticles and their associated MoAs ( Section 4.3). Recommendations for future investigations in this area are proposed.

Antimicrobial Activity of Water-Soluble Silver Complexes Bearing C-Scorpionate Ligands.

The novel hydrosoluble silver coordination polymer [Ag(NO3)(μ-1κN;2κN',N″-TPMOH)]n (1) (TPMOH = tris(1H-pyrazol-1-yl)ethanol) was obtained and characterized. While single crystal X-ray diffraction analysis of compound 1 disclosed an infinite 1D helical chain structure in the solid state, NMR analysis in polar solvents confirmed the mononuclear nature of compound 1 in solution. Compound 1 and the analogue [Ag(μ-1κN;2κN',N″-TPMS)]n (2) (TPMS = tris(1H-pyrazol-1-yl)methane sulfonate) were evaluated with regard to their antimicrobial activities towards the Gram-negative Escherichia coli, Pseudomonas aeruginosa, and Burkholderia contaminans, the Gram-positive Staphylococcus aureus, and the fungal species Candida albicans and Candida glabrata. Compound 1 exhibited minimal inhibitory concentration (MIC) values ranging from 2 to 7.7 µg/mL towards the tested Gram-negative bacteria, 18 µg/mL towards the Gram-positive S. aureus, and 15 and 31 µg/mL towards C. albicans and C. glabrata, respectively. Compound 2 was less effective towards the tested bacteria, with MIC values ranging from 15 to 19.6 µg/mL towards the Gram-negative bacteria and 51 µg/mL towards S. aureus; however, it was more effective against C. albicans and C. glabrata, with MIC values of about 6 µg/mL towards these fungal species. The toxicity of compounds 1 and 2 was assessed by evaluating the survival of the Caenorhabditis elegans model organism to concentrations of up to 100 µg/mL. The value of 50% lethality (LD50) could only be estimated as 73.2 µg/mL for compound 1 at 72 h, otherwise LD50 was >100 µg/mL for both compounds 1 and 2. These results indicate compounds 1 and 2 as novel silver complexes with interesting antimicrobial properties towards bacterial and fungal pathogens.

Electrodes composited by bisbenzimidazole silver(I) coordination polymers as electrocatalysts for hydrogen evolution and H2O2-sensing

Two new silver(Ⅰ) coordination polymers (CPs) {[Ag2(p-HMOPhIDC)(BBP)](H2O)}n (1), {[Ag2(m-HMOPhIDC)(BBP)](H2O)}n (2) (BBP = 1,3-[bis(2,2′-benzimidazole)] propane, p-H3MOPHIDC = 2-(4-methoxyphenyl)–2H-imidazole-4,5-dicarboxylic acid, m-H3MOPHIDC = 2-(3-methoxyphenyl)–2H-imidazole-4,5-dicarboxylic acid), were prepared under hydrothermal condition and structurally characterized. The CPs 1–2 both exhibit binuclear 1D “square waveform” chain structures. Structural analysis shows that the two silver ions in CP 1 are crystallographically independent but chemically identical; whereas the two silver ions in CP 2 are crystallographically independent and chemically different. Electrocatalytic hydrogen evolution reaction (HER) of carbon paste composite electrodes (CPCEs 1–2) prepared by mixing graphite powder with coordination polymers was investigated by variable temperature linear sweep voltammetry (VT-LSV), controlled potential electrolysis (CPE) and electrochemical impedance spectroscopy (EIS) in 0.5 M H2SO4 electrolyte. It was found that the overpotential η10293K of CPCEs 1–2 positively shifted 449 and 172 mV compared with sCPCE (−966 mV), and the Tafel slope of sCPCE and CPCE 1–2 were 276, 160 and 226 mV dec-1, respectively. The results proved that CPCEs 1–2 could effectively catalyze and accelerate the HER behavior. The higher HER activity of the CPCE 1 than CPCE 2 can be attributed to the fact that CP 1 contains more three-coordinated silver ions. Moreover, the recognition performance of CPCEs 1–2 for H2O2 was further studied by chronoamperometry in 0.2 M phosphate buffer solution (PBS, pH = 6). The two sensors can detect H2O2 in a linear range from 0.5 μM to 4 mM with a detection limit of 128 µM for CPCE 1 and 27.1 µM for CPCE 2 at a signal-to-noise ratio of 3, and also revealed long-term stability and good selectivity.

Inducing α-Helicity in Peptides by Silver Coordination to Cysteine.

Short peptide sequences consisting of two cysteine residues separated by three other amino acids display complete change from random coil to α-helical secondary structure in response to addition of Ag+ ions. The folded CXXXC/Ag+ complex involves formation of multinuclear Ag+ species and is stable in a wide pH range from below 3 to above 8. The complex is stable through reversed-phase HPLC separation as well as towards a physiological level of chloride ions, based on far-UV circular dichroism spectroscopy. In electrospray MS under acidic conditions a peptide dimer with four Ag+ ions bound was observed, and modelling based on potentiometric experiments supported this to be the dominating complex at neutral pH together with a peptide dimer with 3 Ag+ and one proton at lower pH. The complex was demonstrated to work as a N-terminal nucleation site for inducing α-helicity into longer peptides. This type of silver-mediated peptide assembly and folding may be of more general use for stabilizing not only peptide folding but also for controlling oligomerization even under acidic conditions.

Synthesis and Photophysical Properties of Silver(I) Coordination Polymers Bridged by Dimethylpyrazine: Comparison of Emissive Excited States between Silver(I) and Copper(I) Congeners.

Highly luminescent silver(I) coordination polymers [Ag2X2(PPh3)2(Me2pyz)]n (X = I, Br, Cl; Me2pyz: 2,5-dimethylpyrazine) were prepared together with copper congeners [Cu2X2(PPh3)2(Me2pyz)]n (X = I, Br). All the complexes showed thermally activated delayed fluorescence from the charge-transfer states in the visible region, from blue to red. The isomorphous relationship among the complexes allowed a detailed discussion of the effect of halogenido ligands and crystal packing on their luminescence energy. The relaxation in the emissive excited states (ESs) was determined to be more remarkable in silver complexes than in copper complexes despite their isomorphous structures, and the electronic effect of halogenido ligands was comparable to the effect of relaxation in emissive ESs.

Silver Coordination Polymers Driven by Adamantoid Blocks for Advanced Antiviral and Antibacterial Biomaterials.

The development of sustainable biomaterials and surfaces to prevent the accumulation and proliferation of viruses and bacteria is highly demanded in healthcare areas. This study describes the assembly and full characterization of two new bioactive silver(I) coordination polymers (CPs) formulated as [Ag(aca)(μ-PTA)]n·5nH2O (1) and [Ag2(μ-ada)(μ3-PTA)2]n·4nH2O (2). These products were generated by exploiting a heteroleptic approach based on the use of two different adamantoid building blocks, namely 1,3,5-triaza-7-phosphaadamantane (PTA) and 1-adamantanecarboxylic (Haca) or 1,3-adamantanedicarboxylic (H2ada) acids, resulting in the assembly of 1D (1) and 3D (2). Antiviral, antibacterial, and antifungal properties of the obtained compounds were investigated in detail, followed by their incorporation as bioactive dopants (1 wt %) into hybrid biopolymers based on acid-hydrolyzed starch polymer (AHSP). The resulting materials, formulated as 1@AHSP and 2@AHSP, also featured (i) an exceptional antiviral activity against herpes simplex virus type 1 and human adenovirus (HAd-5) and (ii) a remarkable antibacterial activity against Gram-negative bacteria. Docking experiments, interaction with human serum albumin, mass spectrometry, and antioxidation studies provided insights into the mechanism of antimicrobial action. By reporting these new silver CPs driven by adamantoid building blocks and the derived starch-based materials, this study endows a facile approach to access biopolymers and interfaces capable of preventing and reducing the proliferation of a broad spectrum of different microorganisms, including bacteria, fungi, and viruses.

Tuning the local coordination environment of silver(I) coordination networks with counterions for enhanced electrocatalytic CO2 reduction

Tuning the local coordination environment of silver(I) coordination networks with counterions for enhanced electrocatalytic CO2 reduction

Sulfonyldibenzoate coordination polymers as bioactive dopants for polysaccharide films with antibacterial and antibiofilm properties

Silver(i) and copper(ii) sulfonyldibenzoate coordination polymers were assembled and applied as bioactive dopants for hybrid biopolymer films with remarkable antibacterial and biofilm inhibition activity.

Ag-based coordination polymer-enhanced photocatalytic degradation of ciprofloxacin and nitrophenol.

Transition-metal coordination complexes have attracted wide attention in molecular chemistry, but their applications still confront a tremendous challenge. Herein, a novel silver coordination polymer with a formula of {[Ag9(TIPA)6](NO3)9·12H2O}n (Ag-TIPA) was prepared by a solvothermal reaction of silver nitrate with triangular tris(4-imidazolylphenyl)amine (TIPA). The crystalline molecular structure was determined by single-crystal X-ray diffraction, which showed that each Ag(I) was coordinated with two nitrogen atoms of TIPA ligands. Such Ag-TIPA was used as a catalyst for the photodegradation of ciprofloxacin and 4-nitrophenol under UV-visible light irradiation. The results exhibited excellent photocatalytic performance and reusability due to high structure stability in an acidic, neutral and alkaline environment. The experimental findings and density functional theory calculations revealed that metal-ligand charge transfer in Ag-TIPA extended the absorption range of light and improved the charge transfer properties of TIPA. To further understand the photodegradation process, the intermediates were predicted and analysed through electrostatic potential, orbital weighted dual descriptor, and liquid chromatography-mass spectrometry techniques. Based on these findings, a possible degradation mechanism was proposed. This study provides new insights into the design and synthesis of Ag-based coordination polymers with novel structures, excellent catalytic activity, and good durability.

Structural, spectroscopic, and chemical bonding analysis of luminescent bis(diphenylphosphino)methane derived binuclear heteroleptic silver(I) complex of norharmane with argentophilic interaction

Silver(I) coordination compounds have a fascinating geometrical diversity, the ability to have different coordination numbers (typically from 2 to 4), and the ability to form argentophilic (Ag∙∙∙Ag) interactions. In this work, a binuclear Ag(I) heteroleptic complex with norharmane ‘β-carboline’ and bis(diphenylphosphino)methane (PP) ligands has been synthesized and characterized by various spectroscopic and single-crystal X-ray diffraction analyses. The bonding of Ag(I) coordination and Ag···Ag interaction is explored in depth. The theoretical approaches employed were perturbation theory within the context of the natural bond orbital (NBO) framework, quantum theory of atoms in the molecule (QTAIM), and electron localization function (ELF) analysis.

Synthesis, X-ray Structures and Hirshfeld Analysis of Two Novel Thiocyanate-Bridged Ag(I) Coordination Polymers

Two novel silver(I) coordination polymers, [Ag(4BP)(SCN)]n (1) and {(4BPH)+[Ag(SCN)2]−}n (2) (4BP = 4-benzoyl pyridine), have been synthesized. The two complexes were prepared using almost the same reagents, which were AgNO3, 4BP and NH4SCN. The only difference was the presence of 1:1 (v/v) HNO3 in the synthesis of 2. In the two complexes, the Ag(I) has distorted tetrahedral coordination geometry. The structure of both complexes and the involvement of the thiocyanate anion as a linker between the Ag(I) centers were confirmed using single-crystal X-ray diffraction. 4BP participated as a monodentate ligand in the coordination sphere of complex 1, while in 2 it is found protonated (4BP-H)+ and acts as a counter ion, which balances the charge of the anionic [Ag(SCN)2]− moiety. The thiocyanate anion shows different coordination modes in the two complexes. In complex 1, the thiocyanate anion exhibits a µ1,1,3 bridging mode, which binds three Ag(I) ions to build a boat-like ten-membered ring structure leading to a two-dimensional coordination polymer. In 2, there are mixed µ1,1 and µ1,3 bridging thiocyanate groups, which form the one-dimensional polymeric chain running in the a-direction. Several interactions affected the stability of the crystal structure of the two complexes. These interactions were examined using Hirshfeld surface analysis. The coordination interactions (Ag-S and Ag-N) have a great impact on the stability of the polymeric structure of the two complexes. Additionally, the hydrogen-bonding interactions are crucial in the assembly of these coordination polymers. The O…H (10.7%) and C…H (34.2%) contacts in 1 as well as the N···H (15.3%) and S···H (14.9%) contacts in 2 are the most significant. Moreover, the argentophilic interaction (Ag…Ag = 3.378 Å) and π- π stacking play an important role in the assembly of complex 2.

Allosterically Driven Assembly of a Multisite Cage-Based [2]Semirotaxane.

The assembly of a [2]semirotaxane from a half-dumbbell endowed with a pyrazine coordination site and a bis-Zn(II) porphyrin cage as a multisite ring is reported. The threading is allosterically driven by the coordination of silver(I) ions to the multiple binding sites of the cage linkers, as shown by NMR studies. Addition of chloride ions destabilizes [2]semirotaxane, leading to its disassembly into its cage and half-dumbbell components.

Synthesis, spectral elucidation, thermal study, DFT calculations and biological application of new nano sized coordination compounds of a barbiturate based ligand

Novel titanium (IV), vanadyl (II), nickel (II), copper (II), cobalt (II), mercury (II) and silver (I) coordination compounds were established from a ligand created from a diazotization coupling process between 1-(4-aminophenyl)ethanone and barbituric acid. Analytical, spectroscopic, and thermal approaches were used to detect the best structural geometry of the compounds. The coordination compounds were constructed with (1M:2L) stoichiometry. With the exception of titanium (IV), vanadyl (II), and silver (I), all chelated compounds were non-electrolytes. Except for the vanadyl complex, which possessed square pyramidal geometry, and the silver one with tetrahedral geometry, the chelates of titanium (IV), copper (II), nickel (II), mercury (II) and cobalt (II) possessed an octahedral one. The ligand functioned as an ON-neutral bidentate moiety. The thermal manner of all compounds was studied by thermogravimetric analysis (TGA). According to XRD and TEM analysis, all compounds were nanosized. Theoretical calculations were performed to gain more information about the structure of the ligand and Ag chelate by DFT/B3LYP/LanL2DZ. The ligand and some of its chelates were explored as antibacterial, antifungal, and antitumor agents. According to the findings, the (H2L) activity was enhanced by complexation. The antitumor activity of the Ag(I) chelate was dramatically higher than that of the ligand and other chelates, with an IC50 of 11.5 gmL-1. For antimicrobial, Cu(II) chelate outperformed other complexes and the control drug against A. brasiliensis, B. cereus and P. vulgaris.

Comparative study of antimicrobial potential and DNA/BSA binding affinity of silver(I) and gold(III) coordination compounds with 1,6-naphthyridine

In the present study, synthesis of silver(I) and gold(III) coordination compounds with 1,6-naphthyridine (1,6-naph), {[Ag(1,6-naph)(H2O)](BF4)}n (1) and [AuCl3(1,6-naph)] (2), was reported. The methods used for the structural characterization of a new compound 1 included IR, NMR (1H and 13C) and UV–Vis spectroscopy, cyclic voltammetry and single-crystal X-ray diffraction analysis. The crystallographic results showed that compound 1 represents silver(I) coordination polymer, in which 1,6-naph ligand acts as a bidentate bridging ligand connecting two Ag(I) ions via its N1 and N6 nitrogen atoms, while the third coordination site of the metal ion is occupied by the water oxygen atom, resulted in a T-shape geometry. Compounds 1 and 2 were evaluated in vitro for antimicrobial activity against five bacterial and two Candida species, while their cytotoxicity was tested on the normal human lung fibroblast cell line (MRC-5). Compound 1 has manifested a remarkable antifungal activity on both tested Candida strains (C. albicans and C. parapsilosis) with minimal inhibitory concentrations (MICs) of 1.43 and 11.38 µM (0.49 and 3.9 µg/mL), respectively, while no significant antimicrobial activity was observed for 2. Moreover, silver(I) coordination polymer 1 inhibits the hyphae formation of C. albicans at subinhibitory concentration. The binding affinity of both compounds 1 and 2 with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA) was studied by fluorescence spectroscopy, indicating their ability to interact with these biomolecules, with compound 2 being more reactive.

Regioselective Coordination toward Silver(I) Ions by Bis- and Tris(Tetra-Armed Cyclen)s via Differential Electron Density of Aromatic Side Arms.

Four types of bis- and tris(tetra-armed cyclen)s were prepared. 2MF is a bis(tetra-armed cyclen) with electron-rich side arms (three 4-methoxybenzyl groups) and electron-deficient side arms (three 3,5-difluorobenzyl groups), connected by a 4,4'-dimethyl-1,1'-biphenyl moiety. 3MFM is a tris(tetra-armed cyclen) with 4-methoxybenzyl and 3,5-difluorobenzyl groups introduced on both ends and the central cyclen, respectively. 4MFM is a V-shaped analogue of 3MFM. 3FMF is a tris(tetra-armed cyclen) where the aromatic side arms at both ends and the central cyclen of 3MFM are exchanged. The regioselective coordination of silver(I) ions by these ligands is reported. Initially, we added Ag+ ions to a compound (2MF) that consists of tetra-armed cyclen with 4-methoxybenzyl groups as an electron-donating substituent on the aromatic rings and 3,5-difluorobenzyl groups as an electron-withdrawing substituent. 1H NMR and 19F{1H} NMR spectroscopy exhibited that the cyclen with the 4-methoxybenzyl groups formed a complex with Ag+ ions first, followed by the cyclen with the 3,5-difluorobenzyl groups. Next, we employed a compound (3MFM) with three cyclen units, where the cyclen at each end was functionalized with three 4-methoxybenzyl groups, and the central cyclen was functionalized with two 3,5-difluorobenzyl groups. Upon adding Ag+ ions, we observed that the cyclen units at both ends formed complexes with Ag+ ions initially, followed by the central cyclen forming a complex with Ag+ ions. When we used 4MFM, which is a V-shaped compound, the Ag+-induced-1H NMR chemical shift changes are almost the same results as the 3MFM. Furthermore, we synthesized a compound (3FMF) by interchanging the substituents on the cyclen units at the ends and the center. Interestingly, the order of the complex formation was reversed in this compound. These results demonstrated that tuning the electron density on the aromatic side arms through substituents makes it possible to achieve regioselective coordination with Ag+ ions in bis- or tris(tetra-armed cyclen)s.

Silver(I) coordination polymers based on nitrile-functionalized mixed-donor ligands of different flexibility

The nitrile-functionalized derivatives of 2,8-dithia-5-aza-2,6-pyridinophane ([12]anePyNS2)(Py = Pyridine), 1-aza-4,7,10-trithiacyclododecane ([12]aneNS3), and N,N’-bis(2-pyridylmethyl)-propylenediamine (Pypn), referred to as L10, L11 and L12, respectively, have been prepared. Following the reaction of these ligands with silver(I) salts, the three coordination polymers (CPs) {[Ag(L10)](BF4)}∞, {[Ag(L11)](BF4)∙½MeCN}∞, and {[Ag(L12)](NO3)}∞, have been isolated and structurally characterized. The structural features of the three CPs depends more on the nature of the un-functionalized ligands rather than on the presence of the nitrile groups. A comparative analysis of the structures of the three CPs is performed in relation to the structures of polymeric silver(I) compounds obtained with nitrile-functionalized pendant arms of related aza- and mixed donor macrocyclic ligands (L1–L9) reported in the literature.

Evaluation of azothioformamides and their copper(I) and silver(I) complexes for biological activity

Redox-active azothioformamides (ATFs) contain an NNCS 1,3-heterodiene motif typically found in other molecular subclasses that exhibit a wide range of cytotoxic and anti-neoplastic effects, either alone or as chelation complexes with various metals. For this study, a small library of ATF compounds was synthesized and tested across a range of microbes, fungi, and cancer cell lines for biological activity, both alone and as metal chelates of copper(I) and silver(I) salts. Alone, the ATF compounds exhibited little antimicrobial activity, but all inhibited the cell growth of A549 lung carcinoma cells (IC50 values of 1–6 μM). As copper(I) and silver(I) coordination complexes, several of the ATFs showed antimicrobial activity against gram positive Staphylococcus aureus and Bacillus subtilis cells (IC50 ∼ 5–20 μM) and the fungi Candida albicans (IC50 ∼ 8–12 μM); as well as cytotoxicity against both lung carcinoma A549 cells and lymphoblastic leukemia K562 cells.

Two one-dimensional silver(I) coordination polymer modified electrodes for hydrogen evolution reaction and H2O2 recognition

Two new Ag(I) coordination polymers (CPs), namely: [Ag4(m-MOPhHIDC)2(BBM)2]n (1) {[Ag(BBM)](NO3)}n (2) (m-MOPhHIDC = m-methoxyanisaldehyde imidazole dicarboxylate, BBM = 2,2-(1,4-butanediyl)bis-1,3-benzimidazole), have been synthesized by solvothermal method and characterized. Structural analyses show that both complexes are one-dimensional chain coordination polymers, but the one-dimensional chains have different shapes, in which CP-1 is "V" shaped, and CP-2 is "wave-shaped". The electrochemical properties of composite electrodes CE-1 and CE-2 formed by mixing two coordination polymers with carbon paste electrodes were investigated respectively. Electrocatalytic hydrogen evolution characteristics of two composite electrodes were investigated by linear scanning voltammetry (LSV) in 0.5 M H2SO4 electrolyte, at 298 K the results show that when the current density reaches 10 mA cm−2, their overpotential positively shifted by 284 and 289 mV compared to CE (905 mV). And the Tafel slope of the CE-1 and CE-2 was 162 and 164 mV dec−1, respectively. The CE-1 exhibited superior electrocatalytic ability than CE-2, which may be attributed to the different coordination modes of central silver ions in the two CPs. In addition, the composite electrodes CE-1 and CE-2 also have a good identification effect on H2O2, and the detection limits of 36.7 and 6.2 μM in the linear range of 0.5-4000 μM were determined by chronoamperometry. Results show that the Ag(I) CPs can be used as effective dualfunctional electrocatalysts.

A Silver Compound with Potential Applications as an Anticancer, Antibacterial, Antifungal, and Anti-Alzheimer's Agent.

This study investigated the biological activity of the silver coordination compound K-22. The IC50 values of K-22 on cancer cell lines range from 0.797 μg/mL to 3.426 μg/mL, indicating that K-22 might preferably inhibit A549, Saos-2, MCF-7, and HT-29 cell proliferation and thus have better therapeutic activity. Furthermore, K-22 stimulated apoptosis via up-regulation of the mRNA and protein expression level of Bax/Bcl-2 ratio in A549, Saos-2, MCF-7, and HT-29. K-22 exhibited antimicrobial activity against S. aureus, E. faecalis, K. pneumonia, P. aeruginosa, C. utilis, and C. albicans. Experimental results show that the compound has inhibitory potential with an IC50 value of 178.10 μM for the BChE (butyrylcholinesterase) enzyme, which has a vital role in the progression of Alzheimer's disease. As a result, compound K-22 exhibits a strong potential for medical use due to its anticancer, antibacterial, antifungal, and anti-Alzheimer properties.