Silver Coordination Research Articles

A Platinum(II) Organometallic Building Block for the Design of Emissive Copper(I) and Silver(I) Coordination Polymers.

The tritopic organometallic ligand trans-MeSC6H4C≡CPt(PMe3)2(C≡N) (L1) was prepared from cis-PtCl2(PMe3)2 and p-ethynyl(methyl thioether)benzene. Its versatility was shown with the formation of [CuX(L1)]n coordination polymers (CPs) with CuX salts in MeCN (X = I (CP1), CN (CP2), SCN (CP3)). These CPs were characterized by X-ray crystallography, thermal gravimetric analysis (TGA), and IR and Raman spectroscopy. CP1 consists of a 1D head-to-tail chain formed by tricoordinated -C≡N-CuI(η2-C≡C)- linkages, whereas CP2 is built upon a central (CuCN)n zigzag chain bearing dangling L1s held by -C≡N-Cu bonds. Finally, CP3 exhibits 2D sheets secured by Cu-N≡C-/-(Me)S-Cu bondings and transversal Cu-S-C≡N-Cu bridges. Concurrently, the CPs formed with AgX (X = NO3- (CP4 and CP5), CF3CO2- (CP6) PF6- (CP7)) exhibits 2D sheets with guest molecules (anion, solvents) inside the tight pores or between layers. These new materials are emissive: L1 (λ0-0 ∼465 nm), CP1-CP7 (500 < λmax < 620 nm). Their photophysical properties (absorption and emission spectra, emission lifetimes (∼0.2 < τe < 120 μs), and quantum yields in the solid state at 77 and 298 K) were analyzed. The various natures of the emissive excited states were addressed by density functional theory (DFT) and time-dependent DFT (TDDFT) computations. For CP1, this state is a triplet halide or pseudohalide to ligand charge transfer 3XLCT (CT = charge transfer; X = I; L = L1) and for CP2, it is 3XLCT (X = CN; L = L1). However, for CP3, it is 3XLCT (X = SCN; L = L1). For CP4, the T1 state is described as a [MeSC6H4(η2-C≡C)-Ag(NO3)]2 → [Pt]/C≡CC6H4SMe CT.

Highly stable silver (I) coordination complex as efficient photocatalyst for the degradation of organic dyes in water

A new zero-dimensional (0D) silver (I) chloride based coordination complex 0 D-Ag2Cl2(L) (1, L = (oxybis(2,1-phenylene))bis(diphenylphosphine)) has been prepared by mixing the silver(I) salt and a bidentate P-ligand at room temperature in solution. 1exhibits a band gap of 3.5 eV and a decomposition temperature (Td) of 280 °C. Such a high Td for molecular complex is a result of the strong Ag-P bonding and the “chelating effect” of the metal of the bidentate P-ligand. It has been used as an efficient photocatalyst for the degradation of organic dyes in water.

Silver-Driven Coordination Self-Assembly of Tetraphenylethene Stereoisomer: Construct Charming Topologies and Their Mechanochromic Behaviors.

A series of silver coordination complexes (CCs) have been synthesized through self-assembly of five pyridine-substituted tetraphenylethylene stereoisomer ligands with silver ions (named Ag-TPE-2by-1-E, Ag-TPE-2by-2-E, Ag-TPE-2by-2-Z, Ag-TPE-2by-3-E, and Ag-TPE-2by-3-Z). These silver CCs show distinct topologies including beaded chain frameworks, linear structures, and discrete metallacycles. The single-crystal analysis results reveal the critical role of the space distribution of the coordination site and stereoisomer ligands in controlling the silver CCs' geometry configuration and modulating the optical properties. Luminescent investigations revealed that Ag-TPE-2by-2-E, Ag-TPE-2by-2-Z, Ag-TPE-2by-3-E, and Ag-TPE-2by-3-Z possess obvious mechanocharomic behaviors, which can be achieved several reversible cycles through repeated grinding and methanol soaking processes. However, the Ag-TPE-2by-1-E showed tenacious stability toward mechanical grinding and temperature. Thus, these silver CCs provide a good platform to investigate the influence of the space distribution of the coordination site of ligands on their geometry and mechanocharomic properties.

Rational synthesis, structural characterization, theoretical studies, antibacterial activity and selective dye absorption of new silver coordination polymers generated from a flexible bis (imidazole-2-thione) ligand

Herein, a competition between the different anions with different size, shape and coordination ability was used for the synthesis of three silver(I)-coordination polymers (Ag-CPs) was investigated. In this study, three 3D-supra-molecular coordination compounds namely, [Ag2L(NO3)2]n (1), {[Ag2L][PF6]2}n (2) and [AgLBr]n (3) (L = 1,1′-(1,5-pentadienyl)bis-(1,3-dihydro-3-methyl-1H-imidazole-2-thione)) have been synthesized and fully characterized via a single crystal X-ray diffraction, powder X-ray diffraction (PXRD), elemental analysis (CHN), FT-IR spectra and thermo gravimetric analysis (TGA). Structural analysis revealed that the counter ions have a notable impact in directing the conformation and coordination mode of ligand, but they have no effect on the structural dimension of the polymers. Furthermore, by increasing the coordination ability of the anions, the coordination geometry of the AgI centers change, from a distorted linear (for 2) to a distorted square pyramidal coordination geometry (for 1). The chains are further stabilized by the intermolecular CH⋯O and CH⋯N for 1, P–F…HC for 2, CH⋯Br and CH⋯N interactions for 3 to form a 3D non-covalent lattice network structure. In contrast to the 1 and 3, polymer 2 exhibits a large capacity and selectivity to adsorb dye from aqueous solutions. Sorption kinetic was investigated by three kinetic models. The electronic band structure and the projection densities of states (PDOS) of compounds 1 and 3 were investigated by means of DFT-D3. The results demonstrated that both compounds are non-magnetic and show a semiconducting character with a direct band gap of ~3 eV. All of the synthesized compounds, possess antibacterial activity against the selected strain of Gram- negative (Escherichiacoli, Pseudomonas aeruginosa) and Gram- positive (Staphylococcus aureus, Bacillus subtilis) bacteria.

Self-assembly of thiolate-protected silver coordination polymers regulated by POMs.

Two polyoxometalate (POM)-based thiolate-protected silver coordination polymers were obtained using different Lindquist-type POM precursors under the same conditions. [Ag10(StBu)6(CH3CN)8(Mo6O19)2·2CH3CN]n (abbreviated as Ag10-Mo6) was observed to feature chain-like structures containing Ag10 clusters linked by [Mo6O19]2- anions through Ag-O bonds and to exhibit unprecedented green photoluminescence at room temperature. Interestingly, [Ag18(StBu)12(CH3CN)5(Mo6O19)2·Mo6O19·2CH3CN]n (abbreviated as Ag18-Mo6) was found to contain 20-membered cycle-Ag10S10 each with a diameter of approximately 11.382 Å and constructed from alternating silver and sulfur atoms and interconnected into an elegant Ag-S sheet by interstitial the Ag3StBu and AgCH3CN motifs, and to also contain [Mo6O19]2- counter ions filling in the spaces made by the cycle-Ag10S10 and strengthening the structure by forming Ag-O bonds. Such a stacking structure for thiolate-protected silver compounds has not been previously reported.

Synthesis, structural diversity, luminescent properties and antibacterial effects of cadmium(II) and silver(I) coordination compounds with bis(1,2,3-benzotriazol-1-yl)alkanes

A series of bis(benzo-1,2,3-triazolyl)alkanes were prepared by the reaction of 1,2,3-benzotriazole with the corresponding dibromoalkanes. Individual isomers of these flexible polydentate ligands were separated by selective copper(II) chloride complex formation. Seven new coordination compounds of 1,3-bis(benzo-1,2,3-triazol-1-yl)propane (L3), 1,4-bis(benzo-1,2,3-triazol-1-yl)butane (L4) and 1,6-bis(benzo-1,2,3-triazol-1-yl)hexane (L6) with cadmium(II) or silver(I) nitrates were prepared, characterized by single crystal X-ray diffraction, IR spectroscopy, thermogravimetric analysis and luminescence studies. It was found that depending on the solvent used, cadmium(II) nitrate forms discrete binuclear complex with the ligand L3 in acetone and 1D coordination polymer in acetonitrile. Ligands L4 and L6 with longer linkers formed 2D coordination polymers with silver nitrate both in acetone and acetonitrile. Silver coordination polymer with L6 demonstrated bactericidal effect towards Staphylococcus albus, Pseudomonas aeruginosa and Klebsiella pneumonia bacteria.

A Novel Supramolecular Silver Coordination Complex Based on a Triazole Carboxylate Ligand: Synthesis and Fluorescence Sensing of Colchicine and a Series of Nitro Explosives

AbstractA novel supramolecular coordination complex [Ag(HMCTCA)(H2MCTCA)] (1) was firstly synthesized by the reaction of a nitrogen heterocyclic organic ligand H2MCTCA (5‐Methyl‐1‐(4‐carboxylphenyl)‐1H‐1,2,3‐triazole‐4‐carboxylic Acid) with AgNO3. It was characterized in detail by some microanalysis means such as elemental analysis, IR, UV, TG and PXRD. Furthermore, the solid fluorescent behavior was explored at room temperature. The results indicated that coordination complex 1 exhibited excellent fluorescent properties. Based on this phenomenon, we discussed its application in fluorescence sensing. The results illustrated that the coordination complex 1 can be applied to detect colchicine and a series of nitro explosives. It is worth noting that coordination complex 1 showed preeminent sensitivity for detecting p‐nitroaniline (PNA), the detection limit was as low as 0.59 μM.

Ag(I)-benzisothiazolinone complex: synthesis, characterization, H2 storage ability, nano transformation to different Ag nanostructures and Ag nanoflakes antimicrobial activity

A new complex of silver monovalent ions with benzisothiazolinone was reported. This silver coordination polymer was characterized by FTIR, elemental analysis, 1H-NMR and 13C-{1H}-NMR). These measurements show that the bit anion in its silver complex behaves as μ-bridge linking two silver(I) ions as a bidentate ligand through the oxygen and nitrogen atoms. This coordinated polymer was showed non-melting ability, high decomposition and non-solubility in water in addition to all organic solvents except the hot DMSO solvent. Therefore, this polymeric complex had has a high porosity showing thereby that an overall H2 uptake of 5.5 mmol g−1 at 77 K and 10 bar. A new method for the synthesis of a mixture of three different morphological silver nano particles (AgNPs) is reported. The new method includes reduction of the newly prepared silver-benzisothiazolinone complex, [Ag(bit)]n (bit = benzisothiazolinone) with sodium borohydride without using stabilizing agent. The resulting silver nanoparticles Ag NPs were characterized by UV–vis spectra, powder XRD, zeta sizer, zeta potential and scanning electron microscopy (SEM). The results showed that [Ag(bit)]n complex gives three different nano-sized structures spherical, wires and flakes. In order to isolate the larger proportion of the nanostructures, experiments were conducted to control the formation of one form of silver as flakes nanosilver or silver nanowires. The prepared silver nanoparticles were screened for their antibacterial activity against K. pneumonia, P. Aeruginosa, S. aureus and E. coli. Inhibition zone diameter IZD results of 2, 4 and 6 mM Ag NPs was found to be in the range of 7.0–8.4 mm for the selected bacteria.

Anion-directed assembly of three cationic silver(I) coordination polymers with bis(imidazolyl)-based linker: Structural characterization and anion exchange study

Three cationic silver(I) coordination polymers, namely {[Ag2(μ-bib)3](SO3CF3)2·(CH3CN)}n (1), {[Ag(μ-bib)](NO3)·(H2O)}n (2), and {[Ag(μ-bib)]BF4}n (3), have been prepared using flexible bis(imidazolyl)butane (bib) ligand and silver salts of different anions. All compounds are characterized by FT-IR, PXRD, elemental analysis, and single-crystal X-ray diffraction. Compound 1, containing triflate (SO3CF3−) anions, exhibits a two dimensional 63-hcb network with an amazing ABCDEF packing mode of the single hexagonal layers. Compound 2, containing nitrate ions, forms a simple one dimensional wavy chain, while compound 3 with BF4− anions, shows a double helix DNA-shaped structure stabilized by Ag⋯Ag interactions between the two strands. The anions in the structures 1–3 are non-coordinating and participate in weak H-bonding, while imidazolyl rings are involved in π⋯π stacking interactions. Anion exchange experiments in aqueous solution, monitored by FT-IR and PXRD analyses, reveal interesting structural transformations.

Formation of alkyne-bridged ferrocenophanes using ring-closing alkyne metathesis on 1,1'-diacetylenic ferrocenes.

Novel alkyne-bridged ferrocenophanes [fc{CO2(CH2)nC≡}2] (2a: n = 2; 2b: n = 3) were synthesized from the corresponding terminal diacetylenic ferrocenes [fc{CO2(CH2)nC≡CH}2] (1a: n = 2; 1b: n = 3) through ring-closing alkyne metathesis (RCAM) utilizing the highly effective molybdenum catalyst [MesC≡Mo{OC(CF3)2CH3}3] (MoF6; Mes = 2,4,6-trimethylphenyl). The metathesis reaction occurs in short time with high yields whilst giving full conversion of the terminal alkynes. Furthermore, the solvent-dependant reactivity of 2a towards Ag(SbF6) is investigated, leading to oxidation and formation of the ferrocenium hexafluoroantimonate 4 in dichloromethane, whereas the silver(I) coordination polymer 5 was isolated from THF solution.

New Microbe Killers: Self-Assembled Silver(I) Coordination Polymers Driven by a Cagelike Aminophosphine.

New Ag(I) coordination polymers, formulated as [Ag(µ-PTAH)(NO3)2]n (1) and [Ag(µ-PTA)(NO2)]n (2), were self-assembled as light- and air-stable microcrystalline solids and fully characterized by NMR and IR spectroscopy, electrospray ionization mass spectrometry (ESI-MS(±), elemental analysis, powder (PXRD) and single-crystal X-ray diffraction. Their crystal structures reveal resembling 1D metal-ligand chains that are driven by the 1,3,5-triaza-7-phospaadamantane (PTA) linkers and supported by terminal nitrate or nitrite ligands; these chains were classified within a 2C1 topological type. Additionally, the structure of 1 features a 1D→2D network extension through intermolecular hydrogen bonds, forming a two-dimensional hydrogen-bonded network with fes topology. Furthermore, both products 1 and 2 exhibit remarkable antimicrobial activity against different human pathogen bacteria (S. aureus, E. coli, and P. aeruginosa) and yeast (C. albicans), which is significantly superior to the activity of silver(I) nitrate as a reference topical antimicrobial.

Three Silver Coordination Polymers with Diverse Architectures Constructed from Pyridine Carboxylic Hydrazide Ligands.

A series of silver coordination polymers (CPs) have been synthesized through self-assembly of three pyridinecarboxylic acid hydrazide (p-, m-, o-position) ligands with silver clusters (named Ag1-iah, Ag2-iah, and Ag3-iah). These silver CPs show different one- and two-dimensional topologies including cross-helical chains, planar network, and parallel helical chains for Ag1-iah, Ag2-iah, and Ag3-iah, respectively. The combination of experimental and computational results reveals the critical role in the space distribution of the coordination site of silver clusters and ligands in controlling the silver CPs' dimensionality and packing arrangement and modulating the optical properties and stability. Luminescent investigations reveal that Ag3-iah can selectively detect dichloromethane or trichloromethane in tetrachloromethane. These silver CPs provide a good model to study the influence of the space distribution of the coordination site of ligands on their packing arrangement and properties.

A 1D silver(I) coordination polymer as luminescent probe for Cu2+ and effective photocatalyst for degradation organic dyes

A silver(I) coordination polymer, [Ag(L)(HNTP)]n (1) (L = 1,4-bis(5,6-dimethylbenzimidazol-1-yl)butane, H2NTP = 2-nitroterephthalic acid) was hydrothermally synthesized and characterized. 1 is a 1D linear chain which is further extended into a 3D supramolecular framework by hydrogen bond interactions. 1 exhibits highly sensitivity for detecting Cu2+ ion. 1 also presents high photocatalytic activities for the degradation of methylene blue (MB) and methyl orange (MO).

Solvent and Counter‐Ion Induced Coordination Environment Changes Towards AgI Coordination Polymers

A series of silver coordination polymers based on the 9,9′‐bis(4,5‐diazafluorene) (BDF‐H2) ligand is presented. The choice of counterions and reaction conditions dictate the observed topology on the final systems by influencing the silver coordination environment. Coordination modes, flexibility of the ligand and extended π–π stacking interactions have allowed the preparation and crystallographic characterisation of one 1D‐ and three 2D‐coordination polymers: 1D‐[Ag(BDF‐H2)(DMSO)]n(X)n (where X = OTf– and ClO4–); 1D‐[Ag2(BDF‐H2) m1‐(TfO)2,m2‐(TfO)2]n(TfO)n, and 2D‐[Ag2(BDF‐H2)3]n(PF6)2n.

Maximizing Ag Utilization in High-Rate CO2 Electrochemical Reduction with a Coordination Polymer-Mediated Gas Diffusion Electrode

We report the preparation and electrocatalytic performance of silver-containing gas diffusion electrodes (GDEs) derived from a silver coordination polymer (Ag-CP). Layer-by-layer growth of the Ag-C...

Crystal structure of poly[[[μ4-3-(1,2,4-triazol-4-yl)adamantane-1-carboxyl-ato-κ5 N 1:N 2:O 1:O 1,O 1']silver(I)] dihydrate

The heterobifunctional organic ligand, 3-(1,2,4-triazol-4-yl)adamantane-1-carboxyl-ate (tr-ad-COO- ), was employed for the synthesis of the title silver(I) coordination polymer, {[Ag(C13H16N3O2)]·2H2O} n , crystallizing in the rare ortho-rhom-bic C2221 space group. Alternation of the double μ2-1,2,4-triazole and μ2-η2:η1-COO- (chelating, bridging mode) bridges between AgI cations supports the formation of sinusoidal coordination chains. The AgI centers possess a distorted {N2O3} square-pyramidal arrangement with τ5 = 0.30. The angular organic linkers connect the chains into a tetra-gonal framework with small channels along the c-axis direction occupied by water mol-ecules of crystallization, which are inter-linked via O-H⋯O hydrogen bonds with carboxyl-ate groups, leading to right- and left-handed helical dispositions.

Solid–solid and solid–liquid conversion of sodium and silver nano coordination polymers

Solid-state conversion of a three-dimensional sodium coordination polymer [Na(μ6-HTar)]n (1), (H2Tar = (+)‐tartaric acid), synthesized by a sonochemical procedure, to a two-dimensional silver coordination polymer [Ag(μ3-HTar)(H2O)]n (2) has been observed upon mechanochemical cation exchange reaction of 1 with AgNO3. The conversion of 2 to 1 via solid-state reaction has also been investigated. These samples were characterized by IR spectroscopy, X‐ray powder diffraction (XRD), thermo gravimetric and differential thermal analyses (TG-DTA), Energy-dispersive X-ray spectroscopy (EDAX) and Scanning Electron Microscopy (SEM). It was observed that the conversion of compound 1 to compound 2 is irreversible. In addition it was confirmed that [Ag(μ3-HTar)(H2O)]n (2) converted to [Ag2(HTar)]n (3) during solid–liquid reaction in water.

Silver(I) coordination polymers from dinucleating naphthyridine ligands

Two novel crystalline silver(I) coordination polymers have been synthesized and structurally characterized, using naphthyridine-based ligands that are typically expected to produce dinuclear metal complexes. Electrical conductivity studies on polycrystalline samples show that structural differences in the polymers lead to different conductivity values. These results highlight the flexible coordination chemistry of d10 silver(I) centers, as well as the challenges of ligand design when targeting well-defined multinuclear silver complexes.

Hierarchical Ag Nanostructures Fabricated from Silver Coordination Polymers for Antibacterial Surface.

A hierarchical silver nanostructure with improved antibacterial property was fabricated utilizing silver coordination polymer. Octadecanethiolate–silver polymer was synthesized to have a layered structure and was coated on silicon wafer by drop-casting method utilizing hydrophobic–hydrophobic interaction. Thus, the silver coordination polymer was calcined under reductive condition to produce zero-valent silver with a hierarchical nanostructure. X-ray diffraction patterns revealed that layered silver coordination polymer successfully transformed to hexagonal silver upon calcination. According to scanning electron and atomic force microscopy, silver coordination polymer with ~145.5 nm size was homogeneously coated on the surface before calcination, and it evolved micrometer-sized lumps and grooves which were composed of ~58.8 nm sized Ag nanoparticles. The hierarchical structure—micrometer lump/groove consisting of Ag nanoparticles—would be advantageous to kill bacteria; micrometer-grooves provide physical condition (pocket for bacteria capture) and the Ag nanoparticles from the neighboring lump endow chemical condition (antibacterial property of released Ag+). The antibacterial activity test on Escherichia coli via colony forming inhibitory assay indeed exhibited an improved antibacterial activity of hierarchical Ag nanostructure compared with the surface simply coated with Ag nanoparticles. From the line profile of atomic force microscopy, the bacterium trapped in the hierarchical Ag nanostructure was shown to interact intimately with Ag surface.

Appealing Copper(I) and Silver(I) Coordination Polymers with an Unprecedented Betainoid Assembling Ligand

Two coordination polymers of coinage metals with a rare pyridinium-betainoid L assembling ligand are reported. These polymers are obtained by self-assembly of the linker L and copper(I) or silver(I) ions in acetonitrile. The compounds were characterized by spectroscopic methods and by elemental analysis. The solid-state structures were unambiguously confirmed by single crystal diffraction studies. These assemblies exhibit original helicoidal arrangements. The UV-Vis. absorption and photoluminescence properties are reported as well.