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The study of the reactivity of heterocyclic thioamides exhibiting antithyroid activity is of scientific and practical interest. For objective evaluation of the reactivity of thioamides with biologically active and biogenic metal ions, reliable thermodynamic parameters of complexation are of great importance. The thermodynamic parameters of complexation can be determined by various complementary methods, which increases the reliability of results. The thermodynamic parameters of the reaction of formation of a silver(I) monocomplex with 1-methyl-2-mercaptoimidazole (logK°, ∆rG°, ∆rH°, ∆rS°) were determined by isothermal titration calorimetry in water at T = 298.15 K. The results were compared with the thermodynamic parameters obtained previously by potentiometric titration using the temperature coefficient method to determine the enthalpy of complexation. [ABSTRACT FROM AUTHOR]

Heteroleptic coumarin-based silver(I) complexes with improved solubility profiles were synthesised using either triphenylphosphine or an N-heterocyclic carbene as adduct ligands, and were fully characterised using IR and NMR spectroscopy, elemental analysis, and, where possible, X-ray crystallography. The triphenylphosphine adducts formed well-resolved structures, where the oxyacetate ligands asymmetrically chelated the silver(I) ion in a bidentate chelating mode, and the silver(I) ion was also bound to two triphenylphosphine ligands. The solubility profile and photostability of the adducts were considerably improved compared to those of previously isolated simple coumarin silver(I) complexes. Analysis of the coumarin N-heterocyclic carbene(NHC) silver(I) adduct indicated that it likely formed as a complex aggregate species with an overall stoichiometry of 1:1:1 coumarin:Ag(I):NHC. The Kirby Bauer assay and broth microdilution assays were used to assess the silver(I) complexes' and adducts' antimicrobial activity against pathogenic strains of Pseudomonas aeruginosa, Escherichia coli, and MRSA. Interestingly, the formation of more soluble complexes did not increase the activity of the silver(I) complexes and, in effect, made them less effective antimicrobial agents, particularly against Escherichia coli and Pseudomonas aeruginosa, although they retained their activity against MRSA. [ABSTRACT FROM AUTHOR]

The synthesis of triarylmethanes was evaluated in the presence of various Brønsted and Lewis acids under the same stoichiometric conditions. An efficient silver(I)‐catalyzed synthesis of triarylmethanes is reported. The reaction offers low catalyst loadings and quasi‐stoichiometric conditions (1–1.2 equiv. of electrophile) to access to symmetrical and unsymmetrical TRAMs in moderate to excellent yields (35 examples). Broad substrate scope was observed, including compatibility with ester and cyano groups. [ABSTRACT FROM AUTHOR]

The understanding of the thermodynamic stability and speciation of metal complexes in solution requires access to their enthalpy and entropy of formation. In this work, we specifically focus our investigation on the complexation process of silver(I) ion in acetonitrile (AN) with substituted mono pyridines and cyclic monoamines. The aim of this study is to provide reliable thermodynamic data to obtain insights on metal complex formation, focusing on ligands donor properties and solvation effects. Carefully designed potentiometric and calorimetric experiments allowed to define the species present at different ligand/metal ratios and to obtain the complex formation constants and enthalpies. In general, the enthalpy terms associated with the complex formation are highly exothermic, while the entropy values are always unfavorable. The formation constants of AgLj species for the ligands investigated in AN are compared with those previously obtained in dimethyl sulfoxide (DMSO) and water. The trends in stability constants and enthalpy values are discussed in relation to the pKa data available in the different solvents. Higher pKa values correspond to greater ligand basicity and result in more stable and more enthalpy stabilized complexes. [ABSTRACT FROM AUTHOR]

The paper presents the thermodynamic parameters of acid–base equilibria of 1-methyl-2-mercaptoimidazole (1MI) and its complexation with the silver(I) ion in aqueous dimethylsulfoxide. An analysis of the solvation contributions of reagents to the change in the Gibbs energy of protonation of 1MI showed that the practically zero changes in the Gibbs energy of the transfer of the reaction from water to a solvent with a composition of 0.1 mole fractions DMSO are due to complete compensation of the solvation contribution of the protonated 1-methyl-2-mercaptoimidazole and proton, and also to the insignificant change in the solvation state of 1MI. At higher DMSO concentrations in the solvent, an increase in the negative values of the Gibbs energy of the 1MI protonation transfer is accompanied by a predominant contribution from increased solvation of the protonated form of 1MI along with the negative contribution from resolvation of proton and 1MI. Both in water and in water–dimethylsulfoxide solvents, the silver(I) ion forms three complex species with 1MI, whose stability increases at increased DMSO contents. Stabilization of 1MI and silver ion transferred from water to the H2O–DMSO solvents makes a negative contribution to the change in the Gibbs energy of the transfer of the monocomplex formation reaction. [ABSTRACT FROM AUTHOR]

Eight terpyridine ligands, 4′-methoxy-2,2′:6′,2″-terpyridine (L1), 2′-methoxy-2,2′:6′,2″-terpyridine (L2), 4′-hydroxyl-2,2′:6′,2″-terpyridine (L3), 4′-chloro-2,2′:6′,2″-tepyridine (L4), 2′-pyridinyl-2,2′:6′,2″-terpyridine (L5), 3′-pyridinyl-2,2′:6′,2″-terpyridine (L6), 2′-furanyl-2,2′:6′,2″-terpyridine (L7), and 2′-thiophenyl-2,2′:6′,2″-terpyridine (L8) were developed as multidentate chelating systems with AgSCN, AgOAc, and AgCN to produce twenty four silver(I) terpyridine complexes (1–24). The silver(I) complexes were characterized by various analytical and spectroscopic techniques, which suggest their distorted tetrahedral geometry. The single crystal X-ray diffraction of 23 revealed its dinuclear behaviour in solution by forming distorted tetrahedral and linear geometries around two silver(I) metal centres. The synthesized compounds were investigated for antibacterial activity. The antibacterial activity was conducted against Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, and Klebsiella pneumoniae at different concentrations. Complex 7 with a 2-furanylterpyridine moiety and with thiocyanate coordinating to the metal central had notable activity compared to Ciprofloxacin against E. coli, K. pneumoniae, and MRSA, but less than silver(I)-sulfadiazine. Complexes 9 and 15 with the 4-methoxy moiety and the 2-furanyl moieties also showed significant bacterial growth inhibition. Generally, AgOAc complexes had higher activity at low concentrations.

A method for preparation of poly(N-sulfoethylaminomethylstyrene) with a degree of functionalization up to 0.54 has been developed. The composition and structure of the products of polymer analogous transformations were characterized by elemental analysis, FTIR spectroscopy, and thermogravimetric analysis. It has been established that materials with a degree of functionalization of 0.35 and 0.5 are capable of selective sorption of noble metal ions in the presence of transition metals. An increase in the sulfoethyl group content increases the degree of extraction of PdII and reduces the degree of extraction of PtIV. It was also found that the studied sorbent with a degree of functionalization of 0.35 selectively extracts AgI ions from multicomponent systems at pH 5.5–6.0 in an ammonium acetate buffer solution. [ABSTRACT FROM AUTHOR]

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

The [Ag2L2(NO3)2]n·(CH3CN)n chained coordination polymer is prepared by the interaction of AgNO3 with diphenyl(2-pyrimidyl)phosphine (L) (1:1) due to the linking of [Ag2L2] fragments by bridging nitrate ions. At room temperature, this polymer exhibits weak blue-green photoluminescence with a quantum yield of 6% and a decay time of 19 µs. It is shown that the [Ag2L3(NO3)2] binuclear complex and the [Ag3L2(NO3)3]n·2(CH2Cl2)n layered coordination polymer are formed at the AgNO3/L molar ratio equal to 2:3 and 3:2, respectively. Based on the XRD data, molecular structures of all three obtained compounds are discussed. [ABSTRACT FROM AUTHOR]

Polymer complexes of the composition {[Cu2(fur)4(bpy)]n • nMeOH} (1) and {[Ag3(fur)(bpy)4]n•2nfur·13.5nH2O} (2) were synthesized by the reactions of copper(ii) and silver(i) acetates, respectively, with anions of furancarboxylic acid (Hfur) and 4,4'-bi-pyridine (bpy) under different synthesis conditions. The structures of the new complexes were established by X-ray diffraction (XRD) analysis. According to the XRD data, complex 1 is a polymer, in which the molecular metal oxide moieties are connected in a monodentate manner through bpy to form a 1D structural motif. The coordination environment of the copper(ii) atom in complex 1 can be described as a square pyramid {CuO4N}; the coordination number is 5. ionic complex 2 contains three nonequivalent Agi atoms in different coordination environment with different coordination numbers of the complexing metal (CNAg(1) = 4; CNAg(2)Ag(3) = 2). The supramolecular level of complex 2 is a 3D structure stabilized by different types of interactions, such as hydrogen bonds, π-stacking and ar-gentophilic interactions. The simultaneous thermal analysis demonstrated that complex 1 undergoes desolvation and decarboxylation at temperatures below 234 °C, whereas the bipyridine moieties coordinated to the copper(ii) atoms are not completely eliminated even at 500 °C. The in vitro biological activity of complexes 1 and 2 was evaluated against the non-pathogenic mycobacterial strain Mycolicibacterium smegmatis. [ABSTRACT FROM AUTHOR]

The reaction between bis(phosphino)ferrocene, [Fe{C5H4P(C6H4CH2NMe2-o)2}2] (1) and AgOTf resulted in disilver complex [(AgOTf)2{µ-Fe{C5H4P(C6H4CH2NMe2)2}2}] (2) which on further treatment with 2,2′-bipyrdine yielded a mixed-ligand complex [Ag2(bipy)2{µ-Fe{C5H4P(C6H4CH2NMe2)2}2}](OTf)2 (3). Reaction of 1 with AuCl(SMe2) in 1:2 molar ratio afforded a digold complex [(AuCl)2Fe{C5H4P(C6H4CH2NMe2)2}2] (4). Treatment of 4 with anhydrous CdCl2 resulted in heterometallic complex [Fe{C5H4P(AuCl)(C6H4CH2NMe2)2(CdCl2)}2] (5). The reactions of 1 with anhydrous CdI2 and HgI2 in 1:2 molar ratios yielded bimetallic complexes [Fe{C5H4P(CdI2)(C6H4CH2NMe2)2}2] (6) and [Fe{C5H4P(HgI2)(C6H4CH2NMe2)2}2] (7), respectively. The molecular structures of 3, 4 and 7 were confirmed by single crystal X-ray analysis. Complexes 3 and 7 crystallized in the triclinic space group with P-1, whereas 4 crystallized in the monoclinic space group with C2/c. Single crystals suitable for X-ray crystallography were obtained using diffusion method where a solution of [Fe{C5H4P(C6H4CH2NMe2)2}2] (1) in dichloromethane was layered on a solution of CdI2 and HgI2 in methanol and stored at room temperature for 24 h, resulted in yellow plates of 6 and 7, respectively. All complexes crystallized with the asymmetric unit containing half a molecule and with the Fe atom on an inversion centre. A Hirshfeld surface analysis indicated that the most significant contributions to the crystal packing of 3 are from H‧‧‧H (50.2%), C‧‧‧H/H‧‧‧C (8.3%), Cl‧‧‧H/H‧‧‧Cl (12.1%), O‧‧‧H/H‧‧‧O (11.3%), F‧‧‧H/H‧‧‧F (9.0%) contacts, while those for 4 are from H‧‧‧H (73.7%), C‧‧‧H/H‧‧‧C (8.9%), Cl‧‧‧H/H‧‧‧Cl (14.5%), Au‧‧‧H/H‧‧‧Au (1.8%) and N‧‧‧H/H‧‧‧N (0.8%) contacts, and those for 7 are from H‧‧‧H (65.5%), C‧‧‧H/H‧‧‧C (6.6%), I‧‧‧H/H‧‧‧I (24.1%) and I‧‧‧C/C‧‧‧I (2.9%) contacts. Crystal structures of silver(I), gold(I) and mercury(II) complexes containing [Fe{C5H4P(C6H4CH2NMe2)2}2] (1) are described. [ABSTRACT FROM AUTHOR]

The reaction between bis(phosphino)ferrocene, [Fe{C5H4P(C6H4CH2NMe2-o)2}2] (1) and AgOTf resulted in disilver complex [(AgOTf)2{µ-Fe{C5H4P(C6H4CH2NMe2)2}2}] (2) which on further treatment with 2,2′-bipyrdine yielded a mixed-ligand complex [Ag2(bipy)2{µ-Fe{C5H4P(C6H4CH2NMe2)2}2}](OTf)2 (3). Reaction of 1 with AuCl(SMe2) in 1:2 molar ratio afforded a digold complex [(AuCl)2Fe{C5H4P(C6H4CH2NMe2)2}2] (4). Treatment of 4 with anhydrous CdCl2 resulted in heterometallic complex [Fe{C5H4P(AuCl)(C6H4CH2NMe2)2(CdCl2)}2] (5). The reactions of 1 with anhydrous CdI2 and HgI2 in 1:2 molar ratios yielded bimetallic complexes [Fe{C5H4P(CdI2)(C6H4CH2NMe2)2}2] (6) and [Fe{C5H4P(HgI2)(C6H4CH2NMe2)2}2] (7), respectively. The molecular structures of 3, 4 and 7 were confirmed by single crystal X-ray analysis. Complexes 3 and 7 crystallized in the triclinic space group with P-1, whereas 4 crystallized in the monoclinic space group with C2/c. Single crystals suitable for X-ray crystallography were obtained using diffusion method where a solution of [Fe{C5H4P(C6H4CH2NMe2)2}2] (1) in dichloromethane was layered on a solution of CdI2 and HgI2 in methanol and stored at room temperature for 24 h, resulted in yellow plates of 6 and 7, respectively. All complexes crystallized with the asymmetric unit containing half a molecule and with the Fe atom on an inversion centre. A Hirshfeld surface analysis indicated that the most significant contributions to the crystal packing of 3 are from H‧‧‧H (50.2%), C‧‧‧H/H‧‧‧C (8.3%), Cl‧‧‧H/H‧‧‧Cl (12.1%), O‧‧‧H/H‧‧‧O (11.3%), F‧‧‧H/H‧‧‧F (9.0%) contacts, while those for 4 are from H‧‧‧H (73.7%), C‧‧‧H/H‧‧‧C (8.9%), Cl‧‧‧H/H‧‧‧Cl (14.5%), Au‧‧‧H/H‧‧‧Au (1.8%) and N‧‧‧H/H‧‧‧N (0.8%) contacts, and those for 7 are from H‧‧‧H (65.5%), C‧‧‧H/H‧‧‧C (6.6%), I‧‧‧H/H‧‧‧I (24.1%) and I‧‧‧C/C‧‧‧I (2.9%) contacts. Crystal structures of silver(I), gold(I) and mercury(II) complexes containing [Fe{C5H4P(C6H4CH2NMe2)2}2] (1) are described. [ABSTRACT FROM AUTHOR]

The stability of coordination compounds of metal ions with ligands is of fundamental importance for elaborating upon practical sensors for the detection and quantification of metal ions in environmental samples. In this work, the stability constants of silver(I) complexes with 2-mercaptoimidazole (2MI) in a mixed water–dimethyl sulfoxide (DMSO) solvent were determined at 298.15 K and 308.15 K. It was found that with increasing temperature, the stability of the complexes decreases. The dependence of lgβ1 on the water−DMSO solvent compositions has its minimum at a concentration of dimethyl sulfoxide of 0.1 mol. fr. To explain the effect of the solvent, the solvation characteristics of the reagents were analyzed. In this regard, the 2MI Gibbs energy of transfer from water to aqueous dimethyl sulfoxide solvents was determined, and the influence of the aqueous DMSO solvent on the thermodynamics of 2MI protonation was analyzed. The stabilization of the silver ion and 2MI during the transition from water to a water–DMSO solvent makes a negative contribution to the change in the Gibbs energy of complexation, while the solvation of a complex particle promotes the complex formation. As a result, the Gibbs energy transfer values are slightly increased. The results of these thermodynamic studies could be useful for the development of sensor materials based on mercaptoimidazoles. [ABSTRACT FROM AUTHOR]

The investigation of the interaction of cyclic trinuclear silver(I) pyrazolate [AgPz]3 (Pz = 3,5-bis(trifluoromethyl)pyrazolate) with pyridine-based chalcones (anthracen-9-yl and phenyl-substituted ones) has been performed by IR-, UV-vis, and NMR spectroscopies in the solution. The carbonyl group participates in coordination with metal ions in all complexes. However, the network of π-π/M-π non-covalent intermolecular interactions mainly influences complex formation. The spectral data suggest retaining the structures for all studied complexes in the solution and solid state. E-Z isomerization in the case of anthracene-containing compounds significantly influences the complexation. E-isomer of chalcones seeks the planar structure in the complexes with [AgPz]3. In contrast, the Z-isomer of chalcone demonstrates the chelating coordination of O- and N atoms to silver ions. The complexation of anthracene-containing chalcones allows the switching of the emission nature from charge transfer to ligand-centered at 77 K. In contrast, phenyl-substituted chalcone in complex with macrocycle demonstrates that the emission significantly shifted (Δ = ca. 155 nm) to the low-energy region compared to the free base. [ABSTRACT FROM AUTHOR]

New silver(I) complexes of 5-(trifluoromethyl)uracil (5TFMU) and 6-(trifluoromethyl)uracil (6TFMU) isomers were synthesized, characterized, and evaluated as antibacterial and antiproliferative agents. Based on elemental and thermogravimetric analyses, the Ag-5TFMU and Ag-6TFMU species are formulated as AgC 5 H 2 F 3 N 2 O 2 and Ag 2 C 5 HF 3 N 2 O 2 , respectively. Infrared and 13C solid-state nuclear magnetic resonance spectroscopies suggest coordination of the trifluoromethyluracil isomers to silver by both nitrogen and oxygen atoms. Confirmation of their structure and connectivity was achieved, in the absence of single crystals of suitable quality, by state-of-the-art structural powder diffraction methods. In Ag-5TFMU, the organic ligand is tridentate and two distinct metal coordination environments are found (linear AgN 2 as well as C 2v AgO 4 geometries), whereas Ag-6TFMU contains a complex polymeric structure with tetradentate dianionic 6TFMU moieties and five distinct AgX 2 (X = N, O) fragments, further stabilized by ancillary (longer) Ag...O contacts. These species presented modest activity over Gram-positive and Gram-negative bacterial strains, whereas Ag-6TFMU was active over a set of tumor cells, with the best activity over prostate (PC-3) and kidney cell lines and selectivity indices of 4.6 and 1.3, respectively. On the other hand, Ag-5TFMU was active over all considered tumor cells except MCF-7 (breast cancer). The best activity was found for PC-3 cells, but no selectivity was observed. The Ag-5TFMU and Ag-6TFMU species also reduced the proliferation of tongue squamous cell carcinoma cell lines SCC − 4 and SCC-15. Preliminary biophysical assays by circular dichroism suggest that the Ag-5TFMU complex interacts with DNA by intercalation, an effect not seen in Ag-6TFMU. Synopsis: New silver(I) complexes with nucleoside analogs are presented. The complexes were shown to possess antibacterial activity over Gram-positive and Gram-negative strains, and antiproliferative action over a panel of tumor cells. [Display omitted] • Silver(I) complexes with trifluoromethyluracil isomers are presented. • The structures were determined by state-of-art powder diffraction studies. • The complexes were active over Gram-positive and Gram-negative bacterial strains. • The silver complexes were active over a panel of human tumor cells. [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound, [Ag2(VO2F2)2(C9H9N3)4], is presented. The molecular complex is based on the heterobimetallic AgI—VV fragment {AgI2(VVO2F2)2(tr)4} supported by four 1,2,4-triazole ligands [4-benzyl-(4H-1,2,4-triazol-4-yl)]. The triazole functional group demonstrates homo- and heterometallic connectivity (Ag—Ag and Ag—V) of the metal centers through the [–NN–] double and single bridges, respectively. The vanadium atom possesses a distorted trigonal–bipyramidal coordination environment [VO2F2N] with the Reedijk structural parameter τ = 0.59. In the crystal, C—H...O and C—H...F hydrogen bonds as well as C—H...π contacts are observed involving the organic ligands and the vanadium oxofluoride anions. A Hirshfeld surface analysis of the hydrogen-bonding interactions is also described.

The crystal of the title salt, [Ag(C12H8N2S)2]ClO4, has C2/c symmetry whereby the silver(I) atom sits on a twofold rotation axis, as does the perchlorate anion, which is disordered about this axis. The thienylquinoxaline ligand is nearly planar with the thienyl ring making a dihedral angle of 10.88 (8)° with respect to the quinoxaline moiety.

A reaction of a cyclic trinuclear copper(I) or silver(I) pyrazolate complex ([MPz]3, M = Cu, Ag) with 1,1′-dimethyl-2,2'-bibenzimidazole (L) leads to the formation of tetranuclear adducts decorated by one or two molecules of a diimine ligand, depending on the amount of the ligand added (0.75 or 1.5 equivalents). The coordination of two L molecules stabilizes the formation of a practically idealized tetrahedral four-metal core in the case of a copper-containing complex and a distorted tetrahedron in the case of a Ag analog. In contrast, complexes containing one molecule of diimine possess two types of metals, two- and three-coordinated, forming the significantly distorted central M4 cores. The diimine ligands are twisted in these complexes with dihedral angles of ca. 50–60°. A TD-DFT analysis demonstrated the preference of a triplet state for the twisted 1,1′-dimethyl-2,2'-bibenzimidazole and a singlet state for the planar geometry. All obtained complexes demonstrated, in a solution, the blue fluorescence of the ligand-centered (LC) nature typical for free diimine. In contrast, a temperature decrease to 77 K stabilized the structure close to that observed in the solid state and activated the triplet states, leading to green phosphorescence at ca. 500 nm. The silver-containing complex Ag4Pz4L exhibited dual emission from both the singlet and triplet states, even at room temperature. [ABSTRACT FROM AUTHOR]

New luminescent heterometallopolymers [(Au‐C6F5)m(AgOSO2CF3)n (PVP)] with different Au:Ag molar ratios were synthesized. The luminescent emissions of these polymers are strongly dependent on the temperature, excitation wavelengths, and the Au(I):Ag(I) molar ratio. The incorporation of a precise amount of Ag(I) atoms in the backbone of [(Au‐C6F5)m(PVP)] metallopolymer allows a controlled tuning of the emission energy in the green‐blue range. [ABSTRACT FROM AUTHOR]

(4-(Diphenylphosphino)pyrimidin-2-yl)diphenylphosphine oxide is unexpectedly formed in 24% yield in the reaction of 2,4-dichloropyrimidine with 2 equiv. of Ph2PLi in THF solution. It was demonstrated that title compound reacts with AgNO3 forming 1D polymer [Ag(L)NO3], wherein P,N,O-bringing coordination of the ligand is observed. At 300 K, both free ligand and the 1D polymer exhibit solid-state photoluminescence maximized at 480 nm and 538 nm with 3.2 ns and 2.95 μs afterglow times, respectively. [ABSTRACT FROM AUTHOR]

Complexes of poly(phenylene methylene) (PPM) with silver(I) ions and tricarbonylchromium(0) moieties, respectively, were synthesized. 13C NMR spectra indicate interaction of phenylene groups with silver(I) and chromium(0), and peak broadening implies dynamic behavior of the silver(I) complexes, with all phenylene groups temporarily involved in coordination, in contrast to the chromium complexes. About 5–10% of the phenylene groups are coordinated to metal atoms. 1H NMR and IR spectra, in the case of chromium(0), and the solubility of silver salts in the presence of PPM provide further evidence of coordination. The complexes are soluble in chloroform, but the silver complexes decay in tetrahydrofuran (second-order kinetics were observed in an example). The photoluminescence (fluorescence) of PPM is maintained upon complexation, although coordination of silver(I) seems to favor the so-called blue phase of PPM relative to the green phase by a factor of approximately two in PL spectra. The pronounced absorption of the tricarbonylchromium(0) units interferes with the blue phase, which almost disappears at a concentration of 50 mg/mL in PLE spectra, whereas the emission maximum of the green phase is hardly affected. This leads to a confinement of the emitted wavelength range of PPM. Thus, the perceived optical emission of PPM can be modified by coordinated entities. [ABSTRACT FROM AUTHOR]

Access to the enthalpy and entropy of the formation of metal complexes in solution is essential for understanding the factors determining their thermodynamic stability and speciation. As a case study, in this report we systematically examine the complexation of silver(I) in acetonitrile (AN) with the following monoamines: n-propylamine (n-pr), n-butylamine (n-but), hexylamine (hexyl), diethylamine (di-et), dipropylamine (di-pr), dibutylamine (di-but), triethylamine (tri-et) and tripropylamine (tri-pr). The study shows that the complex stabilities are quite independent of the length of the substitution chain on the N atom and demonstrates that, in general, the overall enthalpy terms associated with the complex formation are strongly exothermic, whereas the entropy values oppose the complex formations. In addition, we examined the similarity of the formation constants of AgL complexes of the primary monoamines in AN, dimethylsulfoxide (DMSO) and water, which were unexpected on the basis of the difference between the donor properties of solvents. [ABSTRACT FROM AUTHOR]

In this research a novel four-coordinated silver(I) complex with N-donor chelating ligands with formula [Ag(L1)(L2)]NO3, (where 4,5-diazafluoren-9-one = L1 and N-(4,5-diazafluoren-9-ylidene)aniline = L2) has been prepared and characterized with spectroscopic methods (UV-Vis, FT-IR and 1HNMR), elemental analysis, and molar conductivity measurement. The DNA-complex binding mode has been investigated by electronic absorption titration, luminescence titration, and thermodynamic studies and the relationship between the structure and the biological properties has been discussed. The binding constants (Kb) and thermodynamic parameters (enthalpy, entropy, and Gibbs free energy changes) have been calculated. The theoretical studies of the complex structure in the DFT framework have predicted the tetrahedral N4 coordination geometry for Ag(I) center. The molecular docking has been carried out to determine the binding mode and the best orientation of the complex with DNA. The experimental and theoretical results reveal that the Ag(I) complex binds to CT-DNA with a moderate intercalation capability with the partial insertion of the planar ligands between the double-stranded DNA bases and binding constant of 1.66×105 M-1.

A number of new binuclear Ag(I) complexes with benzimidazole derivatives and boron cluster anions [B n H n ]2− (n = 10, 12) have been obtained and structurally characterized. [Display omitted] Silver(I) complexation with boron cluster anions [B n H n ]2− (n = 10, 12) and chelating 1-substituted-2-aldiminebenzimidazoles 1-(1-methylbenzimidazol-2-yl)- N -phenylmetanimine (L1) and 1-(1-benzylbenzimidazol-2-yl)- N -cyclohexylmethanimine (L2) in systems AgNO 3 /[B n H n ]2−/L and {Ag 2 [B n H n ]} m /L, as well as with azaheterocyclic ligands 2,2ʹ-bipyridine (bipy) or 1,10-phenanthroline (phen) in the system AgNO 3 /[B n H n ]2−/L has been first studied. The effect of the organic ligand on the composition and structures of the resulting compounds has been shown. As a result, binuclear complexes [Ag 2 L 2 [μ–B n H n ]] with bridging boron cluster anions with various combinations of coordination modes (edge-edge and edge-face for the [B 10 H 10 ]2− anion, edge–atom and nontrivial asymmetric for the [B 12 H 12 ]2− anion) have been synthesized and structurally characterized for benzimidazole derivatives L1 and L2. When using bipy or phen as ligands, polymeric complexes {Ag 2 L[B 10 H 10 ]} m or {Ag 2 L 2 [μ-B 12 H 12 ]} m have been obtained. [ABSTRACT FROM AUTHOR]

The Zn2+/Ag+-pypo and pysu (pypo = 2-pyridylphosphonate, pysu = 2-pyridylsulfonate) complexes speciation in aqueous solution at I = 0.1 M (KNO3) and 25 °C is described in detail under our experimental synthetic conditions. Protonation and stability constants were determined, and distribution diagrams show protonated and deprotonated complexes formation in the case of Zn2+/Ag+ pypo/pysu binary system, respectively. Moreover, the new complex, {[Zn(H2pypo)2(H2O)2]}n(ClO4)2n·2nH2O, was isolated and its spectral and structural properties were determined. An unusual pypo bidentate coordination mode is described and compared with published ones. [ABSTRACT FROM AUTHOR]

Nine silver(I) N,N′‐diarylformamidine complexes of type [Ag (Ln)2X] (where X = NO3−, CF3COO−, and CF3SO3−, n = 1–5) were synthesised and characterised by physiochemical and spectroscopic techniques. Further confirmation for the formation of the complexes was provided by single‐crystal X‐ray crystallography. All complexes (but one) adopted linear geometry in which coordination was via two N atoms of two formamidine ligands with the anion (X) displaced from coordination sphere. In the structure of the exception, the anion is part of the coordination sphere and a T‐shaped geometry was adopted. The antimicrobial activity of the Ag(I) complexes were investigated against two Gram‐positive bacteria, that is, S. aureus ATCC 25923 and Methicillin‐resistant S. aureus ATCC 700699 (MRSA) and four Gram‐negative bacteria, that is, K. pneumoniae ATCC 31488, S. typhimurium ATCC 14026, P. aeruginosa ATCC 27853 and E. coli ATCC 25922 and they were evaluated based on ciprofloxacin and silver nitrate standards. The newly synthesised target complexes demonstrated promising antibacterial activity against Gram‐positive bacteria although less than the reference drug ciprofloxacin. The best active silver(I) complex contains a nitrate counter‐ion. [ABSTRACT FROM AUTHOR]

Two kinds of silver(I) coordination polymers consisting of the same chemical composition, [Ag(CF3SO3)(L)] [L is 2‐methylidene‐1,3‐bis(nicotinoyloxy)propane], were synthesized and characterized by infrared (IR) and photoluminescence (PL) spectroscopy, elemental and thermal analyses, and single‐crystal X‐ray diffractometry; these are catena‐poly[[(trifluoromethanesulfonato‐κO)silver(I)]‐μ‐2‐methylenepropane‐1,3‐diyl dinicotinate‐κ2N:N′], [Ag(CF3SO3)(C16H14N2O4)]n, and its chloroform monosolvate, {[Ag(CF3SO3)(C16H14N2O4)]·CHCl3}n. The X‐ray crystallographic measurements revealed that the silver(I) compounds exhibit one‐dimensional sinusoidal or helical molecular structures depending on the solvent used for crystallization. Self‐assembly in a methanol/chloroform mixture produces the sinusoidal molecular strand, whereas recrystallization from acetonitrile medium affords a racemic mixture of the helical strands. These compounds display a fluorescence emission arising from both the ligand‐centred transition and the ligand‐to‐metal charge transfer (LMCT) in the solid state under ambient conditions. [ABSTRACT FROM AUTHOR]

The results of a potentiometric and calorimetric study on the complexation of silver(I) with neutral N-donors 1,2-diaminoethane (EN), 1,3-diaminopropane (DAP), 1,4,7-triazaheptane (DIEN), 1,5,9-triazanonane (DPT) and 1,4,7,10-tetraazadecane (TRIEN) in acetonitrile (AN) are reported. The overall enthalpy terms associated with the complex formation are strongly exothermic, whereas the entropy values oppose the complex formation. Polynuclear species are formed by DAP and DPT, the ligands where the N atoms are separated by a longest carbon chain, but not by EN and DIEN. This also occurs in dimethyl sulfoxide (DMSO) where data for the same amines are available, and a comparison can be made. The Ag3L23+ species formed by DPT is stabilized by the formation of large rings, where six Ag–N bonds are formed in an organized, compact, structure, which is proposed on the basis of density functional theory (DFT) calculations. A remarkable, interesting, aspect emerged in this study is the similarity of formation constants for the same complexes in DMSO and AN, unexpected on the basis of the quite large difference between the donor properties of AN and DMSO. A careful analysis of the thermodynamic transfer parameters from AN to DMSO was made on Ag(I)–EN system for all the species participating in the reactions. The results allow to conclude that the solvation of the complexes is mainly responsible for this unexpected behavior. The comparison of the thermodynamic functions available in dimethylformamide (DMF) and propylenecarbonate (PC) indicates the following stability order of Ag-EN and -DIEN complexes: DMSO ≈ AN < DMF < PC. The trend in DMF and PC, as compared to AN, seems to reflect the prevailing importance of the silver(I) ion solvation on the complexation thermodynamics. [ABSTRACT FROM AUTHOR]

The synthesis and use of a suitable metal–organic framework (ZIF-67) as a sensory material for voltammetric measuring of silver(I) is the subject of this investigative work. In this regard, the size exclusion property of the ZIF-67 is coupled with the analytical voltammetry method and as a result, an efficient approach for measuring silver(I) has been obtained with appropriate selectivity and sensitivity. The detailed characterization of the synthesized ZIF-67 as well as the carbon paste electrode modified with it (Fourier transform-infrared spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy–energy-dispersive X-ray analysis, Brunauer–Emmett–Teller method, cyclic voltammetry, and impedance spectroscopy) indicates the exact synthesis of high-purity ZIF-67. Box–Behnken design has been used to optimize the conditions of preparation and operation of the sensor. There is a direct relationship between silver molarity in the enrichment solution and silver stripping current in the 1.0 × 10−10 to 2.5 × 10−7 molarity range. The detection limit was 2.5 × 10−11 M. Proper selectivity of this sensor greatly reduces mercury interference in silver measurement. When using the sensor to measure silver in real samples, results were obtained that agree with the results of the classical method of measuring silver. [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound, [Ag2(VO2F2)2(C9H9N3)4], is presented. The molecular complex is based on the heterobimetallic AgI —VV fragment {AgI 2(VVO2F2)2(tr)4} supported by four 1,2,4-triazole ligands [4-benzyl-(4H-1,2,4-triazol-4-yl)]. The triazole functional group demonstrates homo- and heterometallic connectivity (Ag—Ag and Ag—V) of the metal centers through the [–NN–] double and single bridges, respectively. The vanadium atom possesses a distorted trigonal–bipyramidal coordination environment [VO2F2N] with the Reedijk structural parameter = 0.59. In the crystal, C—HO and C—HF hydrogen bonds as well as C—H contacts are observed involving the organic ligands and the vanadium oxofluoride anions. A Hirshfeld surface analysis of the hydrogen-bonding interactions is also described. [ABSTRACT FROM AUTHOR]

The coordination chemistry towards silver(I) of the small‐ring macrocycles [9]aneN2S (1‐thia‐4,7‐diazacyclononane) and [9]aneNS2 (1,4‐dithia‐7‐azacyclononane) incorporating nitrile‐functionalized pendant arms is considered both in the presence and the absence of exogenous bridging ligands. The aim is to understand the influence of the number and length of the pendant arms on the nuclearity and dimensionality of the resulting complexes. The X‐ray crystal structures of the complexes bis[4,7‐bis(cyanomethyl)‐1‐thia‐4,7‐diazacyclononane‐κ3N,N′,S]silver(I) tetrafluoridoborate, [Ag(C10H16N4S)2]BF4 or [Ag(L1)2]BF4, [4,7‐bis(2‐cyanoethyl)‐1‐thia‐4,7‐diazacyclononane‐κ3N,N′,S](thiocyanato‐κS)silver(I), [Ag(C12H20N4S)(NCS)] or [Ag(L2)(SCN)], and μ‐thiocyanato‐κ2S:S‐bis{[7‐(2‐cyanoethyl)‐1,4‐dithia‐7‐azacyclononane‐κ3N,S,S′]silver(I)} tetrafluoridoborate, [Ag2(C9H16N2S2)2(SCN)]BF4 or [Ag2(L3)2(μ‐SCN)]BF4, are discussed in relation to analogous compounds in the literature. [ABSTRACT FROM AUTHOR]

The two new pyrazineophanes, 5,7-dihydro-1H,3H-dithieno[3,4-b:3′,4′-e]pyrazine, C8H8N2S2, L1, and 3,4,8,10,11,13-hexahydro-1H,6H-bis([1,4]dithiocino)[6,7-b:6′,7′-e]pyrazine, C12H16N2S4, L2, both crystallize with half a molecule in the asymmetric unit; the whole molecules are generated by inversion symmetry. The molecule of L1, which is planar (r.m.s. deviation = 0.008 Å), consists of two sulfur atoms linked by a rigid tetra-2,3,5,6-methylenepyrazine unit, forming planar five-membered rings. The molecule of L2 is step-shaped and consists of two S–CH2–CH2–S chains linked by the central rigid tetra-2,3,5,6-methylenepyrazine unit, forming eight-membered rings that have twist-boat-chair configurations. In the crystals of both compounds, there are no significant intermolecular interactions present. The reaction of L1 with silver nitrate leads to the formation of a two-dimensional coordination polymer, poly[(μ-5,7-dihydro-1H,3H-dithieno[3,4-b;3′,4′-e]pyrazine-κ2S:S′)(μ-nitrato-κ2O:O′)silver(I)], [Ag(NO3)(C8H8N2S2)]n, (I), with the nitrato anion bridging two equivalent silver atoms. The central pyrazine ring is situated about an inversion center and the silver atom lies on a twofold rotation axis that bisects the nitrato anion. The silver atom has a fourfold AgO2S2 coordination sphere with a distorted shape. The reaction of L2 with silver nitrate also leads to the formation of a two-dimensional coordination polymer, poly[[μ33,4,8,10,11,13-hexahydro-1H,6H-bis([1,4]dithiocino)[6,7-b;6′,7′-e]pyrazine-κ3S:S′:S′′](nitrato-κO)silver(I)], [Ag(NO3)(C12H16N2S4)]n, (II), with the nitrate anion coordinating in a monodentate manner to the silver atom. The silver atom has a fourfold AgOS3 coordination sphere with a distorted shape. In the crystals of both complexes, the networks are linked by C—H...O hydrogen bonds, forming supramolecular frameworks. There are additional C—H...S contacts present in the supramolecular framework of II.

Two polymeric mixed-ligand silver(I) complexes, [Ag(µ-nif)(4-pic)]n (1) and [Ag4(µ-nap)4(2-pic)2]n (2), where Hnif: niflumic acid, Hnap: naproxen, 4-pic: 4-picoline and 2-pic: 2-picoline, were synthesized and characterized by single-crystal X-ray diffraction, FT-IR and 1H NMR spectroscopies, elemental and thermal analysis techniques. In 1, nif ligand behaves as a µ3-N,O,O' bridge connecting three silver(I) ions and each silver(I) ion exhibits a seesaw geometry. In 2, nap ligands act as a µ-carboxylato-(O,O') bridge between two silver(I) ions and µ3-carboxylato-(O,O,O') bridge linking three silver(I) ions. Each silver(I) ion occurs in trigonal geometry. To uncover the anticancer properties of the complexes, first, their cytotoxic abilities were tested against three cancer cell lines, HT-29 (human colorectal adenocarcinoma), A-549 (human lung carcinoma), and MDA-MB-453 (human breast adenocarcinoma), and normal 3T3-L1 (mouse fibroblast) cell line by XTT tests. Afterwards, the anticancer mechanism of the complexes was tried to be elucidated through the flow cytometry analyzes. XTT assay results showed that the complexes exhibited the highest cytotoxic activity and selectivity on HT-29 cells among all the cell lines. Flow cytometry analyses revealed that both complexes induced the apoptosis through the mitochondrial membrane depolarization and activation of the caspase cascade in HT-29 cells. [ABSTRACT FROM AUTHOR]

The 4S–Ag(I)–C base pair (4S, 3-((2-(methylthio)pyrimidin-4-yl)thio)propane-1,2-diol; C, deoxycytidine) represents the first metal-mediated base pair comprising an S-glycosidic nucleoside analogue. We report here the synthesis of the phosphoramidite suitable for the automated solid-phase synthesis of DNA oligonucleotides containing 4S and its silver(I)-binding ability. The DNA duplexes comprising a 4S:C mispair exhibit a large thermal stabilization upon the addition of one equivalent of silver ions, giving rise to the formation of the above-mentioned silver(I)-mediated base pair. By formally replacing the sulfur atom in the glycosidic bond by an oxygen atom, i.e., by applying 3-((2-(methylthio)pyrimidin-4-yl)oxy)propane-1,2-diol (4 O) as the artificial nucleoside analogue, the participation of this atom as a donor atom in silver(I)-mediated base pairing is shown to be neglectable. Supplemental data for this article is available online at [ABSTRACT FROM AUTHOR]

In this study, the functional polymers containing heterocyclic ligands were synthesized by microwave modification of a crosslinked poly(vinylbenzyl chloride-divinylbenzene) matrix with 4-tertbutylpyridine, pyrrolidine, and 3-morpholinopropylamine. The sorbents were used to recover Ag(I) from the synthetic and real chloride solutions (4.00 mol/dm3 of NaCl, 0.100 mol/dm3 of HCl). The best Ag(I) sorption was achieved from synthetic and real chloride solutions in the case of pyrrolidine resin (16.2 and 16.7 mg/g, respectively). The sorption kinetic data were well fitted to the pseudo-first-order kinetic model. The degree of silver desorption was approximately 90% using a 1.0% potassium cyanide solution in a 0.50% hydrogen peroxide solution. All resins showed good selectivity for Ag(I) compared to Cu(II), Pb(II), Co(II), Ni(II), and Zn(II) in real chloride solution. On the basis of this study, it can be concluded that the obtained sorbents can be used to recover Ag from various sources such as ores, wastewater, and jewelry scraps. [ABSTRACT FROM AUTHOR]

[Display omitted] • Static experiments, characterization tests and DFT calculations were used to systematically investigate the Ag(Ⅰ) adsorption performance and mechanism. • Chelate resins containing N and S (D840 and TMMR) were applied, comparing with anionic resin D301 in thiosulfate system. • TMMR prepared by grafting thiourea onto CPS has the maximum adsorption capacity of 602.1 mg/g at 298 K. • The cyclic stability of chelation is worse than N protonation. • Dual mechanism of the N and S chelation and the N protonation exhibit better adsorption effect compared to the single action. Chelate resins containing N and S atoms have a strong affinity for silver ions Ag(Ⅰ). In order to compare the effects of different functional groups on adsorption performance, two thiourea based isomeric resins containing S and N atoms (D840 and TMMR) were applied. And considering the silver-containing wastewater in photography, a thiosulfate system and tertiary amino anion resin D301 were used to compare the influence of external factors and specific adsorption mechanism. The adsorption properties were conducted using static experiments. FTIR, FESEM, BET and XPS were used to analyze the resins before and after adsorption. Thermodynamic and kinetic model fitting and DFT theoretical calculations were also carried out. Acidic conditions (pH = 2.0 to 5.0), adsorption dose of 1.5 g/L and reaction time (10–12 h) are beneficial for Ag(Ⅰ) adsorption. The adsorption of Ag(Ⅰ) by resins are more consistent with Langmuir isothermal adsorption model and pseudo-second-order kinetic adsorption model. Inferring from DFT calculation that the adsorption is mainly due to the chelation of S and N and the protonation of N. TMMR prepared by grafting thiourea onto the chlorine sphere matrix has the strongest activity, which is consistent with the experimental results that its maximum adsorption capacity could reach 602.1 mg/g under room temperature, exhibiting excellent application potential. It was inferred that dual mechanism of chelation and N protonation can exhibit better adsorption performance compared to a single action, but chelation has slightly poorer cycling stability compared to N protonation. This work mainly lies in the systematic comparison of Ag(Ⅰ) adsorption on chelate resins and anionic resin, and the study of adsorption mechanism by combining DFT theoretical calculation, forming a complete closed-loop research system and enriching the analysis process. [ABSTRACT FROM AUTHOR]

The reactions of N-heterocyclic carbene CuI and AgI halides with potassium thio- or selenocyanate gave unexpected products. The attempted substitution reaction of bromido(1,3-dibenzyl-4,5-diphenylimidazol-2-ylidene)silver (NHC*—Ag—Br) with KSCN yielded bis[bis(1,3-dibenzyl-4,5-diphenylimidazol-2-ylidene)silver(I)] tris(thiocyanato)argentate(I) diethyl ether disolvate, [Ag(C29H24N2)2][Ag(NCS)3]·2C4H10O or [NHC*2Ag]2[Ag(SCN)3]·2Et2O, (1), while reaction with KSeCN led to bis(μ-1,3-dibenzyl-4,5-diphenyl-2-selenoimidazole-κ2Se:Se)bis[bromido(1,3-dibenzyl-4,5-diphenyl-2-selenoimidazole-κSe)silver(I)] dichloromethane hexasolvate, [Ag2Br2(C29H24N2Se)4]·6CH2Cl2 or (NHC*Se)4Ag2Br2·6CH2Cl2, (2), via oxidation of the NHC* fragment to 2-selenoimidazole. This oxidation was observed again in the reaction of NHC*—Cu—Br with KSeCN, yielding catena-poly[[[(1,3-dibenzyl-4,5-diphenyl-2-selenoimidazole-κSe)copper(I)]-μ-cyanido-κ2C:N] acetonitrile monosolvate], {[Cu(CN)(C29H24N2Se)]·C2H3N}n or NHC*Se—CuCN·CH3CN, (3). Compound (1) represents an organic/inorganic salt with AgI in a linear coordination in each of the two cations and in a trigonal coordination in the anion, accompanied by diethyl ether solvent molecules. The tri-blade boomerang-shaped complex anion [Ag(SCN)3]2− present in (1) is characterized by X-ray diffraction for the first time. Compound (2) comprises an isolated centrosymmetric molecule with AgI in a distorted tetrahedral BrSe3 coordination, together with dichloromethane solvent molecules. Compound (3) exhibits a linear polymeric 1∞[Cu—C[triple-bond]N—Cu—] chain structure with a selenoimidazole moiety additionally coordinating to each CuI atom, and completed by acetonitrile solvent molecules. Electron densities associated with an additional ether solvent molecule in (1) and two additional dichloromethane solvent molecules in (2) were removed with the SQUEEZE procedure [Spek (2015). Acta Cryst. C71, 9–18] in PLATON.

The crystal structure of the title molecular complex, [Ag2{VO2F2}2(C13H17N3O2)4]·4H2O, supported by the heterofunctional ligand tr-ad-COOH [1-(1,2,4-triazol-4-yl)-3-carboxyadamantane] is reported. Four 1,2,4-triazole groups of the ligand link two AgI atoms, as well as AgI and VV centres, forming the heterobimetallic coordination cluster {AgI2(VVO2F2)2(tr)4}. VV exists as a vanadium oxofluoride anion and possesses a distorted trigonal–bipyramidal coordination environment [VO2F2N]. A carboxylic acid functional group of the ligand stays in a neutral form and is involved in hydrogen bonding with solvent water molecules and VO2F2− ions of adjacent molecules. The extended hydrogen-bonding network is responsible for the crystal packing in the structure.

Aspects of the molecular and supramolecular structure of the new dinuclear [Ag(L)(NO3)]2 complex, where L is 2-((E)-(((E)-1-(thiazol-2-yl)ethylidene)hydrazono)methyl)phenol, were discussed. The complex was crystallized in the monoclinic crystal system and P21/n space group. The unit cell parameters are a = 10.3274(2) Å, b = 11.4504(3) Å, c = 12.7137(3) Å and β = 108.2560(10)°. The asymmetric unit comprised one [Ag(L)(NO3)] formula in which the azine and nitrate ligand groups act as NN- and OO-bidentate chelates, respectively. The coordination environment of the Ag(I) is completed by one weak Ag-O bond with another [Ag(L)(NO3)] unit, leading to the dinuclear formula [Ag(L)(NO3)]2. This was clearly revealed by Hirshfeld analysis. Additionally, the Ag…C, O…H and C…C intermolecular interactions played an important role in the molecular packing of the studied complex. The antimicrobial, antioxidant and cytotoxic activities of the [Ag(L)(NO3)]2 complex and the free ligand (L) were discussed. While the [Ag(L)(NO3)]2 complex showed very weak antioxidant activity, the results of the antifungal and cytotoxic activities were promising. The inhibition zone diameters (IZD) and the minimum inhibitory concentration (MIC) values were determined to be 31 mm and 20 μg/mL, respectively, against A. fumigatus, which is compared to 17 mm and 156 μg/mL, respectively, for the positive control Ketoconazole. Generally, the Ag(I) complex has better antimicrobial activities than the free ligand against all microbes except for S. aureus, where the free ligand has higher activity. Additionally, the IC50 value against colon carcinoma (HCT-116 cell line) was determined to be 12.53 ± 0.69 µg/mL, which is compared to 5.35 ± 0.49 µg/mL for cis-platin. Additionally, the Ag(I) complex displays better cytotoxicity than the free ligand (L) (242.92 ± 8.12 µg/mL).

[2.2]Paracyclophane scaffolds have seen limited use as building blocks in supramolecular chemistry. Here, we report the synthesis and characterization of a 1D coordination polymer consisting of silver(I) ions bound to a [2.2]paracyclophane scaffold functionalized with two 4-pyridyl units. The structure of the polymer has been determined from single crystal X-ray diffraction analysis and reveals two different silver coordination motifs that alternate along the 1D coordination polymer. The coordination polymer exhibits strong blue and sky-blue fluorescence in solution and in the crystalline solid state, respectively.

This paper reports a method for preparation of functional derivative – poly(N-2-sulfoethyl)allylamine – obtained when treating poly(allylamine) with sodium vinylsulfonate, and allowing for the complete functionalization of the amino groups. The composition and the structure of the products of the polymer transformation were studied using the elemental analysis, FT-IR spectroscopy, and 1H NMR spectroscopy. In order to obtain the sorption material, it is necessary to use epichlorohydrin, which enables the effective cross-linking of the macromolecule, vs. glutaraldehyde. The sorbent based on the sulfoethylated poly(allylamine) selectively removes silver(I) from its ammonium acetate buffer solution having the рН value from 6.0 to 6.5 and containing some other transition and alkaline earth metal ions. [ABSTRACT FROM AUTHOR]

Experimental multinuclear determination of the chemical shifts, especially 15N and 109Ag, of five silver(I) trinuclear pyrazolate complexes, (PzAg)3, coupled with ZORA (zeroth-order regular approximation) and GIAO (gauge-independent atomic orbital) calculations, has shed new light on these compounds. An almost complete collection of spin-spin coupling constants has been measured for the first time for several of these compounds. The aromaticity of (PzAg)3 was examined using NICS (nucleus-independent chemical shift) and ACID (anisotropy of the induced current density) approaches reaching the conclusion of its absence. [ABSTRACT FROM AUTHOR]

N-Heterocyclic carbene is a versatile ligand for the preparation of copper(i) and silver(i) derivatives bearing the radical anion forms of redox active o-benzoquinone and o -iminobenzoquinone. The paramagnetic three-coordinated copper(i) and silver(i) o -benzosemiquinone and o -iminobenzosemiquinone complexes were prepared and characterized by EPR spectroscopy and X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

A method was developed for the preparation of N-2-sulfoethylated polyaminostyrene (SEPAS) by gel synthesis with a degree of substitution up to 1.2. The composition and structure of the products of polymer-analogous transformations were characterized using elemental analysis and FT-IR spectroscopy. It was found that an increase in the degree of sulfoethylation decreases the basicity of amino groups. This leads to an increase in the selectivity coefficient KAg(I)/Cu(II) in an ammonium acetate buffer solution in the pH range 5.5–6.0, which makes it possible to use SEPAS for the selective extraction of silver(I) from solutions of complex composition. The degree of sulfoethylation does not affect the rate at which the sorption equilibrium is established. [ABSTRACT FROM AUTHOR]

Microwave-assisted hydrothermal reaction of 2-fluoro-3,5,6-tri(1H-1,2,4-triazol-1-yl)-1,4-benzenedicarbonitrile (L1) with silver(I) nitrate yields a coordination polymer [Ag3(L2)2(NO3)]n (1), in which the L2 ligand (HL2 = 2-hydroxy-3,5,6-tri(1H-1,2,4-triazol-1-yl)terephthalonitrile) is obtained by in situ ligand transformation from the L1 precursor. HL2 monohydrate has also been isolated by the microwave-mediated hydrolysis of L1 and structurally characterized. Single-crystal X-ray diffraction reveals that HL2 monohydrate comprises a zwitterionic HL2 moiety, while complex 1 displays an infinite L2-bridged double-chain structure. Given that the HL2 molecule has a large conjugated π system, complex 1 exhibits strong blue luminescence in the solid state at room temperature. [ABSTRACT FROM AUTHOR]