Metal-ligand Ratio Research Articles

Spectroscopic, thermal analysis and antimicrobial activities of supramolecular Cu(II) complexes

A series of Cu(II) complexes of azo dye ligands 4-(4-hydroxy-5-(aryldiazenyl)-2-thioxothiazol-3(2H)-yl)benzenesulfonamide (HLn) were synthesized by the coupling of 3-sulfamoylphenylrhodanine with aniline and its p-derivatives. These ligands and their [Cu(Ln)(CH3COO)(OH2)]H2O complexes were characterized by elemental analyses, IR, 1H NMR, UV–Visible and magnetic measurements as well as thermal analysis and X-ray diffraction. The molar conductance measurements proved that all the complexes are non-electrolytes. IR spectra showed that the ligands (HLn) acts as a monobasic bidentate ligand by coordinating via the nitrogen atom of the azo group (–NN–) and oxygen atom of the deprotonated –OH group moiety, thereby forming a six-membered chelating ring and concomitant formation of an intramolecular hydrogen bond. Spectral studies revealed that the ligand exist in an internally hydrogen bonded azo-enol form rather than the keto-hydrazone form a coordinated to the metal ion in a bidentate fashion. Analytical data revealed that all the complexes exhibited 1:1 metal-ligand ratio. Based on the ESR and electronic spectral data, the bonding parameters of these complexes have been calculated. The thermodynamic parameters of the ligands (HLn) and their Cu(II) complexes are calculated using Coats–Redfern and Horowitz-Metzger methods. The antimicrobial activities of ligands were tested against gram negative bacteria (Escherichia coli), gram positive bacteria (Staphylococcus aureus) and fungal (Candida albicans). The cytotoxic activity of ligands (HLn) was tested against two human cancer HePG-2 (Hepatocellular carcinoma) and MCF-7 (breast cancer). The antioxidant activities of ligands (HLn) were performed by ABTS method.

Naphthoquinone based Chemosensor 2-(2′-aminoethylpyridine)-3-chloro-1,4-naphthoquinone: Detection of metal ions, X-ray -crystal structures and DFT studies

Naphthoquinone based Chemosensor 2; 2-(2′-aminoethylpyridine)-3-chloro-1,4-napthoquinone have been synthesized and characterized. Chemosensor 2 crystallizes in the orthorhombic space group Pbcn and shows extensive intramolecular as well as intermolecular hydrogen bonding interactions. Each molecule of Chemosensor 2 showed interaction with five neighboring molecules via C–H⋯N, N–H⋯N, C–H⋯Cl and C–H⋯O interactions. Slipped π–π stacking interaction was observed in adjacent quinonoid and benzenoid rings. Chemosensor abilities of Chemosensor 2 ligand have been evaluated with metal ions viz. Cu2+, Ni2+, Zn2+, Co2+, Fe3+, Mn2+, Cr3+, Hg2+, La3+ and Cd2+ in methanol, methanol-water mixture and in presence of mild base triethylamine. Stoichiometry of Chemosensor 2 with metal ions such as Cu2+, Ni2+, Zn2+and Co2+ ions was determined by Jobs method in methanol and were found as 1:1 for Cu2+and 2:1 for Ni2+, Zn2+ Co2+. The variation in the metal ligand ratio is observed in aqueous media for Cu2+. Chemosensor 2 can be used selectively for naked eye detection of Cu2+ ions. The association constant obtained in methanol shows the trend Cu2+>Ni2+>Co2+. Cu2+ and two (Ni-1 and Ni-2) Ni2+ complexes were synthesized. Ni-2 complex showed coordination of Chemosensor 2 ligands was through pyridine nitrogen's only. The Chemosensor 2 and its deprotonated forms in methanol, water and triethylamine were also studied by TD-DFT studies.

Synthesis, characterization and antimicrobial activities of a Schiff base derived from phenylalanine and acetylacetone and its Mn(II), Ni(II) and Cu(II) complexes

Complexes of Cu(II), Ni(II) and Mn(II) with a Schiff base derived from condensation reaction of phenylalanine and acetylacetone have been synthesized and characterized analytically and spectroscopically. Melting point of the Schiff base was 188 o C and the complexes decompose within a temperature range of 210-242 o C. The molar conductance values of the complexes were found to be within 15.0-60.0Ω -1 cm 2 mol -1 range while the magnetic moment values indicated the complexes to be paramagnetic. The Infrared spectra of the Schiff base showed the azomithine peak at 1605cm -1 which shifted to 1595-1637cm -1 in the complexes. The analytical and spectral studies revealed that all the metal complexes are in 1:2 Metal-Ligand ratios, with the Schiff base acting as a tridentate ligand towards metal ion via azomethine-N, deprotonated-O of carboxylic group and enolic-O group of acetylacetone. The synthesized ligand and its respective metal (II) complexes were screened for their antibacterial activity against Staphylococcus aureus (Gram-positive), Escherichia coli , Proteus mirabilis , Pseudomonas aeruginosa and Klebsiella pneumoniae (Gram-negative) bacterial strains and antifungal activity against Candida albicans , Fusarium solani and Aspergillus fumigatus . The results revealed that, the Schiff base and the metal complexes showed significant antibacterial and antifungal strength at high concentrations. Keywords: Acetylacetone, Schiff base, complex, antimicrobial, characterization

Quantitative studies of Co(II)-thymoquinone complex using cyclic voltammetry

In this research quantitative studies of Co(II)-thymoquinone complex was performed using cyclic voltammetry. The electrodes used were glassy carbon as working, saturated calomel as reference and platinum as auxiliary electrode. All the work was done at standard temperature (25 ± 1 °C) in aqueous medium using NaCl as supporting electrolyte. Effects of different parameters, i.e. concentration and metal-ligand ratios on complex formation were investigated. Observations obtained by varying the metal-ligand ratio suggested a quasi-reversible electron transfer process in the complex. The effect of concentration followed the Randles-Sevcik equation. Values of the standard electrode potential (E°), diffusion coefficient (D), transfer coefficients (α and β) and different electrochemical parameters were also calculated. The E° for the complex was found to be 0.288 ± 0.01V. The α values ranged between 0.676 ± 0.02 - 1.00 ± 0.02 whereas the values of β were found to be 0.758 ± 0.01 - 1.20 ± 0.01 respectively. Linear regression showed that cyclic voltammetry could be useful for the quantification of Co(II)-thymoquinone complex in pharmaceutical analysis.

Preparation and Characterization of Some Metal Complexes with Heterocyclic Azo Ligand (4-SuBAI)

The preparation and characterization of the Cu (II), Co(II), Ni(II), Zn(II), Cd(II), and Hg(II) metal complexes of heterocyclic azo ligand 2-[(4`-sulphamide phenyl) azo] -4,5-diphenyl imidazole (4-SuBAI) have been studied by elemental analysis, FT-IR and UV-Vis Spectroscopic, magnetic moment and molar conductance methods. The analytical data showed that all chelate complexes were prepared with (metal-ligand) ratio of (1:2). The general formula of these complexes was [ML2X2]. nH2O [were L=2-[(4`-sulphamide phenyl) azo]-4,5-diphenyl imidazole and X=Cl, and the octahedral geometry were suggested for these complexes .

Binding of chlorfenvinphos and malathion with DNA and their detection using new sensitive luminescent Tb(III) complex probe

In this work, the interaction of new luminescent terbium-N(acetoacetyl)-3-allyl-2hydroxybenzaldehyde hydrazone complex in a metal ligand ratio 1:2 in ethanol was studied with different pesticides, using fluorescence technique. The results indicate that the pesticides chlorfenvinphos and malathion exhibit quenching effect on the characteristics emission peak for Tb(III) at λ=545nm. The luminescence variations values using the probe Tb(III)(HBH)2 fit Stern–Volmer equation, where the detection limits are 4.53 and 9.59µmol/L for chlorfenvinphos and malathion, respectively. The thermodynamic parameters associated with the interaction of the complex with the two pesticides were calculated, where the reaction is spontaneous through the obtained negative values of free energy change ΔG, and the process is of exothermic nature with decrease in entropy. Hence the nature of forces acting between the complex and pesticide molecules are Vander Val's and hydrogen bond. Also, it was found that the quenching mechanism is static type. Effect of some relevant interferents on the detection of pesticides has been investigated. The new sensing complex was applied to the determination of the pesticides in different real water samples (tap, river, and waste water) with precise recovery. Also, the effect of different concentrations of pesticides on the fluorescence spectrum of DNA was studied.

A Family of Fe(II)/Cl Supramolecular Coordination Systems Incorporating 5,5′-Di(pyridin-2-yl)-3,3′-bi(1,2,4-triazole)

By using a new N-heterocyclic building block, 5,5′-di(pyridin-2-yl)-3,3′-bi(1,2,4-triazole) (2,2′-H2dbpt), five novel coordination complexes, Fe4(2,2′-Hdbpt)2Cl6(H2O)6 (1), [Fe(2,2′-H2dbpt)Cl2·H2O]n (2), [Fe(2,2′-H2dbpt)Cl2]n (3), [Fe2(2,2′-H2dbpt)Cl4]n (4), and [Fe(2,2′-H2dbpt)0.5Cl2]n (5), based on a Fe(II)/Cl system with diversiform connectivity from zero- to two-dimensional (2D) were constructed successfully. By regulating the metal–ligand ratio and solvents, 2,2′-H2dbpt changed various coordination modes. Consequently, 1 reveals a discrete Fe4(2,2′-Hdbpt)2Cl6(H2O)6 supramolecule. 2 and 3 are pseudo-polymorphic. 2 reveals a helical chain based on the cis-FeCl2N4 unit and the cis-bridging 2,2′-H2dbpt ligand, while 3 reveals a straight-chain based on the trans-FeCl2N4 unit and the trans-bridging 2,2′-H2dbpt ligand. 4 and 5 are also supramolecular isomers. Different from 2 and 3, both of them have a cis-FeCl2N4 unit. Owing to the different rotation angles of pyridine rings in 2,2′-H2dbpt, 4 and 5 reveal ...

N, N coordinating schiff base ligand acting as a fluorescence sensor for zinc(II) and colorimetric sensor for copper(II), and zinc(II) in mixed aqueous media

Two simple and low cost new schiff base compounds of fluorene and derivative of imidazole based chemo sensor were synthesized and characterized by 1H NMR, IR and mass spectroscopic technique. These sensors could simultaneously detect two biologically important metal ions through fluorogenic (Zn2+) and chromogenic (Cu2+ and Zn2+) methods in mixed aqueous solution. However, the sensor functioned as a “turn-on” fluorescence receptor only to Zn2+ ion in presence of other metal ions. The detection limit of HL for Zn2+ (10μM) was below the guidelines of the WHO (76μM). The 2:1 binding stoichiometry of the ligand metal ratio in complexes were established by combined UV–Vis, fluorescence and ESI-MS spectroscopy. In addition, the electronic structure and photo physical properties of the ligands and complexes were calculated by DFT and time-dependent DFT (TDDFT) method. The sensor also showed color changes from colorless to yellow upon selective binding with Zn2+ and Cu2+ metal ions, which were visible to the naked eye. The detection limit of the sensor for Cu2+ (10μM) was found to be below the maximum permissible copper concentration in drinking water as per the guidelines of the World Health Organization (30μM) and therefore it is capable of being a practical system for the monitoring of Cu2+ concentrations in aqueous samples.

Photochemical Reactions of Hydrogen-bonded Coordination Polymers

Crystallization is a kinetic phenomenon and the experimental conditions like solvents, concentration, pH, temperature and time have greater influence on the nature of products in the synthesis of coordination network structures. During crystallization, the solvents and ligands bind to the metal ions reversibly and hence, the least soluble polymer will crystallize first, independent of the metal-ligand ratio used in the crystallization. The kinetic products quite often contain solvents bonded to the metal ions. The removal of these coordinated solvents is likely to transform the kinetically formed coordination polymers (CPs) into thermodynamically stable products. In these structural conversions, supramolecular interactions play a major role. Such structural transformations as well as [2+2] cycloaddition reactions have been demonstrated in many coordination polymeric network structures aided by the directional hydrogen bonding interactions. A number of structural transformations involving the loss of solvent molecules and use of photodimerization reactions in the solid state will be presented in this talk.

Synthesis, physicochemical characterization, DFT calculation and biological activities of Fe(III) and Co(II)–omeprazole complexes. Potential application in the Helicobacter pylori eradication

The reaction between the antiulcer agent omeprazole (OMZ) with Fe(III) and Co(II) ions was studied, observing a high ability to form metal complexes. The isolated microcrystalline solid complexes were characterized by elemental analysis, X-ray powder diffraction (XRPD), Scanning Electron Microscopy (SEM), magnetic measurements, thermal study, FTIR, UV–Visible, Mössbauer, electronic paramagnetic resonance (EPR), and DFT calculations. The metal–ligand ratio for both complexes was 1:2 determined by elemental and thermal analysis. FTIR spectroscopy showed that OMZ acts as a neutral bidentate ligand through the pyridinic nitrogen of the benzimidazole ring and the oxygen atom of the sulfoxide group, forming a five-membered ring chelate. Electronic, Mössbauer, and EPR spectra together with magnetic measurements indicate a distorted octahedral geometry around the metal ions, where the coordination sphere is completed by two water molecules. SEM and XRPD were used to characterize the morphology and the crystal nature of the complexes. The most favorable conformation for the Fe(III)–OMZ and Co(II)–OMZ complexes was obtained by DFT calculations by using B3LYP/6-31G(d)&LanL2DZ//B3LYP/3-21G(d)&LanL2DZ basis set. Studies of solubility along with the antibacterial activity against Helicobacter pylori for OMZ and its Co(II) and Fe(III) complexes are also reported. Free OMZ and both metal complexes showed antibacterial activity against H. pylori. Co(II)–OMZ presented a minimal inhibitory concentration ∼32 times lower than that of OMZ and ∼65 lower than Fe(III)–OMZ, revealing its promising potential use for the treatment of gastric pathologies associated with the Gram negative bacteria. The morphological changes observed in the cell membrane of the bacteria after the incubation with the metal-complexes were also analyzed by SEM microscopy. The antimicrobial activity of the complexes was proved by the viability test.

Two 2D sliver complexes with a symmetric and noncentrosymmetric architecture controlled by the metal–ligand ratio

By controlling the metal–ligand ratio, we obtained two 2D sliver complexes from a symmetric to noncentrosymmetric architecture based on 2,2′-phosphinico-dibenzoic acid (H3L). The four groups around the phosphorus atom of the L3− ligand connect the Ag(i) ions through different coordination modes to form a noncentrosymmetric complex 2.

Synthesis, characterization and coordination properties of 2-(2′-(methylseleno)phenyl)benzimidazole

2-(2′-(methylseleno)phenyl)benzimidazole (1) was synthesized from 2-(methylseleno)benzaldehyde and 1,2-diaminobenzene in presence of acetic acid as a catalyst. The reaction of 1 with Pd(II) and Pt(II) afforded square planar complexes 4 and 5 with metal ligand ratio of 1:2. The structures of benzimidazole ligand 1 and complexes 4 and 5 were determined by single crystal X-ray diffraction. Crystal structures showed formation of cis isomers and the packing patterns showed formation of supramolecular structures via weak van der Waals interactions. As expected, the hard bases 2 and 3 did not react with soft acids Pd(II) and Pt(II).

Synthesis and X-ray crystal structures of N,N,N′,N′-tetraalkylpyridine-2,6-dithiocarboxamides (S-dapt) complexes of cobalt(II) and nickel(II)

Reactions of anhydrous CoX2 (X = Br−, SCN−) and Ni(ClO4)2 with N,N,N′,N′-tetraisobutylpyridine-2,6-dithiocarboxamides (S-dbpt), N,N,N′,N′-tetraisopropyl pyridine-2,6-dithiocarboxamides (S-dppt), and N,N,N′,N′-tetraethylpyridine-2,6-dithiocarboxamides (S-dept) lead to the formation of [Co(S-dbpt)Br2] (1), [Co(S-dppt)(SCN)2] (2), and [Ni(S-dept)2]·(ClO4)2·H2O (3), respectively. The X-ray crystal structures of the three S-dapt ligands and three complexes along with spectroscopic analyzes are presented. The molecular structure investigations of the S-dapt ligands show that the thiamide planes are twisted with respect to the pyridine ring, which is more in the case of phenyl groups. The structures of the Co(II) complexes reveal that an increase in steric crowding on the amide side arms of the ligands has no substantial effect on the geometry adopted by the corresponding complexes. The Co(II) gives only 1 : 1 five-coordinate, ion-paired complexes with a distorted square pyramidal geometry. Ni(II), on the other hand, prefers an octahedral geometry with 1 : 2 metal–ligand ratio. The coordination behavior of S-dapt has been compared to the analogous oxo(O-daap) ligands. Lesser propensity of S atom to get involved in H-bonding interactions ensures an S-N-S type of tridentate coordination by S-dapt.

Platinum and palladium complexes with 5-methyl-5-(2-pyridyl)-2,4-imidazolidenedione: Synthesis, crystal and molecular structure, theoretical study, and pharmacological investigation

The reaction of K2[PtCl4] and K2[PtCl6] with 5-methyl-5-(2-pyridyl)-2,4-imidazolidenedione (L) proceeded with the deprotonation of L forming Pt(II) and Pt(IV) complexes, K[PtCl2(N,N-L)] (1) and K[PtCl4(N,N-L)] (2), respectively. Within several weeks in DMSO/CH3OH solution of both complexes 1 and 2 the crystalline platinum(II) complex, PtCl(N,N-L)(DMSO) (3), was obtained, corresponded to a substitution reaction (on 1 and 2) and unanticipated reduction (on 2). The nature of the reducing agent is unknown. Single crystal X-ray diffraction analysis proved bidentate N-coordinated fashion and square planar arrangement for L and 3, respectively. The quantum chemical calculations supported the crystal packing findings in which intermolecular classical and non-classical hydrogen bonds was found. The reaction of L with K2[PdCl4] and PdCl2 gave the same complex of palladium(II) with 2:1 ligand–metal ratio, Pd(N,N-L)2 (4). DFT studies showed the intramolecular hydrogen bonding has significant effect on the stabilization of trans isomer for this complex. Antibacterial studies against six bacterial strains showed main compounds L, 3, and 4 represent activity with low levels of inhibitory potency. In vitro cytotoxicity studies in MCF-7 and A-549 tumor cell lines on 3 were in accordance with the reported data, the substitution of one chlorido ligand with DMSO molecule highly inactivates in vitro antitumor activity.

Synthesis, Characterization, and Electrochemical Behaviour of Cobalt(II) and Nickel(II) Complexes with N2O2 Chelating Ligand 4,4′-(Biphenyl-4,4′-diyldinitrilo)dipentan-2-one

4,4′-Diaminobiphenyl reacts with 2,4-pentanedione in absolute ethanol in a molar ratio 1 : 2 to form mainly the product of [1 + 2] condensation, 4,4′-(biphenyl-4,4′-diyldinitrilo)dipentan-2-one (H2L). The Schiff base was used as tetradentate chelating ligand to coordinate CoII and NiII chlorides leading to complexes where the ratio of metal ligand was found to be 2 : 1 or 2 : 2. All the synthesized products were characterized by elemental analysis, infrared, electronic, and mass spectroscopy, 1H NMR, and DSC. The electrochemical behaviour of the ligand and its complexes in DMF is also investigated.

Synthesis, Physico-chemical, Spectral and Hypoglycemic Activity of Samarium Complex of Glimepiride, An Oral Antidiabetic Drug

This paper deals with the synthesis and characterization of a glimepiride-samarium complex a rare earth's metal. Glimepiride is an oral hypoglycemic agent. The conductometric titrations were conducted using monovariation method which shows the ligand metal ratio as 2:1. Molar conductance value indicate that complex is non-ionic in nature. Analytical results agree to the molecular formula (C 24 H 34 N 4 O 5 S) 2 Sm.4H 2 O. Rare earth's element Sm shows the high coordination sites. The structure of the complex was assigned as hexagonal in which ligand moleculas joining the central Sm(III) atom with nH 2 O molecules. Infrared spectral studies have supported coordination of sulphonyl oxygen on one side and enolic oxygen attached from other side and four water molecule attached by four co-ordination sides with the samarium ion. Mass spectral and nuclear magnetic resonance studies of the complex proposed structure of the complex on the basis of analytical data.

Synthesis and semi-empirical sparkle PM6 study of substituted dithiophosphoric compounds of gadolinium(III)

Seven gadolinium(III) derivatives containing dialkyl and alkylene dithiophosphate chelating ligands [S2P(OR)2]3·2CH3CN (R = Et, n-Pr, n-Bu and Ph) and [S2POR′O]3·2CH3CN (R′ = CH2CMe2CH2, CH2CEt2CH2 and CMe2CMe2) have been synthesized. The metal complexes have been characterized by elemental analyzes, molecular weight determinations, IR, and UV–Visible spectroscopy. Microanalytical data revealed a 1 : 3 metal–ligand ratio in all complexes. Geometries were fully optimized at the semi-empirical sparkle PM6 level of theory using MOPAC2009 and geometrical structures and electronic properties of the complexes have been evaluated. The optimized geometries were confirmed to be minima on the potential energy surfaces through frequency calculations. Absorption spectra of the complexes have been calculated using ORCA2.9 package utilizing the predicted optimized wave functions. Linear and nonlinear static optical susceptibilities for all complexes were calculated at the same level of theory. The polarizability invariants were, in general, well correlated with the molecular volume and the number of carbons within the alkyl moieties. The largest electric properties were exhibited by the phenyl dithiophosphate complex.

Reactant ratio-modulated entangled Cd(ii) coordination polymers based on rigid tripodal imidazole ligand and tetrabromoterephthalic acid: interpenetration, interdigitation and self-penetration

By adjusting the molar ratio of the reactant metal salt and ligands, three new entangled coordination polymers, [Cd(tib)(tbta)(H2O)]n (1) and [Cd(Htib)(tbta)·Htbta·2CH3OH]n (2) and [Cd2(tib)2(tbta)2(H2O)·10H2O]n (3) (tib = 1,3,5-tris(1-imidazolyl)benzene and H2tbta = tetrabromoterephthalic acid), have been prepared and structurally characterized by X-ray diffraction analyses. Complex 1 is a 2-fold interpenetrated three-dimensional (3D) 8-connected uninodal net with rare hex topology. Complex 2 presents a 2D 63-hcb network, which is interdigitated with each other to form the 3D supramolecular framework stabilized hydrogen bonds and halogen bonds. Interestingly, an unprecedented hydrogen-bonded [(Htbta)2(CH3OH)4] cluster was unmasked in the void of 2. Complex 3 is a complicated 3D self-penetrated framework with a point symbol of {4·6·8}{4·65·84}{66}, which can be seen as a pair of 2-fold interpenetrated networks by breaking bidentate-bridging tib ligand. The comparative study revealed that 1–3 are particularly sensitive to the metal–ligand ratio in this system. The thermal stabilities and photoluminescence behaviors of 1 and 2 were also discussed.

Synthesis, spectroscopic characterization, solid state d.c. electrical conductivity and biological studies of some lanthanide(III) chloride complexes with a heterocyclic Schiff base ligand

Condensation of 2-hydroxy-1-naphthaldehyde with 2-amino-3-carboxyethyl-4,5-dimethylthiophene in 1:1molar ratio, yielded a potentially tridentate Schiff base viz. 2-[N-(2′-hydroxy-1-naphthylidene)amino]-3-carboxyethyl-4,5-dimethylthiophene (HNAT). This ligand formed complexes with lanthanum(III), cerium(III), praseodymium(III), neodymium(III), samarium(III), europium(III) and gadolinium(III) chloride under well defined conditions. These complexes were characterized through elemental analysis, molar conductance, magnetic moment measurements, IR, UV–Vis, FAB mass and 1H NMR spectral studies. Analytical data showed that all the metal complexes exhibited 1:1 metal–ligand ratio. Molar conductance values adequately confirmed the non-electrolytic nature of the metal complexes. The proton NMR spectral observations supplement the IR spectral assignments. The spectral data revealed that the ligand acted as neutral tridentate, coordinating to the metal ion through azomethine nitrogen, ester carbonyl and naphtholate oxygen without deprotonation. The ligand and its lanthanum(III) chloride complex were subjected to XRD studies. The lanthanum(III) chloride complex has undergone a facile transesterification reaction. The solid state d.c. electrical conductivity of some selected complexes were measured as a function of temperature, indicating the semiconducting nature of the metal complexes. The antimicrobial activities were examined by disk diffusion method against some pathogenic bacterial and fungal species.

Catena-Poly[[silver(I)-μ-[9,10-bis(1H-benzimidazol-1-ylmethyl)anthracene]-κ2N3:N3′] bis(nitrato-κO)silver(I)

Yellow needle-shaped crystals of the title compound, {[Ag(C(30)H(22)N(4))][Ag(NO(3))(2)]}(n), were obtained by the reaction of AgNO(3) and 9,10-bis(benzimidazol-1-ylmethyl)anthracene (L) in a 2:1 ratio. The asymmetric unit consists of two Ag(I) cations, one half L ligand and one nitrate anion. One Ag(I) cation occupies a crystallographic inversion centre and links two N-atom donors of two distinct L ligands to form an infinite one-dimensional coordination polymer. The second Ag(I) cation lies on a crystallographic twofold axis and is coordinated by two O-atom donors of two nitrate anions to form an [Ag(NO(3))(2)](-) counter-ion. The polymeric chains are linked into a supramolecular framework via weak Ag···O [3.124 (5) Å] and Ag···π (2.982 Å) interactions (π is the centroid of an outer anthracene benzene ring). The π interactions contain two short Ag···C contacts [2.727 (6) and 2.765 (6) Å], which can be considered to define Ag-η(2)-anthracene bonding interactions. In comparison with a previously reported binuclear Ag(I) complex [Du, Hu, Zhang, Zeng & Bu (2008). CrystEngComm, 10, 1866-1874], this new one-dimensional coordination polymer was obtained by changing the metal-ligand ratio during the synthesis.