Sensing and photocatalytic properties of nanosized Cu(I)CN organotin supramolecular coordination polymer based on pyrazine

Orange prismatic crystals of the supramolecular coordination polymer (SCP) _∞³[Cu(CN)₂(Me₃Sn)(Pyz)], SCP 1 , were synthesized using a self‐assembly method under ambient conditions. Nanosized 1 was obtained using the same molar ratio in water by ultrasonic irradiation. SCP 1 was characterized using single‐crystal X‐ray diffraction, elemental analysis, thermal analysis and Fourier transform infrared spectroscopy. SCP 1 and its nanosized 1 particles were also examined using powder X‐ay diffraction and scanning electron microscopy. The luminescence emission of SCP 1 was studied as well as its use as a sensor for the detection of common organic solvents and metal ions. Also, the catalytic activities of nanosized 1 towards various organic dyes were investigated under ambient conditions, UV irradiation and ultrasonic irradiation. Nanosized 1 as a heterogeneous nanoparticle catalyst exhibits high catalytic activity for the degradation of eosin‐Y and acid blue dyes. The mechanism of degradation investigated using various scavenger techniques is proposed and discussed. The catalytic oxidation process is mainly caused by ?OH radicals.     

X-ray structure of host-guest nanosized organotin supramolecular coordination polymer based on cobalt cyanide and quinoxaline as an efficient catalyst for treatment of waste water

New host-guest supramolecular coordination polymer catalyst ³_∞[Co(μ²CN)₅(CN)(μ²-Me₃Sn)₂(Me₃Sn)(H₂O)(qox)], SCP1 (qox = quinoxaline) has been synthesized and characterized by single crystal X-ray diffraction, FT-IR, UV/Visible and fluorescence spectra, thermal and elemental analyses. The tin atoms act as bridges connecting the Co (CN)₆ building blocks. The structure of SCP1 exhibits an unusual self-coordinated host-guest 3D network with qox as guest molecule. Also, the nanosized1^\ was prepared under ultrasonic irradiation while the morphological features of both were examined by TEM and SEM. SCP1 and nanosized1^\ are used as heterogeneous catalysts for removal of toxic dyes under UV and ultrasonic irradiation. The results show high effectively decolorized of indigo carmine dye (IC) without generation of any hazardous wastes or byproducts. The reaction is first order with respect to IC, while the factors affecting the rate constant of the degradation reaction are investigated. Mineralization of IC was investigated by IR and UV spectra. The trapping experiments were carried out to determine the role of active species used for degradation of the dye. The activation parameters of the reaction have been estimated and a possible mechanism of degradation was proposed and discussed in detail.     

Structure and characterization of organotin bimetallic supramolecular coordination polymers based on copper cyanide building blocks and pyrazine or pyrazine-2-carboxylic acid as new promising anticancer agents

The supramolecular coordination polymers (SCP); _∞³[Cu (CN)₂(Me₃Sn)(pyz)], pyrazine-trimethyltin-bis (cyanide) copper^I SCP 1 , [Cu₂(CN)₃(Ph₃Sn)(pyz)], pyrazine-triphenyltin-tris (cyanide) dicopper^I SCP 3 and [Cu₂(CN)₄(Ph₃Sn)(Pyz2caH)₂], bis-pyrazine-2-carboxylic acid- triphenyltin-tetrakis (cyanide) dicopper^I SCP 4 and the coordination complex (CC), [Cu^II (Pyz2-ca)₂(H₂O)₂]; diaquo-bis-(pyrazine-2-carboxylato) copper^(II) complex: CC 2 , are synthesized by self-assembly method at ambient conditions. Single crystal X-ray structures of SCP 1 and CC 2 indicate the presence of Cu^I and Cu^II which adopt tetrahedral and octahedron geometry, respectively. The structures of SCP 3 and SCP 4 are solved by the density functional theory (DFT) calculations and spectroscopic methods. The Cu centers acquire triagonal plane, linear and tetrahedral geometry, respectively. The CN-R₃Sn-NC spacer and pyrazine or pyrazine-2-carboxylic acid ligands extend the structures to 3D-network. The tested compounds 1–4 are designed and synthesized to examine their effects on viability and proliferation of five human cancer cell lines. Also, they are tested for antioxidant activity using ABTS assay and rate erythrocyte hemolysis.     

An unprecedented 3-D supramolecular framework of {CuCN} coordination polymer based on anhydride: in situ formation of ligand by intramolecular dehydration

Hydrothermal reactions of K₄[Fe(CN)₆]?3H₂O with H₂bimdc (H₂bimdc = benzimidazole-5,6-dicarboxylic acid) afforded a coordination polymer (CP), [Cu(CN)(bimdca)] (1) (bimdca = benzimidazole-5,6-dicarboxylic anhydride), as the first example of the {CuCN}-based CP modified by anhydride. The polymer is characterized by elemental analysis, IR, TG, XRD, and single-crystal X-ray diffraction. In 1, horizontal and vertical parallel chains based on {Cu₂(CN)₄(bimdca)₂} dimer units crisscross resulting in a 2-D network with a (4⁴6²) topology, which is further connected to adjacent 2-D layers generating a 3-D supramolecular framework through intermolecular force between oxygens of anhydride. In addition, 1 exhibits interesting fluorescence and good degradation ability for MB under UV light.     

Mono‐ and tetranuclear copper(I) complexes with N‐heterocyclic chelating and triphenylphosphine ligands: Crystal structures,luminescent and heterogeneous catalytic properties

N‐heterocyclic chelating and triphenylphosphine ligands react with cuprous halide to form a variety of copper(I) complexes, namely, mononuclear [Cu(PBO)(PPh₃)Br]^.CH₂Cl₂ ( 1 ) and [Cu(PBM)(PPh₃)I] ( 2 ) (PBO = 2‐(2′‐Pyridyl)benzoxazole, PBM = 2‐(2′‐Pyridyl)benzimidazole, PPh₃ = triphenylphosphine) and tetranuclear [Cu₄(μ₂‐I)₂(μ₃‐I)₂(PPh₃)₄]^.2CH₂Cl₂ ( 3 ) have been synthesized and characterized. Complexes 1 and 2 are basically alike; both of them are mononuclear and four‐coordinated, possessing a slightly distorted trigonal pyramidal geometry. Complex 3 is tetranuclear and the coordination numbers of the two copper(I) atoms are three and four, Cu(1) forming an approximate trigonal planar coordination environment, while Cu(2) is a slightly distorted trigonal pyramidal geometry, resulting in a distorted chair‐like conformation. Complexes 1 and 2 are emissive in the solid state at ambient temperature, with the maxima at 552 and 602 nm, respectively, due to a MLCT excited state. Moreover, complex 3 manifests promising heterogeneous catalytic activities for the degradation of methylene blue (MB), with degradation efficiency of 99% under ambient light.     

In vitro and in vivo antitumor activity of novel 3D-organotin supramolecular coordination polymers based on CuCN and pyridine bases

Two novel organotin supramolecular coordination polymers (SCP), namely, ³_∞[Me₃SnCu(CN)₂·(EN)₂], 1 and ³_∞[Ph₃SnCu(CN)₂·(3-mpy)₂], 2 are obtained by the reactions of K₃[Cu(CN)₄], ethyl nicotinate (EN) or 3-methylpyridine (3-mpy) and Me₃SnCl or Ph₃SnCl in H₂O/acetonitrile solution at room temperature. 2D-layers are constructed via H-bonds between the parallel 1D-puckered chains which contain nanometer-sized [-CN(R₃Sn)NC-] spacers connecting the tetrahedral (T-4) copper sites. The network structures of 1 and 2 consist of infinite layers connected by interlayer H-bonds forming 3D-framworks. 2 is the first compound in this family containing the Ph₃Sn cation. The electronic absorption spectra of 1 and 2 reveal a broad band at 320 nm due to CT transition while the emission spectra exhibit high energy bands at 400-460 nm due to metal-centered (MC) transitions and low energy bands at 485-530 nm corresponding to MLCT. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the in vitro antitumor effects of the SCP 1 and 2 on human breast cancer cell line, ZR-75-1. Cell cycle analysis revealed that the SCP 1 and 2 induced apoptosis in ZR-75-1 breast cancer cell line through activating caspase-3. Moreover, in vivo model, the compound SCP 2 suppressed tumor growth developed mammary carcinoma by 52.3%. Taken together, our novel compounds selectivity exhibit specific in vivo and in vitro antitumor effects.     

Direct synthesis of CdS nanoparticles via simple one-pot calcination of new two-dimensional Cd(II) coordination polymer

Assembly of quinoxaline with Cd(II) in the presence of SCN^? anion produces a new coordination polymer [Cd(Quinoxaline)(SCN)₂(CH₃CN)] _n [Cd(Quinoxaline)₂(SCN)₂] _n (1) and is characterized by IR, ¹H NMR and ¹³C NMR spectroscopy. The single-crystal X-ray data of compound 1 show that this coordination polymer grows in two-dimensional supramolecular structure. In this polymer, the organic ligand chelate through its one nitrogen atom to cadmium(II) atom and thiocyanate anion acts as a bridge to two cadmium(II) atom in the chains. Also, nanoscale of CdS has been synthesized by calcination at 400, 500 and 600 °C under air atmosphere and characterized by scanning electron microscopy, X-ray powder diffraction and energy-dispersive X-ray. The thermal stability of compound 1 was studied by thermal gravimetric and differential thermal analyses.     

Structure and catalytic activity of host–guest coordination polymers constructed from copper(I) cyanide nets and 1,4-diaminobutane or 1,5-diaminopentane in the presence of water

The reaction of K₃[Cu(CN)₄] and 1,4-diaminobutane (DAB) or 1,5-diaminopentane (DAP) in the presence of Me₃SnCl affords two monometallic host–guest Cu(I) cyanide polymers: {[H₂DAB][Cu₄(CN)₆]·2H₂O}, 1, and{[H₂DAP][H₃O][Cu₄(CN)₇]·2H₂O}, 2, with exclusion of Me₃Sn⁺ cation. The products were characterized by physicochemical and spectroscopic methods. The structure of 1 consists of two-dimensional hexagonal sheets of (CuCN) _n which stack along the b-axis creating honeycomb-shaped channels capable of encapsulating the protonated DAB and water molecules. The structure of 2 consists of a three-dimensional network of [Cu₄(CN)₇] with large cavities that include H₂DAP and water molecules. The rhombic minicycle [Cu₂(μ-CN)₂] fragments represent the basic building blocks of the network structure of 2. The structures of these compounds are stabilized by hydrogen bonding. The SCP 1 and SCP 2 exhibit good catalytic and photocatalytic activities for the degradation of methylene blue (MB) in the presence of H₂O₂. The efficiency of recycled SCP 1 and SCP 2 and the mechanism of degradation of MB dye were also investigated.     

Three Dicyanidometallate(I)‐based Complexes Incorporating Hydrogen‐bonding, π–π Packing and d10–d10 Interactions with Auxiliary 2,2′‐Bipyridyl‐like Ligands

To investigate the influence of the non‐covalent interactions, such as hydrogen‐bonding, π–π packing and d¹⁰–d¹⁰ interactions in the supramolecular motifs, three cyanido‐bridged heterobimetallic discrete complexes {Mn(bipy)₂(H₂O)[Ag(CN)₂]}[Ag(CN)₂] ( 1 ), {Mn(phen)₂(H₂O)[Au(CN)₂]}₂[Au(CN)₂]₂ · 4H₂O ( 2 ), and {Cd(bipy)₂(H₂O)[Au(CN)₂]}[Au(CN)₂] ( 3 ) (bipy = 2,2′‐bipyridine, and phen = 1,10‐phenanthroline), which are based on dicyanidometallate(I) groups with 1:2 stoichiometry of metal ions and 2,2′‐bipyridyl‐like co‐ligands were synthesized and structurally characterized. In compound 1 , hydrogen bonding and π–π interactions governed the supramolecular contacts. In compound 2 , the incorporation of aurophilic, hydrogen bonding and π–π interactions result in a 3D supramolecular network. In compound 3 , hydrogen bonding and π–π stacking interactions result in a 2D supramolecular layer. In the three complexes, hydrogen‐bonding, π–π packing and/or d¹⁰–d¹⁰ interactions can play important roles in increasing the dimensionality of supramolecular assemblies.     

Formation of [FeW12O40]5− under hydrothermal conditions: syntheses,crystal structures,and characterization of [Fe(2,2′-bipy)3]2[HFeW12O40] · 5H2O and (4,4′-H2bipy)6(Hpy)2(H3O)[FeW12O40]3 · 11H2O

Two supramolecular compounds based on tungstoferrate [FeW₁₂O₄₀]^5?, [Fe^II(2,2′-bipy)₃]₂[HFeW₁₂O₄₀] · 5H₂O (1), and [Hpy]₂[4,4′-H₂bipy]₆(H₃O)[FeW₁₂O₄₀]₃ · 11H₂O (2) (py = pyridine, bipy = bipyridine) were synthesized hydrothermally and characterized structurally. The hydrogen bonds between polyoxoanions and water and the edge-to-face π–π interaction between [Fe^II(2,2′-bipy)₃]²⁺ with a shortest C–C distance of 3.513 Å are the main forces to construct the 3-D architecture of 1. In 2, a 3-D supramolecular architecture is assembled by the tungstoferrate anions, protonated 4,4′-bipy cations, and water through hydrogen bonding. The variable-temperature magnetic susceptibilities indicate that 1 is paramagnetic with μ _eff corresponding to one Fe(III) with spin-only contribution, showing that Fe in the coordination cations has a +II oxidation number and low spin state.     

Fe/Zn double metal cyanide catalyzed ring-opening polymerization of propylene oxide: 2. Characterization of active structure of double metal cyanide catalysts

Double metal cyanide (DMC) complexes based on Zn₃[Fe(CN)₆]₂ were synthesized using different molar ratios of ZnCl₂ to K₃[Fe(CN)₆] and special complexing agents. IR spectroscopy, electron spectroscopy for chemical analysis, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and other analytical techniques were employed to characterize these catalysts. The morphology and structure of these DMC catalysts were attributed to the different complexing agents as well as to the different molar ratios of ZnCl₂ to K₃[Fe(CN)₆]. In addition, the catalytic activity was strongly correlated with the morphology and noncrystalline content of DMC catalysts. High-activity catalysts could be prepared by controlling the structure of DMC catalysts by incorporating complexing agents. The active species of DMC catalysts for ring-opening polymerization are Zn²⁺, [Fe(CN)₆]^3–, Cl^–, and the compound of their ligands.     

Highly stable polyoxometalate‐resorcin[4]arene‐based inorganic‐organic complexes for catalytic oxidation desulfurization

Self‐assembly of a resorcin[4]arene‐based ligand (TMR4A) with metal salts and H₃PMo₁₂O₄₀·xH₂O offers two isostructural complexes, namely, [Ni₂Cl(TMR4A)₂(CH₃CN)₂]·[PMo₁₂O₄₀]·4CH₃CN ( 1 ) and [Co₂Cl(TMR4A)₂(CH₃CN)₂]·[PMo₁₂O₄₀]·4CH₃CN ( 2 ). In both 1 and 2 , one Cl^? anion bridges two metal cations, and each metal cation is further chelated by four 2‐mercaptopyridine N‐oxide groups of one TMR4A, producing a [M₂Cl(TMR4A)₂]³⁺ dimer (M = Ni or Co). The negative [PMo₁₂O₄₀]^3? as a counter‐anion balances the positive charge. Markedly, 1 and 2 exhibit high stability in aqueous solutions with different pH values and in organic solvents. Remarkably, the efficient heterogeneous catalytic capability for oxidative desulfurization was studied by suing 1 and 2 as recycled catalysts. Moreover, the electrochemical behaviors of the two compounds were discussed as well.     

Selective Detection of Methomyl Pesticide by a Catalytic Chemosensing Assay

The catalytic chemosensing assay (CCA), a new indicator displacement assay, was developed for selective detection of methomyl, a highly toxic pesticide. Trimetallic complex {[Fe^II(dmbpy)(CN)₄]-[Pt^II(DMSO)Cl]₂-[Ru^II(bpy)₂(CN)₂]} ( 1 ; dmbpy=4,4′-dimethyl-2,2′-bipyridine, bpy=2,2′-bipyridine) was synthesized as a task-specific catalyst to initially reduce and degrade methomyl to CH₃SH/CH₃NH₂/CH₃CN/CO₂. The thus-produced CH₃SH interacts with the trimetallic complex to displace the cis-[Ru^II(bpy)₂(CN)₂] luminophore for monitoring. Other pesticides, including organophosphates and similar carbamate pesticides, remained intact under the same catalytic conditions; a selective sensing signal is only activated when 1 recognizes methomyl. Furthermore, 1 can be applied to detect methomyl in real water samples. In the luminescent mode of the assay, the method detection limit (MDL) of 1 for methomyl (LD₅₀=17 mg kg⁻¹) was 1.12 mg L⁻¹.     

Supramolecular framework adducts constructed of hexamethylenetetramine,aquated alkali metal cationic clusters,and hexacyanoferrates(II/III)

The reaction of alkali metal hexacyanoferrate(II/III) with (CH₂)₆N₄ (hexamethylenetetramine, abbreviated HMT) in an acidic medium yielded crystalline compounds of stoichiometries HK₂[Fe¹¹¹(CN)₆]·2HMT·4H₂O, H₂K₂[Fe¹¹(CN)₆]·2HMT·4H₂O, and HNa₂[Fe¹¹¹(CN)₆]· 2HMT·5H₂O. Their crystal structures are based on a packing of three molecular components: neutral and/orprotonated HMT, hexacyanoferrate, and an alkali metal ion-water cluster. The resulting three-dimensional supramolecular framework is constructed from the coordination of the alkali metal ion by aqua ligands as well as [Fe(CN)₆]{n–} and HMT units, and further stabilization is achieved by hydrogen bonding between water molecules and the noncoordinated nitrogen atoms of HMT and hexacyanoferrate.     

Hydrogen-bonded assemblies of a new polyoxometalate-based 3-D supramolecular architecture

A new hydrogen-bonded 3-D supramolecular architecture [Ni(2,2′-bpy)₃]_1.5[AsW^VI ₁₀W^V ₂O₄₀Ni(2,2′-bpy)₂(H₂O)]·0.5H₂O (2,2′-bpy?=?2,2′-bipyridine) (1) has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis, PXRD, elemental analysis, XPS, and IR spectrum. Compound 1 exhibits photocatalytic activity for methylene blue degradation under visible-light irradiation and shows good stability toward visible-light photocatalysis. Luminescence of 1 is also reported.     

Crystal structure of a new modification of the cyanide-bridged copper(I) coordination compound [CuCN(bpy)] n

The hydrothermal reaction of CuCN and bpy in the presence of an octahedral cluster complex K_2.75Cs_1.25[Re₆Se₈(CN)₄(OH)₂]·H₂O affords a cyanide-bridged chain coordination polymer [CuCN(bpy)] _n (bpy — 2,2′-bipyridyl) (1). The structure is monoclinic, space group C2/c, a = 22.848(2) Å, b = 7.7182(8) Å, c = 14.4331(13) Å, β = 127.805(2)°, V = 2010.9(3) ų, Z = 8, d _x = 1.623 g/cm³. Copper atoms have a tetrahedral coordination environment formed by N atoms of the bpy molecule as well as N and C atoms of ambidentate bridging CN ligands.     

Nanoscale ensembles using building blocks inspired by the [FeFe]-hydrogenase active site

The hydrogenase model [Fe₂(S₂C₃H₆)(CN)₂(CO)₄]²⁻ was employed as a molecular tecton for the construction of supramolecular aggregates. IR spectroscopy indicated that cyanide bridged aggregates are formed when [Fe₂(S₂C₃H₆)(CN)₂(CO)₄]²⁻ was treated with Lewis acids such as Zn(tetraphenylporphyrinate), [Cu(NCMe)(2,2′-bipyridine)]PF₆ and [Cu(NCMe)₄]PF₆. Condensation of [Fe₂(S₂C₃H₆)(CN)₂(CO)₄]²⁻ with the tritopic Lewis acid [Cp¹Rh]²⁺ afforded the novel expanded tetrahedron cage, {[Fe₂(S₂C₃H₆)(CN)₂(CO)₄]₆[Cp¹Rh]₄}⁴⁻. The tetrahedron cage was characterized crystallographically as the PPN salt.     

Dynamic Equilibria in Solvent‐Mediated Anion,Cation and Ligand Exchange in Transition‐Metal Coordination Polymers: Solid‐State Transfer or Recrystallisation?

The solution properties of a series of transition‐metal–ligand coordination polymers [ML(X)_n]_∞ [M=Ag^I, Zn^II, Hg^II and Cd^II; L=4,4′‐bipyridine (4,4′‐bipy), pyrazine (pyz), 3,4′‐bipyridine (3,4′‐bipy), 4‐(10‐(pyridin‐4‐yl)anthracen‐9‐yl)pyridine (anbp); X=NO₃^?, CH₃COO^?, CF₃SO₃^?, Cl^?, BF₄^?; n=1 or 2] in the presence of competing anions, metal cations and ligands have been investigated systematically. Providing that the solubility of the starting complex is sufficiently high, all the components of the coordination polymer, namely the anion, the cation and the ligand, can be exchanged on contact with a solution phase of a competing component. The solubility of coordination polymers is a key factor in the analysis of their reactivity and this solubility depends strongly on the physical properties of the solvent and on its ability to bind metal cations constituting the backbone of the coordination polymer. The degree of reversibility of these solvent‐induced anion‐exchange transformations is determined by the ratio of the solubility product constants for the starting and resultant complexes, which in turn depend upon the choice of solvent and the temperature. The extent of anion exchange is controlled effectively by the ratio of the concentrations of incoming ions to outgoing ions in the liquid phase and the solvation of various constituent components comprising the coordination polymer. These observations can be rationalised in terms of a dynamic equilibrium of ion exchange reactions coupled with Ostwald ripening of crystalline products. The single‐crystal X‐ray structures of [Ag(pyz)ClO₄]_∞ ( 1 ), {[Ag(4,4′‐bipy)(CF₃SO₃)] ? CH₃CN}_∞ ( 2 ), {[Ag(4,4′‐bipy)(CH₃CN)]ClO₄ ? 0.5 CH₃CN}_∞ ( 3 ), metal‐free anbp ( 4 ), [Ag(anbp)NO₃(H₂O)]_∞ ( 5 ), {[Cd(4,4′‐bipy)₂(H₂O)₂](NO₃)₂ ? 4 H₂O}_∞ ( 6 ) and {[Zn(4,4′‐bipy)SO₄(H₂O)₃] ? 2 H₂O}_∞ ( 7 ) are reported.     

A three‐dimensional cyanide‐bridged heterometallic coordination polymer: poly[[diacetonitrilediaqua[μ2‐3,6‐bis(pyridin‐2‐yl)‐1,2,4,5‐tetrazine‐κ4N1,N6:N3,N4]tetra‐μ‐cyanido‐tetracyanidodimanganese(II)molybdate(IV)] dihydrate]

A metal coordination polymer, {[Mn₂Mo(CN)₈(C₁₂H₈N₆)(CH₃CN)₂(H₂O)₂]·2H₂O}_n, has been synthesized by the reaction of Mn(ClO₄)₂·6H₂O with 3,6‐bis(pyridin‐2‐yl)‐1,2,4,5‐tetrazine (bptz) and (Bu₃N)₃[Mo(CN)₈] at room temperature. The polymer was characterized by IR spectroscopy, elemental analysis and X‐ray diffraction, and the magnetic properties were also investigated. The X‐ray diffraction analysis reveals that the compound is a new three‐dimensional coordination polymer with a PtS‐type network. Magnetic investigation shows antiferromagnetic coupling between adjacent Mn²⁺ cations.     

An iron(III) complex salt containing pyrazole as both ligand and counter‐ion: bis(1H‐pyrazol‐2‐ium) pentacyanido(1H‐pyrazole‐κN2)ferrate(III)

The title compound, (C₃H₅N₂)₂[Fe(CN)₅(C₃H₄N₂)], is composed of a mononuclear [Fe(CN)₅(pyrazole)]²⁻ dianion and two 1H‐pyrazol‐2‐ium cations. A three‐dimensional supramolecular network is formed through a rich scheme of N—H...N hydrogen bonds and C—H...π interactions among the cations and anions.