Pseudohalide‐directed Assembly of Two Zinc(II) Coordination Polymers with a 3,4‐Bis(3‐pyridyl)‐5‐(4‐pyridyl)‐1,2,4‐triazole Tecton

The zinc(II) pseudohalide complexes {[Zn(L³³⁴)(SCN)₂(H₂O)](H₂O)₂}_n ( 1 ) and [Zn(L³³⁴)(dca)₂]_n ( 2 ) were synthesized and characterized using the ligand 3,4‐bis(3‐pyridyl)‐5‐(4‐pyridyl)‐1,2,4‐triazole (L³³⁴) and ZnCl₂ in presence of thiocyanate (SCN^–) and dicynamide [dca, N(CN)₂^–] respectively. Single‐crystal X‐ray structural analysis revealed that the central Zn^II atoms in both complexes have similar octahedral arrangement. Compound 1 has a 2D sheet structure bridged by bidentate L³³⁴ and double μ_N,S‐thiocyanate anions, whereas complex 2 , incorporating with two monodentate dicynamide anions, displays a two‐dimensional coordination framework bridged by tetradentate L³³⁴ ligand. Structural analysis demonstrated that the influence of pseudohalide anions plays an important role in determining the resultant structure. Both complexes were characterized by IR spectroscopy, microanalysis, and powder X‐ray diffraction techniques. In addition, the solid fluorescence and thermal stability properties of both complexes were investigated.     

Anion Effects on the Formation of Silver(I) Complexes with the Flexible Ligand 4,4′‐Bis(1,2,4‐triazol‐1‐ylmethyl)biphenyl

The reaction of 4,4′‐bis(1,2,4‐triazol‐1‐ylmethyl)biphenyl (btmb) with silver(I) salts of BF₄^–, NO₃^– and N₃^– led to the formation of four new silver(I) coordination polymers {[Ag(btmb)]BF₄}_n ( 1 ), {[Ag₂(btmb)₃](NO₃)₂(H₂O)₅}_n ( 2 ), [Ag₂(btmb)(N₃)₂]_n ( 3 ), and [Ag(btmb)(N₃)]_n ( 4 ). Their coordination number varies from 2 (in 1 ) to 3 (in 2 ), 4 (in 3 ), and 5 (in 4 ). Different from the single chain structure of 1 , complex 2 displays a 1D ladder‐like double chain framework, whereas complex 3 exhibits a 2D layered architecture. Complex 4 has the same anion as complex 3 but shows a different metal‐to‐ligand ratio and a 1D double‐zigzag chain structure. Both 3 and 4 have Ag ··· Ag argentophilic interactions. The ligand btmb adopts both cis or trans configuration in the studied complexes. A trans‐ or cis‐btmb ligand link silver ions with Ag ··· Ag distances of ≈?18 and 13 Å, respectively. BF₄^– and NO₃^– are non‐coordinating anions in 1 and 2 . N₃^– is the bridging anion in 3 (1,3‐bridging fashion) and 4 (1,1‐bridging fashion). These findings suggest that the coordination numbers around the Ag^I ion correlate to the coordination abilities of anions and the btmb to silver ratio. In addition, the influence of anions on thermal stability were also investigated. This work is a good example that nicely supports the less explored field of anion‐dependent structures of complexes with non‐pyridyl ligands.     

Synthesis,Crystal Structures,and Properties of Copper(II), Zinc(II), and Cadmium(II) Coordination Polymers Based on 5‐Nitro‐isophthalate and 1,2‐(2‐Pyridyl)‐1,2,4‐triazole

Three coordination polymers, namely {[Cu(5‐nipa)(L²²)](H₂O)₂}_n ( 1 ), [Zn(5‐nipa)(L²²)(H₂O)]_n ( 2 ), and {[Cd₂(5‐nipa)₂(L²²)(H₂O)₃](H₂O)_3.6}_n ( 3 ), were prepared under similar synthetic method based on 1,2‐(2‐pyridyl)‐1,2,4‐triazole (L²²) and ancillary ligand 5‐nitro‐isophthalic acid (5‐H₂nipa) with Cu^II, Zn^II, and Cd^II perchlorate, respectively. All the complexes were characterized by IR spectroscopy, elemental analysis, and powder X‐ray diffraction (PXRD) patterns. Single‐crystal X‐ray diffraction indicates that complexes 1 and 2 show similar 1D chain structures, whereas complex 3 exhibits the 2D coordination network with hcb topology. The central metal atoms show distinct coordination arrangements ranging from distorted square‐pyramid for Cu^II in 1 , octahedron for Zn^II in 2 , to pentagonal‐bipyramid for Cd^II in 3 . The L²² ligand adopts the same (η³,μ₂) coordination fashion in complexes 1 – 3 , while the carboxyl groups of co‐ligand 5‐nipa^2– adopt monodentate fashion in 1 and 2 and bidentate chelating mode in 3 . These results indicate that the choice of metal ions exerts a significant influence on governing the target complexes. Furthermore, thermal stabilities of complexes 1 – 3 and photoluminescent properties of 2 and 3 were also studied in the solid state.     

Poly[μ2‐(N‐hydroxypyridine‐2‐carboxamidine)‐μ2‐nitrato‐silver(I)]

In the title complex, [Ag(NO₃)(C₆H₇N₃O)]_n or [Ag(NO₃)(pyaoxH₂)] (pyaoxH₂ is N‐hydroxypyridine‐2‐carboxamidine), the Ag⁺ ion is bridged by the pyaoxH₂ ligands and nitrate anions, giving rise to a two‐dimensional molecular structure. Each pyaoxH₂ ligand coordinates to two Ag⁺ ions using its pyridyl and carboxamidine N atoms, and the OH and the NH₂ groups are uncoordinated. Each nitrate anion uses two O atoms to coordinate to two Ag⁺ ions. The Ag...Ag separation via the pyaoxH₂ bridge is 2.869 (1) Å, markedly shorter than that of 6.452 (1) Åvia the nitrate bridge. The two‐dimensional structure is fishscale‐like, and can be described as pyaoxH₂‐bridged Ag₂ nodes that are further linked by nitrate anions. Hydrogen bonding between the amidine groups and the nitrate O atoms connects adjacent layers into a three‐dimensional network.     

A novel three‐dimensional AgI coordination polymer based on mixed naphthalene‐1,5‐disulfonate and aminoacetate ligands

The three‐dimensional coordination polymer poly[[bis(μ₃‐2‐aminoacetato)di‐μ‐aqua‐μ₃‐(naphthalene‐1,5‐disulfonato)‐hexasilver(I)] dihydrate], {[Ag₆(C₁₀H₆O₆S₂)(C₂H₄NO₂)₄(H₂O)₂]·2H₂O}_n, based on mixed naphthalene‐1,5‐disulfonate (L1) and 2‐aminoacetate (L2) ligands, contains two Ag^I centres (Ag1 and Ag4) in general positions, and another two (Ag2 and Ag3) on inversion centres. Ag1 is five‐coordinated by three O atoms from one L1 anion, one L2 anion and one water molecule, one N atom from one L2 anion and one Ag^I cation in a distorted trigonal–bipyramidal coordination geometry. Ag2 is surrounded by four O atoms from two L2 anions and two water molecules, and two Ag^I cations in a slightly octahedral coordination geometry. Ag3 is four‐coordinated by two O atoms from two L2 anions and two Ag^I cations in a slightly distorted square geometry, while Ag4 is also four‐coordinated by two O atoms from one L1 and one L2 ligand, one N atom from another L2 anion, and one Ag^I cation, exhibiting a distorted tetrahedral coordination geometry. In the crystal structure, there are two one‐dimensional chains nearly perpendicular to one another (interchain angle = 87.0°). The chains are connected by water molecules to give a two‐dimensional layer, and the layers are further bridged by L1 anions to generate a novel three‐dimensional framework. Moreover, hydrogen‐bonding interactions consolidate the network.     

Synthesis,Characterization, and Photoluminescence Properties of Silver(I) Metal‐Organic Polymers with Nanochannels Based on 2‐Sulfoterephthalic Acid and Di(pyridin‐2‐yl)amine Ligands

Two new silver(I) 3D coordination polymers, namely [Ag₃(2‐stp)(dpa)]_n ( 1 ) and {[Ag₂(2‐stp)(H₂O)]?Hdpa}_n ( 2 ) (2‐NaH₂stp=sodium 2,5‐dicarboxysulfonate, dpa=di(pyridine‐2‐yl)amine) were synthesized. The complexes were characterized by elemental analysis, FT‐IR spectra, thermogravimetric analyses (TGA), and single‐crystal X‐ray diffraction. In complex 1 , three neighboring Ag ions are bridged by N‐ and O‐atom, forming a 3D coordination network. The molecular structure of 2 is cation? anion species, forming 3D host? guest supramolecular network with the [Hdpa]⁺ cations encapsulated in the nanochannels. The photoluminescence properties of the complexes were also investigated in the solid state at room temperature.     

Syntheses,Crystal Structures,and Photocatalytic Activities of Three Copper Coordination Polymers Based on Bis(1H‐imidazol‐4‐yl)benzene/3‐(2‐Pyridyl)pyrazole

Three copper(II) coordination polymers (CuCPs), namely, [Cu_0.5(1,4‐bib)(SO₄)_0.5]_n ( 1 ), {[Cu(1,3‐bib)₂(H₂O)] · SO₄ · H₂O}_n ( 2 ), and [Cu(bpz)(SO₄)_0.5]_n ( 3 ), were assembled from the reaction of three N‐donors [1,4‐bib = 1,4‐bis(1H‐imidazol‐4‐yl)benzene, 1,3‐bib = 1,3‐bis(1H‐imidazol‐4‐yl)benzene, and Hbpz = 3‐(2‐pyridyl)pyrazole] with copper sulfate under hydrothermal conditions. Their structures were determined by single‐crystal X‐ray diffraction analyses and further characterized by elemental analyses (EA), IR spectroscopy, powder X‐ray diffraction (PXRD), and thermogravimetric analyses (TGA). Structure analyses reveal that complex 1 is a 3D 6‐connected {4¹² · 6³}‐ pcu net, complex 2 is a fourfold 3D 4‐connected 6⁶‐ dia net, whereas complex 3 is a 1D snake‐like chain, which further expanded into 3D supramolecular architectures with the help of C–H ··· O hydrogen bonds. Moreover, the photocatalytic tests demonstrate that the obtained CuCPs are photocatalysts in the degradation of MB with the efficiency is 86.4 % for 1 , 75.3 % for 2 , and 91.3 % for 3 after 2 h, respectively.     

Copper(II) Complexes with N‐(9‐anthracenyl)‐N′‐(3‐pyridyl)urea (L) and a Derivative of L: Synthesis,Structure, and Fluorescent Properties

Three copper(II) complexes, [Cu₂(OAc)₄L₂] · 2CH₃OH ( 1 ), [CuBr₂L′₂(CH₃OH)] · CH₃OH ( 2a ), and [CuBr₂L′₂(DMSO)] · 0.5CH₃OH ( 2b ) {L = N‐(9‐anthracenyl)‐N′‐(3‐pyridyl)urea and L′ = N‐[10‐(10‐methoxy‐anthronyl)]‐N′‐(3‐pyridyl)urea} have been synthesized by the reaction of L with the corresponding copper(II) salts. Complex 1 shows a dinuclear structure with a conventional “paddlewheel” motif, in which four acetate units bridge the two Cu^II ions. In complexes 2a and 2b , the anthracenyl ligand L has been converted to an anthronyl derivative L′, and the central metal ion exhibits a distorted square pyramidal arrangement, with two pyridyl nitrogen atoms and two bromide ions defining the basal plane and the apical position is occupied by a solvent molecule (CH₃OH in 2a and DMSO in 2b ).     

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(C₃₀H₂₂N₄)][Ag(NO₃)₂]}_n, were obtained by the reaction of AgNO₃ 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(NO₃)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–η²‐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.     

Co‐MOFs Containing Flexible α,ω‐Alkane‐dicarboxylates and Bis(imidazole) Ligands: Synthesis,Structure, and Properties

Three structurally related flexible bis(imidazole) ligands reacted with Co(NO₃)₂ · 6H₂O and succinic acid (L₁) to yield three new metal‐organic frameworks {[Co(L₁)(L₂)] · (H₂O)}_n ( 1 ) [L₂ = 2‐bis(imidazol‐1‐yl)ethane], {[Co(L₁)(L₃)](H₂O)}_n ( 2 ) [L₃ = 1,4‐bis(imidazol‐1‐yl) butane], and {[Co(L₁)(L₄)] · (H₂O)}_n ( 3 ) [L₄ = 1,4‐bis(2‐methyl‐imidazol‐1‐yl)butane], respectively. These complexes were synthesized under solvothermal conditions and characterized by elemental analysis, IR spectroscopy, single‐crystal and powder X‐ray diffraction, as well as thermal analyses. Interestingly, the ligands in these complexes exhibit different conformations and further cause three different configurations. Complex 1 shows a three‐dimensional (3D) framework, which is connected by two‐dimensional (2D) layer structures through hydrogen bonds. Complex 2 is a diamond structure with threefold interpenetration. Complex 3 is a 3D framework linked by hydrogen bonds like complex 1 .     

Syntheses,Structures, and Luminescence of Metal(II) Coordination Polymers based on Flexible 1,1′‐(1,4‐Butanediyl)bis(imidazole) and Tetrachlorobenzene‐1,4‐dicarboxylate Ligands

The coordination polymers, {[Co(bbim)₂(H₂O)₂](tcbdc) · 2H₂O}_n ( 1 ), {[Ni(tcbdc)(bbim)(H₂O)₂] · 2DMF}_n ( 2 ), and {[Cu₂(tcbdc)₂(bbim)₄] · 4H₂O}_n ( 3 ) [bbim = 1,1′‐(1,4‐butanediyl)bis(imidazole) and tcbdc^2– = tetrachlorobenzene‐1,4‐dicarboxylate] were synthesized and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis, luminescence, and single‐crystal X‐ray diffraction analysis. Complex 1 has a double‐stranded chain structure through doubly bridged [Co(bbim)₂] units. Complex 2 exhibits two‐dimensional square grid, whereas complex 3 has a three‐dimensional porous network structure with an unprecedented 4⁴ · 6¹¹ topological structure through interpenetrating square grid. The water molecules in complex 3 occupy the vacancy through three kinds of hydrogen bond interactions. Upon excitation at 370 nm, complexes 1 – 3 present solid‐state luminescence at room temperature.     

Two different one‐dimensional supramolecular chains formed from the reaction of 2‐[1‐(pyridin‐4‐ylmethyl)‐1H‐benzimidazol‐2‐yl]quinoline with two different precursors,Co(NO3)2 and CoCl2

Two different one‐dimensional supramolecular chains with Co^II cations have been synthesized based on the semi‐rigid ligand 2‐[1‐(pyridin‐4‐ylmethyl)‐1H‐benzimidazol‐2‐yl]quinoline (L), obtained by condensation of 2‐(1H‐benzimidazol‐2‐yl)quinoline and 4‐(chloromethyl)pyridine hydrochloride. Starting from different Co^II salts, two new compounds have been obtained, viz. catena‐poly[[[dinitratocobalt(II)]‐μ‐2‐[1‐(pyridin‐4‐ylmethyl)‐1H‐benzimidazol‐2‐yl]quinoline] dichloromethane monosolvate acetonitrile monosolvate], {[Co(NO₃)₂(C₂₂H₁₆N₄)]·CH₂Cl₂·CH₃CN}_n, (I) and catena‐poly[[[dichloridocobalt(II)]‐μ‐2‐[1‐(pyridin‐4‐ylmethyl)‐1H‐benzimidazol‐2‐yl]quinoline] methanol disolvate], {[CoCl₂(C₂₂H₁₆N₄)]·2CH₃OH}_n, (II). In (I), the Co^II centres lie in a distorted octahedral [CoN₃O₃] coordination environment. {Co(NO₃)₂L}_n units form one‐dimensional helical chains, where the L ligand has different directions of twist. The helical chains stack together via interchain π–π interactions to form a two‐dimensional sheet, and another type of π–π interaction further connects neighbouring sheets into a three‐dimensional framework with hexagonal channels, in which the acetonitrile molecules and disordered dichloromethane molecules are located. In (II), the Co^II centres lie in a distorted trigonal–bipyramidal [CoCl₂N₃] coordination environment. {CoCl₂L}_n units form one‐dimensional chains. The chains interact via C—H...π and C—H...Cl interactions. The result is that two‐dimensional sheets are generated, which are further linked into a three‐dimensional framework via interlayer C—H...Cl interactions. When viewed down the crystallographic b axis, the methanol solvent molecules are located in an orderly manner in wave‐like channels.     

A stair‐like two‐dimensional silver(I) coordination polymer of N′‐(3‐cyanobenzylidene)nicotinohydrazide

The structure of the title compound, poly[[[μ₃‐N′‐(3‐cyanobenzylidene)nicotinohydrazide]silver(I)] hexafluoroarsenate], {[Ag(C₁₄H₁₀N₄O)](AsF₆)}_n, at 173 K exhibits a novel stair‐like two‐dimensional layer and a three‐dimensional supramolecular framework through C—H...Ag hydrogen bonds. The Ag^I cation is coordinated by three N atoms and one O atom from N′‐(3‐cyanobenzylidene)nicotinohydrazide (L) ligands, resulting in a distorted tetrahedral coordination geometry. The organic ligand acts as a μ₃‐bridging ligand through the pyridyl and carbonitrile N atoms and deviates from planarity in order to adapt to the coordination geometry. Two ligands bridge two Ag^I cations to construct a small 2+2 Ag₂L₂ ring. Four ligands bridge one Ag^I cation from each of four of these small rings to form a large grid. An interesting stair‐like two‐dimensional (3,6)‐net is formed through Ag^I metal centres acting as three‐connection nodes and through L molecules as tri‐linkage spacers.     

A two‐dimensional network formed by self‐associating silver(I) perchlorate with 3‐[4‐(2‐thienyl)‐2H‐cyclopenta[d]pyridazin‐1‐yl]benzonitrile

In the organometallic silver(I) supramolecular complex poly[[silver(I)‐μ₃‐3‐[4‐(2‐thienyl)‐2H‐cyclopenta[d]pyridazin‐1‐yl]benzonitrile] perchlorate methanol solvate], {[Ag(C₁₈H₁₁N₃S)](ClO₄)·CH₃OH}_n, there is only one type of Ag^I center, which lies in an {AgN₂Sπ} coordination environment. Two unsymmetric multidentate 3‐[4‐(2‐thienyl)‐2H‐cyclopenta[d]pyridazin‐1‐yl]benzonitrile (L) ligands link two Ag^I atoms through π–Ag^I interactions into an organometallic box‐like unit, from which two 3‐cyanobenzoyl arms stretch out in opposite directions and bind two Ag^I atoms from neighboring box‐like building blocks. This results in a novel two‐dimensional network extending in the crystallographic bc plane. These two‐dimensional sheets stack together along the crystallographic a axis to generate parallelogram‐like channels. The methanol solvent molecules and the perchlorate counter‐ions are located in the channels, where they are fixed by intermolecular hydrogen‐bonding interactions. This architecture may provide opportunities for host–guest chemistry, such as guest molecule loss and absorption or ion exchange. The new fulvene‐type multidentate ligand L is a good candidate for the preparation of Cp–Ag^I‐containing (Cp is cyclopentadienyl) organometallic coordination polymers or supramolecular complexes.     

Construction and photocatalytic properties of two metal‐mediated coordination polymers based on benzene‐1,3,5‐tricarboxylic acid and trans‐1‐(pyridin‐3‐yl)‐2‐(pyridin‐4‐yl)ethene

With the rapid development of modern industry, water pollution has become an intractable environmental issue facing humans worldwide. In particular, the organic dyes discharged into natural water from dyestuffs, dyeing and the textile industry are the main sources of pollution in wastewater. To eliminate these types of pollutants, degradation of organic contaminants through a photocatalytic technique is an effective methodology. To exploit more crystalline photocatalysts for the degradation of organic dyes, two coordination polymers, namely catena‐poly[[(3,5‐dicarboxybenzene‐1‐carboxylato‐κO ¹)silver(I)]‐μ‐trans‐1‐(pyridin‐3‐yl)‐2‐(pyridin‐4‐yl)ethene‐κ²N :N ′], [Ag(C₉H₅O₆)(C₁₂H₁₀N₂)]_n or [Ag(H₂BTC)(3,4′‐bpe)]_n , (I), and poly[[(μ₃‐5‐carboxybenzene‐1,3‐dicarboxylato‐κ⁴O ¹,O ^1′:O ³:O ³)[μ‐trans‐1‐(pyridin‐3‐yl)‐2‐(pyridin‐4‐yl)ethene‐κ²N :N′ ]cadmium(II)] monohydrate], {[Cd(C₉H₄O₆)(C₁₂H₁₀N₂)]·H₂O}_n or {[Cd(HBTC)(3,4′‐bpe)]·H₂O}_n , (II), have been prepared by the hydrothermal reactions of benzene‐1,3,5‐tricarboxylic acid (H₃BTC) and trans‐1‐(pyridin‐3‐yl)‐2‐(pyridin‐4‐yl)ethene (3,4′‐bpe) in the presence of AgNO₃ or Cd(NO₃)₂·4H₂O, respectively. These two title compounds have been structurally characterized by IR spectroscopy, elemental analysis, single‐crystal X‐ray diffraction and powder X‐ray diffraction. In (I), the Ag^I ions and organic ligands form a one‐dimensional coordination chain, and adjacent coordination chains are connected by Ag…O interactions to give rise to a two‐dimensional supramolecular network. Each two‐dimensional network is entangled with other equivalent networks to generate an infrequent interlocked 2D→3D (2D and 3D are two‐ and three‐dimensional, respectively) supramolecular framework. In (II), the Cd^II ions are bridged by the HBTC²⁻ and 3,4′‐bpe ligands, which lie across centres of inversion, to give a two‐dimensional coordination network. The thermal stabilities and photocatalytic properties of the title compounds have also been studied.     

catena‐Poly[[silver(I)‐μ‐1,3‐bis(4‐pyridyl)propane] hemi(naphthalene‐1,5‐disulfonate) dihydrate]: a three‐dimensional metallo‐supramolecular sandwich lamellar network

The title compound, {[Ag(C₁₃H₁₄N₂)](C₁₀H₆O₆S₂)_0.5·2H₂O}_n, (I), features a three‐dimensional supramolecular sandwich architecture that consists of two‐dimensional cationic layers composed of polymeric chains of silver(I) ions and 1,3‐bis(4‐pyridyl)propane (bpp) ligands, linked by Ag...Ag and π–π interactions, alternating with anionic layers in which uncoordinated naphthalene‐1,5‐disulfonate (nds²⁻) anions and solvent water molecules form a hydrogen‐bonded network. The asymmetric unit consists of one Ag^I cation linearly coordinated by N atoms from two bpp ligands, one bpp ligand, one half of an nds²⁻ anion lying on a centre of inversion and two solvent water molecules. The two‐dimensional {[Ag(bpp)]⁺}_n cationic and {[(nds)·2H₂O]²⁻}_n anionic layers are assembled into a three‐dimensional supramolecular framework through long secondary coordination Ag...O interactions between the sulfonate O atoms and Ag^I centres and through nonclassical C—H...O hydrogen bonds.     

A Three-dimensional Heteronuclear Polymer of [Ag2Fe（SCN）5（DMF）]n Containing Channels and One-dimensional Ag2S2-S-Ag2S2 Chains with Ag…Ag Interaction

Introduction So far, considerable attention has been paid to mag-netic interaction between two different metal ions.1-3 As a potential bridging ligand, thiocyanate can coordinate to a harder metal center with N atom and softer ones with S atom at the same time, resulting in the formation of small ferromagnetic coupling.2 On the other hand, the Fe(III) atom is a good candidate as a hard acid and Ag(I) is a good candidate as a soft acid, so that the Fe(III) centers could be expected to conn…     

Synthesis,Structures, and Properties of Two Novel Supramolecular Architectures Constructed from [2,3‐f]Pyrazino[1,10]phenanthroline‐2,3‐dicarboxylic Acid

Two new compounds, [Ag(Hppdb)]_n ( 1 ) and {[Ag₂(Hppdb)₂(bpe)] · 5.5H₂O}_n( 2 ) [H₂ppdb = [2,3‐f]pyrazino[1,10]phenanthroline‐2,3‐dicarboxylic acid, bpe = trans‐1,2‐bis(4‐pyridyl)ethylene], were synthesized and characterized. In 1 , Hppdb^– ions link Ag^I cations to form an infinite 1D [–Ag–(Hppdb)–Ag–]_n chain, furthermore, the dimensionality is extended to 2D layers through synergistic π–π stacking, hydrogen‐bonding and weak Ag ··· O interactions. Correspondingly, the dimeric [(Ag)(Hppdb)]₂ subunits in 2 are connected by bpe ligands to generate a loop‐link‐shaped 1D chain motif, which is further joined through a R₂²(18)C–H ··· O hydrogen‐bonding ring to afford interesting diagonal/diagonal inclined catenation 2D + 2D → 3D supramolecular architectures. In addition, solid‐state properties such as photoluminescence and thermal stability of the two compounds were studied.     

Synthesis,Structure and Photoluminescent Properties of Zn(II)/Cd(II)‐Complexes Containing 2,4,6‐Tris‐(benzimidazolyl‐2‐yl)pyridine Ligand

Hydrothermal reactions of tridentate rigid 2,4,6‐tris‐(benzimidazolyl‐2‐yl)pyridine (pytbzim) ligand and Zn(II)/Cd(II) salts generate binuclear complexes {[Cd₂Cl₂(pytbzim)₂(H₂O)₂]·2NO₃}_n ( 1 ) and two isomorphs {[M₂Cl₂(pytbzim)₂(H₂O)₂]Cl₂·2H₂O}_n [M=Cd ( 2 ), Zn ( 3 )]. All complexes include [M₂Cl₂(pytbzim)₂(H₂O)₂] dimers, which are further connected into a three‐dimensional supramolecular networks through ?‐? stacking interaction and hydrogen bonds. The solid state photoluminescent studies reveal good fluorescent properties of the pytbzim ligand and complexes 1 – 2 at room temperature.     

Synthesis,structure and biological activity of diorganotin derivatives with pyridyl functionalized bis(pyrazol‐1‐yl)methanes

Three pyridyl functionalized bis(pyrazol‐1‐yl)methanes, namely 2‐[(4‐pyridyl)methoxyphenyl] bis(pyrazol‐1‐yl)methane (L¹), 2‐[(4‐pyridyl)methoxyphenyl]bis(3,5‐dimethylpyrazol‐1‐yl)methane (L²) and 2‐[(3‐pyridyl)methoxyphenyl]bis(pyrazol‐1‐yl)methane (L³) have been synthesized by the reactions of (2‐hydroxyphenyl)bis(pyrazol‐1‐yl)methanes with chloromethylpyridine. Treatment of these three ligands with R₂SnCl₂ (R = Et, n‐Bu or Ph) yields a series of symmetric 2:1 adducts of (L)₂SnR₂Cl₂ (L = L¹, L² or L³), which have been confirmed by elemental analysis and NMR spectroscopy. The crystal structures of (L²)₂Sn(n‐Bu)₂Cl₂·0.5C₆H₁₄ and (L³)₂SnEt₂Cl₂ determined by X‐ray crystallography show that the functionalized bis(pyrazol‐1‐yl)methane acts as a monodentate ligand through the pyridyl nitrogen atom, and the pyrazolyl nitrogen atoms do not coordinate to the tin atom. The cytotoxic activity of these complexes for Hela cells in vitro was tested. Copyright © 2010 John Wiley & Sons, Ltd.