Two Zinc(II) Coordination Polymers Based on Terphenyl‐2,2′,4,4′‐tetracarboxylate and Dipyridyl Ligands: Syntheses,Crystal Structures,and Luminescent Properties

Two coordination polymers, {[Zn₂(L)(bpy)] · 2H₂O}_n ( 1 ) and [Zn₂(L)(bpe)]_n ( 2 ) [H₄L = terphenyl‐2,2′,4,4′‐tetracarboxylic acid, bpy = 4,4′‐bipyridine, and bpe = 1,2‐bis(4‐pyridyl)ethane], were hydrothermally synthesized under similar conditions and characterized by elemental analysis, IR spectroscopy, TGA, and single‐crystal X‐ray diffraction analysis. Compound 1 has a 3D framework containing Zn–O–C–O–Zn 1D chains. Compound 2 exhibits a 3D framework, which features tubular channels. The channels are occupied by bpe molecules. The differences in the structures demonstrate that the auxiliary dipyridyl‐containing ligand has a significant effect on the construction of the final framework. Additionally, the fluorescent properties of the two compounds were also studied in the solid state at room temperature.     

Syntheses,Crystal Structures,and Fluorescence Properties of Two Transition Metal‐Organic Coordination Polymers Based on 4,4′‐Dimethyl‐2,2′‐bipyridine

Two transition metal‐organic coordination polymers, [Mn₂(1,3‐bdc)₂(Me₂bpy)₂] · Me₂bpy ( 1 ) and [Co(4,4′‐oba)(Me₂bpy)] ( 2 ) were hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, TG, and single‐crystal X‐ray diffraction [1,3‐H₂bdc = benzene‐1,3‐dicarboxylic acid, H₂oba = 4,4′‐oxybis(benzoic acid) Me₂bpy = 4,4′‐dimethyl‐2,2′‐bipyridine]. Compound 1 crystallizes in the orthorhombic system, space group P2₁2₁2₁, with a = 23.371(5), b = 14.419(3), and c = 14.251(3) Å. Compound 2 crystallizes in the monoclinic system, space group P2₁/c, with a = 7.4863(15), b = 18.272(4), c = 16.953(5) Å, and β = 107.44(3)°. The crystal structure of complex 1 is a wave‐like layer with central Mn²⁺ atoms bridged by 1,3‐bdc ligands, whereas the structure of compound 2 presents a ladder chain of hexacoordinate Co²⁺ atoms, in which the metal atoms are bridged by 4,4′‐oba ligands and decorated by Me₂bpy ligands. The two compounds are further extended into 3D supramolecular structures through π–π stacking interactions. Additionally, the compounds show intense fluorescence in solid state at room temperature.     

Effect of Metal Ions on the Structures of Coordination Polymers Based on Biphenyl‐2,2′,4,4′‐Tetracarboxylate

Two new coordination polymers, {[Cd₂(btc)(2,2′‐bpy)₂] · H₂O}_n ( 1 ) and [Zn₂(btc)(2,2′‐bpy)(H₂O)]_n ( 2 ) (H₄btc = biphenyl‐2,2′,4,4′‐tetracarboxylic acid, 2,2′‐bpy = 2,2′‐bipyridine), were synthesized hydrothermally under similar conditions and characterized by elemental analysis, IR spectra, TGA, and single‐crystal X‐ray diffraction analysis. In complexes 1 and 2 , the (btc)^4– ligand acts as connectors to link metal ions to give a 2D bilayer network of 1 and a 3D metal‐organic framework of 2 , respectively. The differences in the structures are induced by diverging coordination modes of the (btc)^4– ligand, which can be attributed to the difference metal ions in sizes. The results indicate that metal ions have significant effects on the formation and structures of the final complexes. Additionally, the fluorescent properties of the two complexes were also studied in the solid state at room temperature.     

Synthesis,Crystal Structures and Fluorescent Properties of Two 2,2′‐Biquinoline‐4,4′‐dicarboxylate‐based Cadmium(II) and Cobalt(II) Complexes

Two metal‐organic coordination polymers with one‐dimensional infinite chain motif, [Cd(bqdc)(phen)₂]_n ( 1 ) and [Co(bqdc)(phen)(H₂O)₂]_n ( 2 ) (H₂bqdc = 2,2′‐biquinoline‐4,4′‐dicarboxylic acid, phen = 1,10‐phenanthroline), have been synthesized under similar solv/hydrothermal conditions and fully structural characterized by elemental analysis, IR, and single‐crystal X‐ray crystallography. Their thermal stability and photoluminescence properties were further investigated by TG‐DTA and fluorescence spectra. In both complexes, the adjacent metal ions (Cd^II for 1 and Co^II for 2 ) are linked together by dicarboxylate groups of bqdc dianions in chelating bidentate and monodentate modes, respectively, generating a zigzag chain for 1 and linear chain for 2 . The relatively higher thermal stability up to 324 °C for 1 and strong fluorescence emissions jointly suggest that they are good candidates for luminescent materials.     

The Synthesis,Photophysical Characterization,and X‐Ray Structure Analysis of Two Polymorphs of 4,4′‐Diacetylstilbene

A palladium(II) acetate‐catalyzed synthesis of 1 that utilizes the novel triazene 1‐{4‐[(E)‐morpholin‐4‐yldiazenyl]phenyl}ethanone as a synthon is described. The room temperature absorption spectra of 1 in various solvents exhibited a π→π* transition in the range of 330–350 nm. Compound 1 was observed to be luminescent, with room‐temperature solution and solid‐state emission spectra that exhibited maxima in the range 400–500 nm. All room‐temperature absorption and emission spectra exhibited some degree of vibrational structure. The emission spectrum of 1 at 77 K in propanenitrile glass was broad and featureless with a maximum at 447 nm. Compound 1 crystallized as a yellow and colorless polymorph. X‐Ray structure analyses of both of these polymorphs and 1‐{4‐[(E)‐morpholin‐4‐yldiazenyl]phenyl}ethanone are presented.     

Electrocrystallization of Tetra‐ and Hexa‐coordinated Silver(II) Compounds Based on 4,4′‐Dimethyl‐2,2′‐Bipyridine Ligand – Single Crystal Structures and Magnetic Studies

In this paper we report on the potential dependent electrocrystallization of [Ag(4,4′‐dimethyl‐2,2′‐bipyridine)₂(NO₃)₂] ( 1 ) and Ag(4,4′‐dimethyl‐2,2′‐bipyridine)(NO₃)₂ ( 2 ) from the same electrolytic bath. Thus it has been shown for the first time that the coordination number of silver ion to ligands can be tuned by the electrocrystallization potential. The single crystal structure analysis [ 1 : C2/c, a = 18.6308(15), b = 14.5708(12), c = 11.5867(10) Å, β = 126.5910(10)°, Z = 4, R = 3.9 %] [ 2 : P2₁/c, a = 8.5865(11) b = 11.0157(14) c = 16.4554(10) Å, β = 111.102(10), Z = 4 , R = 3.5 %] show divalent silver to be in an approximately square planar surrounding. Both complexes are paramagnetic following Curie's law with magnetic moments of 1.86 μ_B and 1.72 μ_B respectively.     

Crystallographic report: A three‐dimensional coordination polymer: [Zn6(btc)4(4,4′‐bipy)5]n (btc = 1,2,4‐benzenetricarboxylate; 4,4′‐bipy = 4,4′‐bipyridine)

The three‐dimensional (3D) coordination polymer [Zn₆(btc)₄(4,4′‐bipy)₅]_n ( 1 ) (btc = 1,2,4‐benzenetricarboxylate; 4,4′‐bipy = 4,4′‐bipyridine) has been prepared hydrothermally. The zinc(II) centers in 1 are bridged by btc ligands to form a trinuclear subunit, which is further linked by 4,4′‐bipy and btc ligands to construct the 3D coordination architecture. Copyright © 2003 John Wiley & Sons, Ltd.     

Five Coordinated Zinc(II) and Tris‐Chelate Cadmium(II) Complexes with 2,2′‐Diamino‐5,5′‐dimethyl‐4,4′‐bithiazole – Syntheses,Spectroscopic Characterization,and Crystal Structure

The new synthesized ligand (DADMBTZ = 2,2′‐diamino‐5,5′‐dimethyl‐4,4′‐bithiazole), which is mentioned in this text, is used for preparing the two new complexes [Zn(DADMBTZ)₃](ClO₄)₂. 0.8MeOH.0.2H₂O ( 1 ) and [Cd(DADMBTZ)₃](ClO₄)₂ ( 2 ). The characterization was done by IR, ¹H, ¹³C NMR spectroscopy, elemental analysis and single crystal X‐ray determination. In reaction with DADMBTZ, zinc(II) and cadmium(II) show different characterization. In 2 , to form a tris‐chelate complex with nearly C₃ symmetry for coordination polyhedron, DADMBTZ acts as a bidentate ligand. In 1 , this difference maybe relevant to small radii of Zn²⁺ which make one of the DADMBTZ ligands act as a monodentate ligand to form the five coordinated Zn²⁺ complex. In both 1 and 2 complexes the anions are symmetrically different. 1 and 2 complexes form 2‐D and 3‐D networks via N‐H···O and N‐H···N hydrogen bonds, respectively.     

A zinc(II) metal–organic framework with a novel topology formed from 4,4′,4′′‐nitrilotribenzoate and 4,4′‐bipyridine ligands

A metal–organic framework with a novel topology, poly[sesqui(μ₂‐4,4′‐bipyridine)bis(dimethylformamide)bis(μ₄‐4,4′,4′′‐nitrilotribenzoato)trizinc(II)], [Zn₃(C₂₁H₁₂NO₆)₂(C₁₀H₈N₂)_1.5(C₃H₇NO)₂]_n, was obtained by the solvothermal method using 4,4′,4′′‐nitrilotribenzoic acid and 4,4′‐bipyridine (bipy). The structure, determined by single‐crystal X‐ray diffraction analysis, possesses three kinds of crystallographically independent Zn^II cations, as well as binuclear Zn₂(COO)₄(bipy)₂ paddle‐wheel clusters, and can be reduced to a novel topology of a (3,3,6)‐connected 3‐nodal net, with the Schläfli symbol {5.6²}₄{5².6}₄{5⁸.8⁷} according to the topological analysis.     

Syntheses,Structures and Characterization of Four Metal‐Organic Frameworks constructed by 2,2′,6,6′‐Tetramethoxy‐4,4′‐biphenyldicarboxylic Acid

Four metal‐organic frameworks (MOFs), {[Mn_3.5L(OH)(HCOO)₄(DMF)] · H₂O} ( 1 ), {[In_2.5L₂O(OH)_1.5(H₂O)₂] · DMF · CH₃CN · 2H₂O} ( 2 ), {[Pb₄L₃O(DMA)] · CH₃CN} ( 3 ), and {[LaL(NO₃)(DMF)₂] · 2H₂O} ( 4 ) were synthesized by utilizing the ligand 2,2′,6,6′‐tetramethoxy‐4,4′‐biphenyldicarboxylic acid (H₂L) via solvothermal methods. All MOFs were characterized by single‐crystal X‐ray diffraction, powder X‐ray diffraction, thermogravimetric analysis, and infrared spectroscopy. In 1 , the Mn²⁺ ions are interconnected by formic groups in situ produced via DMF decomposition to form a rare 2D macrocyclic plane, which is further linked by L^2– to construct the final 3D network. In 2 , 1D zip‐like infinite chain is formed and then interconnected to build the 3D framework. In 3 , a [Pb₆(μ₄‐O)₂(O₂C)₁₀(DMA)₂] cluster with a centrosymmetric [Pb₆(μ₄‐O)₂]⁸⁺ octahedral core is formed in the 3D structure. In 4 , the La³⁺ ions are connected with each other through carboxylate groups of L^2– to generate 1D zigzag chain, which is further linked by L^2– to construct a 3D network with sra topology. Solid photoluminescence properties of 3 and 4 were also investigated.     

Synthesen und Strukturen von Bis(4,4′‐t‐butyl‐2,2′‐bipyridin)‐Ruthenium(II)‐Komplexen mit funktionellen Derivaten des Tetramethyl‐bibenzimidazols

Syntheses and Structures of Bis(4,4′‐t‐butyl‐2,2′‐bipyridine) Ruthenium(II) Complexes with functional Derivatives of Tetramethyl‐bibenzimidazole [(tbbpy)₂RuCl₂] reacts with dinitro‐tetramethylbibenzimidazole ( A ) in DMF to form the complex [(tbbpy)₂Ru( A )](PF₆)₂ ( 1a ) (tbbpy: bis(4,4′‐t‐butyl)‐2,2′bipyridine). Exchange of the two PF₆^? anions by a mixture of tetrafluor‐terephthalat/tetrafluor‐terephthalic acid results in the formation of 1b in which an extended hydrogen‐bonded network is formed. According to the ¹H NMR spectra and X‐ray analyses of both 1a and 1b , the two nitro groups of the bibenzimidazole ligand are situated at the periphery of the complex in cis position to each other. Reduction of the nitro groups in 1a with SnCl₂/HCl results in the corresponding diamino complex 2 which is a useful starting product for further functionalization reactions. Substitution of the two amino groups in 2 by bromide or iodide via Sandmeyer reaction results in the crystalline complexes [(tbbpy)₂Ru( C )](PF₆)₂ and [(tbbpy)₂Ru( D )](PF₆)₂ ( C : dibromo‐tetrabibenzimidazole, D : diiodo‐tetrabibenzimidazole). Furthermore, 2 readily reacts with 4‐t‐butyl‐salicylaldehyde or pyridine‐2‐carbaldehyde under formation of the corresponding Schiff base Ru^II complexes 5 and 6 . ¹H NMR spectra show that the substituents (NH₂, Br, I, azomethines) in 2 ‐ 6 are also situated in peripheral positions, cis to each other. The solid state structure of both 2 , and 3 , determined by X‐ray analyses confirm this structure. In addition, the X‐ray diffraction analyses of single crystals of the complexes [(tri‐t‐butyl‐terpy)(Cl)Ru( A )] ( 7 ) and [( A )PtCl₂] ( 8 ) display also that the nitro groups in these complexes are in a cis‐arrangement.     

Synthesis,Structure, and Clathration Ability of the Microporous Three‐Dimensional Coordination Polymer [{CuCN(4,4′‐bpy)} · 2(4,4′‐bpy)]

The respectively yellow and red coordination polymers [(CuCN)₂(μ‐4,4′‐bpy)] ( 1 ) and [{CuCN(μ‐4,4′‐bpy)} · 2(4,4′‐bpy)] ( 2 ) (4,4′‐bpy = 4,4′‐bipyridine) may be prepared by self‐assembly of CuCN and 4,4′‐bpy at the appropriate molar ratio in acetonitrile solution at 100 °C. In 1 infinite CuCN chains are linked by 4,4′‐bpy ligands into lamellar polymers which exhibit short Cu…C(N) contacts of 2.41(1) Å between one of the crystallographically independent copper atoms and cyanide carbon atoms of a neighbouring corrugated sheet. At a molar ratio of CuCN : 4,4′‐bpy below 2 : 3, the heteroaromatic ligands also adopt a structure‐directing role to afford 3 , in which [(CuCN)₂(μ‐4,4′‐bpy)] sheets are now joined by additional bridging 4,4′‐bpy spacer molecules to provide a three‐dimensional framework, whose nanometer‐sized channels (12.76 × 13.12 Å) accomodate two noncoordinated 4,4′‐bpy guest molecules. A DTA/TGA trace demonstrates that these can be removed in two steps at 150 and 176 °C.     

A two‐dimensional copper(II) coordination polymer based on 2,4′‐oxybis(benzoate) and 4,4′‐bipyridine

The reaction of Cu(NO₃)₂·3H₂O with 2,4′‐oxybis(benzoic acid) and 4,4′‐bipyridine under hydrothermal conditions produced a new mixed‐ligand two‐dimensional copper(II) coordination polymer, namely poly[[(μ‐4,4′‐bipyridine‐κ²N ,N ′)[μ‐2,4′‐oxybis(benzoato)‐κ⁴O ²,O ^2′:O ⁴,O ^4′]copper(II)] monohydrate], {[Cu(C₁₄H₈O₅)(C₁₀H₈N₂)]·H₂O}_n , which was characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single‐crystal X‐ray diffraction. The X‐ray diffraction crystal structure analysis reveals that the Cu^II ions are connected to form a two‐dimensional wave‐like network through 4,4′‐bipyridine and 2,4′‐oxybis(benzoate) ligands. The two‐dimensional layers are expanded into a three‐dimensional supramolecular structure through intermolecular O—H…O and C—H…O hydrogen bonds. Furthermore, magnetic susceptibility measurements indicate that the complex shows weak antiferromagnetic interactions between adjacent Cu^II ions.     

Preparation and physical properties of poly(4,4′‐diamino‐3′‐carbamoylbenzanilide terephthalamide) and poly(4,4′‐diamino‐3′‐carbamoylbenzanilide isophthalamide) films

To prepare thermally stable and high‐performance polymeric films, new solvent‐soluble aromatic polyamides with a carbamoyl pendant group, namely poly(4,4′‐diamino‐3′‐carbamoylbenzanilide terephthalamide) (p‐PDCBTA) and poly(4,4′‐diamino‐3′‐carbamoylbenzanilide isophthalamide) (m‐PDCBTA), were synthesized. The polymers were cyclized at around 200 to 350 °C to form quinazolone and benzoxazinone units along the polymer backbone. The decomposition onset temperatures of the cyclized m‐ and p‐PDCBTAs were 457 and 524 °C, respectively, lower than that of poly(p‐phenylene terephthalamide) (566 °C). For the p‐PDCBTA film drawn by 40% and heat‐treated, the tensile strength and Young's modulus were 421 MPa and 16.4 GPa, respectively. The film cyclized at 350 °C showed a storage modulus (E′) of 1 × 10¹¹ dyne/cm² (10 GPa) over the temperature range of room temperature to 400 °C. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 775–780, 2000     

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.     

The Crystal Structures of two Linearly Polymeric Copper(II) Complexes of 2, 2′‐Bipyridine with threefold Glycolato and Oxalato Bridges

The complex [Cu(HGLYO)₂(bipy)] ( I ) and two new copper(II) coordination polymers with the formulas {[Cu(GLYO)_1‐x(ox)_x(bipy)]·2.5H₂O}_n [GLYO = glycolato dianion, ox = oxalato dianion, bipy = 2, 2′‐bipyridine, x = 0.56 (in II ) or 0.71 (in III )] were synthesized using copper(II) glycolate as starting material and were characterized by IR, UV‐Vis and EPR spectrometry, by magnetic measurements ( II and III ), and by single‐crystal X‐ray diffractometry. Both II and III crystallized as one‐dimensional polymers composed of Cu₂O₂‐centred dimers with a Cu‐Cu distance of 3.282(1)Å (mean of II and III ) that are linked by Cu₂(OCO)₂ rings with a Cu‐Cu distance of 5.237(1)Å (mean of II and III ), both dianions acting as (μ‐1, 1, 2, 3) three‐way bridges connecting the two copper atoms of one dimer with one copper atom of a neighbouring dimer. Each copper atom is coordinated tetragonally in a CuN₂O₄ chromophore. In the mononuclear complex I the copper atom has a tetragonally distorted octahedral environment.     

Trichloroberyllat‐Komplexe von Dimethylcyanamid,Morpholin und 4,4′‐Bipyridin

Trichloroberyllate Complexes of Dimethyl Cyanamide, Morpholine, and 4,4′‐Bipyridine The trichloroberyllate complexes (Ph₄P)[BeCl₃(NCNMe₂)] ( 1 ), (Ph₄P)[BeCl₃{HN(CH₂)₄O}] ( 2 ), and (Ph₄P)₂[(BeCl₃)₂(4,4′‐bipy)] ( 3 ) were prepared by reactions of (Ph₄P)₂[Be₂Cl₆] with dimethyl cyanamide, trimethylsilylmorpholinate, and 4,4′‐bipyridine, respectively, in dichloromethane solutions. 1 ‐ 3 were characterized by X‐ray crystallography and by IR‐spectroscopy. 1 ·CH₂Cl₂: Space group P1, Z = 1, lattice dimensions at 173 K: a = 714.2(1), b = 919.5(2), c = 1233.4(2) pm, α = 94.97(1)°, β = 90.86(1)°, γ = 111.90(1)°, R₁ = 0.0310. In the complex anion [BeCl₃(NCNMe₂)]^? the dimethyl cyanamide ligand is coordinated via a linear Be–N≡C‐NMe₂ arrangement, the CH₂Cl₂ molecules forming linear chains by hydrogen bridges ···HCH···Cl··· with the chlorine atoms of the {BeCl₃^?} groups. 2 : Space group , Z = 2, lattice dimensions at 173 K: a = 1050.9(1), b = 1099.7(1), c = 1308.3(2) pm, α = 87.57(1)°, β = 70.97(1)°, γ = 74.58(1)°, R₁ = 0.0397. The complex anions are dimerized by centrosymmetric puckered eight‐membered [Be–N–H···Cl]₂ rings. 3 ·2CH₂Cl₂: Space group , Z = 2, lattice dimensions at 173 K: a = 1095.4(1), b = 1559.6(2), c = 1869.8(3) pm, α = 79.12(1)°, β = 73.83(1)°, γ = 78.76(1)°, R₁ = 0.0548. The complex contains dianions [Cl₃Be(μ‐bipy)BeCl₃]^2? with Be–N distances of 177.0(6) and 178.5(6) pm. Both {BeCl₃}^? groups form C–H···Cl hydrogen bridges with the dichloromethane molecules.     

Synthesis and Characterization of [Zn2(4,4′‐bipy)n(AcO)4] – One‐dimensional Chain (n = 1) and One‐dimensional Double‐Chain (n = 2) Coordination Polymers

Two new Zn^II(μ‐4,4′‐bipy) coordination polymers with acetate anions, [Zn(4,4′‐bipy)(AcO)₂] ( 1 ) and [Zn₂(4,4′‐bipy)(AcO)₄] ( 2 ), have been synthesized. The compounds were characterized with elemental analysis, IR‐, ¹H NMR‐, ¹³C NMR spectroscopy and studied by thermal analysis, fluorescence measurements and x‐ray crystallography. The structural studies of compound 1 suggest the structure is a coordination polymer of zinc(II) consisting of linear double chains formed by bridging 4,4′‐bipy ligand and connection of the acetate‐bridged centrosymmetric [Zn₂(OAc)₂]²⁺ nodes.     

1,1′‐Diethyl‐4,4′‐bipyridine‐1,1′‐diium bis(1,1,3,3‐tetracyano‐2‐ethoxypropenide): multiple C—H...N hydrogen bonds form a complex sheet structure

In the title salt, C₁₄H₁₈N₂²⁺·2C₉H₅N₄O⁻, the 1,1′‐diethyl‐4,4′‐bipyridine‐1,1′‐diium dication lies across a centre of inversion in the space group P2₁/c. In the 1,1,3,3‐tetracyano‐2‐ethoxypropenide anion, the two independent –C(CN)₂ units are rotated, in conrotatory fashion, out of the plane of the central propenide unit, making dihedral angles with the central unit of 16.0 (2) and 23.0 (2)°. The ionic components are linked by C—H...N hydrogen bonds to form a complex sheet structure, within which each cation acts as a sixfold donor of hydrogen bonds and each anion acts as a threefold acceptor of hydrogen bonds.     

Three isotypic polymeric complexes with rare earth cations,but‐2‐enoate anions and 4,4′‐(ethane‐1,2‐diyl)dipyridine and 4,4′‐(ethene‐1,2‐diyl)dipyridine bridging ligands

Three isotypic rare earth complexes, catena‐poly[[aquabis(but‐2‐enoato‐κ²O,O′)yttrium(III)]‐bis(μ‐but‐2‐enoato)‐κ³O,O′:O;κ³O:O,O′‐[aquabis(but‐2‐enoato‐κ²O,O′)yttrium(III)]‐μ‐4,4′‐(ethane‐1,2‐diyl)dipyridine‐κ²N:N′], [Y₂(C₄H₅O₂)₆(C₁₂H₁₂N₂)(H₂O)₂], the gadolinium(III) analogue, [Gd₂(C₄H₅O₂)₆(C₁₂H₁₂N₂)(H₂O)₂], and the gadolinium(III) analogue with a 4,4′‐(ethene‐1,2‐diyl)dipyridine bridging ligand, [Gd₂(C₄H₅O₂)₆(C₁₂H₁₀N₂)(H₂O)₂], are one‐dimensional coordination polymers made up of centrosymmetric dinuclear [M(but‐2‐enoato)₃(H₂O)]₂ units (M = rare earth), further bridged by centrosymmetric 4,4′‐(ethane‐1,2‐diyl)dipyridine or 4,4′‐(ethene‐1,2‐diyl)dipyridine spacers into sets of chains parallel to the [20] direction. There are intra‐chain and inter‐chain hydrogen bonds in the structures, the former providing cohesion of the linear arrays and the latter promoting the formation of broad planes parallel to (010).