Three-dimensional Coordination Polymer Research Articles

Structural Dynamism and Controlled Chemical Blocking/Unblocking of Active Coordination Space of a Soft Porous Crystal

A three-dimensional biporous soft porous coordination polymer containing active coordination space, made of cadmium(II) and a tripodal carboxylate ligand bearing ether linkages, was synthesized and characterized. Guest-dependent dynamic activities in the active coordination space of the soft porous crystal have been explored. We have demonstrated controlled chemical blocking and unblocking of active pores of the dynamic framework along with guest-dependent contraction and expansion of the channels by single-crystal-to-single-crystal structural transformation studies. Detailed studies revealed up to 70% contraction of the void volume and almost a 100 times increase in gas sorption by controlled phases obtained by guest switching. These types of soft materials with porous scaffolds, also known as soft porous crystals, may have general implications in the preparation of intelligent host materials with zeolitic properties and enzyme-like specificity.

Syntheses and Properties of One–Three-Dimensional Coordination Polymers Constructed by Metallohelicates of Purin-Containing Carboxylate

An acetate-functionalized purine-containing ligand, 2-(6-oxo-6,9-dihydro-1H-purin-1-yl) acetic acid (H2L), and its six new one–three-dimensional (1–3D) coordination polymers, [La(HL)2(NO3)(H2O)2]n (1), [Ce(HL)2(NO3)(H2O)2]n (2), [Pb(HL)2(H2O)2]n (3), [Cd(HL)2(H2O)2]n (4), [Cd(L)]n (5), and [Zn(L)]n (6), were synthesized and characterized. Single-crystal X-ray diffraction analyses reveal that the architectures of complexes 1–6 are built from the metal–organic helixes of ligands H2L. The overall structures range from the double helical chains of 1 and 2, and the 2D helical networks of 3 and 4, to the 3D coordination polymers of 5 and 6, containing 2D homochiral layers based on 1D metal–organic helixes. In those meso compounds, ligands H2L display differently anionic states, bridge modes, and especially unsymmetrical configurations with the sharp distortion between the acetate and purin in favor of constructing helical assemblies as expected. The plentiful hydrogen-bonding sites and π···π interactions origin...

Synthesis, Crystal Structure and Magnetic Properties of a Mn(II) Fluorenedicarboxylate Complex

A new Mn(II) metal-organic framework, [Mn(DFDC)(phen)]n (1) (where H2DFDC=9,9- diethylfluorene-2,7-dicarboxylic acid, phen=1,10-phenanthroline), was solvothermally synthesized and characterized by single-crystal and powder X-ray diffraction (PXRD), elemental and thermal analysis, IR, UV=Vis spectroscopy, fluorescence and magnetic measurements. Single-crystal X-ray analysis reveals that 1 exhibits a three-dimensional coordination polymer structure. The compound crystallizes in the orthorhombic space group Pnna with a=9.1215(9), b=26.436(3), c=10.2428(10) Å, V =2469.9(4) Å3, Z =4, final wR2=0.1323 for 2825 reflections. The Mn(II) ion is coordinated by four oxygen atoms from four different H2DFDC ligands and two nitrogen atoms from one phen ligand in an octahedral coordination geometry. The compound shows ferromagnetic coupling behavior and has high thermal stability up to 420 °C

A three-dimensional Cu–Na heteronuclear coordination polymer based on iminodiacetic acid

A novel Cu-Na heteronuclear three-dimensional coordination polymer, poly[diaquadi-μ5-iminodiacetato-di-μ4-iminodiacetato-tricopper(II)disodium(I)], [Cu3Na2(C4H5NO4)4(H2O)2]n, has been prepared by hydrothermal synthesis. The asymmetric unit contains one and a half copper(II) cations, a sodium cation, two iminodiacetate (ida) ligands and a coordinated water ligand. One of the two independent Cu(II) centres is in a general position and is five-coordinated in a distorted square-pyramidal geometry. A [Cu(ida)] unit is formed via a bis-chelating ida ligand and the coordination sphere of the Cu(II) atom is completed by two O atoms of two different neighbouring [Cu(ida)2] units. These [Cu(ida)2] units are associated with the second Cu(II) cation, which is located on a crystallographic inversion centre and is coordinated in a distorted square-planar geometry by two chelating ida ligands. The carboxylate groups of the ida ligands act as bridges and connect the [Cu(ida)] and [Cu(ida)2] building blocks in a 2:1 ratio, forming two-dimensional arrays. These layers are interconnected into a three-dimensional structure by the sodium ions. Each Na(I) cation is coordinated by six O atoms from five ida ligands and a water molecule. When [Cu(ida)], the Na(I) cations and [Cu(ida)2] are viewed as 5-, 5- and 8-connected nodes, respectively, the three-dimensional network exhibits a (3(2).4(3).5(2).6(3))2(3(2).4(3).5(2).6(3))2(3(4).6(16).7(8)) topology.

Synthesis and characterization of two- and three-dimensional coordination polymers built with 3,5-bis(4′-carboxy-phenyl)-1,2,4-triazole and/or 1,4-bis(imidazol-1-ylmethyl)benzene

Two new coordination polymers, [Cd(bct)(H2O)]·(H2O) (1) and [Zn(bct)(bip)]·2(H2O) (2) (H2bct = 3,5-bis(4′-carboxy-phenyl)-1,2,4-triazole, bip = 1,4-bis(imidazol-1-ylmethyl)benzene), have been synthesized. Their structures have been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectroscopy, and thermogravimetric analysis. Compound 1 is a two-dimensional structure with double-layered network, where bct ligands adopt a μ 4 -k 1,k 1,k 1,k 1 bridging mode linking four five-coordinate Cd ions. Compound 2 exhibits a three-dimensional framework consisting of double-layered helical chains with the bct and bip adopting μ 3 -k 1,k 1,k 1 and μ 2 -k 1,k 1 bridging mode, respectively. Complexes 1 and 2 exhibit intense emissions at 399 and 441 nm, respectively.

A novel three-dimensional AgIcoordination 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 AgI 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 AgI cations in a slightly octahedral coordination geometry. Ag3 is four-coordinated by two O atoms from two L2 anions and two AgI 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 AgI 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.

Poly[μ7-sulfanediyldiacetato-disilver(I)

In the title coordination polymer, [Ag₂(C₄H₄O₄S)], each AgI cation is four-coordinated by three of the four carboxylate O atoms and the S atom from symmetry-related sulfanediyldiacetate ligands, thus defining a distorted tetrahedral geometry at the metal centre. The AgI cations are bridged by sulfanediyldiacetate groups, leading to a two-dimensional layer structure. These layers are interconnected via Ag-S bonds to form a three-dimensional coordination polymer network overall.

Syntheses, Crystal Structures, Thermal Stabilities and Luminescent Properties of Two Pillared Layered Alkaline–Earth Coordination Polymers

Two new three-dimensional pillared layered coordination polymers, [M(2,5-PDC)H2O]n [M(II) = Sr(1), Ba (2)] were synthesized under hydrothermal conditions using alkaline–earth metal centers strontium and barium with 2,5-pyridinedicarboxylic acid as the organic ligand. The structures of two compounds have been determined by single-crystal X-ray diffraction analyses and further characterized by IR spectrum, elemental analyses, powder X-ray diffraction, and thermogravimetric analyses. The compounds are isostructural, confirmed by their powder XRD measurements. They feature a pillared layered framework structures. Within the layer, the dinuclear [M2O2] units through the bridge of the coordination water molecule are found, which are connected by carboxylate groups along the a- and b-axis, respectively. The layers are further pillared by the pyridyl groups of the 2,5-PDC2− ligands. Furthermore, the luminescent properties of two compounds have also been investigated in the solid state.

A three-dimensional coordination polymer of 3-(3,5-dicarboxybenzyloxy)benzoic acid with zinc

The synthesis is reported of the tricarboxylic acid 3-(3,5-dicarboxybenzyloxy)benzoic acid (H₃L) and the product of its reaction under solvothermal conditions with ZnII cations, namely poly[[μ₆-3-(3,5-dicarboxylatobenzyloxy)benzoato](dimethylformamide)-μ₃-hydroxido-dizinc(II)], [Zn₂(C₁₆H₉O7)(OH)(C₃H₇NO)]n, the formation of which is associated with complete deprotonation of H₃L. Its crystal structure consists of a single-framework coordination polymer of the organic L³⁻ ligand with ZnII cations in a 1:2 ratio, with additional hydroxide and dimethylformamide (DMF) ligands coordinated to the ZnII centres. The ZnII cations are characterized by coordination numbers of 5 and 6, being bridged to each other by hydroxide ligands. In the polymeric framework, the carboxylate- and hydroxy-bridged ZnII cations are arranged in coordination-tessellated columns, which propagate along the a axis of the crystal structure, and each L³⁻ ligand links to seven different ZnII centres via Zn-O bonds of two different columns. The coordination framework, composed of [Zn₂(L)(OH)(DMF)]n units, forms an open architecture, the channel voids within it being filled by the zinc-coordinating DMF ligands. This report provides the first structural evidence for the formation of coordination polymers with H₃L via multiple metal-ligand bonds through its carboxylate groups.

An Angular Bis-Oxamate Tecton for the Construction of Heterobimetallic Coordination Polymers

Two novel heterobimetallic three-dimensional coordination polymers, [Cu2Na4L2(CH3OH)2.3(H2O)5.2]·1.7H2O (1) and [CuNa2L(H2O)3.88]·H2O (2), have been obtained by assembling a bis-oxamate copper(II) complex with sodium ions (L = 4,4′-sulfonylbis(phenylene)bis(oxamate). Both coordination frameworks are constructed by connecting {Cu4L4} crosslike anionic units by sodium ions forming polymers with different topologies. The magnetic susceptibility data shows weak antiferromagnetic interaction for both compounds.

Two-Dimensional and Three-Dimensional Coordination Polymers of Hexakis(4-cyanophenyl)[3]radialene: The Role of Stoichiometry and Kinetics

Hexakis(4-cyanophenyl)[3]radialene (1) is a hexadentate ligand that has previously been shown to form isomorphous honeycomb two-dimensional (2-D) coordination polymers {[Ag(1)](X)·2(CH3NO2)}n (X = ClO4, 2a; X = PF6, 2b) upon reaction with AgClO4 and AgPF6. Within these coordination polymers, close contacts were observed between the anions and the electron-deficient [3]radialene core. Here the synthesis and characterization of four new coordination polymers of 1 and copper(I), {[Cu2(1)2](X)2·Y(CH3NO2)}n (X = BF4, Y = 20, 4a; X = PF6, Y = 14, 4b) and {[Cu(1)](X)·2(CH3NO2)}n (X = BF4, 5a; X = PF6, 5b), are reported, along with two further examples of the (6,3) network {[Ag(1)](X)·2(CH3NO2)}n (X = BF4, 2c; X = SbF6, 2d), and an 8-fold interpenetrated (10,3)-b net formed from 1 and AgClO4, {[Ag3(1)](ClO4)3·CH3NO2}n (3). Coordination polymers 2a–2d were synthesized using low ratios of ligand to metal, 1:1 to 1:3, whereas other examples described herein (compounds 3, 4, and 5) were obtained via the use of a cons...

Heat capacities and thermodynamic properties of [Co(AIP)(BPY)0.5·H2O]n·2nH2O

One three-dimensional coordination polymer [Co(AIP)(BPY)0.5·H2O]n·2nH2O (AIP, 5-aminoisophthalic; BPY, 4,4′-bipyridine) has been synthesized solvothermally and characterized by powder X-ray diffraction, FT-IR spectra. The molar heat capacities of [Co(AIP)(BPY)0.5·H2O]n·2nH2O were measured by temperature modulated differential scanning calorimetry (TMDSC) over the temperature range of 188–300K for the first time, and no phase transition or thermal anomaly was detected in the experimental temperature range. The thermodynamic parameters relative to the standard reference temperature 298.15K were derived based on the above molar heat capacities data. Besides, a two-step sequential thermal decomposition mechanism for the material was investigated through the thermogravimetry (TG-DTG) from 300 to 1073K.

First Three-Dimensional Self-Penetrating Coordination Polymer Containing Rare (10,3)-d Subnets: Synthesis, Structure, and Properties

Hydrothermal assembly of ZnII ion, a tripodal ligand with both flexible imidazole and rigid carboxylate groups [HL = 3,5-bis(imidazol-1-ylmethyl)benzoic acid hydrochloride], and rigid bidentate linker 5-iodoisophthalic acid (5-iipa) yields a novel three-dimensional (3D) self-penetrating metal–organic framework [Zn2(L)2(5-iipa)]n (1). Complex 1 exhibits a (62·8)(63·8·102) topology that is unprecedented with the rare (10,3)-d (or utp) subnets. In addition, photoluminescence was also performed on 1.

Homochiral three-dimensional coordination polymer consisting of one-dimensional copper chain: Synthesis, structure and magnetic property

Abstract Novel chiral coordination polymers, l-1 and d-1, with the formula [Cu4(OOCCH(OH)CH2COO)2] were synthesized through a reaction of copper acetate with l-malic acid and d-malic acid, respectively, in the presence of base under solvothermal condition. The X-ray crystallography for l-1 revealed that the copper centers of the complex were alternatively linked by a bis(oxygen) bridge and mixed bridge composing of oxygen and 1,3-carboxylate to construct a one-dimensional (1D) chain structure. These 1D chains interdigitated with each other to give a 3D polymer structure as a result of the coordination interaction linking the neighboring 1-D chain. The magnetic property was studied to show strong antiferromagnetic coupling (J/k = − 596 K) within the chain and negligible one between the one-dimensional chain.

Control of Self-Penetration and Dimensionality in Luminescent Cadmium Succinate Coordination Polymers via Isomeric Dipyridylamide Ligands

Reaction in aqueous solution of cadmium nitrate, succinic acid (H2suc), and one of four possible isomeric dipyridylamide coligands has afforded a series of two-dimensional (2-D) and three-dimensional (3-D) coordination polymers. All were structurally characterized by single-crystal X-ray diffraction. [Cd(suc)(4-pina)]n (1, 4-pina = 4-pyridylisonicotinamide) displays a 3-D 6-connected self-penetrated 446108 mab topology, while {[Cd(suc)(3-pna)]·2.5H2O}n (2, 3-pna = 3-pyridylnicotinamide) has a simple 3-D non-interpenetrated 41263pcu network. The supramolecular isomer 2′ has exactly the same stoichiometry and overall pcu topology as 2 but shows a difference in succinate binding mode. Compounds 1, 2, and 2′ all show similar [Cd(suc)]n layers with embedded {Cd2O2} rhomboid dimers that serve as the 6-connected nodes. {[Cd(suc)(4-pna)(H2O)]·2H2O}n (3, 4-pna = 4-pyridylnicotinamide) manifests an extremely rare 2-D 4-connected 66 layer self-penetrated topology based on cross-pillared [Cd(suc)]n helical chains. Slight adjustment of the donor disposition resulted in the formation of the 2-D (4,4) grid coordination polymer {[Cd(suc)(3-pina)(H2O)]·3.5H2O}n (4, 3-pina = 3-pyridylisonicotinamide), which has [Cd(suc)]n helical chains similar to those in 3 but avoids cross-pillaring. Luminescent and thermal properties of these four new materials are discussed.

Absorption of CO2 and CS2 into the Hofmann-Type Porous Coordination Polymer: Electrostatic versus Dispersion Interactions

Absorption of CO2 and CS2 molecules into the Hofmann-type three-dimensional porous coordination polymer (PCP) {Fe(Pz)[Pt(CN)4]}n (Pz = pyrazine) was theoretically explored with the ONIOM(MP2.5 or SCS-MP2:DFT) method, where the M06-2X functional was employed in the DFT calculations. The binding energies of CS2 and CO2 were evaluated to be -17.3 and -5.2 kcal mol(-1), respectively, at the ONIOM(MP2.5:M06-2X) level and -16.9 and -4.4 kcal mol(-1) at the ONIOM(SCS-MP2:M06-2X) level. It is concluded that CS2 is strongly absorbed in this PCP but CO2 is only weakly absorbed. The absorption positions of these two molecules are completely different: CO2 is located between two Pt atoms, whereas one S atom of CS2 is located between two Pz ligands and the other S atom is between two Pt atoms. The optimized position of CS2 agrees with the experimentally reported X-ray structure. To elucidate the reasons for these differences, we performed an energy decomposition analysis and found that (i) both the large binding energy and the absorption position of CS2 arise from a large dispersion interaction between CS2 and the PCP, (ii) the absorption position of CO2 is mainly determined by the electrostatic interaction between CO2 and the Pt moiety, and (iii) the small binding energy of CO2 comes from the weak dispersion interaction between CO2 and the PCP. Important molecular properties relating to the dispersion and electrostatic interactions, which are useful for understanding and predicting gas absorption into PCPs, are discussed in detail.

Synthesis, characterization, luminescent properties and theoretical study of two new coordination polymers containing lanthanide [Ce(III) or Yb(III)] and succinate ions

Two new three-dimensional coordination polymers [Ce2(C4H4O4)3(H2O)2]n⋅H2O 1 and [Yb2(C4H4O4)3(H2O)2]n⋅H2O 2 have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray, elemental, infrared and thermogravimetric analysis. Both compounds crystallized in the monoclinic system and space group C2/c with cell parameters a=20.1178(2), b=7.98150(10), c=14.03090(10), β=120.9050(10), cell volume=1933.07(3)Å3 for 1, and a=19.7360(3), b=7.59790(10), c=13.7564(2), β=121.3060(10), cell volume=1762.47(4) for 2. The solid-state structures of the two metal–organic frameworks (MOFs) were subjected to detailed analysis using the semiempirical Sparkle/AM1, Sparkle/PM3 and Sparkle/PM6 quantum models. The theoretical results obtained were in good overall agreement with the experimental data, although the Sparkle/PM3 model presented the highest accuracy. The luminescent spectra of 1 and 2 showed emission bands characteristic of the Ce (III) and Yb (III) at 444nm and 970nm, respectively. Thermal analysis revealed that both MOFs lost one molecule of water of hydration and two molecules of coordinated water upon heating. In compound 1, the removal of water occurred in two steps while in 2, water loss occurred in a single step.

Synthesis, Structure, and H2/CO2 Adsorption in a Three-Dimensional 4-Connected Triorganotin Coordination Polymer with a sqc Topology

A 4-connected triorganotin 3D coordination polymer in a lvt [corrected] topology has been shown to possess 1D microchannels along its crystallographic a axis. This main-group-element-containing framework structure shows selective gas adsorption, preferring CO2 and H2 over N2.

Solvothermal syntheses and crystal structures of one 1D and two 3D [PbxIy]-based coordination polymers

Reactions of PbI2 with KI, I2 and 1,2-bis(diphenylphosphino)ethane (dppe) (molar ratio = 1:5:3:4) in MeCN/EtOH under solvothermal conditions afforded a one-dimensional (1D) coordination polymer [(EP)(Pb2I6)]n (EP2 + = ethane-1,2-diylbis(ethyldiphenylphosphonium)) (1) and a three-dimensional (3D) coordination polymer [{(Pb3(μ-I)6)(dppeo)3}·EtOH]n (2) (by-product). Treatment of the same components with H2O2 under similar conditions produced another 3D coordination polymer [{Pb2(μ-I)2(μ3-I)2}(dppeo)]n (dppeo = ethane-1,2-diylbis(diphenylphosphine oxide)) (3). Compound 2 could also be prepared in a medium yield from solvothermal reactions of PbI2 with KI, I2 and dppeo (molar ratio = 1:5:3:4). Compounds 1–3 were characterized by elemental analysis, IR and single crystal X-ray diffraction. Compound 1 contains one 1D anionic [PbI3]nn − chain with EP2 + dications being embedded between chains. The EP2 + dication was in situ generated via the cleavage of CO bond of EtOH followed by alkylation of dppe. Compound 2 consists of trinuclear [Pb3(μ-I)6] fragments that are interlinked via dppeo bridges to form a 3D 6-connected net (a 41263 Schläfli symbol). Compound 3 has a 3D net (with a 66 Schläfli symbol) constructed from 1D [Pb2(μ-I)2(μ3-I)2]n chains linked by dppeo ligands. The dppeo ligand in 3 was formed in situ from the oxidation of dppe by H2O2. The optoelectronic properties of 1–3 were also investigated.

Sonochemical synthesis and characterization of nano-sized lead(II) 3D coordination polymer: Precursor for the synthesis of lead(II) oxybromide nanoparticles

Nanoparticles of a three-dimensional coordination polymer, [Pb(L)(μ2-Br)(H2O)]n (1), (L−=1H-1,2,4-triazole-3-carboxylate), have been synthesized by an ultrasonic method and characterized by scanning electron microscopy, X-ray powder diffraction, IR spectroscopy and elemental analyses. The thermal stability of compound 1 both its bulk and nano-size has been studied by thermal gravimetric (TG) and differential thermal (DTA) analyses and compared each other. Concentration of initial reagents effects and the role of power ultrasound irradiation on size and morphology of nano-structured compound 1, have been studied. Calcination of the compound 1 at 500°C under air atmosphere yields Pb3O2Br2 nanoparticles.