Hydrothermal Syntheses and Crystal Structures of Two Coordination Polymers with Terephthalic Acid and N-Donor Ligand: 2-Methyldipyrido[3,2-f:2′,3′-h]quinoxaline

Two 3D coordination polymers, [Cd(BDC)(Medpq)·H₂O]_n 1, and [Co(BDC)(Medpq)·H₂O] _n 2 (BDC = terephthalic acid, Medpq = 2-Methyldipyrido[3,2-f:2′,3′-h]quinoxaline), have been synthesized by self-assembly. The structure analyses show that both of the two coordination polymers are formed by 1D infinite chains through non-covalent interactions, and both of them are based on 1D zigzag ones. The photoluminescent study of the coordination polymer [Cd(BDC)(Medpq)·H₂O] _n shows that it exhibit fluorescent emission bands at 567.7 nm.     

Syntheses and Characterizations of Two One-Dimensional Coordination Polymers Assembled by Dicarboxylate and N-Donor Coligands

Two new coordination polymers [Mn(oba)(1,10-phen)] _n (1) and [Zn(oba)(Pbim)₂] _n (2) [H₂oba = 2-(3-carboxyphenoxy)benzoic acid, 1,10-phen = 1,10-phenanthro line and pbim = 2-(2-Pyridyl)benzimidazole] have been synthesized and structurally characterized by elemental analysis, IR and X-ray diffraction. Single-crystal X-ray analyses revealed that 2,3′-oba ligand act as a bridging ligand, exhibiting three coordination modes to link metal ion: bis-monodentate, bidentate chelating and monodentate modes. Compound 1 and 2 all demonstrate a 1D chain. There exist intermolecular hydrogen bonds which further connect the 1D structure into 2D supramolecular structure in compound 1 and 2. In addition, the luminescent property for compound 2 is also investigated in the solid state at room temperature.     

Concomitant Crystallization of Copper(II) Sachharinato Complexes with 2-methylpyrazine as a Monomer and an One-dimensional Polymer: Syntheses,Crystal Structures,Spectroscopic and Thermal Properties

The reaction of [Cu(sac)₂(H₂O)₄] · 2H₂O with 2-methylpyrazine (mpyz) leads two complexes, concomitant crystallization of a mononuclear complex [Cu(sac)₂(mpyz)(H₂O)₂] (1) and a polymeric complex [Cu(sac)₂(μ-mpyz)]_n (2). Both complexes have been characterized by elemental analyses, magnetic measurements, FT-IR and ESR, TG-DTA and single-crystal X-ray diffraction analyses. Single-crystal X-ray analyses show that complex 1 consists of discrete molecules in which the copper(II) ions exhibits a square-pyramidal coordination geometry. The individual molecules of 1 are connected into a hydrogen-bonded chain structure, which is further assembled to form a three-dimensional network by π–π stacking interactions. Complex 2 is an 1D coordination polymer in which copper(II) centers are bridged by the mpyz ligand. The chains are further assembled to form two-dimensional frameworks by π–π and C–H···π stacking interactions.     

Hydrothermal Synthesis, Characterization of Mn(II) and Cd(II) Coordination Polymers Assembled from Semi-Rigid Oxo-Bridged Carboxylate and N-Donor Ligands

Two new metal–organic coordination polymers containing Mn(II) and Cd(II) with oxo-bridged and N-donor ligands, [Mn(oba)(2,2′-bipy)] _n (1) and {[Cd(oba)(bib)]·H₂O} _n (2) [2,3′-H₂oba = 2-(3-carboxyphenoxy)benzoic acid, 2,2′-bipy = 2,2′-bipyridine, and bib = 4,4′-bis(2-methylimidazole-1-ylmethyl)biphenyl], have been prepared and characterized by elemental analysis, Fourier infrared spectroscopy, and X-ray diffraction. Complex 1 has a 3D supramolecular network constructed from 1D zigzag chain via π–π stacking interactions. Complex 2 features 1D ladder-like chain which consists of 1D helical arrays and bib pillars. Moreover, photoluminescence properties of the bib ligand and the Cd(II) complex were investigated.     

Hydrothermal Synthesis of Metal–Organic Coordination Polymers Constructed from Asymmetric Semi-rigid V-shaped Dicarboxylate and Nitrogen-Contained Mixed Ligands

Three new coordination polymers, [Ni(2,4′-oba)(1,10-phen)] _n (1), {[Ni (2,4′-Hoba)₂(4,4′-bipy)(H₂O)₂]·2H₂O} _n (2) and [Zn(2,4′-oba) (4,4′-bipy)] _n (3) (2,4′-H₂oba = 2-(4-carboxyphenoxy)benzoic acid, 1,10- phen = 1,10-phenanthroline, and 4,4′-bipy = 4,4′-bipyridine) have been obtained by hydrothermal synthesis. The framework structures of these polymeric complexes have been determined by single-crystal X-ray diffraction studies. Complex 1 exhibits double-helical chains formed by π–π stacking interactions from the phenyl rings of the 1,10-phen ligands. Complex 2 forms a two-dimensional supramolecular architecture directed by hydrogen bonding. Complex 3 exhibits a three-dimensional structure; Schl?fli symbol of {4⁴·6¹⁰·8}. The luminescent property of compound 3 is discussed.     

One-Dimensional Coordination Polymer Assembled by Tetraaza Macrocyclic Nickel(II) Complex and trans-1,4-Cyclohexanedicarboxylate ligand

The reaction of [Ni(L)]Cl₂·2H₂O (L = 3.14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) with trans-1,4-cyclohexanedicarboxylic acid (H₂chdc) generates a 1D coordination and 2D hydrogen-bonded polymer {[Ni(L)(chdc)₂]·2H₂O}_n (1). The polymer complex was characterized by X-ray crystallography, spectroscopy and magnetic susceptibility. Each nickel(II) ion has a distorted octahedral coordination environment with the four secondary amines of the macrocycle in which two trans carboxylate anions of the chdc²⁻ ligand have assembled around each nickel center. The electronic spectrum of 1 in the solid state exhibits a high-spin octahedral environment. The magnetic behavior of 1 reveals a weak intramolecular antiferromagnetic interaction with J values of −1.15(2) cm⁻¹.     

Syntheses, Structures and Luminescent Properties of Three new Zinc(II) Complexes Constructed from Dicarboxylate and N-donor Coligands

Three new metal coordination polymers, [Zn(oba)(bim)]_n (1), [Zn(oba)(2,2′-bipy)]_n (2) and [Zn(oba)(pbim)]_n (3) [H₂oba = 2-(4-carboxyphenoxy)benzoic acid, bim = benzimidazole,2,2′-bipy = 2,2′-bipyridine and pbim = 2-(4-Pyridyl)benzimidazole], were synthesized and structurally characterized by elemental analysis, IR and X-ray diffraction. Compound 1 is a two-dimensional supramolecular framework, which is connected by one-dimensional chains through hydrogen bonding interactions. In compound 2, an alternate arrangement of the right- and left-handed helical chains through interchained π-π stacking interactions, formed a two-dimensional supramolecular framework. Compound 3 exhibited a 2D → 3D interdigital architecture with side arms. In compounds 1, 2 and 3, the oba²⁻ ligands act as bridging ligands exhibiting three coordination modes to link metal ions; i.e., bis-monodentate, bidentate chelating and monodentate modes. The luminescent properties of 1, 2 and 3, were also investigated.     

One-Dimensional Cobalt(II) and Zinc(II) Succinato Coordination Polymers with Nicotinamide: Synthesis, Structural, Spectroscopic, Fluorescent and Thermal Properties

Cobalt(II) and zinc(II) succinato (suc) coordination polymers with nicotinamide (nia), {[Co(μ-suc)(H₂O)₂(nia)₂] · 2H₂O} _n (1) and {[Zn(μ-suc)(H₂O)₂(nia)₂] · 2H₂O} _n (2) have been synthesized and characterized by elemental analyses, magnetic moments, IR and TG-DTA. Single-crystal X-ray analyses of 1 and 2 reveal that these complexes are isostructural and crystallize in triclinic space group Complexes 1 and 2 are 1-D coordination polymers, in which the metal(II) ions exhibit an octahedral geometry with two suc, two nia and two aqua ligands. The nia ligand is N-bonded, while the suc ligand bridges the metal centers through the carboxylate groups. The 1D chains are further assembled to form 3D networks by strong N–H···O and OW–H···O hydrogen bonds. IR spectra confirm the coordination modes of both suc and nia ligands, while TG-DTA data are in agreement with the crystal structures. Fluorescent analysis in the solid state shows that all complexes display intraligand (π–π*) emissions of nia.     

A New Nitrosyl-bridged Bimetallic Nitroprusside Complex: Synthesis,Crystal Structure,Supramolecular Self-assembly and Spectral Behavior of Interactions with DNA

A new nitrosyl-bridged bimetallic nitroprusside complex, [Ba(phen)₃(H₂O)][Fe(CN)₅NO]·1.5phen·2H₂O (phen = 1,10-phenanthroline) (1), has been synthesized and characterized by elemental analysis and single crystal X-ray diffraction. The crystal structure analysis reveals that complex 1 crystallizes in the triclinic space group Pī. The asymmetric structural unit is comprised of one [Ba(phen)₃(H₂O)]²⁺ complex cation, one [Fe(CN)₅NO]^2– complex anion, 1.5-uncoordinated phenanthroline molecules and two lattice water molecules. The complex ions are linked into a 1D chain-like arrangement by the trans CN and NO groups in nitroprusside. The six-coordinated Fe-atom forms a distorted octahedral coordination configuration, and the Ba-atom has a nine-coordinate monocapped antiprismatic geometry. Five types of π–π stacking interactions of phenanthroline and some intra- and intermolecular hydrogen bonds are observed in the 3D supramolecular self-assembly. Absorption spectroscopy, fluorescence titration and viscometry studies of the interaction between complex 1 and calf thymus DNA indicate that complex 1 is a moderate metallo-intercalator with the intrinsic binding constant of 3.70 × 10⁴ M⁻¹ and the linear Stern–Volmer quenching constant of 5.98 × 10⁴ M⁻¹.     

Synthesis, Supramolecular Architecture and DNA Binding Studies of a Novel Heterotrinuclear FeIII/CoII/FeIII Complex: [Co(phen)2][Fe(phen)(CN)4]2·4H2O (phen?=?1,10-phenanthroline)

A novel cyano-bridged heterotrinuclear Fe^III/Co^II/Fe^III complex, [Co(phen)₂][Fe(phen)(CN)₄]₂·4H₂O (1) (phen = 1,10-phenanthroline), has been synthesized under solvothermal conditions, and characterized by elemental analysis, FI-IR spectrum and single-crystal X-ray diffraction. The structure analysis reveals complex 1 is constructed into a 3D supramolecular architecture through abundant intermolecular non-covalent interactions. According to the supramolecular self-assembly of complex 1, five types of π–π stacking models of phenanthroline ligands, hydrogen bonds formed by four lattice water molecules, and C–H···N weak interactions involving cyano groups are all observed. Electronic absorption spectroscopy and fluorescence titration studies of the interaction between complex 1 and calf thymus DNA are suggestive of an intercalative binding mode with an intrinsic binding constant of 7.95 × 10³ M⁻¹ and a linear Stern–Volmer quenching constant of 1.033 × 10⁵ M⁻¹.     

Controllable Self-assembly of Sandwich-type Mixed (phthalocyaninato)(porphyrinato) Rare Earth Triple-Decker Complexes

Two novel sandwich-type mixed (phthalocyaninato)(porphyrinato) rare earth complexes Tb₂[TClPP]₂Pc (1) and Tb₂[TClPP] Pc₂ (2) [Pc = phthalocyaninate, TClPP = meso-tetrakis (4-chlorophenyl) porphyrinate] have been fabricated into nanostructures by a solution-based method. Their self-assembly properties have been comparatively studied by electronic absorption spectroscopy, transmission electron microscope (TEM), X-ray diffraction (XRD) techniques and current–voltage (I–V) measurements. Due to the different number of porphyrin and phthalocyanine ligands interference, the self-assembly of the two molecules results in totally different morphologies in aggregate: one-dimensional (1D) nanoribbon from 1 vs. two-dimensional (2D) nanosheet from 2. The electronic absorption measurements indicated that J-type aggregates have been formed with the increasing red-shifted degree from nanoribbons to nanosheets depending on the competition and cooperation between the inter-molecular π–π interaction and van der Waals for different compounds. Examination by XRD revealed that in the nanostructures of 1 and 2, a dimeric supramolecular structure was formed through an intermolecular π–π interaction and van der Waals between two sandwich-type molecules, which as the building block self-assembles into the target nanostructures. In addition, the nanosheets from 2 were revealed to show excellent semiconducting properties with the conductivity of 3.0 × 10⁻³ S m⁻¹ in air due to readily π-stacks with adjacent planar molecules enhanced by higher ordered crystalline molecular arrangement.     

Hydrothermal Synthesis of Cd(II), Mn(II) and Ni(II) Coordination Polymers Derived from Benzopenone-2,4′-carboxylate and N-door Ligands

Three new coordination polymers [Cd(L)(4,4′-bipy)_0.5]_n (1), {[Mn(L)(bpp)]·H₂O}_n (2) and [Ni(L)(2,2′-bipy)(H₂O)₂]_n(3) [H₂L = Benzopenone-2,4′-dicarboxylic acid, 4,4′-bipy = 4,4′-bipy ridine, bpp = 1,3-di(4-pyridyl) propane and 2,2′-bipy = 2,2′-bipyridine] have been synthesized and structurally characterized by elemental analysis, IR and X-ray diffraction. Single-crystal X-ray analyses revealed that the H₂L ligand acts as a bridge, exhibiting three coordination modes to link metal ion: bidentate chelating, bis-monodentate, monodentate. Compound 1 has 3-connected metal–organic framework with the (6³) topology notation; Compounds 2 and 3 are one-dimensional chain structures. The luminescent properties for compound 1 was investigated.     

Sonochemical Synthesis of New Nano-Belt One-Dimensional Double-Chain Lead(II) Coordination Polymer; As Precursor for Preparation of PbBr(OH) Nano-Structure

Nano-structure of a new 1D double-chain Pb(II) coordination polymer, [Pb(μ-HPDC)(μ-Br)(H₂O)]_n (1), {H₂PDC = 2,3-pyrazinedicarboxylic acid} was synthesized by a sonochemical method. The new nano-structure was characterized by scanning electron microscopy, X-ray powder diffraction, IR spectroscopy and elemental analyses. The structure of compound 1 was determined by single crystal X-ray diffraction and consists of 1D double-chain polymeric units. The coordination number in compound 1 is six and each lead atom is coordinated by two oxygen atoms of HPDC⁻, two nitrogen atoms of HPDC⁻ ligands, one bromide atom and one oxygen of H₂O molecule. The thermal stability of compound 1 was studied by thermal gravimetric and differential thermal analyses. Calcination of the nano-belts of compound 1 at 500 °C under air atmospheres yielded nano-sized particles of PbBr(OH) that characterized by scanning electron microscopy and X-ray powder diffraction.     

Hydrothermal Synthesis and Crystal Structures of Cd(II)-Based 1D Coordination Polymer and Mn(II) Coordination Complex with Mixed N- and O-donor Ligands: [Cd2(4-4′-bpy)2(pa)4]n·0.25(H2O) and [Mn(4-4′-bpy)2(pa)(H2O)3]ClO4·2(H2O)

Two new complexes, [Cd₂(4-4′-bpy)₂(pa)₄] _n ·0.25H₂O (1) (pa = phenylacetate), and [Mn(4-4′-bpy)₂(pa)(H₂O)₃]ClO₄·2H₂O, (2), have been obtained from hydrothermal reaction of Cd(NO₃)₂·4H₂O and Mn(ClO₄)₂·6H₂O with a mixture of the ligands, 2-phenylmalonic acid (2-phmalH₂) and 4-4′-bipyridine (4-4′-bpy). The pa is formed in situ by decarboxylation of phenylmalonic acid. These complexes have been characterized by elemental analysis, FT-IR spectroscopy, thermogravimetric analysis and single-crystal X-Ray diffraction. The Cd(II) center is seven-coordinate and linked via pa ligands to form a binuclear complex in the asymmetric unit of 1. A ladder-like 1D chain of binuclear units is formed by Cd(II)–N coordination bond through 4-4′-bpy ligands. Complex 2 consists of a mononuclear manganese center based on a distorted octahedral geometry and exhibits a supramolecular structure containing hydrogen bonds and extensive π···π and C–H···π interactions.     

One Dimensional Coordination Polymer of Nickel(II)-Squarate with N,N,N′,N′-tetramethylethylenediamine, {[Ni(μ-sq)(H2O)2(tmen)]·H2O}n

A novel 1D coordination polymer {[Ni(μ-sq)(H₂O)₂(tmen)]·H₂O}_n (H₂sq = squaric acid and tmen = N,N,N′,N′ -tetramethylethylenediamine) has been synthesized and structurally characterized by X-ray crystallography. The spectral (IR and UV-vis.) and magnetic susceptibility are reported. The structure of the complex consists of the bidentate tmen ligand bound to Ni(II) center and a bridging squarate in the 1,3-bonding mode. The distorted octahedral geometry of Ni(II) is completed by two aqua ligands. The structure contains chains of squarato-O ¹ ,O ³ -bridged polynuclear nickel(II) units held together by intermolecular hydrogen bonds interactions between water molecules and oxygen atoms of squarate ligand forming a novel R6 motif.     

Crystal Structure and Magnetic Properties of a Novel Helical Coordination Polymer [Cu2(pda)2(phen)2(H2O)2]·6H2O

A novel coordination polymer of Cu^II with flexible ligands, namely, [Cu ₂ (pda) ₂ (phen) ₂ (H ₂ O) ₂ ]·6H ₂ O (1) (H₂pda = 1,3-phenylenediacetic acid, phen = 1,10-phenanthroline), was synthesized by hydrothermal reactions and characterized by single-crystal X-ray diffraction, thermogravimetric analyses, elemental analysis and IR spectroscopy. In complex 1, the Cu^II ions are linked by pda ligands to form 1D helical chains. The adjacent chains are related by the π–π stacking interactions and exhibit opposite chirality, which result in extended 2D heterochiral helical-layers. Furthermore, the 2D helical-layers are assembled into 3D supramolecular edifices through heterochiral helical hydrogen bonding. In addition, the thermal stability and magnetic properties of 1 are reported.     

A New Series Lanthanide-2,6-Pyridinedicarboxylic Acid Complexes Containing Low Dimensionality: Synthesis,Structure and Photoluminescent Properties

Abstract  

Based on the 2,6-pyridinedicarboxylate acid ligand, ten lanthanide complexes with formula, (Hdipa)₃[Ln(L)₃] (Ln = Eu [1], Gd [2], Nd [3], Tb [4], Ce [5], Sm [6], Pr [7], Dy [8] and Er [9]) and [Nd(L)(HL)(H₂O)₂]·4H₂O (10), (where H₂L = 2,6-pyridinedicarboxylic acid and dipa = N-(1-methylethyl)-2-propanamine) have been prepared by different synthetic methods. Structural analyses reveal that complexes 1–3 are isomorphous, zero-dimensional structures, which are further connected to 3D H-bonding networks via extensive intermolecular hydrogen bonds. In the structures of these complexes, the dipa plays a key role in balancing electric charge. For complex 10, the 1D Ln–O–C–O–Ln polymeric chains are linked into a stable 3D H-bonding framework through numerous intermolecular and intramolecular hydrogen bonds. The luminescent properties of complexes 1, 4, 6 and 8 were investigated in detail.     

Synthesis and Characterization of One-Dimensional Zinc(II) Coordination Polymers as Precursors for Preparation of ZnO Nanoparticles via Thermal Decomposition

Two new Zn(II) coordination polymers from the ligand, 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene (bpdh), with different anions; i.e., [Zn(μ-bpdh)(H₂O)₄](ClO₄)₂·2bpdh (1) and [Zn(μ-bpdh)(H₂O)₄](NO₃)₂·2bpdh (2), were synthesized and characterized by IR spectroscopy, elemental analyses and X-ray crystallography. Compounds 1 and 2 are 1D coordination polymers and the zinc atoms are linked by four oxygen atoms from water molecules and two nitrogen atoms of bpdh ligands. There are two uncoordinated bpdh ligands that, along with the perchlorate or nitrate anions, form hydrogen bonds with water molecules. ZnO nanoparticles were obtained by thermolysis of 1–2 in oleic acid at 280 °C in air. The ZnO nanoparticles were characterized by X-ray diffraction and scanning electron microscopy.     

Synthesis and Crystal Structures of Two New Coordination Polymers Based on Diphenic Acid

Two new metal coordination polymers [Zn(dpa)(bim)] _n and [Ni(dpa)(bpp)] _n , (H₂dpa = 3,4′-Biphenyl-dicarboxylic acid, bim = Benzimidazole and bpp = 1,3-Di (4-pyridyl)-propane) have been synthesized and structurally characterized by elemental analysis, IR and X-ray diffraction. Single-crystal X-ray analyses reveal that the 3,4′-diphenic acids act as bridging ligands, exhibiting three coordination modes to link metal ions: μ ₂–η ¹: η ¹, μ ₁–η ¹: η ⁰ and μ ₁ –η¹: η¹. Compound 1 demonstrates a one-dimensional zigzag chain. There exists intermolecular hydrogen bonding interactions in compound 1 which lead to form supramolecular structure. Compound 2 is a two-dimensional (4,4) net, and further assembled twofold interpenetrating net. Furthermore, compound [Zn(dpa)(bim)] _n shows intense photoluminescence at room temperature.     

A Novel Bimetallic Chain Based on [Mo(CN)<Subscript>8</Subscript>]<Superscript>3−</Superscript> and Yb<Superscript>3+</Superscript> Ions as Building Blocks in Which Containing Many Intriguing Structural Features

A novel Mo^V–Yb^III bimetallic chain, {[Yb^III(bpy)₂(DMF)(H₂O)][Mo^V(CN)₈]·0.5bpy·4.5H₂O}_n (1) (DMF = N,N′-dimethylformamide; bpy = 2,2′-bipyridine), has been constructed by the reaction of [Mo(CN)₈]³⁻ with Yb³⁺ and 2,2′-bipyridine. Complex 1 is confirmed as a host–guest supramolecular structure by X-ray structural analysis. The neighboring chains interact with each other with two types of hydrogen bonds and two types of π···π interactions. Thus complex 1 has a unique 3D network. Magnetic analysis of 1 indicates the presence of a strong Yb^III single-ion effect owing to spin–orbital coupling within this system.