Synthesis,Crystal Structure and Thermal Properties of a Novel Ferrocenecarboxylato-Bridged Zinc(II) Dimer [Zn2(µ-OOCFc)4(3-PyCOOCH3)2]

A novel ferrocenyl dimer [Zn₂(μ-OOCFc)₄(3-PyCOOCH₃)₂] (Fc=(η⁵-C₅H₅)Fe(η⁵-C₅H₄)), 1, was obtained by the reaction of Zn(OAc)₂·2H₂O with sodium ferrocenecarboxylate and 1,4-butanediol dinicotinate in methanol solution. X-ray structural analysis reveals that the compound contains two zinc(II) centers symmetrically bridged by four ferrocenecarboxylate anions as O,O′-bridging ligands, leading to a dimeric tetrabridged [Zn₂(μ-OOCFc)₄] core. The zinc(II) ion is in a distorted octahedral environment with four oxygen atoms from four distinct ferrocenecarboxylates, a nitrogen atom from the ligand NC₅H₄CO₂CH₃, and another zinc atom. The symmetry of the complex in the paddle-wheel structure brings the metal centers close, the Zn … Zn intradimer distance being 2.934(11) Å. It is the first example of a zinc(II) dimer with ferrocenecarboxylate anion ligands. Its thermal properties were measured in air.     

X-ray diffraction and vibrational spectroscopic studies of indolecarboxylic acids and their metal complexes: Part VII. Indole-2-carboxylic acid and catena-poly[[diaquazinc(II)]-bis(μ2-indole-2-carboxylato-O:O′)]

The catena-poly[[diaquazinc(II)]-bis(μ²-indole-2-carboxylato-O:O′)], [Zn(I2CA)₂(H₂O)₂]_n has been synthesized and characterized by X-ray diffraction analysis and the infrared and Raman spectroscopic methods. The co-ordination of the indole-2-carboxylate anion to Zn(II) results in the formation of the [Zn(I2CA)₂(H₂O)₂]_n, in which the Zn(II) cations lie on inversion centres in space group P2_1/c, with water ligands in the apical sites of octahedral geometry. Moreover, the infrared and Raman spectra of indole-2-carboxylic acid (I2CA) and the infrared spectrum of deuterated derivative of indole-2-carbocylic acid (I2CA-d2) are recorded in the solid phase. The theoretical wavenumbers, infrared intensities and Raman scattering activities were calculated by density functional B3LYP and mPW1PW91 methods with the 6-311++G(d,p) basis set for I2CA and I2CA-d2 and with the 6-311++G(d,p)/LanL2DZ basis sets for the theoretical model of Zn(I2CA)₂(H₂O)₂]_n. The detailed vibrational assignment has been made on the basis of the calculated potential energy distribution for all molecules.     

Syntheses,Crystal Structures,and Properties of Two IB Group Metal Coordination Polymers Based on 2-(Trifluoromethyl)-1H-Imidazole-4,5-Dicarboxylate

Two new IB group metal coordination polymers, namely, {[Cu₃(TFMIDC)₂(H₂O)₂] · 4H₂O}n (I) and [Ag₂(HTFMIDC)(Py)] _n (II) (H₃TFMIDC = 2-(trifluoromethyl)-1H-imidazole-4,5-dicarboxylic acid, Py = pyridine), have been successfully prepared and structurally characterized by different techniques including single crystal X-ray diffraction (CIF files CCDC nos. 1545402 (I) and 1545403 (II)), IR spectra, and powder X-ray diffraction. Compound I features an interesting two-dimentional (2D) sheet containing 1D left-handed and right-handed helical chains, while compound II exhibits an infinite 1D zig–zag chain structure. Both two coordination polymers further stack through weak interactions to give rise to 3D supramolecular frameworks. Furthermore, the thermal stabilities of I and II as well as the photoluminescent property of II were also studied.     

Tetranuclear Zn(II) and Mononuclear Nickel(II) Complexes Based on Asymmetric Salamo-Type Ligands: Syntheses,Crystal Structures,and Fluorescent Properties

Two new complexes [{Zn(L¹)(μ-OAc)Zn(CH₃CHOHCH₃)}₂] and [Ni(L₂)(H₂O)(CH₃OH)] with asymmetric Salamo-type ligands (H₃L¹ and H₂L²) are synthesized and structurally characterized. In the Zn(II) and Ni(II) complexes, the terminal and central Zn(II) atoms are found to have slightly distorted square pyramidal and trigonal bipyramidal symmetries respectively, while the Ni(II) atom is hexa-coordinated and has a slightly distorted octahedral symmetry. Interestingly, a self-assembling continual zigzag 1D chain is formed by intermolecular hydrogen bonds in the Ni(II) complex. Furthermore, the Zn(II) and Ni(II) complexes in the ethanol solution show intense photoluminescence.     

A 1D linear chain coordination polymer constructed by Cu(II) with H<Subscript>3</Subscript>Tci and Bipy ligands (H<Subscript>3</Subscript>Tci = tris(2-carboxyethyl)isocyanurate,Bipy = 4,4′-bipyridine)

A new coordination polymer [Cu(H₂Tci)₂(Bipy)(H₂O)] · 2H₂O (I) (H₃Tci = tris(2-carboxyethyl)isocyanurate, Bipy = 4,4′-bipyridine) has been synthesized and characterized by elemental analysis, IR, and X-ray single-crystal diffraction. The X-ray diffraction analysis reveals that I (C₃₄H₄₂CuN₈O₂₁) crystallizes in the monoclinic crystal system, space group P2₁/c. In I, the metal centers are linked by Bipy ligands to generate an infinite linear chain and the H₂Tci ligands adopt monodentate coordination mode to graft the linear chain. The adjacent chains are linked by hydrogen bonds to form a three-dimensional supramolecular framework.     

Syntheses,Crystal Structures,and Properties of Two <Emphasis Type="Italic">d</Emphasis><Superscript>10</Superscript> Metal Complexes Based on Ferrocenyl Ligands Bearing Pyrazolyl Pyridine Substituents

Two new complexes, namely, [Cd₂(L¹)₂(NCS)₄(DMF)₂] · 4H₂O (I) and {[Zn₃(L²)₄(SO₄)₃(H₂O)₈] · 3DMF · 6H₂O} _n (II) have been synthesized through self-assembly of Cd(II) or Zn(II) salts with ferrocenyl ligands bearing pyrazolyl pyridine substituents. The two compounds were characterized by IR spectra, element analysis, X-ray powder diffraction, single-crystal X-ray diffraction (СIF files CCDC nos. 949526 (I), 949527 (II)), and thermogravimetric analysis. Complex I crystallizes in the monocline space group P21/c and exhibits a discrete dinuclear structure. The adjacent dinuclear molecules are packed into a 1D linear chain through the hydrogen-bond interactions. Complex II is a neutral one-dimensional infinite zigzag coordination chain. The 3D packing diagram of II contains two types of voids and the solvated DMF and water molecules filled them and stabilized by the hydrogen bonds. In addition, the redox properties of both complexes I and II have also been investigated.     

以3, 5-二甲基-1-羧甲基-4-吡唑甲酸为配体的两个锌的配合物的合成、晶体结构和荧光性能

以3, 5-二甲基-1-羧甲基-4-吡唑甲酸和4, 4'-联吡啶为配体, 合成了1个单核锌(II)配合物[Zn(4,4'-bpy)(Hcmdpca)₂(H₂O)₃]·2H₂O (1)和1个锌(II)的一维配位聚合物[Zn(4, 4'-bpy)(Hcmdpca)₂(H₂O)]·3H₂O (2)(H₂cmdpca=3, 5-二甲基-1-羧甲基-4-吡唑甲酸;4, 4'-bpy=4, 4'-联吡啶), 并用元素分析、红外光谱、X-射线单晶衍射结构分析、热重分析等对其进行了表征。配合物1和2都属于单斜晶系, 空间群为P2₁/c。配合物1的锌离子都位于一个畸变的八面体构型中。配合物1中的独立结构单元间通过分子间氢键作用构成一个三维的超分子结构。而在2中, 锌离子位于一个畸变的四方锥构型中, 每个4, 4'-联吡啶分子桥联2个相邻的 锌(II)离子, 形成一个一维链;这些一维链和水分子通过分子间氢键进一步形成一个三维的结构。此外还考察了1和2的热稳定性和固体荧光性质。     

Hydrogen-bond networks of 1,3-imidazolidine-2-thione: synthesis and structures of complexes of silver(I), copper(I), cadmium(II) and zinc(II)

Solution reactions of silver(I), copper(I), cadmium(II) and zinc(II) salts with 1,3-imidazolidine-2-thione (imdt) under diverse conditions yielded four complexes: [Cd(SC₃H₆N₂)₂(Ac)₂] (1), [Zn(SC₃H₆N₂)₂(Ac)₂] (2), [Cu₂(SC₃H₆N₂)₆]SO₄ (3) and [Ag₂(SC₃H₆N₂)₆]SO₄ (4). Complexes 1 and 2 are 1D and 2D hydrogen-bond aggregations. Complexes 3 and 4 are isostructural 3D hydrogen-bond networks. The diverse coordination modes of imdt and different anions are the major factors for three distinct hydrogen-bond structures.     

Hydrothermal synthesis and structural characterization of a new one-dimensional ladder-shaped metal-organic framework Zn(HTci)(4,4′-bipy)0.5 · H2O (H3Tci = tri(2-carboxyethyl)isocyanurate, 4,4′-bipy = 4,4′-bipyridine)

A new metal-organic coordination polymer, namely, Zn(HTci)(4,4′-Bipy)_0.5 · H₂O (I) (H₃Tci = tri(2-carboxyethyl)isocyanurate, 4,4′-Bipy = 4,4′-bipyridine), has been synthesized under hydrothermal conditions by the reaction of zinc nitrate, H₃Tci, and 4,4′-Bipy with the presence of H₂O and characterized by elemental analysis, IR and X-ray single-crystal diffraction. The X-ray diffraction analysis reveals that I crystallizes in the triclinic system, $P\bar 1$ space group. The unit cell parameters for I: a = 5.248(1), b = 12.537(2), c = 14.597(2) Å, α = 91.91(1)°, β = 91.22(2)°, γ = 95.75(1)°, V = 954.8(3) ų, Z = 2.     

Bis­(saccharinato‐κN)zinc(II) com­plexes with N,N′‐bidentate 2‐amino­methyl­pyridine and 2‐amino­ethylpyridine

The structures of trans‐bis[2‐(amino­methyl)­pyridine‐κ²N,N′]­bis­(saccharinato‐κN)­zinc(II), [Zn(C₇H₄NO₃S)₂(C₆H₈N₂)₂], (I), and [2‐(amino­ethyl)­pyridine‐κ²N,N′]bis­(saccharinato‐κN)­zinc(II), [Zn(C₇H₄NO₃S)₂(C₇H₁₀N₂)], (II), exhibit octa‐ and tetrahedrally coordinated Zn^II atoms, respectively. The di­amine ligands behave as N,N′‐bidentate ligands, while saccharinate (sac) is coordinated through the N atom. In (I), the complex lies about an inversion centre with the Zn atom disordered and displaced by 0.256 (2) Å from a centre of symmetry towards a sac N atom. The crystal structure of (I) is stabilized by N—H⋯O hydrogen bonds and the crystal packing of (II) is determined by hydrogen bonding as well as weak π–π stacking interactions between the sac ligands.     

Solvent extraction of zinc by 2-hexylpyridine in benzene from aqueous mineral acid — Thiocyanate media

Solvent extraction of Zn(II) by 2-hexylpyridine (HPy) in benzene has been studied from aqueous mineral acid—thiocyanate media. The extraction, though dependent on the acidity of the aqueous phase, is poor from mineral acids (HCl, HNO₃ or H₂SO₄). Addition of 0.02M KSCN to the aqueous phase enhances the distribution ratio by a factor of almost one thousand. The stoichiometry of the extracted complex established by the usual slope analysis method indicates that an ionic type complex, e.g. Zn(SCN)₄·(HPyH)₂, is responsible for extraction. Complexing anions like acetate, oxalate or citrate at 1 M concentration mask the extraction of Zn(II) almost completely. Separation factors determined at optimal conditions (0.1M HPy in benzene −0.05M H₂SO₄+0.2M SCN⁻) indicate that Zn(II), along with Hg(II), can be separated in a single extraction from a number of metals, e.g. Cs(I), Sr(II), Ln(III), Y(III), Cr(III) and (VI). Other metals of interest like Cu(II), Co(II), Fe(III), Mo(VI), U(VI) and Tc(VII) are coextracted but the separation factors are large enough to allow separation in a multistage extraction process.     

Zinc coordination polymers with rigid dicarboxylates and semirigid 3,5-bis(imidazole-1-yl) pyridine: syntheses,structural topologies,and luminescent properties

Two metal coordination polymers, {[Zn(bpdc)(bip)]·2H₂O}_n (1) and [Zn(tdc)(bip)] (2) [H₂bpdc?=?biphenyl-4,4’-dicarboxylate, H₂tdc?=?thiophene-2,5-dicarboxylate, bip?=?3,5-bis(imidazole-1-yl)pyridine], have been synthesized and characterized by IR, elemental analysis, XRD, and X-ray single-crystal diffraction. In 1, bpdc and bip link Zn(II) ions into a corrugated 2D layer. The corrugated 2D layers polycatenate each other, yielding a 2D→3D polycatenation net. In 2, dinuclear Zn(II) units are formed by bip and further connected by tdc to construct a 2D 3-connected framework. The luminescent properties of 1 and 2 are investigated in the solid state at room temperature.     

One-dimensional zinc(II) fumarate coordination polymers

A new procedure developed for the synthesis and crystallization of various zinc(II) fumarate hydrate coordination polymers is described. In the first step, anhydrous Zn(II) fumarate, [Zn(C₄H₂O₄)] (1), is synthesized from Zn(II) acetate and fumaric acid in methanol. Subsequently, this product is used as a starting material for growing small crystals of bis–aqua Zn(II) fumarate, [Zn(H₂O)₂(C₄H₂O₄)] (2), triaqua Zn(II) fumarate monohydrate, [Zn(H₂O)₃(C₄H₂O₄)]·H₂O (3), tetraaqua Zn(II) fumarate, [Zn(H₂O)₄(C₄H₂O₄)] (4), and tetraaqua Zn(II) fumarate monohydrate, [Zn(H₂O)₄(C₄H₂O₄)]·H₂O (5). All structures were determined or redetermined by X-ray structure analyses. The hitherto unknown compound 3 exhibits a zig-zag chain structure with five-coordinate Zn(II) ions.     

Syntheses and structures of two novel fluorescent metal–organic frameworks generated from a tridentate donor–acceptor motif ligand

The tridentate organic ligand 4,4′,4′′‐(4,4,8,8,12,12‐hexamethyl‐8,12‐dihydro‐4H‐benzo[9,1]quinolizino[3,4,5,6,7‐defg]acridine‐2,6,10‐triyl)tribenzoic acid ( H₃L ) has been synthesized (as the methanol 1.25‐solvate, C₄₈H₃₉NO₆·1.25CH₃OH). As a donor–acceptor motif molecule, H₃L possess strong intramolecular charge transfer (ICT) fluorescence. Through hydrogen bonds, H₃L molecules construct a two‐dimensional (2D) network, which pack together into three‐dimensional (3D) networks with an ABC stacking pattern in the crystalline state. Based on H₃L and M(NO₃)₂ salts (M = Cd and Zn) under solvothermal conditions, two metal–organic frameworks (MOFs), namely, catena‐poly[[triaquacadmium(II)]‐μ‐10‐(4‐carboxyphenyl)‐4,4′‐(4,4,8,8,12,12‐hexamethyl‐8,12‐dihydro‐4H‐benzo[9,1]quinolizino[3,4,5,6,7‐defg]acridine‐2,6‐diyl)dibenzoato], [Cd(C₄₈H₃₇NO₆)(H₂O)₃]_n, I , and poly[[μ₃‐4,4′,4′′‐(4,4,8,8,12,12‐hexamethyl‐8,12‐dihydro‐4H‐benzo[9,1]quinolizino[3,4,5,6,7‐defg]acridine‐2,6,10‐triyl)tribenzoato](μ₃‐hydroxido)zinc(II)], [Zn₂(C₄₈H₃₆NO₆)(OH)]_n, II , were synthesized. Single‐crystal analysis revealed that both MOFs adopt a 3D structure. In I , partly deprotonated HL ^2? behaves as a bidentate ligand to link a Cd^II ion to form a one‐dimensional chain. In the solid state of I , the existence of weak interactions, such as O—H…O hydrogen bonds and π–π interactions, plays an essential role in aligning 2D nets and 3D networks with AB packing patterns for I . The deprotonated ligand L ^3? in II is utilized as a tridentate building block to bind Zn^II ions to construct 3D networks, where unusual Zn₄O₁₄ clusters act as connection nodes. As a donor–acceptor molecule, H₃L exhibits fluorescence with a photoluminescence quantum yield (PLQY) of 70% in the solid state. In comparison, the PL of both MOFs is red‐shifted with even higher PLQYs of 79 and 85% for I and II , respectively.     

(C5H14N2)[Zn3(HPO4)4], a New 3D Open‐framework Zincophosphate Synthesized by Hydrothermal Reversible Transformation of (C5H14N2)[Zn2(HPO4)3]·H2O

In the system ZnO/H₃PO₄/H₂O/1,4‐diazacycloheptane (C₅H₁₂N₂), a new zincophosphate (ZnPO), (C₅H₁₄N₂)[Zn₃(HPO₄)₄] ( I ), was prepared by hydrothermal transformation (180 °C) of the known ZnPO hydrate (C₅H₁₄N₂)[Zn₂(HPO₄)₃]·H₂O ( II ). The thermally‐induced transformation is reversible; upon keeping the heterogeneous mixture of I and mother liquor at 80 °C recrystallization of II was observed. Single‐crystal X‐ray crystallography revealed that I possesses a unique three‐dimensional (3D) open‐framework structure built from corner‐linked ZnO₄ and HPO₄ tetrahedra. The (3,4)‐connected framework of I differs considerably from the 3D open‐framework ZnPO structure of II . Crystal data for I : Monoclinic system, space group Cc (No. 9) , Z = 4, a = 9.1389(6), b = 23.627(2), c = 9.3073(6) Å, β = 109.463(7)°, T = 298 K.     

Syntheses,crystal structures,and fluorescent properties of two d10 metal complexes based on 2-(benzoimidazol-yl)methyl)-1H-1,2,4-triazole and 1,3,5-benzenetricarboxylate

Two d¹⁰ metal complexes, {[Zn(Hbtc)(bmt)]·DMF·5H₂O} _n (1) and {[Cd(Hbtc)(bmt)]·0.5DMF·0.5H₂O} _n (2) (H₃btc?=?1,3,5-benzenetricarboxylic acid, bmt?=?2-((benzoimidazol-yl)methyl)-1H-1,2,4-triazole), have been synthesized under solvothermal conditions by employing bmt and H₃btc. Single-crystal X-ray diffraction shows that Zn(II) ions are connected by bmt with bidentate-bridging coordination and by 1,3,5-benzenetricarboxylate with bis-monodentate coordination leading to the 2D structure of 1. Complex 2 exhibits a 2D layer structure, in which bmt coordinate tridentate-bridging to Cd(II) and 1,3,5-benzenetricarboxylates coordinate to Cd(II) unidentate/chelating. Photoluminescence and thermogravimetric analyses of the two complexes are investigated.     

A 2D Zn(II) metal-organic framework constructed from 4,4′-(perfluoropropane-2,2-diyl)dibenzoic acid,synthesis, structure and photoluminescence

A Zn(II) metal-organic framework (MOF) [Zn₂(FPDB)₂(pyridine)₂] · 5H₂O (1) was synthesized solvothermally via reaction of Zn(ClO₄)₂ · 6H₂O and 4,4′-(perfluoropropane-2,2-diyl)dibenzoic acid (H₂FPDB). The X-ray single crystal diffraction analysis reveals that 1 crystallizes in monoclinic C2/c space group with a = 23.279(5) Å, b = 7.837(5) Å, c = 26.776(5) Å, β = 106.7(6)° and Z = 4. In 1, two adjacent zinc ions are bridged to form a dinuclear paddle-wheel SBU, and four neighboring SBUs are linked by FPDB ligands to construct a chair-type grid. Distorted grids extended along a and b axes to complete a double-sheet 2D layer and these layers stack with van der Waal's interactions to build the final structure. Compound 1 shows strong luminescence at room temperature in the solid state, suggesting that 1 may be an excellent fluorescent material.     

Zinc(II), Cadmium(II), and Mercury(II) Complexes of 2-Methyl-benzoselenazole

The following zinc(II), cadmium(II) and mercury(II) complexes of 2-methyl-benzoselenazole (L) have been prepared and studied by conductometric and i.r. methods: MLX₂ (M ? Cd, Hg, X ? Cl, Br, I), ML_1.5X₂ (M ? Zn, X ? ClO₄(4 H₂O); M ? Hg, X ? NO₃, ClO₄), ML₂X₂ (M ? Zn, X ? Cl, Br, I, NO₃; M ? Cd, X ? NO₃, ClO₄). The ligand is N-bonded. All the anions are coordinated.     

Containing‐PMBP N2O2‐donors transition metal(II) complexes: Synthesis,crystal structure,Hirshfeld surface analyses and fluorescence properties

Three newly designed containing‐PMBP N₂O₂‐donors complexes, [Co(L¹)(CH₃OH)₂] ( 1 ), [{Zn(L²)(CH₃OH)(H₂O)}₃] ( 2 ) and [Cu₄(L²)₄]?2CHCl₃ ( 3 ), have been synthesized and structurally characterized using elemental analyses, infrared and UV–visible spectroscopies and single‐crystal X‐ray diffraction. X‐ray crystal structure determinations revealed that 1 consists of one Co(II) atom, one completely deprotonated (L¹)^2? unit and two coordinated methanol molecules. Complex 2 consists of three Zn(II) atoms, three completely deprotonated (L²)^2? units, three coordinated methanol molecules and three coordinated water molecules. However, 3 includes four Cu(II) atoms, four completely deprotonated (L²)^2? units and two crystallization chloroform molecules. The Co(II) and Zn(II) atoms in the structures of 1 and 2 adopt slightly distorted octahedral geometries. While, Cu(II) atoms in 3 can be best described as adopting slightly distorted square planar geometries. Complex 2 is a novel structure, and the ratio of H₂L² to Zn(II) atom is 3:3. In addition, two‐, three‐ and three‐dimensional supramolecular structures were constructed for 1 , 2 and 3 . Most importantly, Hirshfeld surface analysis of 1 , 2 and 3 was conducted and fluorescence properties were investigated.     

1,3-双(2-苯并咪唑基)-2-氧杂丙烷与锌配合物的合成、晶体结构及其与DNA作用方式的研究

合成了1,3-双(2-苯并咪唑基)-2-氧杂丙烷合锌(II)配合物, 并用元素分析和X射线衍射进行了表征, 表明其为畸变八面体构型. 用紫外、DNA熔点、荧光、粘度等手段对其与小牛胸腺DNA作用方式进行了研究. 实验结果表明, 由于配合物的八面体构型以及苯并咪唑环的平面性, 其与DNA作用方式可能为部分插入.