Two 3d‐4f Heterometallic Coordination Polymers of Macrocyclic Oxamide with Benzotriazole‐5‐carboxylate Co‐ligand: Syntheses,Crystal Structures and Magnetic Properties

Two heterometallic 3d–4f coordination polymers, [Gd(CuL)₂(Hbtca)(btca)(H₂O)] · 2H₂O ( 1 ) and [Er(CuL)₂(Hbtca)(btca)(H₂O)] · H₂O · CH₃OH ( 2 ) (CuL, H₂L = 2,3‐dioxo‐5,6,14,15‐dibenzo‐1,4,8,12‐tetraazacyclo‐pentadeca‐7,13‐dien; H₂btca = benzotriazole‐5‐carboxylic acid) were synthesized by solvothermal methods and characterized by single‐crystal X‐ray diffraction. Complexes 1 and 2 exhibit a double‐strand meso‐helical chain structures formed by [Ln^IIICu^II₂] (Ln^III = Gd, Er) units by oxamide and benzotriazole‐5‐carboxylate bridges. They are isomorphic except that one free water molecule of 1 is replaced by a methanol molecule. All 1D chains are further interlinked by hydrogen bonds resulting in a 3D supramolecular architecture. The magnetic properties of the compound 1 and 2 are also discussed.     

Structure and Magnetic Properties of Mononuclear Copper(II) Complexes with 2,2‐Bipyrimidine, 2,3‐Bis(2‐pyridyl)pyrazine,and 4‐Terpyridone Based Ligands

Four new complexes of [Cu(bpm)(ox)(H₂O)] ( 1 ), [Cu(tpd)(dca)(H₂O)] ( 2 ), [Cu(bppz)(N₃)₂] ( 3 ), and [Cu(bpm)₂(μ_1,3‐N₃)(N₃)] ( 4 ) (bpm = 2,2′‐bipyrimidine, bppz = 2,3‐bis(2‐pyridyl)pyrazine, tpd = 4‐terpyridone, dca = dicyanamide, ox = oxalate) have been prepared and characterized by X‐ray single‐crystal analysis and variable‐temperature magnetic measurements. Compounds 1–4 are essentially mononuclear Cu(II) complexes. However, in complex 1 , Cu(II) it was found that intermolecular hydrogen bonding through between H₂O and ox formed 1‐D chain structure. In complex 2 it was found that the hydrogen bonding between H₂O and tpd of the next molecule led to for a binuclear Cu(II) complex. In complex 3 , two nitrogen atoms, one of the pyridyl group of bppz and one of N₃^? ligands, are weakly coordinated to neighbor Cu(II) ion thus leading to formation of a 1‐D chain structure. In complex 4 , one nitrogen atom of terminated N₃^? is weakly coordinated to the neighbor Cu(II) site to form a 1‐D polymeric structure. The magnetic susceptibility measurements indicate that complex 1 and 4 exhibit a weak antiferromagnetic interaction whereas a ferromagnetic coupling has been established for complexes 2 and 3 .     

A 3D Nickel(II) Coordination Polymer with cds Nets Constructed from 3‐Pyridin‐4‐yl‐benzoic Acid

A new coordination polymer, [Ni(3,4‐pybz)₂(H₂O)]_n ( 1 ), was hydrothermally synthesized from Ni(NO₃)₂ · 6H₂O and an unsymmetrical 3‐pyridin‐4‐yl‐benzoic acid (3,4‐Hpybz). It was characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis, and single‐crystal X‐ray diffraction. In complex 1 , the 3,4‐pybz ligands act as linear linkers to join 4‐connected nickel(II) ion nodes, to build a 3D 4‐connected twofold interpenetrated 6⁵8‐cds coordination framework. In addition, the magnetic and thermal properties of complex 1 were also investigated.     

Synthesis,Crystal Structure,and Magnetic Properties of a New 2D Twofold Interpenetrated Coordination Polymer [Cu(3,4‐pybz)2]n

A new coordination polymer, [Cu(3, 4‐pybz)₂]_n ( 1 ) [3,4‐Hpybz = 3‐pyridin‐4‐yl‐benzoic acid], was synthesized by hydrothermal reaction of CuCl₂ · 2H₂O and 3,4‐Hpybz, and characterized by elemental analysis, IR spectroscopy, PXRD, and single‐crystal X‐ray diffraction. The structure determination reveals that 1 exhibits a 2D twofold interpenetrated 4‐connected (4,4) network topology, these 2D layers are further enlarged to form the final 3D supramolecular edifice via aromatic π–π stacking interactions. In addition, the magnetic behavior and thermogravimetric analysis of 1 were also studied.     

Synthesis,Structure, and Magnetic Properties of a Random Bimetallic One‐dimensional CoII‐MnII Coordination Polymer with Mixed Azide‐carboxylate Bridges

The 3d–3d random bimetallic compound [Co_2.28Mn_0.72(N₃)₆(mpc‐3)₂(CH₃OH)₂] ( 1 ) (mpc‐3 = N‐methylpyridinium‐3‐carboxylate) was synthesized by partly substituting the Co^II ions in the homometallic compound by Mn^II. Complex 1 was structurally and magnetically characterized. It consists of one‐dimensional chains with the neighboring metal ions being linked alternatively by [(μ‐EO‐N₃)₂(μ‐COO)] (EO = end‐on) triple bridges and double EO azide bridges. Hydrogen‐bonding interactions and π–π interactions are involved in the formation of a three‐dimensional supramolecular network. Magnetic measurements revealed that complex 1 exhibits slow relaxation, which is similar to the homometallic Co^II parent compound whereas the T_B is lower than that of the Co^II analog.     

Hetero‐metallic Lanthanide CPs Involving Sodium: Synthesis,Crystal Structure,and Luminescence Properties

[TbNa(4‐msal)₄(phen)₂]_n ( 1 ) (4‐msal = 4‐methyl salicylic acid), a new hetero‐metallic lanthanide coordination polymer (CP) involving sodium was synthesized. It crystallizes in the monoclinic space group P2₁/n, with a = 20.4809(9) Å, b = 9.8183(2) Å, c = 26.1987(11) Å, α = 90.00°, β = 112.922(5)°, γ = 90.00°, V = 4852.2(3) ų, and Z = 4. The complex was characterized by single crystal and powder X‐ray diffraction, elemental analysis (EA), and Fourier transform infrared (FT‐IR) and luminescence spectroscopy. The luminescence properties of a powder sample of 1 were studied at room temperature and the luminescence lifetime and total quantum yield (QY) were determined.     

Magnetic Exchange Interactions in Dinuclear Copper(II) and Nickel(II) Complexes with μ‐Oxalato Bridges. The Structure of μ‐Oxalato(O,O′, O″, O‴)‐bis{[1, 8‐di(2‐pyridyl)‐3, 6‐dithiaoctane‐N,N′, S,S′]nickel(II)} Dinitrate Dihydrate

A copper(II) and two nickel(II) dinuclear oxalato‐bridged compounds of formulae [{Cu(bpdto)}₂(μ‐ox)](ClO₄)₂ ( 1 ), [{Ni(bpdto)]₂(μ‐ox)](ClO₄)₂( 2 ), and [{Ni(bpdto)}₂(μ‐ox)](NO₃)₂·2H₂O ( 3 ), where bpdto = 1, 8‐bis(2‐pyridyl)‐3, 6‐dithiaoctane and ox = oxalate = C₂O₄^2— anion, have been synthesized and characterized. The crystal structure of 3 was determined by single‐crystal X‐ray analysis. It is a dinuclear complex with i symmetry in which the oxalate ligand is coordinated in bis(didentate) fashion to the inversion centre‐related nickel atoms. The distorted octahedral environment of each nickel atom is completed by two sulphur atoms in the equatorial plane and by two pyridyl nitrogen atoms in axial positions. Magnetic susceptibility measurements over the range 5 — 299K, show antiferromagnetic interactions that are weak in 1 (J = —12.8 cm^—1) and strong in 2 and 3 (J = —37.8 and —40.9 cm^—1, respectively), which in the case of 3 is in keeping with the observed structural parameters.     

Three 2D Ln‐Sulfoterephthalate Complexes with 4,4′‐Bisbiphenyl‐imidazole Featuring Helical Chains

A series of Ln‐sulfoterephthalate coordiantion polymers, namely, [Ln(2‐stp)(4,4′‐bbpi) (H₂O)₂] · H₂O [Ln = Eu ( 1 ), Tb ( 2 ), Dy ( 3 )] (2‐H₃stp = 2‐sulfoterephthalate; 4,4′‐bbpi = 4,4′‐bisbiphenyl‐imidazole), were prepared by hydrothermal method and characterizatied by EA, IR, TGA, and PXRD technologies. Single crystal X‐ray diffraction analyses show that the three complexes are isostructral two‐dimensional network featuring helical chain structures. The fluorescence studies show that the emissions of the coordination polymers exhibit the characteristic peaks of lanthanide ions, which means they could be potential fluorescence materials.     

A New 3D Manganese(II) Coordination Polymer with 4,4‐Dicarboxy‐2,2′‐bipyridine and 1,10‐Phenanthroline: Synthesis,Structural, and Magnetic Properties

A new 3D Mn^II metal‐organic framework compound {Mn(phen)(dcbp)}_n (H₂dcbp = 4,4‐dicarboxy‐2,2′‐bipyridine, phen = 1,10‐phenanthroline) was isolated under hydrothermal conditions and structurally characterized. In the compound, the dcbp ligand is deprotonated to give a neutral species (metal:ligand with 1:1 stoichiometry). Along the c axis, the neighboring Mn^II ions are linked by two carboxylate bridges in µ₂‐coordinating mode to generate a 1D zigzag chain, and these chains are interlinked by dicarboxylate groups of long dcbp ligands to generate a 3D (4,4)‐connected structure with the (4².8⁴) net topology. IR and UV/Vis spectroscopy and variable temperature magnetic susceptibility measurements were made, which indicated weak antiferromagnetic interactions between the Mn^II ions of the compound.     

Synthesis and Characterization of a Metal‐Organic Coordination Polymer

A novel energetic microporous metal‐organic coordination polymer {[Ni(tnbpdc)(bpy)(H₂O)₂] · 1.5(DMF)}_n ( 1 ) (tnbpdc = 2, 2′,6, 6′‐tetranitro‐4, 4′‐biphenyl dicarboxylate, bpy = 4, 4′‐bipyridine) was prepared solvothermally and characterized by elemental, IR spectroscopic, and single‐crystal X‐ray diffraction analyses. The X‐ray crystal structure of 1 revealed a rectangular‐shaped grid constructed with tnbpdc linkers and bpy linkers, with the free tunnel size estimated as 11 × 15 Ų. The thermal stability of the compound was evaluated by differential scanning calorimetry and thermogravimetric analysis. Such complexes may find application as novel heat‐resistant energetic materials.     

Influence of Secondary Bonds on the Network Assembly and Property in Lead(II) 3‐Sulfobenzoate Coordination Polymer

A unique 3‐D Pb^II coordination polymer containing ligands 1,2‐bis(4‐pyridyl)ethylene (bpe) and 3‐sulfobenzoate (3‐sb), [Pb(3‐sb)(bpe)_0.5]_n ( 1 ) has been synthesized by hydrothermal reaction and characterized by elemental analysis, IR, TGA, ¹H NMR, powder X‐ray analysis, and fluorescent spectrum. The single‐crystal X‐ray analysis shows that eight coordination bonds can be divided as five primary bonds and three secondary bonds. The secondary bonds largely enhance the solid stability and provide a high‐dimensional network assembly. The complex also displays strong fluorescent property.     

Synthesis,Structures, Luminescent and Magnetic Properties of Heterometallic 5p‐4f Compounds with Ethylenediaminetetra­acetate

A series of heterometallic Ln^III–Sb^III edta‐containing compounds with the formulas [Sb₂(edta)₂Ln]NO₃ · nH₂O [edta = ethylenediaminetetraacetate; Ln = Eu, n = 7 ( 1 ); Gd, n = 7.5 ( 2 ) and Tb, n = 8 ( 3 )] were synthesized and characterized by elemental analyses (EA), powder X‐ray diffraction (PXDP), Fourier transform infrared spectroscopy (FT‐IR), and thermogravimetric analyses (TGA). Their fluorescence and magnetic properties were also studied. The thermal analysis demonstrates the compounds formation of the antimony, lanthanide ions, and edta^4– ligands. FT‐IR spectra reveal that the antimony and lanthanide ions are connected through the carboxylate bridges. The studies of luminescence properties show that compounds 1 and 3 exhibit typical luminescence in the visible region. Furthermore, magnetic properties reveal compounds 2 and 3 have weak ferromagnetic behavior.     

Synthesis,Crystal Structure,and Photocatalytic Properties of a Zinc(II) Coordination Polymer Based on 3‐Hydroxy‐2‐pyridinecarboxylic Acid

The zinc(II) compound, [Zn₃(HL)₆]_n ( 1 ) (H₂L = 3‐hydroxypyridine‐2‐carboxylic acid) was synthesized by a solvothermal reaction of Zn(NO₃)₂ · 6H₂O and 3‐hydroxypyridine‐2‐carboxylic acid as raw materials. The structure of complex 1 was determined by single‐crystal X‐ray diffraction analysis and further characterized by elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, as well as powder X‐ray diffraction. X‐ray structure analysis demonstrates that the complex crystallizes in the monoclinic system, space group P2₁/n. There are three zinc ions in the asymmetric unit, which are either five‐coordinate or six‐coordinate. The asymmetric units are further bridged by the carboxylate of the organic ligands, featuring a 2D framework. The solid state diffuse‐reflectance UV/Vis spectra reveals that complex 1 has semiconducting nature with the energy bandgap (E_g) estimated to be 3.11 eV. The photocatalytic properties of complex 1 in degradation of organic dyes were further investigated. Results showed that the complex could degrade 54 % of the dye methylene blue solution within 120 min under UV irradiation light and reused for five times without the decline of the photocatalytic activity.     

Structure and Magnetic Property of a New 3D Nicotinic Acid Bridged Nickel Polymer

A new three‐dimensional nicotinic acid bridged polymer [Ni₂(nic)₄(H₂O)] ( 1 ) had been synthesized by hydrothermal synthesis and characterized by IR, Raman, elemental analysis, magnetic suszeptibility measurements, and single crystal structural analysis. The structure of 1 has a three‐dimensional stair‐shaped architecture, in which the building units are “mushroom‐shaped” channels. Magnetic measurements show a ferromagnetic interaction between the two nickel atoms in one dimer and an antiferromagnetic coupling between adjacent dimer units.     

A New Coordination Polymer [Pb(1,4‐BDC)]n Containing a Unique μ6‐Bridging Coordination Mode

A new coordination polymer, [Pb(1,4‐BDC)]_n ( 1 ) (1,4‐H₂BDC = 1,4‐benzenedicarboxylic acid), has been synthesized under solvothermal conditions. Its structure was determined with single‐crystal X‐ray diffraction studies and further characterized by inductively coupled plasma (ICP) spectrometry, elemental analysis, IR spectroscopy, thermogravimetric analysis, and X‐ray powder diffraction studies. The results revealed that complex 1 has a two‐dimensional network with (6, 3) topology observed in the [110] direction. Moreover, the layers are connected into a framework through 1,4‐BDC^2? ligands. The μ₆‐bridging coordination mode adopted by 1,4‐BDC^2? is unprecedented in metal/1,4‐BDC^2? complexes.     

Syntheses,Structures and Magnetic Behaviours of two Mixed‐Metal Inorganic‐Organic Hybrid Frameworks with N‐(Phosphonomethyl)iminodiacetate

Two mixed‐metal‐center inorganic‐organic hybrid frameworks incorporating N‐(Phosphonomethyl)iminodiacetate(H₄pmida), [Zn₂V₂O₂(pmida)₂(H₂O)₁₀]·H₂O ( 1 ) and [Zn₂V₂O₂(pmida)₂(H₂O)₁₂]·2H₂O ( 2 ), were synthesized by hydrothermal reactions and characterized by elemental analysis, IR spectra, UV‐Vis spectra and single crystal X‐ray analysis. In complex 1 , the centrosymmetric dimeric [V₂O₂(pmida)₂]^4– unit connected to neighboring Zn²⁺ through the phosphonate group, while 2 the [V₂O₂(pmida)₂]^4– unit uncoordinated with the Zn²⁺ in the presence of NaOH. Magnetic measurements in the range 2‐300 K have shown weak antiferromagnetic interaction between the adjacent vanadium ions in complexes.     

Synthesis,Structures, and Properties of Four Novel Coordination Compounds based on a Flexible Tetrakis(imidazol‐1‐ylmethyl)methane Ligand

Four coordination polymers, namely, [Zn₂(TIYM)(2,6‐PYDC)₂]_n · n(CH₃OH) · 3n(H₂O) ( 1 ), [Cu(TIYM)(2,6‐PYDC)]_n · 3n(H₂O) ( 2 ), [Co(TIYM)(2,6‐PYDC)]_n · n(CH₃OH) · 3n(H₂O) ( 3 ), and [Cd₂(TIYM)(2,6‐PYDC)₂(H₂O)]_n · n(H₂O) ( 4 ) with the flexible N‐containing ligand [tetrakis(imidazol‐1‐ylmethyl)methane (TIYM)] and the N‐containing dicarboxylic acid [2,6‐pyridinedicarboxylic acid (2,6‐PYDC)] were prepared. Compounds 1 – 4 show various structures because of different N–C_center–N angles (θ) of TIYM ligands and changing coordination modes of 2,6‐PYDC. Compounds 1 , 2 , and 3 display a similar 1D ladder‐like chain, whereas 4 gives a 1D quad‐core lifting platform shaped belt. The structural diversities in 1 – 4 suggest that the multiple coordination modes or the different freely twist angles of ligands and the presence of different metal atoms play important roles in the resulting structures of the coordination polymers. Furthermore, the solid‐state luminescence properties of 1 and 4 , and the magnetic properties of 3 were investigated.