Two coordination polymers of manganese(II) isophthalate and their preparation,structures, and magnetic properties

Two manganese coordination polymers, [Mn₂(ip)₂(dmf)]·dmf (1) and [Mn₄(ip)₄(dmf)₆]·2dmf (2) (ip=isophthalate; dmf=N,N-dimethylformamide), have been synthesized and characterized. X-ray crystal structural data reveal that compound 1 crystallizes in triclinic space group P?1, a=9.716(3) Å, b=12.193(3) Å, c=12.576(3) Å, α=62.19(2)°, β=66.423(17)°, γ=72.72(2)°, Z=2, while compound 2 crystallizes in monoclinic space group Cc, a=19.80(3) Å, b=20.20(2) Å, c=18.01(3) Å, β=108.40(4)°, Z=4. Variable-temperature magnetic susceptibilities of compounds 1 and 2 exhibit overall weak antiferromagnetic coupling between the adjacent Mn(II) ions.     

Synthesis, crystal structures and catalytic properties of two 1D cobalt(II) coordination polymers

Two new cobalt(II) coordination polymers, namely [Co_1.5(PhCOO)₃(bbbm)_1.5(H₂O)] _n (1) and [Co(chdc)(bbbm)] _n (2) (bbbm = 1,1′-(1,4-butanediyl)bis-1H-benzimidazole, H₂chdc = 1,4-cyclohexanedicarboxylic acid), have been synthesized and structurally characterized by single crystal X-ray diffraction. The cobalt(II) centers display different environments, with trigonal–bipyramidal and octahedral geometries in 1 and a tetrahedral geometry in 2. The 1D linear chains of complex 1 and ladder-like chains of complex 2 are bridged by bbbm in bis-monodentate coordination mode; the variation of the carboxylate co-ligand effectively tunes the resulting framework architecture. The degradation of methyl orange in a photochemical Fenton-like process using complexes 1 and 2 as catalysts was investigated.     

Syntheses,crystal structures,and magnetic properties of three coordination polymers based on manganese(II) and 2,6-naphthalenedicarboxylate

Three novel coordination polymers, namely, [Mn(ndc)(bpy)] _n  · n(H₂O) (1), [Mn(ndc)(phen)] _n (2), and [Mn₃(ndc)₃(bpy)₂] _n (3) (H₂ndc = 2,6-naphthalenedicarboxylic acid, bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline) have been hydrothermally synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction analysis. Complexes 1–3 exhibit three-dimensional metal-organic frameworks (MOFs); 1 and 2 are assemblies of the same secondary building units (SBUs), linear infinite chains {Mn(CO₂)₂} _n , forming one-dimensional channel, while complex 3 is constructed by trinuclear clusters {Mn₃(CO₂)₆} SBUs. Magnetic properties of complexes 1 and 3 are also discussed with respect to the bridging mode of the carboxylate groups.     

Synthesis, structures, and magnetism of copper(II) and manganese(II) coordination polymers with azide and pyridylbenzoates

Three transition-metal coordination polymers with azide and/or carboxylate bridges have been synthesized from 4-(3-pyridyl)benzoic acid (4,3-Hpybz) and 4-(4-pyridyl)benzoic acid (4,4-Hpybz) and characterized by X-ray crystallography and magnetic measurements. Compound 1, [Cu(4,3-pybz)(N(3))](n), consists of 2D coordination networks in which the uniform chains with (μ-EO-N(3))(μ-COO) double bridges are cross-linked by the 4,3-pybz ligands. Compound 2, [Cu(2)(4,4-pybz)(3)(N(3))](n)·3nH(2)O, consists of 2-fold interpenetrated 3D coordination networks with the α-Po topology, in which the six-connected dinuclear motifs with mixed (μ-EO-N(3))(μ-COO)(2) (EO = end-on) triple bridges are linked by the 4,4-pybz spacers. Compound 3, [Mn(4,4-pybz)(N(3))(H(2)O)(2)](n), contains 2D manganese(II) coordination networks in which the chains with single μ-EE-N(3) bridges (EE = end-to-end) are interlinked by the 4,4-pybz ligands, and the structure also features a 2D hydrogen-bonded network in which Mn(II) ions are linked by double triatomic bridges, (μ-EE-N(3))(O-H···N) and (O-H···O)(2). Magnetic studies indicated that the mixed azide and carboxylate bridges in 1 and 2 induce ferromagnetic coupling between Cu(II) ions and that 3 features antiferromagnetic coupling through the EE-azide bridge. In addition, compound 1 exhibits antiferromagnetic ordering below 6.2 K and behaves as a field-induced metamagnet. A magnetostructural survey indicates a general trend that the ferromagnetic coupling through the mixed bridges decreases as the Cu-N-Cu angle increases.     

Structural and magnetic properties of three one-dimensional azido-bridged copper(II) and manganese(II) coordination polymers

Three one-dimensional (1D) azido-bridged coordination polymers of formula [Cu(L)(N3)2]n (1), [Cu2(Me-L)(N3)4]n (2), and [Mn(L)(N3)2]n (3) have been synthesized and structurally characterized, and their magnetic properties studied, where L and Me-L are 2-(pyrazol-1-ylmethyl)pyridine and 2-(3-methylpyrazol-1-ylmethyl)pyridine, respectively. Compound 1 consists of 1D chains in which the Cu(II) ions with a square pyramidal geometry are alternately bridged by an end-to-end (EE) and an end-on (EO) azido ligands, both adopting a basal-apical disposition. Compound 2 exhibits an unprecedented chain topology built via three different kinds of EO azido bridges. Four Cu(II) ions in the square pyramidal environment are alternately bridged by single and double EO bridges to form a tetranuclear cyclic ring, and neighboring rings are interlinked by double EO bridges to generate a "chain of rings". The intraannular double azido ions are disposed between metal ions in a basal-basal fashion, and the other two kinds of azido ions adopt the basal-apical disposition. Compound 3 consists of 1D concave-convex chains in which cis-octahedrally coordinated Mn(II) ions are alternately bridged by double EE and double EO bridges. There exist pi-pi interactions between the ligands bound to the neighboring Mn(II) ions bridged by the EO bridges. Temperature- and field-dependent magnetic analyses reveal alternate ferromagnetic interactions for 1, dominating ferromagnetic interactions for 2, and alternating ferro- and antiferromagnetic interactions through the EO and EE azido bridges for 3, respectively.     

Synthesis,crystal structures and properties of three glutarato and adipato bridged manganese(II) coordination polymers under ambient conditions

Three Mn(II) polymers Mn(H₂O)₄(C₅H₆O₄) 1, [Mn(H₂O)₂(C₅H₆O₄)]·H₂O 2 and Mn(H₂O)(C₆H₈O₄) 3 were synthesized (H₂(C₅H₆O₄) = glutaric acid, H₂(C₆H₈O₄) = adipic acid) under mild ambient conditions. The [Mn(H₂O)₂]²⁺ units in 2 are interlinked by the glutarate anions with a η⁴μ₃ bridging mode to form 2D (4·8²) topological networks, which are stacked via interlayer hydrogen bonds into a 3D (4³·6⁵·8²)(4⁷·6³) topological net. Compound 3 crystallizes in the acentric space group P2₁ and exhibits significant ferroelectricity (remnant polarization Pr = 0.371 nC cm⁻², coercive field Ec = 0.028 kV cm⁻¹, saturation of the spontaneous polarization Ps = 0.972 nC cm⁻²). The adjacent MnO₆ octahedrons in 3 are one atom-shared to generate the Mn₂O₁₁ bi-octahedron, leading into 1D metal oxide chains. The resulting chains are interconnected by the η⁵μ₅ adipate anions to form new 2D (4⁸·6²) networks, which are held together via strong interlayer hydrogen bonds into 3D α-Po topological supra-molecular architecture. The temperature-dependent magnetic susceptibility data of 1–3 shows overall anti-ferromagnetic interactions between the metal ions bridged by the carboxylate groups.     

Synthesis,structures and magnetic properties of three metal-organic frameworks containing manganese(II)

Two new Mn(II) coordination polymers formed with molecular formula [Mn(H₂O)₂(HBTC)·(H₂O)] 1 and [Mn(H₂O)₂(4,4′bipy)(HBTC)₂]·(H4,4′bipy)₂ 2, where BTC = 1,2,4-benzenetricarboxylate and 4,4′bipy = 4,4′bipydine, have been synthesized via hydrothermal approach and characterized by single crystal X-ray diffraction techniques. 1 is composed of Mn–H₂O–Mn 1D chains and further the chains are linked by HBTC ligands to form a 2D network in the ab plane; 2 is constructed by Mn–4,4′bipy–Mn 1D chains along the b direction with Mn²⁺ ions coordinated to H₂BTC and water as terminal ligands to form a 2D network. We also prepared a third compound with the molecular formula of [Mn(H₂O)(HBTC)·(H₂O)] which has been recently structurally reported elsewhere. The magnetic properties of the three compounds have been studied in detail under variable temperatures.     

Synthesis,crystal structures and catalytic properties of three-dimensional nickel(II) and manganese(II) coordination polymers with dicarboxylate and semi-rigid bis(imidazole) ligands

Two coordination polymers (CPs), namely [Ni(L)(chdc)] _n (1) and [Mn(L)(ndc)(H₂O)] _n (2) (L = 4,4′-bis(imidazol-1-ylmethyl)biphenyl, H₂chdc = 1,2-cyclohexanedicarboxylic acid, H₂ndc = 2,6-naphthalenedicarboxylic acid), have been hydrothermally synthesized and characterized by physicochemical and spectroscopic methods and also by single-crystal diffraction. Both CPs feature 3D-diamond-like networks with point symbol of 6⁶; CP-1 displays a 2-fold interpenetrated net, while CP-2 presents a non-interpenetrated framework. The thermal stabilities, solid-state luminescence properties and catalytic activities of both CPs for degradation of methyl orange in a Fenton-like process were investigated.     

Zinc(II) and manganese(II) coordination polymers constructed by 2-naphthyl imidazole dicarboxylate: syntheses,structures and properties

Three coordination polymers [Zn(μ₃-HNIDC)(CH₃OH)]_n (H₃NIDC = 2-(2-naphthyl)-1H-imidazole-4,5-dicarboxylic acid) (1), [Mn(μ₂-HNIDC)(4,4′-bipy)]_n (4,4′-bipy = 4,4′-bipyridine) (2) and [Mn₂(μ₂-HNIDC)₂(phen)₂]_n (phen = 1,10-phenanthroline) (3) have been solvothermally synthesised and structurally characterised by single-crystal X-ray diffraction, elemental analyses, thermal analyses and IR spectra. Polymer 1 displays a three-dimensional open architecture with one-dimensional (1D) channels. Polymer 2 exhibits a sheet structure containing infinite rectangles. Polymer 3 presents a 1D wave chain structure. The solid-state photoluminescence of 1 has been investigated as well.     

Synthesis,structures and photoluminescence of two Er(III) coordination polymers

Two new erbium compounds, [Er₂(BDC)₃(DMF)₂] (1) and [Er₂(CQC)₃(DMF)₃(H₂O)]?·?DMF?·?H₂O (2), where BDC stands for 1,4-benzenedicarboxylate, CQC for 2-(4-carboxyquinolin-2-yl)quinoline-4-carboxylate, and DMF for N,N-dimethylformamide, have been synthesized through pre-heating and cooling-down crystallization. In 1 the Er(III) is seven-coordinate with oxygen atoms from six BDC and one DMF, forming a three-dimensional open-framework structure. Compound 2 possesses a 2D structure based on dinuclear Er(III) building units. The photoluminescence of 1 has also been investigated.     

Synthesis,structures and adsorption properties of two new magnesium coordination polymers

Two new magnesium coordination polymers, [Mg(9,10-ADC)(H₂O)₂(DMF)₂]_n (1) and [Mg₆(1,4-NDC)₅(HCO₂)₄(DMF)(H₂O)]_n·2n[H₂N(CH₃)₂]·2n(DMF) (2) (9,10-ADC = 9,10-anthracenedicarboxylate; 1,4-NDC = 1,4-naphthalenedicarboxylate) have been solvothermally synthesized. Compound 1 displays a one-dimensional linear chain structure, which is orderly constructed from magnesium metal cations connecting with carboxylic oxygen atoms of 9,10-H₂ADC along the a axis. Compound 2 exhibits a three-dimensional framework composed of infinite chains of corner-sharing octahedral MgO₆ with 1,4-NDC ligands forming one-dimensional channels along the a axis, where guest molecules reside. When guest molecules are removed, no structural transformation is found to occur, generating a robust structure with permanent porosity. The studies of CO₂ absorption suggest that compound 2 is a promising adsorbent material for CO₂.     

Synthesis,crystal structures and magnetic and electrochemiluminescence properties of three manganese(II) complexes

Three novel complexes, namely, penta‐μ‐acetato‐bis(μ₂‐2‐{[2‐(6‐chloropyridin‐2‐yl)hydrazinylidene]methyl}‐6‐methoxyphenolato)‐μ‐formato‐tetramanganese(II), [Mn₄(C₁₃H₁₁ClN₃O₂)₂(C₂H₃O₂)_5.168(CHO₂)_0.832], 1 , hexa‐μ₂‐acetato‐bis(μ₂‐2‐{[2‐(6‐bromopyridin‐2‐yl)hydrazinylidene]methyl}‐6‐methoxyphenolato)tetramanganese(II), [Mn₄(C₁₃H₁₁BrN₃O₂)₂(C₂H₃O₂)₆], 2 , and catena‐poly[[μ₂‐acetato‐acetatoaqua(μ₂‐2‐{[2‐(6‐chloropyridin‐2‐yl)hydrazinylidene]methyl}‐6‐methoxyphenolato)dimanganese(II)]‐μ₂‐acetato], [Mn₂(C₁₃H₁₁ClN₃O₂)(C₂H₃O₂)₃(H₂O)]_n, 3 , have been synthesized using solvothermal methods. Complexes 1 – 3 were characterized by IR spectroscopy, elemental analysis and single‐crystal X‐ray diffraction. Complexes 1 and 2 are tetranuclear manganese clusters, while complex 3 has a one‐dimensional network based on tetranuclear Mn₄(L¹)₂(CH₃COO)₆(H₂O)₂ building units (L¹ is 2‐{[2‐(6‐chloropyridin‐2‐yl)hydrazinylidene]methyl}‐6‐methoxyphenolate). Magnetic studies reveal that complexes 1 – 3 display dominant antiferromagnetic interactions between Mn^II ions through μ₂‐O bridges. In addition, 1 – 3 also display favourable electrochemiluminescence (ECL) properties.     

Synthesis,structures, and fluorescence of two cadmium(II) coordination polymers with a semirigid bis-benzimidazole

Compounds [CdLCl₂] _n (1) and {[Cd(L)₂(ClO₄)]·ClO₄} _n (2), where L?=?1,3-bis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene, have been synthesized by hydrothermal method, and characterized by element analysis, IR spectra, Powder XRD, and X-ray crystallographic diffraction. Cd(II) in 1 and 2 are both trigonal bipyramidal. Different cadmium salts of chloride and perchlorate lead to different configurations of [Cd₂L₂]²⁺, trans-form in 1 but trans and cis-forms in 2. The 1-D beaded chains of 1 are further linked to generate a 3-D supramolecular architecture by strong π–π stacking interactions as well as intermolecular C–H?···?Cl hydrogen bonds. In 2, the 1-D beaded chains are further assembled by intermolecular C–H?···?O hydrogen bonds to form a 2-D layer. Solid-state fluorescent properties of 1 and 2 were investigated at room temperature.     

Syntheses, structures, and properties of zinc(II), cadmium(II), cobalt(II), and manganese(II) coordination polymers with tetraiodoterephthalate

The coordination chemistry of a rigid periodinated ligand, 2,3,5,6-tetraiodo-1,4-benzenedicarboxylic acid (H₂BDC-I₄), with a series of transition metal ions has been explored to afford five new coordination polymers {[M(BDC-I₄)(MeOH)₄](H₂BDC-I₄)(MeOH)₂} _n (M?=?Zn^II for 1, Cd^II for 2, Co^II for 3 and Mn^II for 4) and {[Mn(BDC-I₄)(MeOH)₄](DMF)} _n (5). All these complexes have been characterized by elemental analysis, IR spectroscopy, thermogravimetric (TG) analysis, and X-ray crystallography. Single-crystal X-ray diffraction reveals that complexes 1?C4 are isostructural and have a one-dimensional chain structure. Upon the addition of the solvent DMF, the infinite linear chain array in 4 is converted to a 1-D wave-like chain motif in 5 with a different space group ( $ P\overline{1} $ for 4 and P2₁/c for 5). The difference between structures 1?C4 and 5 can be attributed to the coordination mode of carboxylate changing from trans to cis fashion. The Zn^II and Cd^II complexes 1 and 2 display similar emissions in the solid state, which essentially are intraligand transitions.     

Synthesis,crystal structures,and magnetic properties of three isomorphous helical coordination polymers

Three isomorphous coordination polymers of general formula {[M(H₂bna)·(DMF)₂·(H₂O)₂]·DMF}_n (M = Co for 1, Mn for 2, Ni for 3, respectively, where H₄bna = 2,2′-dihydroxy-[1,1′]-binaphthalene-3,3′-dicarboxylate) were synthesized under solvothermal conditions and characterized by FTIR, single crystal X-ray diffraction, thermogravimetric analysis, and X-ray power diffraction analysis. All three polymers crystallize in the same monoclinic space group P2₁/n. The complexes are assembled into 1D helical chains, and each adjacent helical chain of the same chirality is further connected to form a chiral layer by hydrogen bond interactions. The layers are packed in alternating left-(M) and right-handed (P) chirality arrays. Magnetic studies reveal the presence of antiferromagnetic coupling interactions in complexes 1 and 2.     

Three novel Cd(II) coordination polymers: Synthesis,crystal structures,fluorescence and thermal properties

Three novel Cd(II) coordination polymers, {[Cd(C₄BIm)(N₃)(OAc)]·C₂H₅OH}_n (1), [Cd(C₄BIm)(H₂O)₃(SO₄)]_n (2) (C₄BIm = 1,4-bis(benzimidazolyl)butane) and [Cd(bbbm)_1.5(NO₃)₂]_n (3) (bbbm = 1,1′-(1,4-butanediy)bis-1H-benzimidazole) have been prepared and characterized spectroscopically and crystallographically. In polymer 1, C₄BIm–Cd chains and N₃–Cd chains criss-cross to a layer structure. Polymer 2 possesses a concave–convex chain structure. Polymer 3 exhibits a two-dimensional (2-D) rhomboid grid network, the dimensions of the grid is 25.807 × 13.771 Å, and the diagonal-to-diagonal distances are 28.608 × 21.145 Å. The fluorescence properties and the thermal stabilities of the three polymers were investigated.     

Synthesis, crystal structures and properties of four manganese coordination polymers with 4,4-bipyridine-derived ligands

Four new coordination polymers, namely Mn₂(4,4-bpy)₂(o-tol)₄ 1, Mn₂(4,4-bpy)₂(m-tol)₄ 2, Mn₂(bpp)₂(m-tol)₄ 3 and {[Mn₂(4,4-bpy)₂(p-tol)₄][Mn(4,4-bpy)₂(H₂O)₂(p-tol)₂]}·6H₂O 4 have been synthesized from 4,4′-bipyridine (4,4-bpy), 1,3-bis(4-pyridyl)-propane (bpp), o-toluic acid (o-Htol), m-toluic acid (m-Htol) and p-toluic acid (p-Htol). All four complexes feature dinuclear Mn₂(tol)₄ moieties, which are bridged by 4,4-bpy or bpp ligands to form 1D double-chain structures. The resulted 1D double-chains are assembled via hydrogen bonding or π···π stacking into 2D supramolecular layers. The complexes were characterized by physico-chemical (thermal behavior) and infrared spectroscopy. Variable temperature magnetic characterization suggest weak antiferromagnetic coupling exchange between dimeric Mn(II) centers (J = ?0.46 cm^?1 for 1, ?0.56 cm^?1 for 2, ?1.28 cm^?1 for 3 and ?0.59 cm^?1 for 4).     

Two manganese(II) coordination polymers containing semirigid bis(benzimidazole) ligands: synthesis,crystal structures,and catalytic properties

Two ternary mixed Mn(II) coordination polymers (CPs), namely [Mn(L1)(Hnip)₂] _n (1) and [Mn(H_0.5L2)₂(H_1.5btc)₂] _n (2) (H₂nip = 5-nitroisophthalic acid, L1 = 1, 4-bis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene, H₃btc = 1,3,5-benzenetricarboxylic acid, L2 = 4,4′-bis(benzimidazol-1-ylmethyl)biphenyl), have been synthesized under hydrothermal conditions and structurally characterized. CP 1 exhibits a non-interpenetrated six-connected pcu framework with the point symbol {4¹²·6³}, while CP 2 features a metal-carboxylate loop-like chain, which is further assembled into a 3D supramolecular network via hydrogen bonds and π–π interactions. The thermal stabilities, luminescence, and catalytic properties of both CPs for the degradation of methyl orange in a Fenton-like reaction have also been investigated.     

Two azido-bridged cobalt(II) coordination polymers with nicotinate co-ligand: synthesis, structures and magnetic properties

By utilizing nicotinic acid as a co-ligand, two new azido-bridged cobalt(II) complexes with the formulae [Co(2)(N(3))(nic)(2)Cl(H(2)O)](n) (1) and [Co(N(3))(nic)](n) (2) (nic = nicotinate) have been synthesized under solvothermal condition and structurally characterized. Complex 1 exhibits a rare three-dimensional (3D) Kagomé topology with [Co4] units as connecting nodes. Complex 2 is also a 3D structure which contains 1D Co(II)-μ-1,1-azido chains as rod-shaped SBUs. Magnetic data analysis shows that ferromagnetic coupling intra-[Co4]-cluster and antiferromagnetic interaction inter-[Co4]-cluster exists in complex 1, while complex 2 exhibits metamagnetism with a critical field of 5.5 kOe.