Anion-directed assembly of two fluorescent Cd(II) coordination polymers with a versatile multidentate N-donor building block 3-(2-pyridyl)-4,5-bis(4-pyridyl)-1,2,4-triazole

Assembly of Cd(II) nitrate with a novel tripyridyltriazole building block 3-(2-pyridyl)-4,5-bis(4-pyridyl)-1,2,4-triazole (L¹) and pseudohalide anion dicyanamide (dca) or azide (N₃) yields two coordination polymers {[Cd(L¹)₂(dca)₂](H₂O)₂}_n (1) and {[Cd₂(L¹)(μ_1,1-N₃)₂(μ_1,3-N₃)(N₃)](H₂O)_1.5}_n (2). Single crystal X-ray diffraction analysis indicates that the Cd(II) centers in 1 are bridged by the bidentate L¹ ligands to form 1D arrays, which are further extended to a 3D network via hydrogen bonding and aromatic stacking. Significantly, the L¹ ligands in 2 display the unusual pentadentate coordination and the azide anions take different μ_1,1-, μ_1,3-, and unidentate binding modes, interlinking the Cd(II) ions to afford a complicated 3D open framework with the inclusion of lattice water guests. Both complexes exhibit strong solid state fluorescent emissions at room temperature.     

Four coordination polymers derived from 4-amino-3,5-bis(3-pyridyl)-1,2,4-triazole and copper sulfate

The reaction of 4-amino-3,5-bis(3-pyridyl)-1,2,4-triazole (3-bpt) with copper sulfate in EtOH/H₂O solvent yields four coordination polymers [Cu(3-bpt)(H₂O)₄](SO₄)·H₂O (1), [Cu(3-bpt)(H₂O)₄][Cu(3-bpt)(H₂O)₃(SO₄)](SO₄)·7H₂O (2), [Cu(3-bpt)(H₂O)₃(SO₄)]·2H₂O (3) and [Cu(3-bpt)(H₂O)(SO₄)] (4), showing one-dimensional undulated chain, zigzag chain and two-dimensional network. The formations of compounds 1, 2 and 3 are controlled by the EtOH/H₂O ratio. The synthesis of compound 4 may be controlled by the EtOH/H₂O ratio and the temperature because it is prepared under solvothermal condition. The thermal properties have been investigated.     

3-甲基-4-对甲苯基-5-（2-吡啶基）-1，2，4-三唑的合成和表征

1,2,4-三唑类化合物在农药、医药及化工领域有着广泛的应用,其与-些金属离子形成的配合物具有自旋转换功能。为了制备研究新的具有自旋转换功能的1,2,4-三唑配合物,以a-吡啶甲酸为原料,经多步反应合成3-甲基-4-对甲苯基-5-（2-吡啶基）-1,2,4-三唑,并用IR、MS、^1H—NMR对其结构进行了确证。     

4-氨基-3,5-二(4-吡啶)-1,2,4-三氮唑的新合成方法

4-氨基-3,5-二(4-吡啶)-1,2,4-三氮唑的合成方法已有报道,但合成条件严格,要求纯氮气保护.本文的合成方法简单易行,无须氮气保护,只需反应物直接混合加热就可得到产物.     

3-苯基-4-对甲苯基-5-（2-吡啶基）-1，2，4-三唑的合成和表征

1,2,4-三唑类化合物在农药、医药、生物、信息材料及化工领域有着广泛的应用,报道了3-苯基-4-对甲苯基-5-（2-吡啶基）-1,2,4-三唑的合成,并用红外、核磁（^1H—NNR、）及质谱对其结构进行了确证。     

Syntheses,structures and photoluminescence properties of two 2D Cd(II) coordination polymers based on a semirigid tridentate N-donor ligand

The assembly of a semirigid tridentate N-donor ligand with Cd(II) ions afforded two novel coordination polymers, [Cd(tipa)(H₂O)₂·2NO₃·2DMF·H₂O]_n (1), [Cd₂(tipa)₂Cl₄·2DMF·6H₂O]_n (2), where tipa = tris(4-(1H-imidazol-1-yl)phenyl) amine. Structural analyses indicate that the two compounds feature 2D layered networks. A 3-connected uninodal net with point symbol of (8²·10) is constructed in compound 1 by the connection of tipa and metal ions, in which the terminally coordinated water molecules prevent further extension of the layer. Compound 2 features [Cd₂Cl₄] motifs, which are bridged by tridentate tipa ligands into a 2D (3,6)-connected layer. The results show that tipa with different dihedral angles between benzene ring and terminal imidazole groups can act as versatile building blocks for the generation of various networks. Moreover, the photoluminescence properties of 1 and 2 in the solid state at room temperature have been investigated.     

Syntheses and topological networks of two azide complexes based on 4-amino-3,5-bis(3-pyridyl)-1,2,4-triazole ligands

Two new azide complexes, [Cd₂(3-abpt)(N₃)₄]_n (1) and [Cu(3-abpt)₂(N₃)₂] (2) (3-abpt = 4-amino-3,5-bis(3-pyridyl)-1,2,4-triazole), have been prepared and structurally characterized. Complex 1 displays an interesting 2D polymeric structure with rarely reported 3,7-connected (3²;4)(3⁴;4⁶;5⁶;6⁵) network in the Schafli notation. Complex 2 contains mononuclear pieces, and they are linked each other through weak CuN coordination bonds to form a 2D sheet with (4, 4) topology. The thermal stability and fluorescent property of 1 have also been investigated.     

Lanthanide coordination polymers constructed from 5-(4-pyridyl)-isophthalic acid: Synthesis,structure and photoluminescent properties

Nine lanthanide coordination polymers [Ln₂(pyip)₃(H₂O)₄·DMF·3H₂O]_n (Ln = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho) based on the pyip^2 − ligand {H₂pyip = 5-(4-pyridyl)-isophthalic acid} have been synthesized under solvothermal conditions. X-ray crystallographic studies reveal that 1–9 are isostructural and crystallize in the triclinic system, space group P2₁/c, and exhibit a 3D framework. Topological analysis reveals that the 3D framework can be simplified to a uninodal 6-connected pcu alpha-Po primitive cubic type structure. Meanwhile, the luminescent properties of these nine coordination polymers in the solid state are also investigated. Especially the Eu and Tb compounds show bright red and green luminescence with luminescence lifetimes of 0.39 and 0.80 ms, respectively.     

Three new d10 coordination polymers based on 2-(2-pyridyl)benzimidazole ligand: Synthesis,structures and properties

Three coordination polymers containing 2-(2-pyridyl)benzimidazole (PyHBIm) ligand, namely {[Zn₃(PyBIm)₃(PyHBIm)₂(tma)(H₂O)]?H₂O}_n (1), [Zn(PyHBIm)(oba)]_n (2), [Cd(PyHBIm)(oba)]_n (3), (tma = trimesate, oba = 4,4′-oxybis-(benzoate)), have been prepared through hydrothermal reaction. Compound 1 exhibits one-dimensional (1D) helical structure. However, compounds 2 and 3 display 1D meso-helical structure. These 1D structures are further assembled into three-dimensional (3D) networks through aromatic π–π stacking interactions and hydrogen bonding interactions. Moreover they all exhibit strong photoluminescence at room temperature and may be good candidates for potential luminescence materials.     

Syntheses,structures and photocatalytic properties of two coordination polymers based on bis(1,2,4-triazol-4-ylmethyl)benzene and multicarboxylates

Two coordination polymers {[Cu₄(OH)₂(btrb)₂(btc)₂]·4H₂O}_n (1) and {[Cd₂(btrb)(adc)₂(H₂O)]·H₂O}_n (2) were synthesized with hydrothermal method and characterized (btrb = 1,4-bis(1,2,4-triazol-4-ylmethyl)benzene, btc = 1,3,5-benzenetricarboxylate, adc = 1,3-adamantanedicarboxylate). 1 shows an unusual (3,10)-connected two-dimensional metal–organic framework based on the tetranuclear copper(II) cluster [Cu₄(μ₃-OH)₂]. 2 is an interesting three-dimensional network based on the one-dimensional metal–organic nanotube. 1 shows good photocatalytic activity for the degradation of methyl blue (MB). The luminescence of 2 was investigated.     

Structural diversity in Cu(II) and Cd(II) coordination complexes with 4-amino-1,2,4-triazole ligand

The syntheses and structures of the series of metal complexes, namely [CuCl₂(L)₂·H₂O)]_n (L = 4-amino-1,2,4-triazole), 1; {[Cu(L)₄][ClO₄]₂.H₂O}_n, 2; and [Cd₂Cl₄(L)₂.2H₂O]_n, 3 are reported. These were prepared by the self-assembly of Cu(II) and Cd(II) salts with L in MeOH/H₂O system. All these complexes have been characterized by elemental analysis, IR spectrum, and single crystal X-ray diffraction. Complexes 1–2 show 1-D polymeric infinite chains, while complex 3 shows 2D pleated net. The anions Cl⁻ in complexes 1 and 3 act as bridging or terminal ligands to the metal atoms while the ClO₄⁻ anions in 2 are not coordinated to the metal centers.     

Syntheses,structures and photocatalytic properties of three copper(II) coordination polymers

Three coordination polymers [Cu₂(obtz)₂(tdc)₂]_n (1), {[Cu(obtz)₂(H₂O)₂][Cu₂(obtz)₂(sip)₂]5.5H₂O}_n (2) and [Cu(obtz)(nip)]_n(3) were synthesized by the hydrothermal reaction (obtz = 1.2-bis(1,2,4-triazol-1-ylmethyl)benzene, tdc = 2.5-thiophenedicarboxylate, sip = 5-sulfoisophthalate, nip = 5-nitroisophthalate). 1 shows a ladder-like one-dimensional chain with two side arms. 2 is comprised of two distinct and crystallographically independent polymeric motifs. The first motif in 2 is the ladder-like one-dimensional anionic chain with two side arms. The second motif in 2 is the cationic chain. 3 exhibits the intriguing 2-fold interpenetrated network based on the undulated 2D (4.4) network. 1, 2 and 3 are good photocatalysts for the degradation of methyl orange (MO) under UV irradiation.     

Two Cd(II) coordination polymers based on 3,6-bis(imidazol-1-yl)carbazole: Syntheses,structures and photocatalytic properties

Hydrothermal reactions of CdCl₂·2.5H₂O with 3,6-bis(imidazol-1-yl)carbazole (bmcz), 2-amine-1,4-benzenedicarboxylic acid (2-NH₂-1,4-H₂BDC) or 1,4-naphthalenedicarboxylic acid (1,4-H₂NDC) afforded two coordination polymers, [Cd(2-NH₂-1,4-BDC)(bmcz)]_n (1) and [Cd(1,4-NDC)(bmcz)]_n (2). Complexes 1 and 2 were characterized by elemental analysis, IR, powder X-ray diffraction, and single-crystal X-ray diffraction. 1 and 2 are isomorphic and exhibit 3D supermolecular structures. The solid state luminescent and optical properties of 1 and 2 at ambient temperature were also investigated. A comparative study on their photocatalytic activity toward the degradation of methylene blue in polluted water was explored.     

Pseudo-isomeric zinc/copper coordination polymers based on 3-(2-pyridyl)pyrazole-5-carboxylic acid

Reaction of 3-(2-pyridyl)pyrazole-5-carboxylic acid (H₂L) with Zn(II) or Cu(II) perchlorate yielded [ZnL]_n (1) and [CuL]_n (2) with similar composition. The ligand L^2 − adopts the same μ₃κ⁵ coordination mode. The Zn(II) and Cu(II) atom takes square pyramid coordination polyhedron with some discrepancy. Bigger difference in the dimeric secondary building blocks leads to distinct two-dimensional metal–organic frameworks. The Zn(II) complex fluoresces stronger than the free ligand. The Cu(II) polymer displays strong antiferromagnetic intra-dimer exchange and ferromagnetic inter-dimer exchange.     

Two new three-dimensional (3,4)-connected lanthanide (III) coordination polymers based on 2-(3-Pyridyl)-1H-imidazole-4, 5-dicarboxylate: Structures and luminescent properties

Two new lanthanide (III) coordination polymers, namely, {[Eu₃(μ₃-HPyIDC)₄]·Cl}_n, (1) and {[Tb₂(μ₃-HPyIDC)₂(μ₂-Ox) (H₂O)₂]·4H₂O}_n (2) (H₃PyIDC = 2-(3-Pyridyl)-1H-4, 5-imidazoledicarboxylic acid; Ox = oxalate), were successfully synthesized under hydro(solvo)thermal conditions and structurally characterized. Compound 1 displays a 3D framework with new (3,4)-connected {4.8.10}₄{4.8⁴.12}₂{4².8⁴} topology built by 3-connected μ₃-HPyIDC⁻ nodes and 4-connected metal ions. Compound 2 exhibits a rare (3,4)-connected dmc topology, in which μ₃-HPyIDC⁻ anions are 3-connected nodes and metal ions are 4-connected nodes. Moreover, the thermal stabilities and luminescence of compounds 1–2 were also investigated.     

Synthesis and characterizations of a novel dia-type Ag–BPT coordination polymer with tetranuclear motifs as jointing points (BPT = 3,5-bis(3-pyridyl)-1,2,4-triazole)

The hydrothermal reaction of AgNO₃ and 4-amino-3,5-bis(3-pyridyl)-1,2,4-triazole (NH₂-BPT) generated an unprecedented three-dimensional coordination polymer {[Ag₂(BPT)] · NO₃}_n (1). The crystal structure reveals that two independent Ag(I) centers are linked via cisoid μ₅-BPT anions to form a unique tetranuclear cluster, which is further interconnected to four neighbors to give a 3D cationic framework with dia-topology.     

Synthesis,structure and electrochemical properties of tris (2-(2-pyridyl)-4-methylcarbonylquinoline) ruthenium(II) hexafluorophosphate

A novel ruthenium complex with 2-(2-pyridyl)-4-methylcarbonylquinoline ligand has been prepared and characterized: the first crystal structure of such complex along with its physical and chemical properties are also described.