Synthesis,structure, and thermal properties of 3-D coordination polymers constructed from asymmetrical carboxylates

Three new coordination polymers constructed from asymmetric ligands were synthesized under hydrothermal conditions and characterized with single crystal X-ray analysis, infrared, and thermal gravimetric methods. Complex 1 exhibits a 3-D network constructed from rod-shaped secondary building units. Pyrimidine-4-carboxylic acid (bpa) was used as the starting material, but under hydrothermal conditions bpa formed 2,2′-pyrimidine-4,4′-dicarboxylic acid (bpda) in situ, which further connected with Pb. 3-D two-fold interpenetration of complex 2 was obtained by the similar method as described for 1, except that Cd(NO₃)₂ · 6H₂O was used instead of Pb(NO₃)₂ · 6H₂O to react with bpa. Complex 3 shows a three-connected 3-D network. Furthermore, the photoluminescence properties of 1 and 2 were studied.     

Two fluorescent coordination polymers constructed from mixed rigid and flexible carboxylate ligands: Formation of cross-linking helical and zigzag chains

Two 3D coordination polymers with different structure motifs, [Zn₂(PCPA)₂(IN)₂]_n (1) and [Co(PCPA)(IN)]_n (2) (PCPA=p-chlorophenoxyacetate, IN=isonicotinate), first constructed from mixed rigid and flexible carboxylate ligands, have been obtained under hydrothermal condition and characterized by elemental analyses, IR spectra, thermogravimetric analysis, fluorescent spectra and single crystal X-ray diffraction analysis. The most intriguing structural feature is that each complex exhibits both infinite helical Zn(μ₂-carboxylate) or Co(μ₃-carboxylates) chain units with 2₁ helices and zigzag M₂(IN)₂ (M=zinc and cobalt) chain units by reason of two different carboxylate ligands coordinating to metal centers. Additionally, compounds 1 and 2 show similar blue fluorescence in the solid state at room temperature.     

Mixed-ligand coordination polymers constructed from flexible 2,2′-biphenyldicarboxylate and rigid isomeric bipyridines

Six coordination polymers have been synthesized and characterized based on dpa and isomeric bipyridine mixed ligands with various metal ions. Complex 1 exhibits a two-dimensional layer structure. Complex 2 is isomorphic to complex 1, with only small differences in bond lengths and bond angles. Complex 3 shows a one-dimensional chain structure composed of interesting pentanuclear Co building units. Complex 4 possesses a two-dimensional (4, 4) layer network, which crystallizes in a homochiral space group. During the synthesis process of complex 4, the dpa ligands decompose and form 2-bpa ligands, which connect with Ni atoms and produce the two-dimensional complex 5. Complex 6 exhibits a three-dimensional supramolecular structural feature constructed from discrete building units with π–π interactions. Furthermore, the magnetic properties of complex 2 are studied.     

Different aliphatic dicarboxylates affected assemble of new coordination polymers constructed from flexible-rigid mixed ligands

In this article, seven coordination polymers: [Cd(C₅H₆O₄)(C₁₀H₈N₂)]_n (1), [Zn(C₅H₆O₄)(C₁₀H₈N₂)]_n (2), [Cd(C₆H₈O₄)(C₁₀H₈N₂)]_n (3), {[Mn(C₁₀H₈N₂)(H₂O)₄] (C₄H₄O₄)·4H₂O}_n (4), [Mn₅(C₄H₄O₄)₄(O)]_n (5), [Cd(C₄H₄O₄)(C₁₀H₈N₂)(H₂O)]_n (6) and [Zn(C₆H₆O₄)(C₁₂H₈N₂)(H₂O)]_n (7) were synthesized and characterized by single-crystallographic X-ray diffraction. Compounds 1 and 2 are two-dimensional layers connected by glutarate anions and 4,4′-bpy. Unlike compounds 1 and 2, compound 3 is a two-fold interpenetration network. Compound 4 is a one-dimensional chain-like structure, which is further extended to two-dimensional supramolecular layer structure with hydrogen bond. During the synthesis of compound 4, to our surprise, we got compound 5; compound 5 is an interesting three-dimensional network composed of pentanuclear Mn(II) building units and succinate anions. Compound 6 is also a two-dimensional supramolecular layer structure composed of one-dimensional chain-like structure with hydrogen bonds and Π-Π interactions. Compound 7 is also a one-dimensional chain-like structure, which is further connected with the same kind of interaction to generate two-dimensional supramolecular layer structure. Furthermore, compounds 1 and 2 both exhibit fluorescent property at room temperature.     

三个二羧酸配体配位聚合物的合成、结构表征和荧光性质

以羧酸配体 2,2''-(1,4-亚苯基双(亚苯基))双(硫二基)二苯甲酸(H₂L¹)和 2,2''-(2,3,5,6-四甲基-1,4-亚苯基)双(亚甲基）双(硫二基)二苯甲酸(H₂L²)分别与金属盐反应,通过溶剂热方法合成了 3个配位聚合物：{[Ni(L¹)(H₂O)₄]·2H₂O}_n (1)、[Zn(L¹)(DMA)₂]_n(2)和[Co(L²)(DMF)₂]_n (3),其中DMA=N,N-二甲基乙酰胺,DMF=N,N-二甲基甲酰胺。对配合物1~3进行了单晶X射线衍射、元素分析、红外光谱、热重分析、粉末X射线衍射和固体紫外可见光谱测试和表征。单晶X射线衍射表明：3个配合物均为一维锯齿形链状结构,并通过氢键作用形成三维骨架,且配体均表现为反式构象。此外,对配合物2固态荧光性质进行了研究。     

三个二羧酸配体配位聚合物的合成、结构表征和荧光性质

以羧酸配体2,2''-（1,4-亚苯基双（亚甲基））双（硫二基）二苯甲酸（H₂L¹）和2,2''-（2,3,5,6-四甲基-1,4-亚苯基）双（亚甲基）双（硫二基）二苯甲酸（H₂L²）分别与金属盐反应,通过溶剂热方法合成了3个配位聚合物：{[Ni（L¹）（H₂O）₄]·2H₂O}_n （1）、[Zn（L¹）（DMA）₂]_n （2）和[Co（L²）（DMF）₂]_n （3）,其中DMA=N,N-二甲基乙酰胺,DMF=N,N-二甲基甲酰胺。对配合物1~3进行了单晶X射线衍射、元素分析、红外光谱、热重分析、粉末X射线衍射和固体紫外可见光谱测试和表征。单晶X射线衍射表明：3个配合物均为一维锯齿形链状结构,并通过氢键作用形成三维骨架,且配体均表现为反式构象。此外,对配合物2固态荧光性质进行了研究。     

Hydrothermal synthesis and structural characterization of two unprecedented photoluminescent coordination polymers constructed from Cd salt and mixed ligand

Two new Cd-containing coordination polymers {Cd₂(succ)₂(1,10′-phen)₂} _n (1) and {Cd(glut)(1,10′-phen)(H₂O)} _n (2) are described. Complex 1 exhibits an interesting 2-D structure in which the binuclear Cd centers are linked by succinate anions. Complex 2 possesses an interesting 1-D chain-like structure. The IR and TG properties of the two compounds are studied. Furthermore, these two complexes exhibit photoluminescence.     

Syntheses and structural characterization of transition metal(II) coordination polymers containing 4,4′-dipyridyldisulfide

The reactions of Zn(NO₃)₂ · 6H₂O and FeSO₄ · 7H₂O with 4-PDS (4-PDS = 4,4′-dipyridyldisulfide) and NH₄SCN in CH₃OH afforded the complexes [Zn(NCS)₂(4-PDS)]_n (1) and [Fe(NCS)₂(4-PDS)₂ · 4H₂O]_n (2), respectively, while the reaction of CoCl₂ · 6H₂O with 4-PDS in CH₃OH gave the complex {[Co(4-PDS)₂][Cl]₂ · 2CH₃OH}_n, (3). These complexes have been characterized by spectroscopic methods and their structures determined by X-ray crystallography. The 4-PDS ligands in 1 are coordinated to the metal centers through the nitrogen atoms to form 1-D zigzag-chains, and the distorted tetrahedral coordination geometry at each zinc center is completed by a pair of N-bonded thiocyanate ligands. Compound 2 has a 1-D channel-chain structure and each octahedral Fe(II) metal center is coordinated by four 4-PDS ligands and two trans N-bonded thiocyanate ligands. Weak SS interactions in complex 1 link the 1-D chains into 2-D molecular sheets. In complex 2, the channel chains are interlinked through SS interactions to form molecular sheets, which interpenetrate through the SS interactions to form 3-D structures with large cavities that are occupied by the water molecules. Compound 3 also has a 1-D channel-chain structure with each square-planar Co(II) metal center coordinated by four 4-PDS ligands. Multiple C–HCl hydrogen bonds and SO interactions in 3 link the 1-D chains into 2-D structures.     

Synthesis,characterization and property study of new coordination polymers constructed from flexible dicarboxylates and bidentate nitrogen mixed ligands

Five new coordination polymers, [Cd(1,2′-cy)_0.5(bix)H₂O]_n (1), [Cd₂(1,2′-cy)₂(1,10′-phen)₂(H₂O)₂] (2), {[Co(1,2-cy)(2,2′-bipy)(H₂O)₂]·2H₂O}_n (3) {[Cd(succ)(1,10′-phen)H₂O]·H₂O}_n (4), and {[Cd(succ)(2,2′-bipy)H₂O]·2H₂O}_n (5) (1,2-cy = 4-cyclohexene-1,2-dicarboxylate, succ = succinic acid, bix = 1,4-bis(imidazol-1-ylmethyl)benzene, 1,10′-phen = 1,10-phenanthroline, 2,2′-bipy = 2,2′-bipyridine), have been synthesized and characterized by single-crystallographic X-ray diffraction. Complex 1 shows a two-dimensional covalent layer structure. Complex 2 exhibits a two-dimensional supramolecular layer network composed from discrete fundamental units. Complex 3 exhibits a one-dimensional covalent chain-like structure, which further extends to a two-dimensional supramolecular structure with hydrogen bonding and π-π interactions respectively. Complexes 4 and 5 show three-dimensional supramolecular networks composed from one-dimensional chain-like covalent structures. Furthermore, the magnetic property of complex 3 and fluorescent properties of complexes 1, 2, 4 and 5 have also been studied.     

Synthesis and crystal structures of three novel coordination polymers constructed from Ag(I) thiocyanate and nitrogen donor ligands

Three supramolecular coordination polymers (SCPs) [(AgSCN)₂L] {L = 4,4′-bipyridine (bpy) (1), trans-1,2-bis(4-pyridyl)ethylene (tbpe) (2) and phenazine (phenz) (3)} have been synthesized and structurally characterized by single-crystal X-ray diffraction. Synthesis was affected in H₂O/acetonitrile/NH₃ media at room temperature. The bpy, tbpe and phenz bipodal ligands adopt different conformations which would affect the skeleton of the (AgSCN)_n building blocks that allow the interconnection of the (AgSCN)_n fragments and propagation of the network structure in three dimensions. Supramolecular interactions such as hydrogen-bonding, argentophilic interaction and π–π stacking play an important role in the assembly of these coordination polymers.     

Synthesis,structure, and photoluminescence of a series of lanthanide coordination polymers constructed from nitrogen containing organic ligands

We have synthesized four coordination polymers with two different nitrogen containing organic ligands and different lanthanide metal ions, under hydrothermal condition. [{Ln₂(bpdc)₃(H₂O)₂}] _n (Ln = Dy (1), Sm (2)) (bpdc = 2,2-bipyridine-3,3-dicarboxylic acid) are isostructural, with 2-D supramolecular layer structure composed from 1-D chains. Like 1 and 2, [{Ln(pzda)₂(H₂O)₂} · 4H₂O] _n (Ln = Dy (3), Nd (4)) (pzda = pyrazine-2,6-dicarboxylic acid) are also isostructural with 1-D chain-like structures. The photoluminescence of 2 is studied.     

Syntheses and structural characterization of inifinite coordination polymers from bipyridyl ligands and zinc salts

The reaction of ZnSiF₆·6H₂O with 4,4′-dipyridyldisulfide (4-PDS) in CH₃OH afforded the complex [Zn(4-PDS)₂(SiF₆)·3CH₃OH] _n , 1, while the reaction of Zn(ClO₄)₂·6H₂O with l,2-bis(4-pyridyl)ethane (bpa) in CH₃OH gave the complex [Zn(bpa)₂(ClO₄)₂·CH₃OH] _n , 2. The 4-DPS ligand in 1 is coordinated to the metal centers through both nitrogen atoms to form a 3-D open channel and the distorted octahedral coordination geometry at each zinc center is completed by a pair of trans-F-bonded hexafluorosilicate molecule. Compound 2, the channel-type 1-D chains are interlinked through C–H···O interaction to form 3-D structure with large cavities that are occupied by the methanol molecules.     

Syntheses and characterizations of four metal coordination polymers constructed by the pyridine-3,5-dicarboxylate ligand

A series of metal-organic frameworks, namely [Ni(PDB)(H₂O)]_n (1), [Pb(PDB)(H₂O)] · (H₂O) (2), [Co₂(PDB)₂(bpy)₂(H₂O)₄] · 4H₂O (3) and [Co₂(PDB)₂(phen)₂]_n (4) (H₂PDB = pyridine-3,5-dicarboxylic acid, bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline), have been synthesized based on pyridine-3,5-dicarboxylate acid and two neutral chelate ligands, with different metal ions such as Ni^II, Co^II and Pb^II, under hydrothermal conditions. The framework structures of these polymeric complexes have been determined by the X-ray single crystal diffraction technique. In the four complexes, the pyridine-3,5-dicarboxylate acid ligand exhibits diverse coordination modes, which play an important role in the construction of metal-organic frameworks. The thermal analyses of these four complexes have been measured and discussed. In addition, complex 2 shows strong phosphorescent emission at room temperature and the magnetic measurement of the polymer of 4 reveals a typical antiferromagnetic exchange.     

Synthesis,X-ray crystal structures,and luminescent properties of two coordination polymers constructed from transition metal complexes of mixed flexible–rigid ligands

Two new coordination polymers [Ni(C₆H₁₀O₄)(C₁₀H₈N₂)] _n (1) and [Zn₃(C₆H₁₀O₄)₃(C₁₂N₂H₈)₂] _n (2) have been synthesized under hydrothermal conditions. Complex (1) exhibits an interesting three-dimensional interpenetrating network, whereas complex (2) has a two-dimensional network. The IR and TG properties of these two complexes are studied. Furthermore, complex (2) exhibits photoluminescence. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis and crystal structures of three novel coordination polymers generated from AgCN and AgSCN with flexible N-donor ligands

The solvothermal reactions of AgX (X = CN, SCN) with mbix [mbix = 1,3-bis(imidazole-l-yl-methyl)benzene] or bix [bix = 1,4-bis(imidazole-l-yl-methyl)benzene] afforded the polymers [AgCN(mbix)]_n (1), [(AgCN)₄(bix)₂]_n (2) and [(AgSCN)₂(mbix)]_n (3). They were all characterized by infrared spectroscopy, elemental analysis and X-ray single-crystal analysis. The structure of 1 contains a 3-fold-interpenetrated 2D network, while that of 2 exhibits 2-fold parallel interpenetration. There is no interpenetration observed in 3. Compounds 2 and 3 show 3D supramolecular structures built from 2D networks through weak π ? π interactions. The photoluminescent properties of the present compounds were also investigated.     

Syntheses,structures, and properties of transition metal coordination polymers based on a long semirigid tetracarboxylic acid and multidentate N-donor ligands

Six transition metal coordination polymers based on a semirigid tetracarboxylic acid and the multidentate N-donor ligands have been synthesized by the hydrothermal method, namely, {[Co(H₂obda) (μ₂-H₂O) (H₂O)₂]·2H₂O}_n (1), {[Co(obda)_0.5(bpe) (H₂O)₂]·3H₂O}_n (2), {[Zn(H₂obda) (H₂O)₄]·H₄obda·6H₂O}_n (3), {[Zn(bpy) (H₂O)₄]·H₂obda}_n (4), {[Ni(bpy) (H₂O)₄]·H₂obda}_n (5) and {[Cu(H₂obda) (bpy)₂]}_n (6) (H₄obda = 1,4-bis(4-oxy-1,2-benzene dicarboxylic acid)benzene, bpe = 1,2-Bis(4-pyridyl)ethylene), bpy = 4,4′-bipyridine). Compounds 1–6 were structurally characterized by the elemental analyses, infrared spectra, and single crystal X-ray diffractions. Compounds 1–2 exhibit the 2D quadrilateral and polygonal layered grid structures, respectively; a 3D supramolecular structure of 2 has been build via π···π and hydrogen bonds interactions. Compounds 3–6 reveal the 1D zigzag and linear chains structures, respectively; furthermore, 3–5 display the diverse 3D supramolecular structures via hydrogen bonds, respectively. The 1-D infinite water chain in 3 has been found between the lattice water molecules. In addition, the thermogravimetric analyses of 1–6, magnetic property of 1, and photoluminescence of 3–4 have been investigated, respectively.     

Two new coordination polymers constructed by angular tripyridyl ligand: syntheses,structures, and properties

U-shaped tripyridyl ligand 2,6-bis(pyridine-4-carboxamido)pyridine (L) was synthesized and used to assemble metal complexes. The resulting new complexes [Mn(L)₃(SCN)₂] _n (1) and [Co(L)₃(SCN)₂] _n (2) are isostructural, crystallizing in the monoclinic C2/c space group. In compounds 1 and 2, each metal is in a slightly distorted octahedron ligated by six nitrogens from four L and two SCN^?. Complexes 1 and 2 possess infinite 1-D zigzag polymeric chain structures where L adopts bridge and terminal coordination. These 1-D coordination polymers assemble into 3-D supermolecules of compounds 1 and 2 through hydrogen bonds. Fluorescence measurements and thermal analysis show that 1 emits strong fluorescence with a single broad band centered at 410?nm upon excitation at 357?nm and the polymeric chain structure is stable up to 340°C.     

Synthesis and structural characterization of two dimensional cadmium(II) coordination polymers

Reactions of Cd(NO₃)₂?·?4H₂O with NH₄SCN, ppz (ppz?=?piperazine) and bpa (bpa?=?bis(4-pyridyl)ethane) in CH₃OH afforded the cavity-containing rectangular grids {Cd(SCN)₂(ppz)} _n (1) and {Cd(NCS)₂(bpa)} _n (2). The ppz ligand in 1 is coordinated to the metal through both nitrogen atoms to form the 1-D zig-zag chain structure and distorted {CdN₄S₂} octahedral coordination geometry at each Cd center is completed by pairs of bidentate thiocyanato ligands. Complex 2 has the 2-D arrangement constructed through 1-D double μ(N,S) end-to-end bridging thiocyanato groups bridging Cd(II) chains interconnected through disordered bpa ligands.     

Synthesis,structures, and properties of a series of similar structural coordination polymers with triphosphonate anions as ligands

The hydrothermal reactions of metal precursors with aminotri(methylenephosphonic acid) yielded a series of similar structural coordination polymers of general formula {M[HN(CH₂PO₃H)₃](H₂O)₃}_n [M = Mg(II) (1), Mn(II) (2), Co(II) (3), Zn(II) (4) and Cd(II) (5)]. Compounds 1–5 were characterized by X-ray single crystal diffraction, elemental analyses, and thermogravimetric analyses. Compounds 1–5 all reveal the wave-like 1D chain structures and the structures are constructed by two types of eight-membered, square-like rings linked alternatively via the phosphonate oxygen atoms, generating double-channel systems. The magnetic studies of 2 and 3 reveal that antiferromagnetic interactions are mediated between the metal ions.