Novel triazole-bridged cadmium coordination polymers varying from zero- to three-dimensionality

Cadmium salts with different triazole ligands have led to a series of novel triazole-cadmium compounds varying from zero- to three-dimensionality. [Cd(2)(deatrz)(2)(H(2)O)Br(4)] (1) (deatrz = 3,5-diethyl-4-amino-1,2,4-triazole) is a zero-dimensional complex which uses a triazole ligand together with micro-OH(2) as bridges to form a 1D chain via hydrogen-bonding contacts. [[Cd(3)(deatrz)(2)Cl(6)(H(2)O)(2)].2H(2)O](n) (2), [[Cd(dmtrz)Cl(2)].1.5H(2)O](n)(3) (dmtrz = 3,5-dimethyl-1,2,4-triazole), and [[Cd(3)(deatrz)(4)Cl(2)(SCN)(4)].2H(2)O](n)(4) are polymeric 1D chains. 2 and 4 were constructed via trinuclear cadmium units bridged by triazole ligands and chloride atoms, while 3 consists of micro(2)-Cl, micro(3)-Cl, and triazole bridges, cross-linked by hydrogen bonding to give a 3D framework. [[Cd(3)(dmatrz)(4)(SCN)(6)]](n)(5) (dmatrz = 3,5-dimethyl-4-amino-1,2,4-triazole) shows a two-dimensional structure whose fundamental units are trinuclear metal cations bridged via triazole ligands. The complex [[Cd(dmtrz)(SCN)(2)]](n)(6) is the first three-dimensional example in N1,N2-didentate-bridged triazole-metal compounds. Six complexes exhibit six types of bridging modes of N1,N2-triazole in combination with single-atom bridges. 2, 4, and 5 are the unprecedented examples of polymeric chains and planes constructed via trinuclear metal ion clusters, whereas 3 is the first example of the micro(3)-Cl bridging mode in triazole-metal complexes. We have briefly discussed the variety of dimensionalities based on the tuning of different organic ligands and anions.     

Syntheses,structures, and luminescence of three anion-dependent cadmium coordination polymers

Self-assembly of the flexible ligand 1,3,5-tri(1,2,4-triazol-1-ylmethyl)-2,4,6-trimethylbenzene (ttmb) with Cd(II) salts gave three coordination polymers {[Cd(ttmb)₂](SO₄)(H₂O)₁₆} _n (1), {[Cd(ttmb)₂(H₂O)₂](NO₃)₂(H₂O)₆} _n (2), and {[Cd(ttmb)₂(H₂O)₂](ClO₄)₂(H₂O)₇} _n (3). Complex 1 has a (3,6)-connected CdCl₂-type 2-D network. However, 2 and 3 show the 2-D (4,4) network and 1-D double chain, respectively. Complexes 1, 2, and 3 exhibit luminescent emission maxima at 306, 339, and 298?nm, respectively, in the solid state at room temperature.     

Syntheses, structures and luminescence properties of lanthanide coordination polymers with helical character

A series of lanthanide coordination polymers, (Him)_n[Ln(ip)₂(H₂O)]_n [Ln=La(1), Pr(2), Nd(3) and Dy(4), H₂ip=isophthalic acid, im=imidazole] and [Y₂(ip)₃(H₂O)₂]_n·nH₂O (5), have been synthesized and characterized by elemental analyses, infrared (IR), ultraviolet-visible-near infrared (UV-Vis-NIR) and single-crystal X-ray diffraction analyses. The isostructural compounds 1–4 possess 3-D structures with three different kinds of channels. Compound 5 features a 2-D network making of two different kinds of quadruple-helical chains. Compounds 2 and 3 present the characteristic emissions of Pr(III) and Nd(III) ions in NIR region, respectively. Compound 4 shows sensitized luminescence of Dy(III) ions in visible region.     

Syntheses and luminescence of four supramolecular coordination complexes with flexible ligand

Four d ¹⁰-based complexes with chemical formulae {[Zn(L¹)₂(H₂O)₂(4,4′-Bipy)₂] (I), {[Zn₂(L¹)₄(Mi)] · 4H₂O} (II), {[Zn(L¹)₂(Phen)] · H₂O} (III) {[Cd(L¹)₂(Phen)] · 2H₂O} (IV) (HL¹ = p-hydroxy phenylacetic acid, 4,4′-Bipy = 4,4′-bipyridine, Phen = 1,10-phenanthroline, Mi = 1,4-bis(imidazol-1-yl)butane) have been synthesized and structurally characterized by single crystal X-ray diffraction (CIF files CCDC nos. 1047119 (I), 1047120 (II), 1047121 (III), 1047122 (IV)). The significant effect of assistant ligands and metal ions on assembly of I?IV has been demonstrated, which leads to the formation of distinct crystalline products. Complexes I?IV show various coordination motifs with different existing forms and coordination modes of the organic ligands. Furthermore, extend supramolecular networks are connected by secondary interactions such as hydrogen-bonding and aromatic stacking. The thermal stability and luminescent properties of the compounds were discussed in detail.     

Crystal structure and fluorescent properties of a 2D cadmium coordination polymer

A new 2D cadmium(II) coordination polymer {[Cd(MBD)(L)]·(H₂O)₂} _n (1) (H₂MBD = 5-methoxycarbonyl-benzene-1,3-dicarboxylic acid, L = 1,3-bis(benzimidazol-l-yl)-2-propanol) is synthesized, in which the starting linker (benzene-1,3,5-tricarboxylic acid) undergoes selective monoesterification during the synthesis. In the structure of complex 1, each cadmium center is octahedrally coordinated by four O atoms from three carboxylate groups and two N of distinct L ligands. A detailed structural analysis reveales that compound 1 exhibits a unique 2D binodal (3,5)-connected (4².6⁷.8)(4².6) topology structure. Furthermore, the 2D layer is extended into a 3D network through π-π stacking interactions. The solid-state fluorescence properties of 1 are investigated at room temperature.     

Aqua cadmium cyanide coordination polymer with nitronyl nitroxide radical

A new three-dimensional diamagnetic metal nitronyl nitroxide radical coordination polymer with an aqua cadmium cyanide framework Cd(NIT4py)(H₂O)Cd(CN)₄·H₂O 1, was synthesized. X-ray crystallography reveals that the structure consists of 3D aqua cadmium cyanide built up by octahedral Cd^II coordinating to NIT4py and tetrahedral Cd^II (CN)₄ units. Magnetic measurements show that the χ_mT values are nearly constant at higher temperature. The lower χ_mT values at lower temperature are related to intermolecular antiferromagnetic interactions of the radicals, which arise due to the hydrogen bonded network (T_N = 21 K).     

Synthesis, crystal structure, and luminescence properties of coordination polymers based on cadmium isonicotinates

Heating a solution of cadmium nitrate and isonicotinic acid in N,N′-dimethylformamide or dimethyl sulfoxide gave three new coordination polymers, [Cd(Inic)₂] · 0.5DMF (I), [Cd₃(DMSO)₆(Inic)₂(SO₄)₂] (II), and [{Cd(DMSO)(Inic)}₂(SO₄)] · 2H₂O (III), which were studied by X-ray crystallography. Compounds I and III were characterized by IR spectroscopy and elemental and thermogravimetric analyses and luminescence spectroscopy.     

Syntheses,crystal structures,and luminescence of carboxylato-bridged coordination compounds

Two 2-D metal carboxylate coordination compounds [Tb(pydc)(ox)_1/2(H₂O)₂] (1) and [Cd(pydc)(me)(H₂O)]₂ · H₂O (2) (pyridine-2,5-dicarboxylic acid = pydc, oxalic acid = ox, me = methanol) have been synthesized under hydrothermal conditions. Carboxylates are building blocks in the formation of zigzag chain and cockle stair-like chain structures for 1 and 2, respectively. Both the compounds have been structurally determined by single-crystal X-ray diffraction, and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and fluorescence spectra.     

Bridged coordination polymer multilayers with tunable properties

Coordination multilayers consisting of Pd(II) pincer-type complexes and poly(vinyl pyridine) were synthesized and characterized. Film properties were found to be dependent on and could be tuned by varying bath deposition concentrations, polymer molecular weight, and solution additives that compete with binding. Generally, smoother, thinner films were obtained with lower poly(vinyl pyridine) deposition bath concentrations. Likewise, film thickness and roughness could be reduced by employing a higher-molecular-weight poly(vinyl pyridine). Film properties could also be influenced by using acetonitrile as a solution additive, effectively driving the binding equilibrium slightly toward the free species.     

Pyridine effected tunable luminescence properties of a 1D cadmium(II) polymer with tetranuclear second building units

One novel 1D polymer, [Cd₂(m-BrPhHIDC)₂(4,4′-bipy)(H₂O)₂]_n (1) (m-BrPhH₃IDC = 2-(3-bromophenyl)-1H-imidazole-4,5-dicarboxylic acid; 4,4′-bipy = 4,4′-bipyridine), has been hydrothermally synthesised and characterised by single-crystal X-ray diffraction, elemental analysis, IR, powder X-ray diffraction (PXRD) and thermogravimetric analysis. Polymer 1 composed of tetranuclear square [Cd₂(m-BrPhHIDC)₂] second building units and 4,4′-bipy bridges shows the interesting tunable luminescence properties aroused by pyridine. A luminescence enhance mechanism has been proposed.     

瑞香素稀土配合物的合成和性质

自六十年代以来陆续发现稀土化合物具有一系列特殊的药效作用 ,使稀土元素在药物上的应用展现出广阔前景。目前 ,已有不少稀土化合物应用于临床 ,如抗凝血药物 3 磺酸异烟酸钕、左旋糖酸镨、钕混合物 ;消炎药水杨酸钐等。合成具有生物活性配体的稀土配合物是寻找有效稀土药物的一条途径。瑞香素是一具有抗菌、抗炎、抗凝血等生物活性的香豆素类化合物 ,其分子结构为 :稀土与香豆素类的配合物的合成与性质研究己有不少报道[1,2 ] 。为了进一步研究这类配合物的性质和生物活性 ,我们合成了六种瑞香素稀土配合物。1　实验部分1 .1　仪器及试剂…     

不同V型辅助配体构筑的两个镉配位聚合物的合成、结构和荧光性质

在溶剂热条件下，合成了 2 个基于 V 型辅助配体(bipmo、bppmo)的镉配位聚合物{[Cd(bipmo)(NDC)]·1.75H₂O}_n (1)和{[Cd(bppmo)(NDC)(H₂O)]·H₂O}_n (2)，其中 H2NDC=2，6 萘二羧酸，bipmo=双(4 (1H 咪唑 1 基)苯基)甲酮，bppmo=双(4 (吡啶 4 基)苯基)甲酮。利用单晶X射线衍射、键价和分析、红外光谱和元素分析对其结构进行了表征。研究发现，配合物1具有二重互穿的{63}拓扑结构。配合物2同样是 3 连接的{6³}拓扑，却存在三重穿插结构。分析表明，V型配体对最终结构的形成有很大影响。此外，对配合物1和2的发光性质也进行了详细研究。     

不同V型辅助配体构筑的两个镉配位聚合物的合成、结构和荧光性质

在溶剂热条件下,合成了2个基于V型辅助配体（bipmo、bppmo）的镉配位聚合物{[Cd （bipmo）（NDC）]·1.75H₂O}_n（1）和{[Cd （bppmo）（NDC）（H₂O）]·H₂O}_n（2）,其中H₂NDC=2,6-萘二羧酸,bipmo=双（4-（1H-咪唑-1-基）苯基）甲酮,bppmo=双（4-（吡啶-4-基）苯基）甲酮。利用单晶X射线衍射、键价和分析、红外光谱和元素分析对其结构进行了表征。研究发现,配合物1具有二重互穿的{6³}拓扑结构。配合物2同样是3-连接的{6³}拓扑,却存在三重穿插结构。分析表明,V型配体对最终结构的形成有很大影响。此外,对配合物1和2的发光性质也进行了详细研究。     

Syntheses,structures, and luminescence of coordination compounds based on N-containing polycarboxylates

Six coordination compounds constructed by two structurally related flexible nitrogen-containing polycarboxylate ligands 2,2′-(2,2′-(ethane-1,2-diylbis(oxy))bis(2,1-phenylene))bis(methylene)bis(azanediyl)dibenzoic acid (H₂L1) and 5,5′-(2,2′-(ethane-1,2-diylbis(oxy))bis(2,1-phenylene))bis(methylene)bis(azanediyl)diisophthalic acid (H₄L2) have been synthesized: [Ni(H₂O)₆]?·?L1?·?(C₂H₅OH)_0.5?·?H₂O (1), [Co(L1)(L3)]?·?CH₃OH (2), [Ni(L1)(L3)]?·?CH₃OH (3), [Zn(L1)(L3)]?·?CH₃OH (4), [Cd(L1)(L3)]?·?CH₃OH (5), and [Zn(L2)_0.5(phen)]?·?C₂H₅OH (6), where L3?=?3,4?:?9,10?:?17,18?:?23,24-tetrabenzo-1,12,15,26-tetraaza-5,8,19,22-tetraoxacyclooctacosan and phen?=?1,10-phenanthroline. The crystal structures have been determined by single-crystal X-ray diffraction. Compound 1 displays a discrete structure, which is further linked by hydrogen bonds to form a 2-D supramolecular layer. Compounds 2–5 display similar structures. These compounds possess 1-D meso-chain structures linked by L1 and metals. The C–H?···?π interactions from neighboring chains extend the chains in different directions, giving a 3-D plywood network. Compound 6 possesses 2-D layers, which are further linked by hydrogen-bonding interactions to generate a 3-D supramolecular architecture.     

Solvent-dependent structural diversity of cadmium(II) coordination polymers: syntheses,characterizations, and luminescence properties

By changing the solvent, three cadmium(II) coordination polymers (CPs), [Cd(NH₂-BDC)(DMA)(H₂O)]_n (1), {[Cd(NH₂-BDC)₂(DMF)₂]·H₂O}_n (2) and {[(Me₂NH₂)₂Cd₂(NH₂-BDC)₃(H₂O)]·DMF·8H₂O}_n (3), have been synthesized based on the V-shaped linker 5-aminoisophthalic acid and Cd(NO₃)₂·4H₂O under the same reaction temperature (140 °C) (NH₂-BDC = 5-aminoisophthalate, DMA = N,N-dimethylacetamide, DMF = N,N-dimethylformamide). Compound 1 features a 1-D ladder-like infinite chain. Compound 2 is a 2-D (4,4) net when the dinuclear [Cd₂(COO)₄O₄] is regarded as a quadruply-connected node. Compound 3 shows a 2-D hamburger-like structure. Luminescent properties of 1–3 were detected at room temperature under the same excitation and emission wavelengths of 200–600 nm with the same interval of 5 nm. Moreover, the calculation of lattice constants and volumes, and density of states of CPs 1 and 2 were carried out to get better insight into the nature of the structure and luminescence.     

Chiral coordination polymer as a luminescence sensor for small organic molecules

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Uranyl sensitization of samarium(III) luminescence in a two-dimensional coordination polymer

Heterometallic carboxyphosphonates UO(2)(2+)/Ln(3+) have been prepared from the hydrothermal reaction of uranyl nitrate, lanthanide nitrate (Ln = Sm, Tb, Er, Yb), and phosphonoacetic acid (H(3)PPA). Compound 1, (UO(2))(2)(PPA)(HPPA)(2)Sm(H(2)O)·2H(2)O (1) adopts a two-dimensional structure in which the UO(2)(2+) metal ions bind exclusively to the phosphonate moiety, whereas the Ln(3+) ions are coordinated by both phosphonate and carboxylate functionalities. Luminescence studies of 1 show very bright visible and near-IR samarium(III)-centered emission upon direct excitation of the uranyl moiety. The Sm(3+) emissive state exhibits a double-exponential decay with lifetimes of 67.2 ± 6.5 and 9.0 ± 1.3 μs as measured at 594 nm, after excitation at both 365 and 420 nm. No emission is observed in the region typical of the uranyl cation, indicating that all energy is either transferred to the Sm(3+) center or lost to nonradiative processes. Herein we report the synthesis, crystal structure, and luminescent behavior of 1, as well as those of the isostructural terbium, erbium, and ytterbium analogues.     

Syntheses, structures and properties of cadmium benzenedicarboxylate metal-organic frameworks

The products isolated from the reaction between Cd(NO3)2 x 4H2O and 1,4-benzenedicarboxylic acid (H2bdc) in DMF are very dependent on the conditions. At 115 degrees C, the reaction gives [Cd(bdc)(DMF)]infinity, which has a three-dimensional network structure, whereas at 95 degrees C, 1 is formed alongside [Cd3(bdc)3(DMF)4]infinity 2, which has a two-dimensional network structure. When the reaction is carried out under pressure, it yields [Cd3(bdc)3(DMF)4]infinity 3, which is a supramolecular isomer of 2. The structure of 3 differs from that of 2 regarding the way the Cd3(O2CR)6 units are interlinked to form layers. When the reaction was carried out in DMF that had undergone partial hydrolysis, the only isolated product was [(NMe2H2)2[Cd(bdc)2] x 2DMF]infinity 4. Compound 4 has a three-dimensional triply-interpenetrated diamondoid structure, with dimethylammonium cations and DMF molecules included within the pores. The reaction between Cd(NO3)2 x 4H2O and H2bdc in DEF gave [Cd(bdc)(DEF)]infinity 5, regardless of the solvent quality. Compound 5 has a three-dimensional network structure. The reaction of Cd(NO3)2 x 4H2O and 1,3-benzenedicarboxylic acid (H2mbdc) in DMF gave [Cd(mbdc)(DMF)]infinity 6 which has a bilayer structure. The thermal properties of the new materials have been investigated, and the coordinated DEF molecules from 5 can be removed on heating to 400 degrees C without any change in the powder X-ray diffraction pattern. The H2 sorption isotherm for the desolvated material shows marked hysteresis between adsorption and desorption, and less adsorption than predicted by simulations. Kinetic data indicate that the hysteresis is not due to mass transfer limitations, and the most likely explanation for this behaviour lies in partial collapse of the framework to an amorphous phase under the conditions of activation.     

Size Effects on the Luminescence Properties of Polymer Nanowires简

Poly（3-（2-methoxyphenyl）thiophene） （PMP-Th） nanowires were fabricated using porous anodic alumina （PAA） as template through electrochemical polymerization by cyclic voltammetry. The control on the size of nanowires was confirmed by electron microscopy. The results indicated that the luminescence spectra of PMP-Th nanowires in PAA nanochannels were blue-shifted and emission intensity was enhanced compared to the emission of the PMP-Th film. Moreover, the luminescent spectra of PMP-Th nanowires were size dependent, which may result from the change in the degree of confinement of nanowires in PAA. F6rster energy transfer from PAA to PMP-Th molecules is considered to be responsible for the enhancement of luminescence from PMP-Th nanowires in PAA. The results show that the emission properties of polymers with nanostructures can be tuned by controlling their size.     

Synthesis,structure and luminescent properties of a new two-dimensional (4,4) network cadmium coordination polymer with dicyanamide and benzimidazole ligands

The new cadmium coordination polymer [Cd(bim)₂(dca)₂]_n (1), (bim?=?benzimidazole, dca?= dicyanamide) was synthesized and characterized by IR, thermogravimetric analysis and luminescent properties. The coordination geometry of cadmium atom is distorted octahedral, coordinated equatorially by four nitrogen atoms from four dicyanamide ligands, and axially by two nitrogen atoms from two benzoimidazoles. Each dca ligand links two cadmium(II) atoms and 1 forms a two-dimensional (4,4) network.