CdII Coordination Polymers Research Articles

Structural diversity and fluorescent properties of CdII coordination polymers with 5-halonicotinates regulated by solvent and ligand halogen-substituting effect

Seven CdII coordination polymers have been prepared from CdCl2 and 5-halonicotinic acids (HL–X, X = F or Cl) in different solvent media using a similar layered diffusion method. A pair of polymorphic isomers [Cd(L–F)2]n (1 and 2) can be assembled from CH3CN–H2O and CH3OH–H2O systems, respectively, featuring the 3-D (3,5)-connected (4·62)(4·67·82) network (5-connected node for each CdII ion and 2- or 3-connected linker for the two different types of L–F− ligand) and the 3-D (3,6)-connected ant framework with the point symbol of (4·62)2(44·62·88·10). While in DMF–H2O solvent, a 2-D layered complex [Cd(L–F)Cl(DMF)]n (3) is obtained with the (3,5)-connected net of (3·4·5)(32·4·5·62·74) topology, where the chloride anion is involved in coordination. When the HL–Cl ligand is utilized instead of HL–F, the assembling reactions in CH3CN–H2O and DMF–H2O media lead to the 3-D (3,5)-connected network of [Cd(L–Cl)2]n (4) and the 2-D (3,5)-connected net of [Cd(L–Cl)Cl(DMF)]n (6), which are isostructural to complexes 1 and 3, respectively. [Cd(L–Cl)2(H2O)2]n (5) can be generated from the CH3OH–H2O medium, showing a 2-D (4,4) layered structure, and the similar reaction in the C2H5OH–H2O solvent will produce a 3-D coordination framework {[Cd(L–Cl)2(H2O)0.5](C2H5OH)0.75(H2O)0.25}n (7) with the (3,6)-connected (3·4·5)(32·44·55·62·72) net. These structural divergences can be ascribed to the significant solvent modulation and halogen-substituting effect of 5-halonicotinates. Furthermore, their solid-state properties such as thermal stability and fluorescence have also been investigated.

Alkali-metal-regulated construction of superhydrophilic ZnII and CdII coordination polymers with perhalogenated terephthalate ligands

By simply introducing different alkali metal ions as structure-directing agents, four new coordination polymers with the formulae [Cd3(BDC-F4)3(DMF)2(MeOH)6]n (1), [Cd(BDC-F4)(DMF)2(H2O)2]n (2), [Zn2Na2(BDC-Cl4)3(DMF)4(μ2-MeOH)]n (3) and [ZnK(BDC-Cl4)1.5(DMF)(Me2NH)]n (4) (BDC-F4 = 2,3,5,6-tetrafluoro-benzenedicarboxylate; BDC-Cl4 = 2,3,5,6-tetrachloro-benzenedicarboxylate; DMF = dimethylformamide and Me2NH = dimethylamine) have been synthesized and structurally characterized. Complex 1 presents an open three-dimensional (3D) 3-nodal (3,4)-connected framework, 2 has a one-dimensional (1D) chain structure, 3 features a 3D 4-nodal (3,4,5,6)-connected coordination network constructed from the new ZnII–NaI heterometallic tetranuclear cluster, and 4 shows a 3D 4-nodal (3,5,6)-connected network based on the unique ZnII–KI heterometallic tetranuclear cluster. The results reveal the significant influence of alkali-metal ions on the structural topologies of complexes 1–4. Interestingly, compounds 1–4 all exhibit high water solubility, and futher evaporation of their water solution will result in a 1D coordination polymer {[Cd4(BDC-F4)4(H2O)11]·3.5H2O}n (5) consisting of the unprecedented polymeric [CdII–H2O]n chain, and a zero-dimensional (0D) complex [Zn(H2O)6]·(BDC-Cl4)·4H2O (6) containing the discrete [Zn(H2O)6]2+ cationic and BDC-Cl4 dianionic moieties. Furthermore, the solution chemistry of complexes 5 and 6 has been investigated by electrospray ionization (ESI) mass spectrometry and molar electrical conductivity. The photoluminescent properties of complexes 1–6 have also been explored, which interestingly indicate a strong blue emission of complex 1 in the solid state at room temperature.

A crystal engineering rationale in designing a CdII coordination polymer based metallogel derived from a C3 symmetric tris-amide-tris-carboxylate ligand

A crystal engineering rationale was employed to generate coordination polymer based metallogels derived from a C3-symmetric tris-amide-tris-carboxylate ligand, namely N,N′,N′′-bis-(4-carboxylate) trimesicamide (L1). Reactions of L1 with various metal salts such as Cd(NO3)2, Cu(NO3)2, Co(NO3)2 and Zn(NO3)2 in pure water resulted in metallogels G1, G2, G3 and G4, respectively. The gels were thermo-irreversible indicating their coordination polymeric nature. Crystallization of L1 and Cd(NO3)2 from a MeOH–water mixture afforded the coordination polymer CP1, the composition of which was established as [{Cd(μ3-L1)(H2O)}·13H2O]∝ from single crystal X-ray diffraction. The crystal structure of CP1 revealed the existence of a 3-fold interpenetrated highly undulating (6,3)-network topology having a large solvent accessible area volume. The results clearly supported the crystal engineering rationale, on which the generation of metallogels was based.

Synthesis and characterization of CuII, CdII and PbII coordination polymers derived from 1,4-benzene- and 1,1' -ferrocenedicarboxylate and 2-aminobenzothiazole

Synthesis and characterization of CuII, CdII and PbII coordination polymers derived from 1,4-benzene- and 1,1' -ferrocenedicarboxylate and 2-aminobenzothiazole

A 2-D CdI2 coordination network with 7-oxabicyclo[2.2.1]-5-heptene-2,3-dicarboxylate: synthesis, crystal structure, and luminescent properties

The in situ reaction of Cd(ClO4)2·6H2O with 7-oxabicyclo[2.2.1]-5-heptene-2,3-dicarboxylic anhydride in the presence of lithium hydroxide affords a 2-D CdII coordination polymer, [Cd(L)(H2O)]∞ (1) (L = 7-oxabicyclo[2.2.1]-5-heptene-2,3-dicarboxylate), which exhibits an unusual (3,6)-connected (46.66.83)(43)2 CdI2-type topology. The luminescent and thermal properties of 1 were investigated.

Two unique (4,5,6)-connected 2D CdII coordination polymers based on the 5-nitro-1,2,3-benzenetricarboxylate ligand

Two new 2D coordination polymers, [Cd3(nbta)2(H2O)4] (1) and [Cd3(nbta)2(bbi)2H2O)2] (2) (H3nbta = 5-nitro-1,2,3-benzenetricarboxylate, bbi = 1,1′-(1,4-butanediyl)bis(imidazole)) have been synthesized and structurally characterized by single X-ray structure analysis. The versatile conformations and binding modes of the nbta ligand as well as the coordination environment of the CdII atoms result in two unique (4,5,6)-connected 2D CdII-coordination polymers, both of which show enthralling helical structures.

Substituent effect of R-isophthalates (R = –H, –CH3, –OCH3, –tBu, –OH, and –NO2) on the construction of CdIIcoordination polymers incorporating a dipyridyl tecton 2,5-bis(3-pyridyl)-1,3,4-oxadiazole

A series of CdII coordination polymers have been designed and hydrothermally synthesized by using a bent dipyridyl tecton 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (3-bpo) and R-isophthalic acids (H2ip-R; R = –H, –CH3, –OCH3, –tBu, –OH, and –NO2), which exhibit diverse 1D and 2D polymeric coordination networks. The results demonstrate that the substituent effect of R-isophthalates does play a decisive role in directing the structural assemblies of this system, in which secondary interactions such as H-bonding and π⋯π stacking are generally observed to extend the coordination motifs. Notably, the 3-bpo building block shows adaptable conformations (cisoid-I, cisoid-II, and transoid) to facilitate the structural diversity of these complexes. Solid state properties such as thermal stability and fluorescence for these crystalline materials will also be presented.

Recent advances in CdII coordination polymers: Structural aspects, adaptable assemblies, and potential applications

In the past few years, CdII coordination polymers have received much attention due to their diverse structures and interesting properties. This mini-review presents a short summary of the structural styles for such metal-organic networks based on their extended dimensions. Moreover, the influence factors on assemblies and some potential applications will also be commented.

Synthesis and Structure of a Thiocyanato-Bridged One-Dimensional CdII Coordination Polymer

Synthesis and structure of a new thiocyanato-bridged one-dimensional coordination polymer, [Cd(NCS)2(TPPO)] n (1, TPPO = triphenylphosphine oxide), have been described. The title compound crystallizes in the monoclinic P21/c space group with the unit cell parameters: a = 9.4917(4) A, b = 22.2895(11) A, c = 11.3300(5) A, β = 117.433(3)°, V = 2127.49(17) A3, and Z = 4. The single crystal X-ray diffraction revealed that the structure of 1 features thiocyanate bridges and 1D zigzag chains. The chains consist of thiocyanato-bridged five-coordinated Cd atoms. And the coordination fashion of thiocyanate group is different from the previous reported five-coordinated Cd-NCS systems. The synthesis and structure of a thiocyanato-bridged one-dimensional supramolecular, [Cd(NCS)2 (TPPO)] n (1, TPPO = triphenylphosphine oxide), have been described.

In situ attained CdII-coordination polymer with (3,4,9)-connected topology based on trinuclear CdII clusters

A new trinuclear Cd II -coordination polymer based on in situ generated 5-nitrobenzene-1,2,3- tricarboxylate (nbtc 3- ) ligand exhibits a previously unknown 2D (3,4,9)-connected (3.4 2 )(3 2 .4 3 .5) (3 6 .4 11 .5 10 .6 8 .8) topology as well as 3D H-bonding pillared architecture. A new Cd II -coordination polymer, namely, [Cd 3 (nbtc) 2 ·4H 2 O] n ( 1 ), has been hydrothermally synthesized with in situ generated 5-nitrobenzene-1,2,3-tricarboxylate (nbtc 3− ) ligand. Single-crystal X-ray diffraction study reveals that compound 1 is constructed from trinuclear Cd II clusters and exhibits a previously unknown 2D (3,4,9)-connected (3.4 2 )(3 2 .4 3 .5)(3 6 .4 11 .5 10 .6 8 .8) topology as well as 3D H-bonding pillared architecture. In addition, the photoluminescent property and thermal stability of 1 were also discussed.

A coordination polymer of Cd with benzene-1,3-dicarboxyl-ate and 1,4-bis-[1-(2-pyridylmeth-yl)benzimidazol-2-yl]butane.

The title CdII coordination polymer, catena-poly[[{1,4-bis­[1-(2-pyridylmeth­yl)benzimidazol-2-yl]butane}cadmium(II)]-μ-benzene-1,3-dicarboxyl­ato], [Cd(C8H4O4)(C30H28N6)]n, was obtained by reaction of CdCO3, benzene-1,3-dicarboxylic acid (H2btc) and 1,4-bis­[1-(2-pyridylmeth­yl)benzimidazol-2-yl]butane (L). The CdII cation is six-coordinated by an N2O4-donor set. L acts as a bidentate ligand and btc anions link CdII centers into a chain propagating parallel to [010].

A novel CdII coordination polymer with helical units and mix-connected network topology constructed form 2-propyl-4,5-imidazoledicarboxylate and N-donor co-ligands

Abstract A novel 2D coordination polymer, formulated as [Cd2(Hpimdc)2(bpp)(H2O)]n (bpp = 1,3-bis(4-pyridyl)propane, H3pimdc = 2-propyl-4,5-imidazoledicarboxylate), has been hydro-thermally synthesized and structurally characterized, which shows unusual multifarious helical structures and (3,4)-connected network with (4.82)2(42.83.10) topology. The photoluminescent property and thermal stability of 1 were also discussed.

{[Cd2(pyt)2(chdc)(H2O)](H2O)2}n: A unique bilayer coordination polymer with mixed-connected network topology (Hpyt = 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol and H2chdc = 1,4-cyclohexanedicarboxylic acid)

A unique CdII coordination polymer {[Cd2(pyt)2(chdc)(H2O)](H2O)2}n (1) has been obtained by hydrothermal reaction and characterized by IR, microanalysis, and powder X-ray diffraction (here Hpyt=5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol and H2chdc=1,4-cyclohexanedicarboxylic acid). Single crystal X-ray diffraction reveals that complex 1 has an unusual bilayer coordination framework with mixed-connected network topology, in which two adjacent [Cd(pyt)]n layers are spaced by chdc pillars. Thermal stability of 1 has also been discussed.

An unusual chain cadmium(II) coordination polymer:catena-poly[[(2,2′-bipyridyl-κ2N,N′)cadmium(II)]-di-μ-chlorido-[(2,2′-bipyridyl-κ2N,N′)cadmium(II)]-di-μ-thiocyanato-κ2N:S;κ2S:N

The title complex, [CdCl(NCS)(C10H8N2)]n, represents an unusual Cd(II) coordination polymer constructed by two types of anionic bridges and 2,2'-bipyridyl (bipy) terminal ligands. These two types of bridges are arranged around inversion centers. The distorted octahedral coordination of the Cd(II) center is provided by two chloride ions, one N- and one S-donor atom from two thiocyanate ions, and a pair of N atoms from the chelating bipy ligand. Interestingly, adjacent Cd(II) ions are interconnected alternately by paired chloride [Cd...Cd = 3.916 (1) A] and thiocyanate bridges [Cd...Cd = 5.936 (1) A] to generate an infinite one-dimensional coordination chain. Furthermore, weak interchain C-H...S interactions between the bipy components and thiocyanate ions lead to the formation of a layered supramolecular structure.

Synthesis, Structure and Characterization of a Novel One‐dimensional Tube‐like Cadmium Coordination Polymer

AbstractBy the self‐assembly of 2‐aminobenzimidazole (L), Nadca (Nadca = dicyanamide sodium) and CdCl2, a novel one‐dimensional (1D) CdII coordination polymer [Cd(μ1,5‐dca)(μ1,3,5‐dca)L]n (1) (L = 2‐aminobenzimidazole) has been synthesized and structurally characterized by single crystal X‐ray diffraction, element analysis and FT‐IR spectra. In 1 μ1,5‐bidentate and μ1,3,5‐tridentate dca ligands bridge CdII ions to form a 1D tube‐like structure, which presents a new 1D tubular structural motif of (3.4(2))(3(2).4(2).5(3)) topology in M‐dca systems (M = metallic). Solid‐state blue fluorescence spectrum of 1 also has been determined and compared with that of free ligand.

Catena-Poly[[triaquacadmium(II)]-μ2-pyrazine-2,3-dicarboxylato

The title CdII coordination polymer, [Cd(C6H2N2O4)(H2O)3]n, was synthesized by reacting Cd(NO3)2·3H2O and pyrazine-2,3-dicarboxylic acid under hydro­thermal conditions. Single-crystal X-ray studies reveal that self-assembly between the bridging ligands and metal ions results in a one-dimensional coordination polymer, in which the CdII ion is hepta-coordinated and shows a [CdNO6] penta­gonal–bipyramidal geometry.