Two d 10-metal coordination polymers constructed from flexible ligands: Syntheses, crystal structures, and luminescent properties

Two new complexes, Zn(Glut)(Bix) · 2H₂O (I) and Cd(Pda)(Bimb) (II) (H₂Glut = glutaric acid, H₂Pda = 1,3-phenylenediacetic acid, Bix = 1,4-bis(imidazol-1-ylmethyl)benzene and Bimb = 1,4-di(1H-imidazol-1-yl)butane) were obtained under hydrothermal conditions by employing mixed ligands with metal salts and characterized by elemental analysis, IR, TGA, and Single crystal X-ray diffraction. Complex I presents a two-dimensional 2-fold interpenetrating layer structure. Whereas complex II is a two-dimensional layer network and exhibits a typical (4,4) topological net. The infrared spectra, thermogravimetric and luminescent properties were also investigated in detail for two complexes.     

Organic acid effect on the structures of Cd(II) metal-organic complexes based on 2-(3-pyridyl)imidazo[4,5-<Emphasis Type="Italic">f</Emphasis>]-1,10-phenanthroline

Three new Cd(II) complexes consisting of phenanthroline derivative and organic acid ligands, formulated as [Cd₃(3-PIP)₂(L¹)₆] (I), [Cd(3-PIP)(L²)] · H₂O (II), and [Cd(3-PIP)(L³)] (III) (3-PIP = 2-(3-pyridyl)imidazo[4,5-f]-1,10-phenanthroline, HL¹ = 3,5-dinitrobenzoic acid, H₂L² = oxalic acid, H₂L³ = benzene-1,3-dicarboxylic acid), have been synthesized via the hydrothermal reaction and characterized by single-crystal X-ray diffraction, elemental analyses and FT-IR spectra. Complex I is a trinuclear structure. Complex II features a 1D zigzag chain. Complex III shows a twisted double chain of binuclear units sustained by double carboxylate bridges. Three complexes are further extended into 3D supramolecular frameworks by hydrogen bonding and π-π-stacking interactions. The structural differences among I–III show that the organic carboxylates have important effects on the structures. Furthermore, the supramolecular interactions are the critical factors in determining the final structures of the complexes. In addition, the thermal stabilities and luminescent properties of complexes I and II are also investigated.     

Construction of two metal coordination polymers based on 1,4-terephthalate and 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene

Two new metal-organic frameworks, namely, Cd(BDC)(Btx) · 0.25(H₂O) (I) and Co₃(BDC)₃(Btx)₄(H₂O)₄ (II) (H₂BDC = 1,4-terephthalate acid and Btx = 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, TGA, and single crystal X-ray diffraction. Complex I exhibits a scarcely reported an eight-connected (4²⁴.6⁴) net with dinuclear cadmium clusters as secondary building units, whereas complex II displays a three-dimensional co-ordination polymer with a rare (4,6)-connected net described by the (4⁴.6²)₂(4⁸.6⁷) Schläfli symbol. In addition, the luminescence measurements reveal that complex I exhibits strong fluorescent emissions in the solid state at room temperature.     

Copper(II), zinc(II), and cadmium(II) coordination polymers with 2-methylglutarato and 4,4′-dipyridyldisulfide

Three new coordination polymers of copper(II), zinc(II) and cadmium(II), Cu(H₂O)(Dpds)(2-MGA) (I), [Zn(Dpds)(2-MGA)] · 1.25H₂O (II) and [Cd(H₂O)(Dpds)(2-MGA)] · 0.25H₂O (III) (Dpds = 4,4′-dipyridyldisulfide, H₂MGA = (RS)-2-methyl glutaric acid), have been synthesized and characteried by X-ray single crystal structure determination. The Cu atoms in I are alternately bridged by Dpds ligands and 2-methylglutarato ligands to generate 1D chain. The resulted chains are assembled via S...S weak interactions into 2D layers, which are through twofold 2D parallel/2D parallel mode inclined interpenetration to induce 3D supramolecular architecture. In II, the ZnN₂O₂ tetrahedras are bridged by 2-MGA anion and Dpds ligands to form 2D (4,4) networks, which are assembled via hydrogen bonds to 3D supramolecular architecture. The centrosymmetric binuclear units Cd₂(2-MGA)₂ in III are bridged by Dpds ligands to form 1D repeated rhomboids chains, which are interlinked via S...S weak interactions into 2D layer, and the resulting 2D sheets are inclined parallel into 3D network.     

Mixed-ligand CoII and CdII complexes with 4-aminoantipyrine

Self-assembly of 4-aminoantipyrine (AAP) and 5-nitroisophthalic acid (H₂NIP) with Co(CH₃COO)₂ or Cd(NO₃)₂ in CH₃OH–H₂O at room temperature generated {[Co₂(AAP)(NIP)(H₂O)₈][Co(AAP)(NIP)₂(H₂O)₂](H₂O)_4.5} (1) and {[Cd(AAP)(NIP)(H₂O)](H₂O)} _n (2), which were further characterized by X-ray diffraction, IR spectra, elemental analysis and solid-state fluorescence spectra. The structure analysis indicates that 1 contains two individual fragments, one NIP-bridged six-coordinate binuclear Co^II cation and a mononuclear Co^II dianion. The binuclear units are connected into 1-D chains via O–H?···?O hydrogen bond interactions, which were further assembled into a 2-D supramolecular layer bridged by the mononuclear Co^II unit. Complex 2 is a linear NIP bridged seven-coordinate Cd^II polymeric chain with the terminal AAP ligands as decorations, and are further extended into 2-D network by classic hydrogen bonds and π?···?π stacking interactions. Both solid complexes exhibit emission spectra from intraligand electron transfer at room temperature.     

Hydrothermal synthesis, crystal structure of three novel complexes based on thiabendazole and 1,4-benzenedicarboxylate ligands

Three novel metal-organic complexes [Co(BDC)(TBZ)₂] (I), [Cd₂(BDC)₂(TBZ)₂(H₂O)₂] · 2(H₂O) (II), [Mn₂(BDC)(TBZ)₄(SO4)] (III) (BDC = 1,4-benzenedicarboxylate, TBZ = thiabendazole) have been prepared and characterized by IR spectrum, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. X-ray structure analysis reveals that both three complexes are one-dimensional chain polymers. The 1D chain architecture of I is constructed from terephthalic acid and cobalt atoms. A simultaneous presence of chelating and monodentate coordination modes of BDC ligands is observed in complex II. In complex III, the coordinated BDC ligands adopt monodentate mode and with SO ₄ ^2? anions alternately bridge the Mn²⁺ ions into 1D chains. The 3D structures of the three complexes are stabilized by π-π stacking interactions and hydrogen-bonds.     

Syntheses,structural characterization,and properties of Mn(II) and Cd(II) complexes from 5-[4-(1H-imidazol-1-Yl)phenyl]-1H-tetrazole

Reactions of Mn(II) and Cd(II) salts with 5-(4-(1H-imidazol-1-yl)phenyl)-1H-tetrazole (HL) under hydrothermal conditions result in complexes [Mn(L)₂(H₂O)₄] · 2H₂O (I) and [Cd(L)₂(H₂O)₂] (II), which have been characterized by single crystal and powder X-ray diffractions (CIF files CCDC nos. 943861 (I), 943862 (II)), IR spectroscopy, element and thermogravimetric analyses. Two complexes exhibit structural diversity dependent on different metal salts. Complex I shows discrete mononuclear structure, which can be further linked to build a 3D supramolecular framework through hydrogen bonding interactions. Complex II displays 1D zigzag-chain structure, and an extended 3D framework can be formed by hydrogen bonding. Interestingly, tetranuclear water clusters were generated in I, which can be linked by Mn²⁺ ions to show 1D metal-bridged water cluster-chain structure. The present work provides an example that metal centers impact on coordination modes of ligand and consequent structural variation of resulted complexes. Moreover, fluorescence property of II was investigated.

     

Construction of Cd(II) complexes based on 2-(1H-imidazol-1-methyl)-1H-benzimidazole and 1,4-benzenedicarboxylate

Three new Cd(II) complexes incorporating both 2-(1H-imidazol-1-methyl)-1H-benzimidazole (imb) and 1,4-benzenedicarboxylate (bdic^2?), [CdCl(bdic)_1/2(imb)₂]_n (1), {[Cd(bdic)(imb)(H₂O)]·DMF·2H₂O}_n (2), and [Cd(bdic)(imb)]·3H₂O}_n (3), have been prepared and structurally characterized by single crystal X-ray diffraction. Bdic^2? anions connect the?Cd-imb-Cd-imb?chains leading to a 2-D structure of 1. Bdic^2?(A) and bdic^2?(B) anions link the binuclear [Cd₂(imb)₂(H₂O)₂] units forming a 2-D structure of 2. Complex 3 features a 2-D structure involving supramolecular “double-layer” motifs. IR spectra and thermogravimetric curves are consistent with the results of the X-ray crystal structure analysis; 1–3 exhibit good fluorescence in the solid state at room temperature.     

Syntheses,crystal structures,and properties of three two-dimensional complexes constructed by flexible (2,3-pyridylmethyl)amine

Three two-dimensional coordination polymers [Cd(2,3-Pyma)Cl₂] _n (I), {[Cd(2,3-Pyma)(1,4-Chdc)] · 4H₂O}n (II) and {[Zn₂(2,3-Pyma)(1,2,4,5-Bttc)(H₂O)₄] · 6H₂O} _n (III) (2,3-Pyma = (2,3-pyridylmethyl) amine, H₂-1,4-Chdc = 1,4-cyclohexanedicarboxylic acid, and H₄-1,2,4,5-Bttc = 1,2,4,5-benzenetetracarboxylic acid) have been synthesized and structurally characterized by single crystal X-ray crystallography (CIF files CCDC nos. 989461 (I), 1055685 (II) and 1055686 (III)). Three complexes are all twodimensional layer networks bridged by the flexible 2,3-Pyma ligands or the carboxylate ligands. It is noted that the flexible 1,4-Chdc ligands bind the Cd²⁺ ions into a helical chain structure in complex II. The photoluminescence and thermal properties are investigated.     

Synthesis and properties of Cu(II) and Pd(ii) complexes with chiral bis-α-sulfanyl oxymes,the derivatives of natural monoterpene, α-pinene

Coordination compounds Cu₂(H₂L¹)Cl₄ (I), Pd₂(H₂L¹)Cl₄ (II), Cu₂(H₂L²)Cl₄ (III), and Pd₂(H₂L²) Cl₄ (IV) with chiral bis-α-sulfanyloximes, the derivatives of the monoterpenoid (−)-α-pinene, were obtained. The complexes I and III are paramagnetic (μ_eff = 2.45 and 2.67 μ_B, respectively), II and IV are diamagnetic. According to IR spectroscopy, in the compounds I–IV the nearest environment of Cu and Pd atoms includes N, S, and Cl atoms. The values of μ_eff and parameters of ESR spectra of the solid phase and solutions of I and III show a binuclear structure of the Cu(II) complexes. Parameters of the ¹H and ¹³C NMR spectra of compounds II and IV indicate the formation of binuclear Pd(II) complexes of C ₂ symmetry and the closure of fivemembered chelate rings PdNSC₂. The PdCl₂ fragments are in transoid position. H₂L¹ and H₂L² are tetradentate bridging chelating ligands.     

Design and synthesis of two-dimensional pillared MOF layers by connecting infinite one-dimensional chains via 4,4′-bipyridine

Two novel metal-organic frameworks, [Cd(Bna)(DMF)₂(H₂O)₂] _n · nDMF (I) (Bna = 2,2′-dihydroxy-l,l′-dinaphthyl-3,3′-dicarboxylate) and [Cd(Bna)(Bipy)(DMF)₂] _n (II) (Bipy = 4,4′-bipyridine) have been synthesized under mild conditions and structurally characterized. Crystal structural analyses reveal that complex I adots a 1D spiral structure with DMF guest molecules in the spiral by hydrogen bondings. Complex II is constructed by -Cd-Bna-Cd- zigzag chains, which are further connected by Bipy into a 2D sheet. X-ray powder diffraction and thermogravimetric analyses for I and II show that they are highly themally stable in the solid state.     

Complexes of [(iPrO)2P(O)NHC(S)NHCH2]2CH2 with Co(II), Ni(II), Zn(II), and Pd(II): Reaction of [(iPrO)2P(O)NHC(S)NHCH2]2 with KOH Leading to the Imidazolidine-2-Imine Derivative

Reaction of O,O′-diisopropylphosphoric acid isothiocyanate (iPrO)₂P(O)NCS with NH₂(CH₂)_nNH₂ (n = 3, 2) leads to the N-phosphorylated bis-thioureas [(iPrO)₂C(S)NHP(O) NH]₂Z (Z = —(CH₂)₃—, H₂L^I ; —(CH₂)₂—, H₂L^II ). Reaction of the potassium salt of H₂L^I with Co(II) and Zn(II) in aqueous EtOH leads to complexes of formula M₂(L-O,S)₂. The metal cation in both complexes is coordinated by two deprotonated ligands through the sulfur atoms of the thiocarbonyl groups and the oxygen atoms of the phosphoryl groups. Reaction of K₂L^I with Ni(II) and Pd(II) in the same conditions leads to M₂(L-N,S)₂ complexes. In both compounds, the metal center is found in a square-planar N₂S₂ environment formed by the C=S sulfur atoms and the P—N nitrogen atoms of two deprotonated ligands L^I . Reaction of H₂L^II with KOH leads to a product of heterocyclization, in which one of the thiourea fragments is retained. Compounds obtained were investigated by IR, UV-Vis, ¹H and ³¹P NMR spectroscopy, and microanalysis.     

Hydrothermal synthesis and crystal structure of a new 2D metal-organic framework: [Gd(Oba)(Ox)0.5(H2O)2]n (H2Oba = 4,4′-oxybis(benzoic acid); H2Ox = oxalic acid)

A new coordination polymer [Gd(Oba)(Ox)_0.5(H₂O)₂] _n (I) (H₂Oba = 4,4′-oxybis(benzoic acid), H₂Ox = oxalic acid) has been synthesized by hydrothermal reactions and characterized by elemental analysis and single-crystal X-ray diffraction. In I, two Gd³⁺ ions are bridged by Oba ligands to form 1D ribbon chains, which are further connected by Ox ligands, generating a 2D layer structure.     

Synthesis and characterization of mononuclear copper(II) and dinuclear cadmium(II) complexes with di-(2-picolyl)sulfide

The reaction of CuCl₂ · 2H₂O and CdCl₂ with di-(2-picolyl)sulfide (dps) leads to the formation of mononuclear copper(II) and binuclear cadmium(II) complexes, [Cu(dps)Cl₂] · H₂O (1) and [(dps)(Cl)Cd^II(μ-Cl)₂Cd^II(Cl)(dps)] (2). The copper atom in (1) is coordinated to one sulfur and two nitrogen atoms from the dps ligand and two chlorides in a distorted square-pyramidal environment. Complex (2) has two distorted octahedra sharing the basal edge that contain the bridging chloro ligands, each of which resides at a center of inversion. Cyclic voltammetric data show that (1) undergoes two reversible one-electron waves corresponding to Cu^II/Cu^III and Cu^II/Cu^I processes. However, cyclic voltammetry of (2) gives two irreversible reduced waves.     

Two new organic-inorganic hybrid compounds induced by γ-[Mo8O26]4− and [PMo12O40]3−

Two new organic–inorganic hybrid compounds, [Cu^II(btb)_1.5(γ-Mo₈O₂₆)_0.5(H₂O)]·2H₂O (1) and [Cu^II₂(btb)₄(PMo^VMo^VI₁₁O₄₀)]·2H₂O (2) (btb = 4-butyl-1,4-bis(1,2,4-triazole), have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis, IR spectra and elemental analyses. In 1, there exists a ladder-like metal-organic chain with the bidentate [γ-Mo₈O₂₆]^4? anions inserting into the grids. Adjacent chains share the same Cu-btb lines of the ladder to form a 2-D layer. Compound 2 also has a ladder-like metal-organic chain. The tetradentate [PMo₁₂O₄₀]^3? anions embed in the grids. The same Cu-btb line is shared by adjacent chains to build a 2-D layer. The btb ligands link adjacent layers to form a 3-D framework. Moreover, we also have investigated the electrochemical and photocatalytic properties of 1 and 2.     

Complexes of N-(thio)phosphorylthioureas AdNHC(S)NHP(X)(OiPr)2 (X?=?O, S) with cobalt(II), zinc(II), and cadmium(II). Crystal structure of Co[AdNHC(S)NP(S)(OiPr)2]2

Reaction of the potassium salts of N-(thio)phosphorylated thioureas of common formula AdNHC(S)N(H)P(X)(OiPr)₂ (Ad = adamantyl; X = O, HL ^I ; X = S, HL ^II ) with Co(II), Zn(II), and Cd(II) cations in aqueous EtOH leads to M(L ^I,II -X, S) ₂ chelate complexes. The Cd(II) complex Cd(L ^I ) ₂ could not be isolated under analogous conditions because of its hydrolytic lability. The structure of the resulting compounds was studied by means of spectroscopy and microanalysis; in addition, the molecular structure of the complex Co(L ^II ) ₂ was elucidated by single crystal X-ray diffraction analysis. The cobalt atom is in a tetrahedral S₄ environment formed by the C=S and P=S sulfur atoms of two deprotonated ligands L ^II . The magnetic properties of Co(L ^I,II ) ₂ were investigated and the photoluminescent properties of the complexes are also reported.     

Fine tuning of the Cd(II)–bis(benzimidazole) networks by changing carboxylate anions

Three new polymeric frameworks, [Cd(bbbi)(ita)(H₂O)]?·?H₂O (1), [Cd(bbbi)(fma)] (2), and [Cd(bbbi)(fma)(H₂O)]?·?2H₂O (3) (bbbi?=?1,1-(1,4-butanediyl)bis-1?H-benzimidazole, H₂ita?=?itaconic acid, and H₂fma?=?fumaric acid), have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 is a 2-D (4,4) network containing infinite 1-D zigzag Cd(II)-bbbi chains linked by auxiliary ita ligands. In the structure of 2, infinite 1-D linear Cd(II)-bbbi chains are linked by fma ligands to generate an undulated 2-D (4,4) network. In 3, an in situ ligand transformation occurred with malate converted to H₂fma by dehydration. Thus, a 2-D (4,4) grid network constructed from bbbi and fma was obtained. The carboxylates with different substituents play an important role in the formation of the final frameworks and coordination modes of Cd(II). Thermal stability and luminescent properties of 1–3 were investigated.     

Crystal structures of some lanthanide(III) complexes with acylhydrazone and their coordination chemistry

Three new lanthanide(III) complexes with N-(2-propionic acid)-salicyloylhydrazone (H₂L, C₁₀H₁₀N₂O₄) ligand [La(HL)₂(NO₃)(H₂O)₂]₃ ·4H₂O(I), [Gd(HL)₃] · 2(C₂H₅)₃ N(II) and [Er(L)(HL)(H₂O)₂] · 2H₂O(III) has been synthesized and characterized by elemental analyses, IR, UV, and molar conductivity. The crystal structures of three complexes have been determined by X-ray single-crystal diffractometer. In complex I, the La³⁺ ion is ten-coordinated by two tridentate ligands, one bidentate nitrate, and two water molecules. In complex II, the Gd³⁺ ion has a coordination number of nine by three tridentate ligands. In complex III, the Er³⁺ ion is eight-coordinated by two tridentate ligands and two water molecules. In all structures, tridentate ligands are coordinated by carboxyl O and acyl O atoms and azomethine N atom to form two stable five-membered rings sharing one side in the keto mode as indicated by the results of crystal structures and infrared spectral analysis.     

Syntheses,structures, and properties of three MOFs based on tertbutylphenyl imidazole dicarboxylate

By hydrothermal reactions of a newly designed ligand, 2-(p-tert-butylphenyl)-1H-imidazole-4,5-dicarboxylic acid (H₃BuPhIDC) with Cd(II) or Zn(II), three metal-organic frameworks, [Cd(μ₃-HBuPhIDC)(H₂O)]·2H₂O (1), [Cd(μ₃-HBuPhIDC)(4,4′-bipy)_0.5] (4,4′-bipy = 4,4′-bipyridine) (2), and [Zn₂(μ₃-HBuPhIDC)₂(CH₃OH)₂] (3), have been obtained and characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction. In 1, small countless diamond grids form a mesh structure and then are bridged through μ₃-HBuPhIDC^2? linkers building a 3-D framework. Compared with 1, 4,4′-bipy participates in the construction of a 3-D structure of 2. Polymer 3 shows an interesting 3-D open architecture, which contains infinite 1-D octagonal channels built by left- and right-handed helical chains. Thermal and solid-state photoluminescence properties of the polymers have been investigated.     

Cadmium coordination polymers based on biimidazole and bibenzimidazole: Syntheses,crystal structures and fluorescent properties

Three new Cd^II complexes with two analogous ligands of 2,2′-biimidazole (H₂biim) and 2,2′-bibenzimidazole (H₂bbim), have been synthesized and characterized by elemental analyses, IR spectroscopy as well as single crystal X-ray diffraction. The results reveal that the structures of the complexes range from one-dimensional (1D) chains in [Cd(H₂biim)(N₃)₂]_n (1) to two-dimensional (2D) layer in [Cd(bbim)_0.5(Hbbim)]_n (2) and three-dimensional (3D) network in [Cd₃(biim)₂(Hbiim)(N₃)]_n (3), with various modes of these ligands, which is tuned by different polarity of solvents and pH values. The fluorescent spectra of these complexes and ligands have been also investigated in the solid state at room temperature.