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1.
《Polyhedron》2012,31(1):51-57
Condensation of picolinaldehyde with methyl 4-amino-3-hydroxy-benzoate resulted in the acquisition of a tridentate Schiff-base ligand (HL) which contains a structural moiety typical of octahedrally cored grid-type analogs. Reactions of HL with Zn(NO3)2 in the presence of Ln(NO3)3 [Ln = Sm(III), Tb(III) and Yb(III)] result in two types of complexes, viz. [Zn(HL)(L)]2[Ln(NO3)5] [Sm(III), 1a and Tb(III), 1b] and [Zn(HL)L]2[Yb(NO3)5]·C3H6O (1c). Despite applying two different synthetic protocols, the transition metal ion displayed a greater propensity towards the meridional tridentate pocket, which is reflected by XRD analysis, the ESI-MS technique and further supported by elemental analysis and IR characterization of each compound. In addition, we have compared the luminescence properties of 1a, 1b and 1c with the previously synthesized [Zn(HL)(L)]2[Zn(NO3)4] (1d) to investigate whether a different metal in the outer coordination sphere could somehow tune the compounds’ spectral behavior.  相似文献   

2.
Two novel coordination polymers, [Ag(L1)(NO3)]n 1 and [Ag(L2)2(ClO4)]n 2 [L1 = 1‐(1‐benzotriazole‐yl‐)triazole, L2 = 1‐(4‐chloro‐pyridazine‐yl‐)triazole] have been synthesized and characterized. Single‐crystal X‐ray analyses show that the Ag(I) atom is in a four‐coordinated distorted tetrahedron environment, which are linked by the coordinated nitrate group and L1 into a two‐dimensional network in complex 1 . While in the complex 2 , the Ag(I) is also in a distorted tetrahedron environment consisting of four N atoms to present a one‐dimensional infinite chain, the intermolecular π? π stacking action extends further the repeated units into three‐dimensional topological framework. The biological activities of the title compounds have been studied. The results indicate that two ligands exhibit excellent radical‐scavenging activities and certain fungicidal activities, and both Ag(I) complexes only have good antibacterial activities. Furthermore, the studies on luminescent properties of the complexes in the solid state indicate that the Ag(I) complexes exhibit weaker fluoresce intensity than that of ligands at room temperature. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

3.
A series of five new ZnII and CdII mixed‐ligand coordination polymers, namely, {[Zn(L1)(4,4′‐bpy)] · (ClO4) · 2H2O} ( 1 ), {[Zn(L2)(4,4′‐bpy)0.5] · (ClO4)} ( 2 ), {[Zn(L3)(4,4′‐bpy)] · (NO3) · 2H2O} ( 3 ), {[Cd(L4)(4,4′‐bpy)0.5(NO3)] · 5H2O} ( 4 ), and {[Zn(L4)(4,4′‐bpy)] · Cl · H2O} ( 5 ) [4,4′‐bpy = 4,4′‐bipyridine, L1 = 4‐carboxy‐1‐(4‐carboxybenzyl)pyridin‐1‐ium chloride, L2 = 3‐carboxy‐1‐(4‐carboxybenzyl)pyridin‐1‐ium chloride, L3 = 4‐carboxy‐1‐(3‐carboxybenzyl)pyridin‐1‐ium chloride, and L4 = 3‐carboxy‐1‐(3‐carboxybenzyl)pyridin‐1‐ium chloride], were obtained by the reactions of the 4,4′‐bipyridine with four dicarboxylate zwitterionic pyridine ligands. Single‐crystal X‐ray structural analyses reveal that the five complexes demonstrate different molecular frameworks coming from various coordination modes and flexibilities of different dicarboxylate zwitterionic pyridine ligands and central metal atoms. Mononuclear twofold dinuclear 2D twofold interpenetrating net for 2 , four‐coordinate mononuclear twofold interpenetrating 2D layer for 3 , mononuclear 2D layer arranged in parallel and with large grids for 4 , and twofold trans interpenetrating 2D network for compound 5 . The structural diversities in 1 – 5 indicate that the nature of the ligands and the presence of different metal atoms have a great influence on central metal coordination modes and the structural topologies of the metal‐organic molecular architectures. In addition, π ··· π stacking interactions also play important roles in the final crystal packing and supramolecular frameworks. The powder X‐ray diffraction, elemental analysis, and photoluminescence properties of 1 – 5 were studied, which show that architectures play an important role in emission bands and intensities.  相似文献   

4.
Summary Ni(NO3)2·6H2O reacts with 2,4-pentanedione S-methylisothiosemicarbazonehydrogen iodide (H2L·HI) in aqueous solution; addition of ammonia then yields [NiL(NH3)]·2H2O, the crystal structure of which has been determined. In the square-planar [NiL(NH3)]·2H2O complex, the ligand, 2,4-pentanedione S-methylisothio-semicarbazone occupies three coordination sites with the bonds to the central atoms involving the terminal nitrogen atoms of the isothiosemicarbazide fragment [Ni–N(3) 1.831 Å and Ni–N(2) 1.842 Å] and the oxygen of the 2,4-pentanedione moiety [Ni–O 1.844 Å]. The template reaction of [NiL(NH3)]·2H2O with 2,4-pentanedione and triethyl orthoformate, HC(OEt)3, gave, by heating the complexes, NiL1 (1) (L1 = dianion of the quadridentate NNNN macrocyclic ligand 2,10-bis(methylthio)-5,7,12,14-tetramethyl-1,3,4,8,9,11 -hexaazacyclotetradeca-2,4,6,9,12,-14-hexaene) and NiL2 (2) (L2 = dianion of the quadridentate ONNO ligand 3-acetyl-6-thiomethyl-9-methyl-5,7,8-tri-azadodeca-3,6,9-triene-2,11-dione) presents described.  相似文献   

5.
Five novel coordination polymers, [(Cu(L1)2OH) · Cl · 3H2O] ( 1 ) [L1 = bis(N‐imidazolyl)methane], [Cd(L1)2(NCS)2] ( 2 ), [Zn(L1)2(NCS)2] ( 3 ), [Cu(L1)2(NO3)2] ( 4 ), and [Cu(L2)1.5(NCS)2] ( 5 ) [L2 = 1,4‐bis(N‐imidazolyl)butane] were obtained from self‐assembly of the corresponding metal salts with flexible ligands and their structures were fully characterized by X‐ray diffraction (XRD) analysis, Fourier Transform Infrared (FT‐IR) spectroscopy, elemental analysis and thermogravimetric (TGA) measurements. X‐ray diffraction analyses revealed that complexes 1 , 2 , 3 , and 4 exhibit 1D double‐stranded chain structures, which result from doubly bridged [CuOH], [M(NCS)2] (M = Cd, Zn), and [Cu(NO3)2] units, respectively. The polymeric copper complex 5 displays 1D ladder structure., These complexes, with the exception of complex 1 , are stable up to 300 °C.  相似文献   

6.
Bibracchial lariat ethers L3 and L4, derived from the condensation of N,N′-bis(2-aminobenzyl)-1,10-diaza-15-crown-5 or N,N′-bis(2-aminobenzyl)-4,13-diaza-18-crown-6 with salicylaldehyde, form binuclear complexes with Co(II), Ni(II), Cu(II) and Zn(II). Our studies show that the different denticity and crown moiety size of the two related receptors give rise to important differences on the structures of the corresponding complexes. Single crystal X-ray diffraction analysis shows that the [Ni2(L3)(H2O)2]2+ and [Cu2(L3)(NO3)]+ complexes constitute a rare example in which an oxygen atom of the crown moiety is bridging the two six coordinate metal ions. In contrast, none of the oxygen atoms of the crown moiety is acting as a bridging donor atom in the [Co2(L4)(CH3CN)2]2+, [Cu2(L4)]2+ and [Zn2(L4)]2+ complexes. This is attributed to the larger size the crown moiety and the higher denticity of L4 compared to L3. In [Co2(L4)(CH3CN)2]2+ the metal ions show a distorted octahedral coordination, while in the Cu(II) and Zn(II) analogues the metal ions are five-coordinated in a distorted trigonal bipyramidal environment. In [Cu2(L3)(NO3)]+ the coordinated nitrate anion acts as a bidentate bridging ligand, which results in the formation of a 1D coordination polymer.  相似文献   

7.
Two coordination polymers, namely [Cd(HL)2]n · nH2O ( 1 ) and [Zn(L)]n ( 2 ) (H2L = benzimidazole‐2‐butanoic acid), were prepared by solvothermal reaction of Cd(NO3)2 or Zn(NO3)2 and H2L. The structures of these two compounds were determined by the single‐crystal X‐ray diffraction analyses and further characterized by IR spectroscopy, elemental analyses, powder X‐ray diffraction analyses, and thermal analyses. Compound 1 is a two‐dimensional (2D) layer framework, which is further packed into a 3D supramolecular framework by intermolecular hydrogen bonds, whereas compound 2 is a three‐dimensional (3D) framework with 3‐connected etb topology. The H2L ligand in compounds 1 and 2 displays two different anionic forms (HL and L2–), which then adopt two different coordination modes. Moreover, thermal stabilities and luminescent properties of these two compounds were also investigated.  相似文献   

8.
Coordination polymers with a new rigid ligand 1,3-bis(1,2,4-triazol-1-yl)adamantane (L) were prepared by its reaction with cadmium(II) or silver(I) nitrates. Crystal structure of the coordination polymers was determined using single-crystal X-ray diffraction analysis. Silver formed two-dimensional coordination polymer [Ag(L)NO3]n, in which metal ions are linked by 1,3-bis(1,2,4-triazol-1-yl)adamantane ligands, coordinated by nitrogen atoms at positions 2 and 4 of 1,2,4-triazole rings. Layers of the coordination polymer consist of rare 18- and 30-membered {Ag2L2} and {Ag4L4} metallocycles. Cadmium(II) nitrate formed two kinds of one-dimensional coordination polymers depending on the metal-to-ligand ratio used in the synthesis. Coordination polymer [Cd(L)2(NO3)2]n was obtained in case of a 1:2 M:L ratio, while for M:L = 2:1 product {[Cd(L)(NO3)2(CH3OH)]·0.5CH3OH}n was isolated. All coordination polymers demonstrated ligand-centered emission near 450 nm upon excitation at 370 nm.  相似文献   

9.
Two coordination polymers [Ag(dach)]n(NO3)n ( 1 ) and [Ag(teda)(F3CSO3)]n ( 2 ) (dach = 1, 2‐diaminocyclohexane, teda = 1, 4‐diazabicyclo[2.2.2]octane) have been synthesized and characterized by X‐ray single crystal analysis and cytotoxicity investigation. Compound 1 has a one‐dimensional chain‐like structure which is extended by ligand unsupported Ag···Ag interactions, hydrophobic interaction and hydrogen bonds into a three‐dimensional supramolecular array while compound 2 shows three‐dimensional diamond‐like framework constructed by coordination bonds. The high cytotoxities of these two compounds imply that they are potential candidates for antitumor agents.  相似文献   

10.
Three cadmium(II) coordination polymers, [CdBr2(L1)] n (1), [CdI2(L2)] n (2), and Cd2Br4(L3)2 (3), where L1?=?1,3-bis(5,6-dimethylbenzimidazole)propane, L2?=?1,4-bis(5,6-dimethylbenzimidazole)butane, and L3?=?1,6-bis(5,6-dimethylbenzimidazole)hexane, have been synthesized by hydrothermal methods and characterized by elemental analyses, IR spectra, TGA, PXRD, and X-ray crystallographic diffraction. Complex 1 contains a 1-D helical chain in which CdBr2 units are linked by L1. For 2, each CdI2 is connected by two different conformations of L2 to form a 1-D zigzag chain. For 3, each CdBr2 is linked by L3 bridges to afford a binuclear structure. These results indicate that the spacer length of the ligands play important roles in assembly of Cd(II) coordination polymers. Thermogravimetric analyses and solid-state luminescent properties of the complexes have also been investigated.  相似文献   

11.
Three zinc(II) nitrite coordination polymers, [Zn(4-bpdb)(NO2)2]n (1), {[Zn(3-bpdb)(NO2)]·0.5H2O}n (2) and [Zn(3-bpdh)(NO2)2]n (3), 4-bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene, 3-bpdb = 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene and 3-bpdh = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene} were prepared and characterized by elemental analyses and IR spectroscopy. Compound 3 was structurally characterized by single-crystal X-ray diffraction and is one-dimensional polymer with coordination environments of distorted octahedral, ZnN2O4. The thermal stabilities of compounds 1–3 were studied by thermal gravimetric (TG) and differential thermal analyses (DTA). Direct calcination of the compounds 1–3 at 600 °C under air atmospheres yields different morphologies of nano-sized ZnO.  相似文献   

12.
Two series of zinc(II) complexes of two Schiff bases (H2L1 and H2L2) formulated as [Zn(HL1/HL2)]ClO4 (1a and 1b) and [Zn(L1/L2)] (2a and 2b), where H2L1 = 1,8-bis(salicylideneamino)-3,6-dithiaoctane and H2L2 = 1,9-bis(salicylideneamino)-3,7-dithianonane, have been prepared and isolated in pure form by changing the chemical environment. Elemental, spectral, and other physicochemical results characterize the complexes. A single crystal X-ray diffraction study confirms the structure of [Zn(HL1)]ClO4 (1a). In 1a, zinc(II) has a distorted octahedral environment with a ZnO2N2S2 chromophore.  相似文献   

13.
An unusual heterobimetallic bis(triphenylphosphane)(NO2)AgI–CoIII(dimethylglyoximate)(NO2) coordination compound with both bridging and terminal –NO2 (nitro) coordination modes has been isolated and characterized from the reaction of [CoCl(DMGH)2(PPh3)] (DMGH2 is dimethylglyoxime or N,N′‐dihydroxybutane‐2,3‐diimine) with excess AgNO2. In the title compound, namely bis(dimethylglyoximato‐1κ2O,O′)(μ‐nitro‐1κN:2κ2O,O′)(nitro‐1κN)bis(triphenylphosphane‐2κP)cobalt(III)silver(I), [AgCo(C4H7N2O2)2(NO2)2(C18H15P)2], one of the ambidentate –NO2 ligands, in a bridging mode, chelates the AgI atom in an isobidentate κ2O,O′‐manner and its N atom is coordinated to the CoIII atom. The other –NO2 ligand is terminally κN‐coordinated to the CoIII atom. The structure has been fully characterized by X‐ray crystallography and spectroscopic methods. Density functional theory (DFT) and time‐dependent density functional theory (TD‐DFT) have been used to study the ground‐state electronic structure and elucidate the origin of the electronic transitions, respectively.  相似文献   

14.
Reactions of Ni(NO3)2 · 6H2O) in EtOH(iso-PrOH) with optically active bis(menthane) ethylene-diaminodioxime (H2L1), pinano-para-menthane ethylenediaminodioxime (H2L2), pinano-para-menthane propylenediaminodioxime (H2L3) and bis(pinane) propylenediaminodioxime (H2L4) were used to synthesize [Ni(H2L1)NO3[NO3 · 2H2O (I), [Ni(HL2)]NO3 (II), [Ni(HL3)]NO3 (III), and [Ni(HL4)]NO3 (IV). X-ray diffraction study of paramagnetic complex Ieff = 3.04 μB and diamagnetic complexes II and III revealed their ionic structures. A distorted octahedral polyhedron N4O2 in the cation of complex I is formed by the N atoms of tetradentate cycle-forming ligand, i.e., the H2L1 molecule, and the O atoms of the NO 3 ? anion acting as a bidentate cyclic ligand. In the cations of complexes II and III, containing a pinane fragment, the coordination core NiN4 has the shape of a distorted square formed on coordination of tetradentate cycle-forming ligands, i.e., anions of the starting dioximes. The structure of diamagnetic complex IV is likely to be similar to the structures of complexes II and III.  相似文献   

15.
Two metal coordination polymers, [Cd(ipa)(L1)(H2O)]n (1) and [Cd(ipa)(L2)]n (2) [H2ipa?=?isophthalic acid, L1?=?3,5-bis(imidazole-1-yl)pyridine and L2?=?3,5-bis(benzoimidazo-1-ly)pyridine], have been synthesized and structurally characterized by IR, elemental analysis, XRD, and X-ray single-crystal diffraction. Complex 1 shows a twofold cds topological net and 2 features a 3-D pcu topological net. Luminescent properties of 1 and 2 were investigated in the solid state at room temperature.  相似文献   

16.
Two different coordination polymers are obtained from d10 metal ions [Zn(II) and Cd(II)] and N,N′-ethylenebisacetamide (EBA). {[Zn(EBA)1.5(NO3)]?·?(NO3)} n (1) is a 1-D coordination polymer assembled from zinc ions and EBA molecules acting as a bridging ligand. Cd(H2O)2Cl2(EBA) (2) is constructed from 1-D inorganic polymeric chains {Cd(OH2)2Cl2} n and uncoordinated N,N′-ethylenebisacetamide molecules. These chains are interconnected through hydrogen bonds resulting in a 3-D supramolecular network. The luminescent properties of the organic molecule EBA, as well as of the coordination polymers 1, and 2 have been investigated.  相似文献   

17.
Two homochiral coordination polymers based on a chiral reduced Schiff base ligand, namely poly[(μ5‐4‐{[(NR,1S)‐(1‐carboxylato‐2‐phenylethyl)amino]methyl}benzoato)zinc(II)], [Zn(C17H15NO4)]n, (1), and poly[(μ5‐4‐{[(NR,1S)‐(1‐carboxylato‐2‐phenylethyl)amino]methyl}benzoato)cobalt(II)], [Co(C17H15NO4)]n, (2), have been obtained by hydrothermal methods and studied by single‐crystal X‐ray diffraction, elemental analyses, powder X‐ray diffraction, thermogravimetric analysis, IR spectroscopy and fluorescence spectroscopy. Compounds (1) and (2) are isostructural and crystallize in the P212121 space group. Both display a three‐dimensional network structure with a one‐dimensional channel, with the benzyl group of the ligand directed towards the channel. An investigation of photoluminescence properties shows that compound (1) displays a strong emission in the purple region.  相似文献   

18.
The synthesis of two 1D coordination polymers [Zn2L12]n 1 and [Zn2L22]n 2 , based on the H2L1 (bis (salicylidene)‐3‐oxapentane‐1,5‐diamine) and the H2L2 (bis (5‐methylsalicylaldehyde)‐3‐oxapentane‐1,5‐diamine) ligands, have been described and characterized by IR, elemental analysis and X‐ray single crystal analyses. In coordination polymer 1 , each Zn2+ ion is five‐coordinated by three oxygen atoms and two nitrogen atoms from deprotonated ligand forming a square pyramidal configuration. It is worth noting that phenolic oxygens of the deprotonated H2L1 adapt monodentate and monoatomic bridging coordinated modes resulting in one‐dimensional linear chain structure in which macro rings alternately connect small rings. The coordination polymer 2 is a four‐coordinated one‐dimensional zigzag chain in which geometric structure around the Zn (II) atom can be described as distorted tetrahedron. The antioxidant activity of the coordination polymers 1 – 2 and the ligands were determined by superoxide and hydroxyl radical scavenging method in vitro. The results demonstrated that the coordination polymers exhibit more effective antioxidant activity than the ligands. Moreover, compared with emissive bands of the free ligands in the solid state and DMF solvent, the photoluminescent transition of the Zn (II) coordination polymer 1 – 2 may be attributed to ligand‐to‐ligand charge‐transfer regulated by Zn (II) ion.  相似文献   

19.
Reactions of copper(II) acetate with N1‐subsitituted salicylaldehyde thiosemicarbazones [R1R2C2=N3–N2H–C1(=S)–N1HR3;R1 = 2‐HO–C6H4–, R2 = H : R3 = Me (H2L1), Et (H2L2)] are described. Copper(II) acetate was reacted with H2L1 and H2L2 ligands in the presence of polypyridyl co‐ligands, and this led to the formation ofmononuclear complexes, [Cu(κ3‐O, N, S‐L1)(κ2‐N, N‐bipy)] ( 1 ),[Cu(κ3‐O, N, S‐L)(κ2‐N, N‐phen)] [L = L1 ( 3 ), L2 ( 4 )], [Cu(κ3‐O, N, S‐L)(κ2‐N, N‐tmphen)] [L =L1 ( 5 ), L2 ( 6 )] and a dinuclear complex, [Cu2L22(bipy)] ( 2 ) (bipy = 2, 2′‐bipyridine, phen = 1, 10‐phenanthroline, tmphen = 3, 4, 7, 8‐tetramethyl‐1, 10‐phenanthroline). In dinuclear complex 2 , one ligand is O, N3,S‐chelating, while second is O, N3,S‐chelation‐cum‐N2‐bridging; and in all others thio‐ligands are O, N3,S‐chelating. The μeff values for the complexes lie in the range of 1.79–1.83 BM. Complexes 1 , 3 – 6 have square pyramidal arrangement, whereas complex 2 has two independent molecules in the crystal lattice, and each molecule has trigonal bipyramidal square planar (5:4) coordination pair. Complexes 2 , 4 , and 6 showed fluorescence properties.  相似文献   

20.
Two metal-organic coordination polymers [Cu(bpy)2(H2O)2](NO3)2·4.5C2H5OH (1) and [Cu2(bpy)(H2O)(L-pha) 2](NO3)2·H2O (2) (L-Hpha = L-phenylalanine, bpy = 4,4′-bipyridyl) are prepared by slow evaporation of an aqueous alcoholic solution of copper nitrate, L-phenylalanine, and 4,4′-bipyridyl. The structure and composition of the obtained compounds are determined by single crystal XRD. The framework of compound 1 is positively charged and forms two types of intersecting channels. Compound 2 is a homochiral metal-organic coordination polymer whose structure contains L-phenylalanine anions.  相似文献   

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