Search

An unexpected polyhydroxyl-bridged tetranuclear ZnII complex and a benzoquinone compound derived from metal-ion promoted reactivity of Schiff base ligands were synthesized and characterized. The reaction of zinc(II) acetate dihydrate with oxime-type Schiff base ligand HL1 [HL1 = 1-(3-((3,5-dibromosalicylaldehyde)amino)phenyl) ethan-1-one O-benzyl oxime] in methanol, acetone and acetonitrile resulted in the chemoselective cleavage of the C=N bond of the Schiff base HL1 and then the further addition of acetone to two salicylaldehyde molecules derived from cleavage of the C=N bond in situ α,α double aldol reaction promoted by ZnII ions. The newly formed ligands H4L2 coordinate to four ZnII ions forming a defect-dicubane core structure [ZnII 4(H2L2)2(μ3-OCH3)2(μ-OCH3)2(CH3OH)2] (1) bridged exclusively by oxygen-based ligands. The similar ligand HL3 [HL3 = 1-(3- ((3,5-dichlorosalicylaldehyde)amino)phenyl)ethan-1-one O-benzyl oxime)] was employed to react with CdII acetate dihydrate under the same reaction conditions. No aldol addition occurred but a unexpected benzoquinone compound 2,5-bis(((3-(1-((benzyloxy)imino)ethyl) phenyl)imino)methyl)-1,4-benzoquinone (2) formed. The results provided interesting insights into one-pot routes involving in situ reactions act as a strategy for obtaining a variety of polymeric/polynuclear complexes which are inconvenient to obtain from directly presynthesizing the ligands. [ABSTRACT FROM AUTHOR]

Two novel metal-organic coordination complexes [Cd(Zalto profen)2(H2O)3](H2O) (1), [Zn(Zaltoprofen)(H2O)]n(2) (where zaltoprofen = 5-(1-carboxyethyl)-2-(phenylthio)phenylacetic acid) have been synthesized under normal conditions and hydrothermal conditions, respectively. And characterized by single crystal X-ray diffraction, elemental analysis, spectral method (IR), powder X-ray diffraction (XRD), and fluorescent properties. Compound 1 crystallizes in the monoclinicCcspace group while compound 2 in the monoclinic system with space groupP21/c. [Cd(Zaltoprofen)2(H2O)3](H2O) (1) features 0-D structural, the hydrogen-bonds play a vital role in determining the crystal packing and construction of the extended 3-D supramolecular network. [Zn(Zaltoprofen)(H2O)]n(2) displays a 2D net with alternately arranged left- and right-handed helical chains. The O–H···O hydrogen bonding play an important role in stabilizing the structure. Supplemental materials are available for this article. Go to the publisher's online edition ofSynthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistryto view the supplemental file. [ABSTRACT FROM PUBLISHER]

[Zn4(L1)2(OAc)2(CH3CH2OH)2] and [CuL2(H2O)] with new asymmetric Salamo-type ligands have been synthesized and characterized. There are two coordination geometries (trigonal bipyramidal and square pyramidal) in the Zn(??) complex, and the Cu(II) complex has square-pyramidal geometry. A self-assembling continual zigzag chain is formed by intermolecular hydrogen bonds in the Cu(II) complex. The self-assembling array of the Zn(II) complex is linked by intermolecular C–H?O and C–H?? interactions. Blue emissions of the Zn(II) and Cu(II) complexes in DMF solution are exhibited by fluorescence. [ABSTRACT FROM AUTHOR]

A new Cu(II) complex, [Cu(L)2], has been synthesized via the complexation of copper(II) acetate monohydrate with a new oxime-type ligand (HL = 1-(3-{[(E)-3-bromo-5-chloro-2-hydroxybenzylidene]amino}phenyl)ethanone oxime). X-ray crystallographic analysis reveals that the complex is a mononuclear complex. The Cu(II) atom is four-coordinated by the phenolate O atoms and imine N atoms from two oxime-type ligands, in a square-planar geometry in which the dihedral angle of two coordination plane (Cu1N1O1 and Cu1N#1O#1) is 0°. The crystal packing of the Cu(II) complex shows that a notable feature of this structure resides in the formation of a novel 3D supramolecular networks through intermolecular O–H···N, C–H···O, and C–H···π interactions. Supplemental materials are available for this article. Go to the publisher's online edition ofSynthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistryto view the supplemental file. [ABSTRACT FROM PUBLISHER]

A supramolecular CuII complex, [Cu(L)(H2O)] (H2L: 4,4′,6,6′-tetrachloro-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol), has been synthesized and structurally characterized. X-ray crystallographic analysis shows that the complex is a centrosymmetric mononuclear CuII complex, and the CuII atom is penta-coordinated by two phenolic O atoms and two oxime N atoms from the deprotonated Salen-type ligand, and one oxygen atom from the coordinated water molecule. A self-assembling continual supramolecular structure is formed by intermolecular O3-H3···O2 and O3-H3···Cl1 hydrogen bonds. [ABSTRACT FROM AUTHOR]

An unexpected dinuclear Cu(II) complex, [Cu2(L2)2] (H2L2 = 3-methoxysalicylaldehyde O-(2-hydroxyethyl)oxime), has been synthesized via complexation of Cu(II) acetate monohydrate with H4L1. Catalysis by Cu(II) results in unexpected cleavage of two N–O bonds in H4L1, giving a dialkoxo-bridged dinuclear Cu(II) complex possessing a Cu–O–Cu–O four-membered ring core instead of the usual bis(salen)-type tetraoxime Cu3–N4O4 complex. Every complex links six other molecules into an infinite-layered supramolecular structure via 12 intermolecular C–H ··· O hydrogen bonds. Furthermore, Cu(II) complex exhibits purple emission with maximum emission wavelength λmax = 417 nm when excited with 312 nm. [ABSTRACT FROM PUBLISHER]

A tetranuclear Zn(ΙΙ) complex, [Zn4L2(OAc)2(CH3OH)2] with an unsymmetric Salen-type bisoxime (H3L = 6-hydroxy-4′,6′-dibromo-2,2′-[ethylenediyldioxybis(nitrilomethylidyne)]diphenol), has been synthesized and structurally characterized. There are two kinds of coordination geometry (trigonal bipyramidal and square pyramidal) in the Zn(ΙΙ) complex. The molecule has serious distortion probably from the asymmetry. The complex exhibits blue emission with the maximum emission wavelength λ max = 423 nm when excited with 340 nm. [ABSTRACT FROM PUBLISHER]

Two solvent-induced complexes, [CoL2(CH3OH)2] (1) and [CoL2(CH3CH2OH)2] (2), have been synthesized by the reaction of an oxime-type ligand (HL, 4-[(Ethoxyimino)(phenyl)methyl]-5-methyl-2-phenyl-1H-pyrazol-3(2H)-one) with cobalt(II) acetate tetrahydrate in different solvents. X-ray crystallographic analyses have indicated that complexes 1 and 2 have a similar structure, consisting of one CoII atom, two L− units, and two coordinated methanol or ethanol molecules. Interestingly, two CoII atoms in the structures of complexes 1 and 2 are all six-coordinated, approaching a staved octahedral geometry, but complexes 1 and 2 are grown up in methanol/chloroform and ethanol, respectively. Right because of this, solvent effect cause to the difference of the crystal structures: complex 1 forms an infinite supramolecular chain by intermolecular hydrogen bonds, while complex 2 exhibits three-dimensional supramolecular networks through intermolecular hydrogen bonds and C-H···π interactions. [ABSTRACT FROM AUTHOR]

Abstract: Four new luminescent complexes, namely, [Eu(aba)2(NO3)(C2H5OH)2] (1), [Eu(aba)3(H2O)2]·0.5 (4, 4′-bpy)·2H2O (2), [Eu2(aba)4(2, 2′-bpy)2(NO3)2]·4H2O (3) and [Tb2(aba)4(phen)2(NO3)2]·2C2H5OH (4) were obtained by treating Ln(NO3)3·6H2O and 4-acetamidobenzoic acid (Haba) with different coligands (4, 4′-bpy=4, 4′–bipyridine, 2, 2′-bpy=2, 2′-bipyridine, and phen=1, 10-phenanthroline). They exhibit 1D chains (1–2) and dimeric structures (3–4), respectively. This structural variation is mainly attributed to the change of coligands and various coordination modes of aba molecules. Moreover, the coordination units are further connected via hydrogen bonds to form 2D even 3D supramolecular networks. These complexes show characteristic emissions in the visible region at room temperature. In addition, thermal behaviors of four complexes have been investigated under air atmosphere. The relationship between the structures and physical properties has been discussed. [Copyright &y& Elsevier]

Abstract: Four supramolecular complexes [MnL1(H2O)2] (1), {[CoL2(OAc)(H2O)]2Co}·5CH3CH2OH (2), {[NiL3(OAc)(CH3OH)]2Ni}·2CH3COCH3·2CH3OH (3) and {[ZnL2(OAc)]2Zn}·CHCl3 (4), have been synthesized and characterized by elemental analyses, IR, UV–Vis spectra and X-ray diffraction techniques. All the complexes have the trinuclear configuration except for MnII complex being mononuclear configuration. Every trinuclear complex contains two acetate ions coordinate to the three metal ions via a familiar M–O–C–O–M (M=Co, Ni, Zn) coordinated mode. Although complexes 1 and 3 display 1D supramolecular chains, the different coordination environments (mononuclear in 1, trinuclear in 3) provoke divergence in the structures and aggregations of the chain subunits. Complex 2 forms a 3D hydrogen-bonding supramolecular networks possessing a channel composing of six O–H···O hydrogen bonds, while complex 4 exhibits a 2D hydrogen-bonding supramolecular networks with the formation of “grottos” occupied by chloroform molecules through intermolecular hydrogen-bond interactions. The spectral properties of the title complexes have been further discussed in detail. [Copyright &y& Elsevier]

Abstract: Three new supramolecular complexes, [Cu(L1)H2O] n (1), [Zn(L2)(H2O)2] n (2), and [Cd(L2)(H2O)2] n (3), have been synthesized and characterized by FT-IR spectra, fluorescence spectra, and thermal analyses. And the structures of complexes 1–3 have been elucidated by X-ray analyses. Complex 1 is square pyramidal geometry with an unusually long bond (2.262Å) from penta-coodinated CuII center to the oxygen atom of the apical coordinated water molecule. Molecules are linked by hydrogen bonding between the coordinated water and the phenolic oxygen atoms of adjacent molecules, thus formed a self-assembling continual zigzag chain supramolecular structure. The crystal structure of complex 2 (or 3) has indicated that the complex consists of one ZnII (or CdII) atom, one L2− unit and two coordinated water molecules, the coordination number of the ZnII (or CdII) atom is six, and formed an infinite metal–water chain supramolecular structure by intermolecular hydrogen bonds and π–π stacking of neighboring benzene rings. Meanwhile, the thermal and photophysical properties of the resulted complexes have also been discussed. [Copyright &y& Elsevier]

Highlights: [•] A halogen-substituted Salen-type bisoxime has been synthesized firstly. [•] A new complex [ZnL(H2O)2] n has been synthesized and characterized structurally. [•] The complex forms a self-assembling infinite dual metal–water chain-like structure. [•] Some new results are very important to coordination and supramolecular chemistry. [Copyright &y& Elsevier]

Abstract: An unprecedented linear supramolecular manganese(III)-lithium(I) coordination polymer, [MnIIIL(OH)2LiI] n , has been prepared and structurally characterized. The polymer is a one-dimensional infinite Mn(III)–O–Li(I) chain supramolecular structure formed by intermolecular O–H···O and O–H···Cl hydrogen bonds and π–π stacking of neighboring benzene rings. [Copyright &y& Elsevier]

Using 3-MeOsalamo H2L (H2L = 1,2-bis(3-methoxysalicylideneaminooxy)ethane) with Zn(OAc)2·2H2O, Ln(NO3)3·6H2O (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, and Tb), and 4,4′-bipy (4,4′-bipyridine) or H2bdc (terephthalic acid), three new families of heteromultinuclear ZnII-LnIII complexes: [{Zn(L)Ln(NO3)3(CH3OH)}2(4,4′-bipy)] (Ln = La (1·2CH3OH) and Ce (2)), [{Zn(L)Ln(NO3)3}2(4,4′-bipy)] (Ln = Pr (3), Nd (4), Sm (5), Eu (6), Gd (7), and Tb(8)), [{(ZnL)2Ln}2(bdc)2]·(NO3)2·2CHCl3 (Ln = Ce (9), Pr (10) and Sm (11·2CH3CH2OH)), and ²∞[Zn(L)Ln(bdc)1.5] (Ln = Eu (12) and Gd (13·2CHCl3)) were obtained, respectively. Complexes 1-8 are heterotetranuclear dimers based on [Zn(L)Ln] moieties which are linked through the exo-dentate 4,4′-bipy having nitrogen-donor atoms. Heterohexanuclear complexes 9-11 constructed from almost linear trinuclear cationic [(ZnL)2Ln] moieties which are linked through the exo-dentate (bdc)2- bearing oxygen-donor atoms. Two 2D coordination polymers 12 and 13 are also assembled by [Zn(L)Ln] units with (bdc)2- linker. Furthermore, the luminescence properties of complexes 1-13 have been studied. An appropriate and selective linker could enhance the construction of a Salamo-type zinc(II)-lanthanide(III) complex possessing efficient luminescent properties. [ABSTRACT FROM AUTHOR]

Two novel mono- and heptanuclear Ni(II) complexes, [Ni(HL 1 ) 2 (EtOH) 2 ]·2EtOH ( 1 ) and [Ni 7 (L 2 ) 3 ( μ 3 -OMe) 2 ( μ 3 -OH) 6 (MeOH) 6 ] ( 2 ), have been synthesized by the reaction of Ni(II) acetate with H 2 L 1 and H 2 L 2 , respectively. In the Ni(II) complex 1 , the ligand H 2 L 1 was partially deprotonated, only NO donor atoms of one salicylidene moiety of the (HL 1 ) − unit coordinate to Ni(II) atom. While all the three H 2 L 2 ligands in the Ni(II) complex 2 were completely deprotonated. The seven Ni(II) atoms are all hexa-coordinated, and have two coordination environments. The fluorescence properties of the ligands, the Ni(II) complexes 1 and 2 have been discussed. [ABSTRACT FROM AUTHOR]

Abstract: Two new lanthanide supramolecular complexes, [Tb(qoa)2(H2O)2]⋅NO3 ⋅ H2O (1) and [Er(qoa)3] ⋅ 2H2O (2) [qoa=(8-quinolinyloxy)acetate] were obtained by treating the corresponding nitrates and (8-quinolinyloxy)acetic acid (Hqoa) under hydrothermal conditions. Complex 1 possesses a 1D zigzag chain bridged by the qoa anions, which is further connected to form a 3D supramolecular framework via hydrogen bonds and π–π attractions. Compound 2 is a mononuclear structure and the coordination units are further assembled to a 1D helical chain parallel to the b-axis via hydrogen bonds. Obviously, various coordination modes of the qoa anions and the intermolecular attractions have effect on the formations of two complexes. The solid-state luminescent behavior of 1 has been investigated at room temperature. [Copyright &y& Elsevier]

Abstract: Five new lanthanide supramolecular complexes, namely, [Sm(oqa)2(H2O)4]2 (ClO4)2 ·(bpy)2 (1), [Ln(oqa)3]·2H2O [Ln=Sm(2), Gd(3)] and [Ln(oqa)2(NO3)(H2O)] [Ln=Pr(4), Eu(5)] (oqa=4-oxo-1(4H)-quinolineacetate, bpy=4,4′-bipyridine), have been synthesized under hydrothermal conditions. These complexes exhibit three typical structure features. Complex 1 possesses a dimeric structure, which is further connected together through hydrogen bonds and π–π attractions, forming a 3D supramolecular framework. Compounds 2–3 are isomorphous and contain 1D ring-like chains, which are further interconnected by the oqa ligands into 2D sheet-like structures. 4 and 5 exhibit eight-connected 3D network of 424·64-bcu topology. The various coordination modes of carboxylate ligands and the selection of the counterions have clearly affected the topological structures. Furthermore, the solid-state luminescent properties of complexes 1, 2 and 5 were investigated at room temperature and they show intense, characteristic emissions in the visible region. [Copyright &y& Elsevier]

Abstract: Reactions of 4-oxo-1(4H)-quinolineacetic acid (Hoqa) and varied metal salts of Zn(II), Cd(II) and Ag(I) resulted in the formation of three new coordination polymers, namely, [Zn(oqa)2]·H2O (1), [Cd(bpy)(oqa)2(H2O)2]·4H2O (2) and [Ag(bpy)(oqa)]·2H2O (3) (bpy=4,4′-bipyridine). Complex 1 has a three-dimensional (3D) polymeric network with diamondoid topology; compounds 2–3 exhibit one-dimensional (1D) chain structure characteristics, which are further assembled through π–π stacking attractions and hydrogen bonds, forming the 3D supramolecular frameworks. In addition, the solid-state luminescent properties of the ligand Hoqa and complexes 1–2 have been investigated at room temperature. [Copyright &y& Elsevier]