New nano-particle La(III) supramolecular compound as a precursor for preparation of lanthanum oxybromide-, hydroxide-, and oxide-nanostructures

Nano-particles of a new La(III) supramolecular compound [La(4,4′-bipy)(H₂O)₂(NO₃)_3.75Br_0.25] · (4,4′-Hbipy) (1), have been synthesized from reaction of 4,4′-bipy with La(NO₃)₃ and NaBr by the sonochemical method. For the first time LaOBr, La(OH)₃ and La₂O₃ nano-structures were prepared from [La(4,4′-bipy)(H₂O)₂(NO₃)_3.75Br_0.25] · (4,4′-Hbipy) (1) by calcination at 400, 500, and 700°C, respectively. The structure of 1 was determined by X-ray crystallography and the nano-structures were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). Thermal stabilities of nano and crystal samples of 1 were studied and compared with each other.     

Syntheses,crystal structures,and catalytic activities of three new Cu(II) coordination polymers based on 2-(1H-1,2,4-triazole)-1-acetic acid

Three new coordination polymers, {[Cu(trza)(2,2′-bipy)(H₂O)]?·?(ClO₄)} _n (1), {[Cu(trza)(2,2′-bipy)(H₂O)]?·?(BF₄)} _n (2), and {[Cu(trza)(4,4′-bipy)]?·?(H₂O)?·?(ClO₄)} _n (3) (Htrza?=?2-(1H-1,2,4-triazole)-1-acetic acid), have been synthesized and characterized by single-crystal X-ray diffraction analysis. Both 1 and 2 exhibit 1-D chain structure while 3 displays 2-D layer structure. The catalytic activities of 1 and 3 in the green oxidative coupling of 2,6-dimethylphenol have been investigated.     

Syntheses,structures, and properties of supramolecular complexes with bipyridine and amino-Schiff-base derived from salicylaldehyde with glycine

The reactions of stoichiometric amounts of Cu(CH₃COO)₂ · 2H₂O or Ni(CH₃COO)₂ · 2H₂O with KHL (potassium salt of salicylideneglycine) and 4,4′-bipy or 2,2′-bipy ethanol afforded [Cu₂(L)₂(μ-4,4′-bipy)(4,4′-bipy)₂] · 2H₂O (1) (L = salicylideneglycine) and Ni(OAc)₂(2,2′-bipy) (H₂O)₂ (2), respectively. The structure of 1 contains two Cu(II)'s, bridged by 4,4′-bipy; each copper is square pyramidal. Complex 2 contains a Ni(II) in highly distorted octahedral geometry. The two complexes were constructed into 3-D interwoven networks by typical H-bonding (i.e., O?H ··· O and N?H ··· O) and some other intra- or intermolecular weak interactions (i.e., C?H ··· O).     

Crystal structure of metal-organic coordination polymers [Cu(bpy)2(H2O)2](NO3)2·4.5C2H5OH and [Cu2(bpy)(H2O)(L-pha)2](NO3)2·H2O

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.     

The construction of two lanthanide coordination polymers based on 5-hydroxyisophthalate and bipyridine

Two lanthanide coordination polymers, [Tm₂·(5-IPA)₄·(2,2′-Hbipy)₂]·3H₂O (1, 5-H₂IPA?=?5-hydroxyisophthalic acid, 2,2′-bipy?=?2,2′-bipyridine) and [Er·(5-HIPA)₃·(4,4′-bipy)₃·(H₂O)₂]·3H₂O (2, 4,4′-bipy?=?4,4′-bipyridine), have formed by hydrothermal synthesis. Complex 1 exhibits a 2-D coordination network containing parallelepiped-shaped voids occupied by guest 2′2-bipy molecules. Complex 2 possesses a 1-D linear chain structure. The 1-D chains are linked by 4,4′-bipy molecules to form a 3-D supramolecular framework. IR spectroscopy, elemental analysis, and thermogravimetric analysis were also investigated.     

Hydrothermal synthesis,structures and characterization of two new copper(II) triphosphonate compounds

Two copper(II) triphosphonate compounds, Cu[(APTPH₄)(phen)(H₂O)]?·?2.16H₂O (1) and [Cu(APTPH₄)(2,2′-bipy)(H₂O)]?·?2.63H₂O (2), have been prepared by a low temperature hydrothermal reaction from 1-aminopropane-1,1,3-triphosphonic acid (APTPH₆), CuO and a second ligand, phen?=?1,10-phenanthroline, or 2,2′-bipy?=?2,2′-bipyridyl. These two compounds were characterized by single crystal X-ray diffraction, elemental analysis, IR and TG. Crystal data for 1: Monoclinic, space group P2₁ /c, a?=?14.4830(7)?Å, b?=?9.1721(5)?Å, c?=?16.7403(8)?Å, β?=?90.101(2)°. For compound 2: Triclinic, space group P 1, a?=?7.1215(7)?Å, b?=?10.460(2)?Å, c?=?14.671(2)?Å, α?=?82.983(2)°, β?=?83.882(2)°, γ?=?80.617(2)°. In both compounds, each Cu²⁺ ion is five-coordinate with two oxygen atoms from the triphosphonate, two nitrogen atoms from the second ligand and one water molecule, to form a distorted square-pyramidal geometry. Both complexes have 3D supramolecular structures constructed by hydrogen bonds and π–π stacking interactions.     

Three rare heteromultinuclear 3d-4f salamo-like complexes constructed from auxiliary ligand 4,4′-bipy: Syntheses,structural characterizations,fluorescence and antimicobial properties

Three rare heteromultinuclear complexes, _∞[NiL(4,4′-bipy)Pr (NO₃)₃]·(CH₃)₂CHOH ( 1 ), [{CuLSm (NO₃)₃}₂(4,4′-bipy)]·CH₃OH ( 2 ) and [{CuL (CH₃CH₂OH)Eu (NO₃)₃] ( 3 ) with a symmetrical salamo-like hexadentate ligand H₂L have been synthesized, and characterized by FT-IR, UV–vis and X-ray crystallography. Complex 1 is a 1D coordination polymer constructed from heterobimetallic [Ni(L)Pr (NO₃)₃] units which are connected by the exo-dentate ligand 4,4′-bipy bearing nitrogen-donor atoms. Complex 2 is a heterotetranuclear dimer based on [Cu(L)Sm (NO₃)₃] moieties which are linked through the exo-dentate 4,4′-bipy hasing nitrogen-donor atoms. Complex 3 is a heterodinuclear structure, Cu (II) atom is five-coordinate possessing a distorted square pyramidal geometry, and Eu (III) atom is a deca-coordinate adopting a distorted bicapped square antiprism. In addition, fluorescence and antimicobial properties of the ligand H₂L and its complexes 1 – 3 have also been discussed.     

A series of new oxo-vanadium(IV) complexes with octahedral coordinated vanadium centers

A series of new oxo-vanadium(IV) complexes, [VOCl0.69(OH)0.31 (2,2′-bipy)2]Cl·2H2O (1, 2,2′-bipy?=?2,2′-bipyridine) [(VO)₂Cl₄(4,4'-bipy)₃ (H₂O)₂] (2, 4,4'-bipy?=?4,4'-bipyridine), [VO(ida)(H₂O)]_n (3, H₂ida?=?iminodiacetic acid), and [(VO)₂(oa)₄]_n·4n(H₃O)·n(H₂O) (4, H₂oa?=?oxalic acid), have been synthesized and structurally characterized. 1 contains a [VOCl_0.69(OH)_0.31(2,2′-bipy)₂]⁺ cation, Cl ^– anion and two free H₂O molecules. 2 exhibits a binuclear centrosymmetric moiety built up from two [VOCl₂(4,4'-bipy)(H₂O)] units and one bridging 4,4'-bipy ligand, which provides a rare example of a 4,4'-bipy molecule acting as monodentate ligand. 3 displays a neutral chain [VO(ida)(H₂O)]_n constructed by the linkages of [VO(H₂O)]²⁺ units and ida^2? bridging ligands, while 4 offers the only example of three kinds of oa^2- ligands coexisting within the same anionic chain [(VO)₂(oa)₄^4-]_n. Their spectroscopic properties were investigated, and the magnetic susceptibility of 4 shows antiferromagnetic behavior.     

Synthesis and Structure of Copper(II) Nitrate Complexes with 2, 6‐Bis(pyrazolyl)pyridine

Three mononuclear copper(II) complexes of copper nitrate with 2, 6‐bis(pyrazol‐1‐yl)pyridine ( bPzPy ) and 2, 6‐bis(3′,5′‐dimethylpyrazol‐1‐yl)pyridine ( bdmPzPy ), [Cu(bPzPy)(NO₃)₂] ( 1 ), [Cu(bPzPy)(H₂O)(NO₃)₂] ( 2 ) and [Cu(bdmPzPy)(NO₃)₂] ( 3 ) were synthesized by the reaction of copper nitrate with the ligand in ethanol solution. The complexes have been characterized through analytical, spectroscopic and EPR measurements. Single crystal X‐ray structure analysis of complexes 1 and 2 revealed a five‐coordinate copper atom in 1 , whereas 2 contains a six‐coordinate (4+2) Cu^II ion with molecular units acting as supramolecular nodes. These neutral nodes are connected through O–H ··· O(nitrate) hydrogen bonds to give couples of parallel linear strips assembled in 1D‐chains in a zipper‐like motif.     

Two new coordination host frameworks for the inclusion of 4-amino-benzophenone guest molecules

The synthesis and structural characterization of novel organometallic coordination polymers are reported. The reaction of Cd(NO₃)₂ and 4,4′-bipy in CH₃OH/H₂O gave a 2D coordination network formulated as {[Cd(4,4′-bpy)₂·(H₂O)₂](NO₃)₂·4H₂O}¹⁰, which was used to capture an organic guest species (4-amino-benezopheone, C₁₃H₁₁NO (3)) to obtain {[Cd(4,4′-bpy)₂(NO₃)(H₂O)]·NO₃·(C₁₃H₁₁NO)₂} (1). Using L (L=4,4′-trimethylenedipyridine) instead of 4,4′-bipy, {[Cd(L)₂(H₂O)₂]·2H₂O·2NO₃·C₁₃H₁₁NO} (2) was synthesized, which has an interesting configuration.     

Synthesis and crystal structures of 3D supramolecular compounds: [ M (4,4′-bipy)2(H2O)4] · (4,4′-bipy)2 · (3,5-daba)2 · 8H2O ( M =Zn,Mn)

Two new supramolecular compounds [M(4,4′-bipy)₂ (H₂O)₄] ·?(4,4′-bipy)₂ ·?(3,5-daba)₂ ·?8H₂O (M=Zn(1) or Mn(2), 4,4′-bipy =?4,4′-bipyridine, 3,5-daba =?3,5-diaminobenzoic acid anion) were synthesized and characterized by elemental analysis and X-ray crystal diffraction. In [M(4,4′-bipy)₂(H₂O)₄]²⁺, the M(II) is coordinated by two nitrogen atoms from two 4,4′-bipy molecules and four oxygen atoms from four waters to form an octahedral configuration. There exist uncoordinated 4,4′-bipy molecules, 3,5-diaminobenzolate counterions and water guests in the compounds. The 3D structures of the title supramolecular compounds are constructed by rich hydrogen bonds among [M(4,4′-bipy)₂(H₂O)₄]²⁺, uncoordinated 4,4′-bipy molecules, water molecules and 3,5-daba, containing a diverting hexa-member water ring.     

Synthesis,crystal structure,and magnetic properties of a linear trinuclear Cu(II) complex

A new linear trinuclear Cu(II) complex, [Cu₃(NTA)₂(4,4′-bpt)₄(H₂O)₂]?·?10H₂O (H₃NTA?=?nitrilotriacetic acid, 4,4′-bpt?=?4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole) (1), was obtained from evaporation of an aqueous solution containing Cu(NO₃)₂?·?6H₂O, 4,4′-bpt, nitrilotriacetic acid (H₃NTA), and NaOH. 1 was characterized using single-crystal X-ray diffraction, IR, and elemental analysis. In the trimer, the three linear copper ions are bridged by two NTA carboxylate groups in a syn–anti conformation and connected by 4,4′-bpt to produce a 1-D array. Temperature-dependent magnetic susceptibilities reveal the presence of weak antiferromagnetic exchange between metal centers.     

Design,synthesis and magnetic properties of a ladderlike complex constructed by secondary building units

A secondary building unit (SBU), [Ni(2,2′-bipy)(5-npa)(H₂O)] _n [where 2,2′-bipy = 2,2′-bipyridine, 5-npa = 5-nitroisophthalic dianion], was synthesized as starting material of a polystep reaction. A ladderlike complex (LLC) Ni(II) coordination polymer, {[Ni(2,2′-bipy)(5-npa)(4,4′bipy)_0.5]·(H₂O)} _n , was constructed by polystep reaction using this SBU. In LLC, two SBUs were cross-linked by 4,4′-bipy [where 4,4′-bipy = 4,4′-bipyridine] forming a 1-D ladderlike structure. The magnetic properties of the LLC and SBU are discussed.     

OBSERVATIONS ON THE CONFORMATION OF IMINODIACETATE(2-) ION IN MIXED LIGAND COPPER(II) COMPLEXES WITH NITROGEN HETEROCYCLES AS SECONDARY LIGANDS. CRYSTAL STRUCTURE OF (2,2′-BYPIRIDINE)(IMINODIACETATO)COPPER(II) HEXAHYDRATE

Abstract

(2,2′-Bipyridine)(iminodiacetato)copper(II) hexahydrate, [Cu(IDA)(2,2′-bipy)]·6H₂O, has been obtained and studied by X-ray diffraction. The compound (triclinic system, space group P1, Z = 2; R = 0.036 and R = 0.040 for 7541 independent reflections) consists of asymmetric dinuclear entities, [Cu(IDA)(2,2′-bipy)]₂, and uncoordinated H₂O molecules in a hydrogen bonding network. Both Cu(II) atoms of each dinuclear entity are chemically very similar. Each Cu(II) atom exhibits a flattened, square pyramidal coordination. Two N atoms of 2,2′-bipy and the N and one O atoms of IDA are at the square base; another O atom of the same terdentate IDA is at the apical position. Two weak interactions between each Cu(II) atom and one O atom from IDA which chelates the second contribute to the dinuclear entity. On the basis of these results and the known structure of other Cu(II) complexes with IDA and imidazole or 4,4′-bipy, an attempt to rationalize the nearly coplanar or perpendicular conformation of the two five-membered IDA-Cu(II) chelate rings in such mixed-ligand copper(II) complexes is made.     

UO22+-polycarboxylate heterometallic complexes: structure,spectra, and photocatalytic properties

[Cu₂(UO₂)₄(suc)₄(pac)₄] (1), [(Cu(H₂O)₂)(4,4′-bipy)₂][(UO₂)₂(H₂O)₂(Hca)₂]·3H₂O (2), and [(Cu(H₂O)₂)(UO₂)(bta)]·4H₂O (3) were synthesized by the reaction of succinic acid and 3-pyridinecarboxylic acid, citric acid and 4,4′-bipyridine, or 1,2,4,5-benzenetetracarboxylic acid ligands with Cu(NO₃)₂·3H₂O and UO₂(CH₃COO)₂·2H₂O. The complexes were characterized by IR and UV–vis spectroscopy, powder X-ray diffraction, single-crystal X-ray diffraction, and photoluminescence spectroscopy. Photocatalytic activities of the complexes were also investigated.     

Structural Diversity of Metallosupramolecular Assemblies from Cu(phen)2+ (phen = 1,10‐Phenanthroline) Building Blocks and 4,4′‐Bipyridine

Attempts to crystal engineer metallosupramolecularcomplexes from Cu(phen)²⁺ building blocks and the prototypical,rod‐like, exo‐bidentate ligand 4,4′‐bipyridine (4,4′‐bipy) by layering techniques are described. Reactions of Cu(phen)²⁺ (phen = 1,10‐phenanthroline) with 4,4′‐bipy in the presence of NO₃^– counterions yielded two distinct, discrete, dinuclear, C_i symmetric, dumbbell‐typecomplexes, [{Cu(NO₃)₂(phen)}₂(4,4′‐bipy)] ( 1 ) and [{Cu(NO₃)(phen)(H₂O)}₂(4,4′‐bipy)](NO₃)₂ ( 2 ), depending upon the mixture of solvents used for crystallization. In compound 1 , a mono‐ and a bidentate nitrato group coordinate to Cu²⁺, whereas in 2 the monodentate nitrato groups are replaced by aqua ligands, which introduce additional hydrogen‐bond donor functionality to the molecule. The crystal structure of 1 was determined by single‐crystal X‐ray analysis at 296 and 110 K. Upon cooling, a disorder‐order transition occurs, with retention of the space group symmetry. The crystal structure of 2 at room temperature was reported previously [Z.‐X. Du, J.‐X. Li, Acta Cryst. 2007 , E63, m2282]. We have redetermined the crystal structure of 2 at 100 K. A phase transition is not observed for 2 , but the low temperature single‐crystal structure determination is of significantly higher precision than the room temperature study. Both 1 and 2 are obtained phase‐pure, as proven by powder X‐ray diffraction of the bulk materials. Crystals of [Cu(phen)(CF₃SO₃)₂(4,4′‐bipy) · 0.5H₂O]_n ( 3 ), a one‐dimensional coordination polymer, were obtained from [Cu(CF₃SO₃)₂(phen)(H₂O)₂] and 4,4′‐bipy. In 3 , Cu(phen)²⁺ corner units are joined by 4,4′‐bipy via the two vacant cis sites to form polymeric zig‐zag chains, which are tightly packed in the crystal. Compounds 1 – 3 were further studied by infrared spectroscopy.     

Syntheses,crystal structures and antibacterial activities of M(II) benzene-1,2,3-triyltris(oxy)triacetic acid complexes

Four metal(II) complexes with benzene-1,2,3-triyltris(oxy)triacetic acid (H₃L), {[Co_1.5(L)(H₂O)₆]·6H₂O}_n (1), {[Co_1.5(L)(4,4′-bipy)_1.5(H₂O)₄]·4H₂O}_n (2), {[Co(HL)(2,2′-bipy)(H₂O)₂]·1.5H₂O}_n (3), and {[Cu(HL)(phen)(H₂O)₂]·H₂O}_n (4) (4,4′-bipy = 4,4′-bipyridine; 2,2′-bipy = 2,2′-bipyridine; phen = phenanthroline), were prepared and structurally characterized. Complex 2 displays a 1-D structure, while 1, 3, and 4 reveal 0-D structures, which further extend to 3-D supramolecular networks by hydrogen bonding interactions, of which 1 and 4 contain double-helical chains, 2 includes meso-helices, and 3 comprises single-helices. Furthermore, the thermal stabilities and antibacterial activities of the complexes were studied.     

A one-dimensional organic–inorganic hybrid constructed by saturated Keggin polyoxoanions and [CuI(4,4′-bipy)] n n + chains

A one-dimensional (1-D) organic–inorganic hybrid compound {(H₃O)[Cu^I(4,4′-bipy)]₃[SiW₁₂O₄₀]} · 1.5H₂O (1) has been synthesized from hydrothermal reaction of Keggin polyoxometalate, cupric nitrate and 4,4′-bipyridine (4,4′-bipy). Single crystal X-ray diffraction shows 1-D zigzag chains built up of saturated Keggin polyoxoanions and infinite [Cu^I(4,4′-bipy)] _n ^{n +} units. Zipper-like arrangement of adjacent zigzag chains by hydrogen-bonding interactions leads to a 2-D layer and π–π interactions of 4,4′-bipy ligands from adjacent layers further result in the 3-D structure of 1. All Cu atoms in 1 are three-coordinated with “T-type” geometries, indicating they are univalent in the resultant compound. This result has further been confirmed by the absence of signal in the EPR spectrum of 1.     

Copper(I) and copper(II) complexes with pyrazine-containing pyridylalkylamide ligands N-(pyridin-2-ylmethyl)pyrazine-2-carboxamide and N-(2-(pyridin-2-yl)ethyl)pyrazine-2-carboxamide

Four copper(II) complexes and one copper(I) complex with pyridine-containing pyridylalkylamide ligands N-(pyridin-2-ylmethyl)pyrazine-2-carboxamide (HL^pz) and N-(2-(pyridin-2-yl)ethyl)pyrazine-2-carboxamide (HL^pz?) were synthesized and characterized. The X-ray crystal structures of [Cu₂(L^pz)₂(4,4?-bipy)(OTf)₂] (1, OTf?=?trifluoromethanesulfonate, 4,4?-bipy?=?4,4?-bipyridine) and [Cu(L^pz)(py)₂]OTf·H₂O (2, py?=?pyridine) revealed binuclear and mononuclear molecular species, respectively, while [Cu(L^pz)(μ₂-1,1-N₃)]_n (3), [Cu(L^pz?)(μ₂-1,3-N₃)]_n (4), and [Cu(HL^pz)Cl]_n (5) are coordination polymer 1-D chains in the solid state.     

Hydrothermal synthesis,crystal structure and magnetic properties of a copper(II) phosphonate

The treatment of 3-ammonium-1-hydroxypropylidene-1,1′-bisphosphonate (H₇ahdp) and 4,4′-bipy with CuCl₂?·?2H₂O resulted in a metal phosphonate [Cu(H₅ahdp)?·?H₂O] _n . Its crystal structure has been characterized by single X-ray crystallography. Although there is no 4,4′-bipy in the lattice structure, it plays a very important role in forming the one-dimensional chain of the polymer. Hydrogen bonds link the chains into a 3D network. The dinuclear secondary building units are observed in the compound. The determination of variable-temperature magnetic susceptibilities (5?～?300?K) shows weak intrachain antiferromagnetic coupling between copper(II) centers. The magnetic data were fitted to the appropriate equations derived from the Hamiltonian H?=??2JS ₁ S ₂, giving the parameter J?=??25.78?cm^?1. Its thermal properties were also investigated.