Monomeric and polymeric copper(II) hexaaza macrocyclic complexes with btc anions (btc=1,2,4,5-benzenetetracarboxylic acid)

Two topologically different 3D CuII metal-organic frameworks assembled from the same ligands: control of reaction conditions

Bifunctional ligands containing both carboxylic and sulfonate groups can adopt versatile coordination modes to produce novel metal-organic frameworks (MOFs) with high-dimensional networks and interesting topologies. Using 2,2'-disulfonylbiphenyl-4,4'-dicarboxylic acid (H₄L) as a linker and 4,4'-bipyridine (4,4'-bpy) as a co-ligand, two novel 3D Cu^II MOFs, {[Cu₂(L)(4,4'-bpy)_2.5(H₂O)]·1.7H₂O}_n, (1), and {[Cu₂(L)(4,4'-bpy)₂]·DMA·3H₂O}_n, (2), have been synthesized and structurally characterized by X-ray crystallography (DMA is N,N-dimethylacetamide). MOF (1) shows an unprecedented trinodal 4,4,5-connected topology network with the Schläfli symbol (4.6².7³)(4³.6⁵.7.8)(6.7³.8.10), while MOF (2) indicates a binodal 4,6-connected fsc network with the Schläfli symbol (4⁴.6¹⁰.8)(4⁴.6²). MOFs (1) and (2) were further characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction and thermogravimetric analysis. MOF (1) shows a high water and chemical stability. The proton conductivity of (1) and CO₂ adsorption of (2) were also investigated.

Preparation, characterization and luminescence properties of core-shell ternary terbium composites SiO2(600)@Tb(MABA-Si)•L

Two novel core-shell structure ternary terbium composites SiO₂₍₆₀₀₎@Tb(MABA-Si)·L(L:dipy/phen) nanometre luminescence materials were prepared by ternary terbium complexes Tb(MABA-Si)·L₂·(ClO₄)₃·2H₂O shell grafted onto the surface of SiO₂ microspheres. And corresponding ternary terbium complexes were synthesized using (CONH(CH₂)₃Si(OCH₂CH₃)₃)₂ (denoted as MABA-Si) as first ligand and L as second ligand coordinated with terbium perchlorate. The as-synthesized products were characterized by means of IR spectra, ¹HNMR, element analysis, molar conductivity, SEM and TEM. It was found that the first ligand MABA-Si of terbium ternary complex hydrolysed to generate the Si-OH and the Si-OH condensate with the Si-OH on the surface of SiO₂ microspheres; then ligand MABA-Si grafted onto the surface of SiO₂ microspheres. The diameter of SiO₂ core of SiO₂₍₆₀₀₎@Tb(MABA-Si)·L was approximately 600 nm. Interestingly, the luminescence properties demonstrate that the two core-shell structure ternary terbium composites SiO₂₍₆₀₀₎Tb(MABA-Si)·L(dipy/phen) exhibit strong emission intensities, which are 2.49 and 3.35 times higher than that of the corresponding complexes Tb(MABA-Si)·L₂·(ClO₄)₃·2H₂O, respectively. Luminescence decay curves show that core-shell structure ternary terbium composites have longer lifetime. Excellent luminescence properties enable the core-shell materials to have potential applications in medicine, industry, luminescent fibres and various biomaterials fields.

Synthesis and characterization of a macrocyclic copper complex containing the 14-membered 1,3,5,8,10,12-hexaazacyclotetradecane unit

In this work, a new macrocyclic copper complex, [Cu(ACE)(SCN)2]; ACE: 1,3,6,10,12,15-hexaazatricyclo[13.3.1.16,10]eicosane, was prepared and characterized by elemental analysis, FT-IR, Raman spectroscopy and single-crystal X-ray diffraction. X-ray analysis of [Cu(ACE)(SCN)2] reveals an elongated octahedral geometry around the copper atom in a centrosymmetric CuN6 environment.

Crystal structure of trans-(1,8-dibutyl-1,3,6,8,10,13-hexa-aza-cyclo-tetra-decane-κ(4) N (3),N (6),N (10),N (13))bis-(perchlorato-κO)copper(II) from synchrotron data

The Cu^II ion in the title compound shows a slightly distorted octa­hedral coordination geometry with four N atoms of the aza­macrocyclic ligand and two perchlorate anions. In the crystal, mol­ecules are linked by N–H⋯O and C–H⋯O hydrogen bonds, forming a three-dimensional network.

The structure of the title compound, [Cu(ClO₄)₂(C₁₆H₃₈N₆)] has been determined from synchrotron data, λ = 0.62988 Å. The asymmetric unit comprises one half of the Cu^II complex as the Cu^II cation lies on an inversion center. It is coordinated by the four secondary N atoms of the macrocyclic ligand and the mutually trans O atoms of the two perchlorate ions in a tetra­gonally distorted octa­hedral geometry. The average equatorial Cu—N bond length is significantly shorter than the average axial Cu—O bond length [2.010 (4) and 2.569 (1) Å, respectively]. Intra­molecular N—H⋯O hydrogen bonds between the macrocyclic ligand and uncoordinating O atoms of the perchlorate ligand stabilize the mol­ecular structure. In the crystal structure, an extensive series of inter­molecular N—H⋯O and C—H⋯O hydrogen bonds generate a three-dimensional network.