Search

A mono-nuclear copper (II) complex 1, formulated {[Cu(phen)2(CO3)]·7H2O} has been synthesized and characterized by X-ray diffraction studies, FTIR, and thermogravimetric (TG) analysis. However, there is a self-assembly structure of (H2O)38 cluster in this complex 1, and it is worth reporting. The adjacent (H2O)38 clusters connect together resulting in an infinite 2D water layer structure. The water morphology is stable at room temperature, but upon thermal decomposition, the water loss is irreversible. A mono-nuclear copper (II) complex 1, formulated {[Cu(phen)2(CO3)].7H2O} has been synthesized and characterized by X-ray diffraction studies, FTIR, and thermogravimetric (TG) analysis. However, there is a self-assembly structure of (H2O)38 water cluster in this complex 1, and it is worth reporting. The discrete (H2O)38 cluster connects together resulting in an infinite 2D water layer structure. The alternate arrangement of the complex 1 and the 2D water layer produce infinite through-channels along a axis direction, and the part moieties of complex 1 are located inside these channels. The water rings are stable at room temperature, and when thermally decomposes the water loss is irreversible.

Two novel metal−organic frameworks (MOFs) of Co(II), {[Co(bpdc)(bpdap)]·1.5H2O}n (1) and [Co(bpdc)(Hpb)(H2O)]n (2) (bpdap = N,N‘-bis(2-pyridyl)-2,6-diaminopyridine, H2bpdc = biphenyl-4,4‘-dicarboxy...

A new V-shaped bis-monodentate ligand L (L = 2,3′-dipyridylamine) (1) has been designed and synthesized by alkylation reaction of pyridylamine. An investigation of the charge distributions of the coordination atoms and single-point energy calculations of four conformers of ligand L based on the geometry of conformers optimized by the DFT (density functional theory) method was carried out. The results show that the four conformers of ligand L take on two stable and two less stable configurations. Theory forecasts that two relatively stable configurations present in complexes as probable coordination motifs of the ligand, and that steric hindrance of pyridine nitrogen atoms in isomers will affect its coordination ability together with the electronic factor. This forecast has been demonstrated by the coordination chemistry of ligand L, that is, configuration (a) and (b) of the ligand occur in the following reported complexes, which combines with AgI or CuII through two coordination modes (bidentate bridging or a monodentate mode) resulting in coordination polymers {[Ag (L)2]NO3}n (2), [Cu2(L)2(maa)4]n (maa = methacrylic acid) (3), and the mononuclear molecule [Cu(L)4](ClO4)2·2CH3CH2OH (4). The ligand assumes different coordination modes in the three complexes because of different levels of steric hindrance of the pyridine nitrogen atoms in the conformers. Interestingly, polymers 2 and 3 assume a 1D helical structure and a linear framework, respectively, and 4 has a 2D supramolecular architecture induced from hydrogen bond interactions. In addition, the magnetic properties of 3 have been explored, which shows a strong antiferromagnetic interaction.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Two novel supramolecular complexes [Cu(bpapa)(dhbd)]·CH3OH (1) and [Cu(bpapa)(ma)]·ma (2) (bpapa=bis[6-(2-pyridylamino)pyrid-2-yl]amine, dhbd=2,3-dihydroxybutanedioate dianion, ma=α-methacrylate) were rationally designed, synthesized and characterized by single crystal X-ray diffraction, IR, electronic spectroscopy and thermogravimetric analyses. Complex 1 was the first oligo-α-pyridylamino complex based on hydroxypolycarboxylate and self-assembled into a 3D honeycomb configuration network with open channels and tubes containing 1D ladder-shaped double chains formed by hydrogen bonds and aromatic π-π stacking interactions. Complex 2 constructed a 2D supramolecular network extended by 1D chains from dimeric supramolecular synthon through noncovalent supramolecular interactions. In the two complexes, the chelating monohelical ligand adopted all-anti configuration. Density functional theory calculations were applied to 1 and 2.

A new ligand dpa (dpa=3,4′-dipyridylamine) (1) has been designed and synthesized, which reacted with AgNO3 and ZnCl2, respectively, resulting in two new complexes, [Ag(dpa)2]NO3 (2) and [ZnCl2(dpa)2] (3). The complexes have been characterized by thermogravimetric analysis, spectroscopic techniques, and single crystal X-ray diffraction. 2 is one-dimensional (1D) helical chain structure formed by hydrogen bonding interaction, and the helices are connected by the electrostatic interaction between Ag(I) ions and O atoms from NO 3 − , leading to a two-dimensional (2D) supramolecular structure. For 3, the mononuclear [ZnCl2(dpa)2] is almost a regular tetrahedral configuration, which generates a dimeric structure constructed through N–H⋯Cl hydrogen bonds and π–π interactions between pyridine rings. The adjacent dimeric units extend further into two-dimensional rippled network structure by two kinds of hydrogen bonds (N–H⋯Cl, C–H⋯Cl) in different directions. On the basis of experiment, both two complexes were calculated by DFT-B3LYP/LANL2DZ in gaussian 03.

Two novel supramolecular complexes, [Cu(bpapa)(mal)]·H2O·CH3OH (1) and {[Cu(bpapap)](Hmal)2}·2H2O (2) [bpapa=bis-[6-(2-pyridylamino)pyrid-2-yl]amine, bpapap=2,6-bis-[6-(pyrid-2-ylamino)pyrid-2-ylamino]-pyridine, mal=maleate dianion] were rationally designed and synthesized based on flexible multidentate ligands and copper(II) maleate. Complexes 1 and 2 were all characterized by elemental analysis, spectroscopic techniques, thermal analysis and single crystal X-ray diffraction analysis. Complex 1 is of an infinite 3-D supramolecular framework constructed by 2-D sheets to contain 1-D helical chains formed by intermolecular hydrogen bond interactions between the non-coordinated oxygen atoms from maleate and nitrogen atoms from amino groups of bpapa. Complex 2 also takes a 3-D supramolecular structure, which is built from 2-D rhombic sheets produced by sequential dimer units. Interestingly, three pairs of symmetrical hydrogen bonds generate these dimer units.

Two novel 1-D coordination polymers, {[Cu(Hhbd)(bpy)]·3H2O}n (1) and {[Cu(Hhbd)(phen)]·H2O·MeOH}n(2) [Hhbd = α-hydroxybutanedioicate dianion, bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline], were rationally designed and synthesized with an identical construction strategy, using Hhbd ligands as bridges and chelating aromatic ligands as terminal ligands. Interestingly, the chelating aromatic ligand and the –OH groups of the Hhbd ligand play an important role in the self-assembly of the polymeric coordination chain by providing potential supramolecular recognition sites for π–π aromatic stacking and hydrogen-bond interactions, resulting in the self-assembly of the molecular double chains to give a 3-D supramolecular framework with 1-D open channels. More significantly, in 1 the host framework encapsulates unprecedented centrosymmetric cyclic (H2O)8 clusters that have a chair conformation and are connected into 1-D arrays by supramolecular association along the 1-D open channels. In contrast, the channels of 2 contain lattice water and disordered methanol molecules. TGA and XRPD show that the host frameworks of 1 and 2 are stable when the guest solvent molecules are removed from the channels. Variable-temperature magnetic susceptibility measurements for both complexes indicate the presence of weak antiferromagnetic exchange interactions between adjacent copper(II) ions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)