Search

The title compound, {[La2(CH3COO)2(C8H10O4)2(H2O)4]·2H2O}n or [La2(ac)2(e,a-cis-1,4-chdc)2(H2O)4]·2H2O, where ac is acetate and 1,4-chdc is cyclo­hexane-1,4-di­carboxyl­ate anion, is a binuclear lanthanum(III) complex. Each metal atom is deca­coordinated by four O atoms from two distinct 1,4-chdc2− ligands, four O atoms from three acetate groups and two O atoms from coordinated water mol­ecules to form a distorted bicapped square-anti­prismatic geometry. Two non-coordinated water mol­ecules are also present in the formula unit. The most remarkable feature of this compound is that it possesses a only cis conformation for cyclo­hexane-1,4-di­carb­oxy­lic acid, although the raw material consists of a mixture of cis and trans isomers. The μ3-η2:η2 coordination mode of the bridging acetate group and the flexible di­carboxyl­ate fragments of 1,4-chdc2− results in the formation of infinite two-dimensional lanthanide–carboxyl­ate layers within the crystal structure. The directionality of strong inter­molecular O—H...O and weakC—H...O inter­actions provides robustness to the layers, which leads to the construction of a three-dimensional supra­molecular network. The crystal studied was refined as a two-component twin. [ABSTRACT FROM AUTHOR]

Metal carboxylates possess wide range of intriguing structural topologies due to their diverse ligational behavior of carboxylate group. Two new polymorphs of monomeric complex, [Ca(dga)(H2O)5].H2O (1) and the three-dimensional metal-organic framework, [Ba(dga)(H2O)] (2) (dgaH2 = diglycolic acid) have been grown by gel diffusion technique at room temperature. Colourless transparent crystals were obtained within one week. Single crystal X-ray diffraction study reveals that the title compounds crystallized in monoclinic P21/n in 1 and orthorhombic system with space group Pnma in 2. The monomeric units, CaO8 interact each other via extensive hydrogen bonding among the coordinated and the lattice water molecules with the carboxylate oxygen atoms to form a 2D supramolecular sheet like structure in 1. The adjacent BaO8 polyhedra are connected by diglycolate ligand forming the 3D frame work with porous architecture in 2. Elemental analysis, FTIR, UV-Visible, thermogravimetric, powder X-ray diffraction and solid state photoluminescence studies were also carried out. [ABSTRACT FROM AUTHOR]

A 2D barium complex formulated as [Ba(C6H4NO3)(Cl)(H2O)]n was successfully synthesized by gel diffusion technique using hydrosilica gel medium at room temperature. Single crystal X-ray diffraction studies confirm that the complex is triclinic with space group P1 and exhibits a 2D framework by the interconnection of oxobridge and chlorobridge in alternative layers. The unit cell dimensions are a = 5.7737(2)Å, b = 6.8503(2)Å, c = 11.5378(4)Å, α = 106.432(2)°, β = 100.644(2)°, γ = 93.049(2)°. The crystal structure is further stabilized by a 3D one through a pair of N-H ... O intermolecular hydrogen bonds to form R2²(8) ring motifs. Each barium cation is nine coordinated to form distorted tricapped trigonal prism geometry. The gel grown crystals were characterized by several physico-chemical techniques including elemental analysis, FT-IR, UV-Visible spectral studies, powder X-ray diffraction and thermogravimetry. [ABSTRACT FROM AUTHOR]