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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)(H 2 O) 5 ].H 2 O (1) and the three-dimensional metal-organic framework, [Ba(dga)(H 2 O)] (2) (dgaH 2 = 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 P2 1 /n in 1 and orthorhombic system with space group Pnma in 2. The monomeric units, CaO 8 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 BaO 8 polyhedra are connected by diglycolate ligand forming the 3D framework with porous architecture in 2. Elemental analysis, FT-IR, UV-Visible, thermogravimetric, powder X-ray diffraction and solid state photoluminescence studies were also carried out.

AbstractA novel coordination polymer, poly[(μ-diacetato)(tetraphthalato)pentabarium(II)], with acetate bridged moiety has been successfully grown by gel diffusion technique. Single crystal X-ray diffraction analysis showed that the compound crystallizes in triclinic space group

A 2D barium complex formulated as [Ba(C 6 H 4 NO 3 )(Cl)(H 2 O)] 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 P 1 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, ␣ = 106.432(2) • , ␤ = 100.644(2) • , ␥ = 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 R 2 2 (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.

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