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    Lanthanide Complexes with Pyridine-2,6-Dicarboxylic Acid: Synthesis, Crystal Structure, Thermal and Magnetic Properties of [LnPDA)2(PDAH2)] • (DMAH2)2(DMAH0.5)2
    (Pleiades Publishing Inc, 2016) Sharif, S.; Khan, B.; Sahin, O.; Khan, I. U.
    Mild solvothermal synthesis, structures, thermal and magnetic properties of coordination complexes [Ln(PDA)(2)(PDAH(2))] center dot (DMAH(2))(2)(DMAH(0.5))(2)(I-IV) (PDA = pyrdine-2,6-dicarboxylate anion, DMAH = dimethylamine, Ln = Ce, Nd, Sm, and Ho) are described. The DMAH molecules in I-IV, generated in situ from hydrolysis of N,N-dimethylformamide, are responsible to assemble three dimensional coordination polymers through N-H center dot center dot center dot O and C-H center dot center dot center dot O hydrogen bonds. Distorted tricapped trigonal prismatic LnO(6)N(3) geometry having 14 triangular faces is attributed to mean deviation of dihedral angles while nitrogen shows fairly triangular faces having dihedral angle close to 60 degrees C (CIF files CCDC nos. 872065 (I), 872070 (II), 872069 (III), and 872066 (IV)). Curie-Weiss law and the overall magnetic behavior are typical for the presence of antiferromagnetic exchange coupling interactions between lanthanide. Thermal decomposition analyses reveal removal of ammonia and resultant complexes showthermal stability. Complexes have been further characterized by using elemental analyzer and FT-IR spectroscopy.
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    Öğe
    Synthesis, Crystal Structures of Gadolinium(III) and Erbium(III) Complexes Derived from Pyridine-2,6-Dicarboxylic Acid and Fluorescent Sensing of Picric Acid
    (Pleiades Publishing Inc, 2021) Sharif, S.; Zaheer, S.; Mumtaz, M. W.; Sahin, O.; Ahmad, S.; Zulfiqar, S.; Adnan, A.
    Two new complexes of gadolinium(III) and erbium(III) with pyridine-2,6-dicarboxylic acid (H(2)Pydc),{Na-3[Gd(Pydc)(3)]center dot 2H(2)O}(n) (I) and [Er(HPydc)(3)]center dot 10H(2)O (II), were prepared and their crystal structures were determined by X-ray crystallography (CIF files CCDC nos. 940633 (I) and 872068 (II)). The gadolinium atom in I is nine-coordinate (GdN3O6) and exhibits a tricapped trigonal prismatic geometry having 14 triangular faces. The Pydc ligand adopts chelating and, mu(3)- and mu(5)-bridging coordination modes. The 1D chains are further joined by Na atoms to generate a 3D coordination polymer. The structure is additionally stabilized by H-bonding. The Erbium polyhedron in II is also a tricapped trigonal prism (ErN3O6). The HPydc anions in II behave as tridentate chelating ligands. The complex molecules are connected to each other through hydrogen bonding interactions to form a three-dimensional network. Fluorescence titration experiments for complex II displayed highly sensitive fluorescence quenching efficiency of 98.3% against picric acid.