Copper(II) and zinc(II) complexes of pyridine-2,6-dicarboxylic acid

Crystal structure, DNA binding studies, nucleolytic property and topoisomerase I inhibition of zinc complex with 1,10-phenanthroline and 3-methyl-picolinic acid

“…Consequently, the Zn-N bond length (mean value = 2.151 Å ) is longer than the Zn-O bond length (mean value = 2.081 Å ). In contrasts, the corresponding Zn-N and Zn-O bond lengths of the Zn-picolinate moieties are reverse in bis(pyridine-2,6-carboxylatoj 3 N,O,O 0 )zinc(II) trihydrate (Okabe and Oya 2000) and in trans-diaquabis(3-hydroxypicolinato-j 2 N,O) zinc(II) dihydrate (Di Marco et al 2004), i.e., the Zn-N bonds is shorter than the Zn-O bonds in these complexes. The carboxylate oxygen and carbonyl atoms of the 3-methyl-picolinate ligands form hydrogen bonds with the lattice water molecules.…”

X-Ray Structure Characterization of Palladium(II) Ternary Complexes of Pyridinedicarboxylic and Phthalic Acid with Phenanthroline and Bipyridine

“…The coordination bond distances indicate that cayboxylate O atom either in PDCA ligand or in PHT ligand (in this case, one of the O atom) has the strongest interaction with Pd(II) atom with the bond Pd-O distance value ranging from 1.964 (1) 15) Cu(II) 16) or Zn(II), 16) with lanthanoid metals such as La(III) 17) or Ce(III) 18) or with an alkaline metal such as Li(I), 19) 2,6-PDCA behaves as the dianionic tridentate ligand, in which two O atoms of the two carboxylate groups in both sides of N atom and the pyridine N atom are bonded to the metal ions. Therefore, in the presence of other bidentate N, NЈ heterocyclic ligands, phen and bpy, the tridentate 2,6-PDCA behaves preferably as a bidentate N, O ligand.…”

Polymeric and monomeric dipicolinate complexes with 4-hydroxymethyl pyridine: spectral, structural, thermal and electrochemical characterization

“…The interest of metal complexes with dpc and its protonated forms, Hdpc and H 2 dpc, stems from their interesting structural features with various coordination modes [10], stabilization of unusual oxidation states [11], chemical analysis of iron at low concentration [12] and catalysis [13]. It is known that there are a range of different coordination modes with possible monodentate [14], bidentate [15,16], tridentate [17,18] or bridging (polymeric, trimeric or dimeric) [19,20] in transition metal-dipicolinate complexes depending on whether the divalent anionic dpc, protonated anionic Hdpc or diprotonated H 2 dpc forms are coordinated to metal ions ( Fig. 1) [21].…”