The syntheses, crystal structures, spectroscopic and thermal characterization of new pyridine-2,5-dicarboxylate compounds

In this study, four new M(II)-isocinchomeronic acid (pyridine-2,5-dicarboxylic acid) complexes with ethylenediamine (en) and 2,2'-bipyridine (bipy), namely [Co(en)3][Co(pydc)2(H2O)2]·2H2O (1), [Ni(Hpydc)2(H2O)2] (2), [Cu(en)2(H2O)][Cu3(pydc)4(en)2(H2O)2]·3H2O (3) and [Cu(bipy)3][Cu(pydc)(bipy)2]·2Cl·12H2O (4) (H2pydc = pyridine-2,5-dicarboxylic acid), have been synthesised. Elemental, thermal analyses and IR spectroscopic studies have been carried out in order to characterise the complexes. The molecular structures of the complexes have been determined using single crystal X-ray diffraction. The geometry displayed by the Co(II) (1) and Ni(II) (2) ions is distorted octahedral. The Cu(II) ions display a square pyramidal geometry and distorted octahedral geometry in 3, while each Cu(II) ion exhibits a distorted octahedral geometry in 4. Molecules of each complex are linked into a 3D framework structure by N-H?O, O-H?O and C-H?O hydrogen bonds. © 2015 Elsevier Ltd. All rights reserved.ARC Centre of Excellence in Cognition and its Disorders Singapore-MIT Alliance for Research and Technology CentreThe authors acknowledge Aksaray University, Science and Technology Application and Research Centre, Aksaray Turkey for the use of the Bruker SMART BREEZE CCD diffractometer (purchased under grant No. 2010K120480 of the State of Planning Organisation). The authors are indebted to the X-ray laboratory of Dicle University Science and the Technology Application and Research Centre, Diyarbakir, Turkey for use of the X-ray diffractometer. Appendix