Synthesis and characterization of new coordination polymers based on 2,3-/3,4-pyridinedicarboxylates and bispyridine ligands, with structural diversity

Abstract

New coordination polymers, formulated as {bpaH(2)[Cu(mu-2,3-pydc)(2)]}(n) (1), [Cd(mu-23-Pydc)(mu-bpa)(0.5)(H2O)(2)](n) (2), {[Co-2(mu(4)-3,4-pydc)(2)(mu-bPe)(H2O)(2)]H2O)(n), (3) and [Cu-2(pic)(4)(mu-4,4'-bipy)}.(4,4'-bipy).2H(2)O (4) have been synthesized based on the bispyridine ligands; 1,2-bis(4-pyridyl)ethane (bpa), 1,2bis(4-pyridyl)ethylene (bpe) and 4,4'-bipyridine (4,4'-bipy) along with dianionic 2,3-and 3,4-pyridinedicarboxylate (2,3-pydc and 3,4-pydc) and mono anionic picolinate (pic) ligands, respectively. All the complexes have been characterized by elemental and IR spectroscopy and single-crystal X-ray diffraction studies. 1 has proton transfer products of bpaH2 cations and shows 1D double chain. Using of the 2,3pydc and 3,4-pydc ligands in 2 and 3 in the presence of Cd(II) and Co(II) ions generate 1D 2D inclined polycatenated structure in 2 and 4,5 connected {4(4).6(2).10(4)}{4(4).6(2)) 4,5T6 topology in 3, respectively. The picolinate ligand in dinuclear structure of 4 was occurred by partial decarboxylation of 2,3-pydcH(2) in the process of the solvothermal reaction. 4,4'-Bipyridine molecules act as both a template via rare weak C-H center dot center dot center dot N interaction and a bridge between Cu(II) centers in the self-assembly process of supramolecular structure of 4. Thermal decomposition behavior of complexes and luminescent property of 2 are also presented herein. (C) 2016 Elsevier Ltd. All rights reserved.