Structural diversity of syn-2-pyridinealdoxime in Cu(II) coordination polymer with bipyridine as auxiliary ligands [Articol]

Abstract

The interaction of copper(II) nitrate, syn-2-pyridinealdoxime (PaoH), and 4,4′-bipyridine (bpy) in a 1:2:1 ratio (in mixture of water, methanol and N,N-dimethylformamide (dmf)) resulted in the formation of the compound {[Cu4(Pao)2(L)2(bpy)2](NO3)2∙2dmf∙4H2O}n. The coordinated ligand (L)2- is formed as a result of in situ chemical transformation of the PaoH ligand. The structure of this compound was determined by single-crystal X-ray diffraction. The compound has been found to be formed from a symmetric cationic coordination polymer, in which bridging bpy ligands link the structural units [Cu4(Pao)2(L)2]2+, nitrate anions, dmf and water as crystallization molecules. The outer-sphere components of the crystal are linked to the cation polymers by a system of hydrogen bonds. The intra- and intermolecular interactions present in the crystal were identified and quantified, and their 2D footprint diagrams were illustrated using Hirshfeld surface analysis.