Three new pyridine-2,6-dicarboxylate copper(II) compounds with coordinated pyrimidine-based ligands: Synthesis, characterization and crystal structures

Abstract

Three new Cu(II) compounds of pyridine-2,6-dicarboxylic acid (H 2pdc) with substituted pyrimidines as additional ligands have been synthesized and structurally characterized using X-ray diffraction, i.e. [Cu(pdc)(4HOpym)(H2O)2](H2O)2 (1) (4HOpym = 4-hydroxypyrimidine), [Cu(pdc)(anpym)(H2O)] (2) (anpym = 2-amino-5-nitropyrimidine) and [Cu(pdc)(clnpym)(H2O)](H2O) (3) (clnpym = 2-chloro-4-nitropyrimidine). The three compounds are further characterized by IR, EPR and ligand field spectroscopy. The geometry around the Cu(II) ions is distorted octahedral for (1) and distorted square pyramidal for (2) and (3). Inter- and intramolecular hydrogen bondings play an important role in the structure and packing of the compounds.