Three variants of novel Co(II) complex with NSAID mefenamic acid and <i>N,N</i>′-donor ligand neocuproine

Abstract

Abstract Three variants of novel cobalt(II) complex with deprotonated mefenamic acid ( mef ) and N,N ′-donor ligand neocuproine ( neo ) are described, namely; two differently colored and shaped crystal polymorphs of complex [Co( mef ) 2 ( neo )] ( 1a and 1b ) and a pyridine solvate [Co( mef ) 2 ( neo )]· py ( 2 ). The complexes have been characterized by infrared and UV-VIS spectroscopy, elemental analysis and single-crystal X-ray structure analysis. Although the complexes 1a , 1b and 2 crystallize in different crystal systems and space groups and differ in shapes of coordination polyhedra, the crystal structures of all three complexes contain analogous neutral units with Co(II) atom hexacoordinated by two chelate bonded mefenamato ligands and one chelate bonded neocuproine ligand, yielding CoN 2 O 4 chromophore. The main structural difference between 1a , 1b and 2 is the conformation of the coordinated mef ligands, which affects the crystal packing of the complexes.