Synthesis and Crystal Structures of Nickel(II) and Cobalt(II) Complexes with 3-Methoxysalicylaldehyde Benzoylhydrazide

Abstract

Two isostructural mononuclear complexes, [Ni(HL)(H₂L)]·ClO₄·1.5CH₃OH (1) and [Co(HL)(H₂L)]·ClO₄·CH₃CN·2H₂O (2), have been synthesized (H₂L = 3-methoxysalicylaldehyde benzoylhydrazide). In complexes 1 and 2, each metal atom is coordinated by four O atoms and two N atoms from two H₂L ligands, forming a distorted octahedral coordination configuration. Additionally, in complex 1, the two neighboring molecules are found to form a centrosymmetric dimer through N (hydrazine)-H···O (phenolate/methoxyl) hydrogen bonds and the p-p stacking interactions between the two phenyl rings. The dimers are further constructed into an extended one dimensional chain structure through hydrogen bands. Unlike complex 1, complex 2 does not form dimer/chain but is rather a simple, discrete complex.