Effect of differently substituted methoxybenzoates on the supramolecular assemblies of three [Cu(N-hyden)2](o-/m-/p-methoxybenzoate)2 complexes: Synthesis, spectroscopic characterization and single crystal structure determination

Abstract

Three new anhydrous [copper(II)(N-hyden)2](o-/m-/p-methoxybenzoate)2 complexes, 1–3, (where N-hyden=N-(hydroxyethyl)ethylenediamine) have been prepared by the dropwise addition of N-hyden to the hydrated copper(II) o-/m-/p-methoxybenzoate compounds suspended in a methanol–water (4:1 v/v) mixture, followed by evaporation of the resulting solution at room temperature. They have been characterized by elemental analyses, spectroscopic techniques (FT-IR and UV–Vis), conductance measurements and magnetic susceptibility studies. Single crystal X-ray structure determination showed that complexes 1 and 3 crystallize in the monoclinic system with space group P21/c, while complex 2 crystallizes in the triclinic system with space group P1¯; all in centrosymmetric space groups. The X-ray analysis of complexes 1–3 clearly revealed their ionic structures, consisting of one complex cation, [Cu(N-hyden)2]2+, and two respective substituted arylcarboxylate (o-/m-/p-methoxybenzoate) anions. The Cu(II) center in each complex is octahedrally coordinated to two tridentate N-hyden ligands, in which two nitrogen and one oxygen atoms of two N-hyden ligands are coordinated in trans geometries. The crystal lattices in complexes 1–3 are stabilized by non-covalent interactions such as N–H⋯O, O–H⋯O hydrogen bonding and C–H⋯π interactions.