Trinuclear and mononuclear copper(II) complexes incorporating tetradentate 2,2′-[1,1′-(ethylenedioxydinitrilo)diethylidyne]diphenol ligand: Syntheses, crystal structures, spectral and thermal behaviors

Abstract Mononuclear and trinuclear Cu(II) complexes with chemical formula [CuL]·CH 3 OH (1) and [{(Cu( μ -L)) 2 (OAc) 2 }Cu] (2), where H 2 L = 2,2′-[1,1′-(ethylenedioxydinitrilo)diethylidyne]diphenol, have been synthesized and characterized by elemental analyses, 1 H NMR, IR and UV–vis spectra et al. Crystallographic data of complex 1 reveal the formation of an asymmetric mononuclear structure and a slight distortion toward tetrahedral geometry from the square planar structure, in which the introduction of the non-coordinated methanol molecule lead to the assembly of the 1D chains by hydrogen bonding, Cu⋯ π and π ⋯ π interactions. Complex 2 have the elongated square pyramidal geometries for the two terminal Cu(II) ions and an octahedral coordinated geometry for the central Cu(II) ion. In complex 2 , two acetate ions coordinate to three Cu(II) ions adopting a familiar syn – syn ( μ M-O-C-O-M) coordinated fashion. The central Cu(II) ion sits in a crystallographic inversion centre. Therefore, the whole molecule of complex 2 is rigorously centrosymmetric, and forms a 3D supramolecular networks through intermolecular C–H⋯O and C–H⋯ π interactions.