Compartmental ligands. Part 10. Syntheses and crystal and molecular structures of the copper(II) complexes of Schiff bases derived from 1-(pyrrol-2-yl)butane-1,3-dione and 1,3-bis-(2-aminophenoxy)propane, and from pyrrole-2-carbaldehyde and 3,6-dioxaoctane-1,8-diamine

Abstract

The synthesis of the acyclic Schiff bases H₄L⁷ and H₂L⁸, derived from 1-(pyrrol-2-yl)butane-1,3-dione and 1,3-bis(2-aminophenoxy)propane, and from pyrrole-2-carbaldehyde and 3,6-dioxaoctane-1,8-diamine, respectively are reported, together with their respective copper(II) complexes. Crystals of [Cu(H₂L⁷)] are monoclinic; R= 0.0549 for 1 901 observed reflections. The copper is co-ordinated in the inner (N₂O₂) compartment with a trans mode of attachment by the ligand; the approximately square-planar co-ordination geometry shows a significant tetrahedral distortion. The pyrrole and ether functions are not bonded to the copper. In the structure of [Cu(HL⁸)(O₂CMe)](R= 0.0363, 4 800 reflections), the co-ordination geometries of the copper atoms in the two independent molecules are tetragonally-distorted octahedral, the two long axial bonds being to one acetate oxygen and to one of the ether oxygen atoms; one pyrrole residue is not co-ordinated to copper.