Synthesis and crystal and molecular structures of new copper and zinc complexes with aza-14-crown-4 ether having di(α-pyridyl)-substituted bispidine subunit

Abstract

The complexes [Cu(L)(H2O)](ClO4)2 · 2H2O (I) and [Zn(L)Cl2] · C2H5OH (II), where L is the macrocyclic substituted aza-14-crown-4 ether molecule containing di(α-pyridyl)bispidine insert, were synthesized and studied by X-ray diffraction. The Cu atoms in complex I and the Zn atoms in complex II have equal coordination numbers of 5 and different highly distorted polyhedra (the CuN4O tetragonal pyramid and ZnN3Cl2 trigonal bipyramid). Ligand L in structure I performs the tetradentate tetrachelate (4N) structural function and in II, it performs the tridentate bis-chelate (3N) function. The key difference between the structures of complexes I and II is determined by different conformations of both the aza-macrocycles and bispidine substituents of ligand L.