Complexation of metal salts with macrocyclic polyethers in aprotic organic solvents. Crystal structures of ionic complexes [CuCl·15-C-5·CH 3CN] 2[Cu 2Cl 6] and {[Cu·15-C-5·(CH 3CN) 2][Cu 3Cl 8]} n

Abstract

Interaction of CuCl 2 and CuCl 2·2H 2O with 15-C-5 in acetonitrile medium affords ionic complexes (CuCl·15-C-5·CH 3CN) 2(Cu 2Cl 6) ( I) and [(Cu·15-C-5·(CH 3CN) 2(Cu 3Cl 8)] n ( II) having copper in the inner cavity of the macrocycle. The copper polyhedron in the cation of I is a pentagonal bipyramid with axial chloride and acetonitrile. Copper atoms in the anion are bonded with bridging and terminal chlorides located in the apices of a strongly distorted square. The axial positions of the pentagonal bipyramid of the cation of complex II are occupied by two acetonitrile molecules. There are only bridging chlorides in the anion [Cu 3Cl 8] n 2−. The polyhedron of central copper in the anion is a square bipyramidal, that of the two terminal ones is square pyramidal. Complexes I and II decompose on heating with successive liberation of acetonitrile ligand, degradation of crown ether and reduction of copper(2+) chloride into α-CuCl.