Crystal structure of diaqua(3,14-diethyl-2,6,13,17-tetraazatricyclo[16.4.0.07,12]docosane)copper(II) dichloride tetrahydrate

Abstract

The crystal structure of the novel hydrated CuII salt, [Cu(L)(H2O)2]Cl2·4H2O (L = 3,14-diethyl-2,6,13,17-tetraazatricyclo[16.4.0.07,12]docosane, C22H44N4) has been determined using synchrotron radiation. The asymmetric unit contains one half of the [Cu(L)(H2O)2]2+ cation (completed by crystallographic inversion symmetry), one chloride anion and two lattice water molecules. The copper(II) atom exists in a tetragonally distorted octahedral environment with the four N atoms of the macrocyclic ligand in equatorial and two O atoms from water molecules in axial positions. The latter exhibit a long axial Cu—O bond length of 2.7866 (16) Å due to the Jahn–Teller distortion. The macrocyclic ring adopts a stable trans-III conformation with typical Cu—N bond lengths of 2.0240 (11) and 2.0441 (3) Å. The complex is stabilized by hydrogen bonds formed between the O atoms of coordinated water molecules and the NH groups as donors, and chloride anions as acceptors. The chloride anions are further connected to the lattice water solvent molecules through O—H...Cl hydrogen bonds, giving rise to a three-dimensional network structure.