Crystallographic and molecular mechanics study of the copper perchlorate complex of a larger reinforced macrocycle

Abstract

The crystal structure of the five-co-ordinate copper(II) complex of 7-methyl-7-nitro-1,5,9,13-tetraazabicyclo[11.2.2]heptadecane, [CuL⁷(H₂O)][ClO₄]₂·H₂O, has been determined. The blue crystals crystallised in the orthorhombic space group Pbca with a= 14.625(4), b= 19.083(2), and c= 17.476(4)Å, Z= 8, and R= 0.059. The copper ion is co-ordinated to four macrocyclic nitrogen atoms with an average Cu–N distance of 2.05 Å, and a water molecule occupies an axial co-ordination site with Cu–O 2.22 Å. The conformation and chemical properties of the complex are discussed with the aid of molecular mechanics calculations.