A new dicopper(II) complex with macrocyclic hexaaza bearing hydroxyethyl pendants

A new dicopper(II) complex with 3,6,9,16,19,22-hexaaza-6,19-bis(2-hydroxyethyl)-tricyclo[22,2,2,211,14]triaconta-1,11,13,24,27,29-hexaene(L), was synthesized and characterized. The crystal structure of [Cu2L(N3)2](ClO4)2·2H2O has shown that both Cu2+ ions are in penta-coordination environment with distorted trigonal bipyramid consisting of three N atoms from diethylenetriamine moieties, one N atom from azide and one O atom from hydroxyethyl pendant, and the separation of Cu⋯Cu is 8.11 Å. The two aromatic rings are close to each other, the shortest distance being 3.71 Å for C11⋯C21, and the benzene ring planes from a dihedral angle of 70.9° in molecule. ES-MS spectra showed that the main species, [Cu2(L–H)N3]2+ and [Cu2(L–2H)]2+, were formed by deprotonation of the hydroxyethyl pendants and releasing azides from the Cu(II) complex stepwise.