New macrocyclic dicopper(II) complex: synthesis, structure and stability

The macrocyclic ligand of 3,6,9,16,19,22-hexaazatricyclo [22.2.2.211,14]-triacoltta-1(26),11(12),13,24,27,29-hexaene(L, BP) was synthesized by [2+2] condensation of p-phthaldehyde and diethylenetriamine. This ligand was used as a building block to synthesize dicopper(II) complex [BPCu2(II)](ClO4)4 (1). Protonation constants and metal ion stability constants of the mononuclear and dinuclear copper(II) macrocyclic complexes have been measured potentiometrically. Structural investigation indicated that the two Cu(II) ions are separated in the macrocycle ligand evidenced by the crystallographic structure [BPCu2(II)(Ph–CO2−)2](ClO4)2 (2). Complex 2 crystallizes in the triclinic space group P1̄, with cell constants a=9.333(3) Å, b=13.841(4) Å, c=19.025(6) Å, α=102.446(5)°, β=90.929(6)°, γ=93.691(5)°, V=2393.6(13) Å3 and Z=2.