Synthesis and spectroscopic characterization of copper(II) tetraazaiminooxime macrocyclic complexes—A tetragonal distortion analysis

Herein we describe the synthesis and spectroscopic (infrared and UV–vis) analysis of [CuII(dohpn)(L)]n+ (dohpn = imineoximic tetraazamacrocyclic ligand 2,3,9,10-tetramethyl-1,4,8,11-tetraazaundecane-1,3,8,10-tetraen-11-ol-1-olate) and L = SCN−, I−, Cl− (n = 0) and 4-aminopyridine (ampy), 4,4′-bipyridine (bipy), imidazole (im), 2-aminopyrazine (ampz) and water (n = 1+). The following order of the Jahn-Teller stabilization energy (cm−1) was observed: I−(6452) < Cl−(6477) < NCS−(6494) < ampy(6562) < im(6614) < bipy(6685) < ampz(6739) < H2O(7813) and the energy of the crystal field transition was correlated with the tetragonal distortion in the structures.