Tuning the bridging modes of Cu-azido complexes with Schiff bases by varying the terminal groups

Three azido-bridged copper(II) complexes, [Cu2(L1)2(μ1,1,3-N3)2]n·2nH2O (1), [Cu4(L2)4(μ1,1-N3)2(μ1,1,3-N3)2]n (2), and [Cu2(L3)2(μ1,1-N3)2] (3), where L1, L2, and L3 are the deprotonated forms of 4-bromo-2-[(2-methylaminoethylimino)methyl]phenol (HL1), 4-bromo-2-[(2-ethylaminoethylimino)methyl]phenol (HL2), and 4-bromo-2-[(2-isopropylaminoethylimino)methyl]phenol (HL3), respectively, have been prepared and structurally characterized by single-crystal X-ray diffraction analysis and IR spectra. The slight differences in the terminal groups of the Schiff bases lead to different bridging modes of the azido groups.