Copper(II)-azido complexes constructed from polypyridyl amine ligands

A novel 1-D polymer Cu(II) complex bridged by perchlorate ions and azide ligand with the structural formula [Cu(DPA)(N3)(μO,O–ClO4)]n (1), {[Cu(Ldpdmen)(μ1,3-N3)]ClO4}n (2), {[Cu2(μ-Lpy)(μ-1,1,3-N3)(μ-1,3-N3)](ClO4)2}n (3) and {[Cu2(LT)(μ2-1,3-N3)(N3)(H2O)](ClO4)2radical dotH2O}n (4) where DPA = di(2-pyridylmethyl)amine, Ldpdmen = N,N′-bis(2-pyridylmethyl)-N,N′-dimethylethylenediamine and Lpy = 2,6-bis[bis(2-pyridylmethyl)aminomethyl]pyridine and LT = 3,5-bis[bis(2-pyridylmethyl) aminomethyl]toluene were synthesized. The complexes were characterized by spectroscopic techniques (IR and visible) and by single crystal X-ray crystallography. The magnetic properties were also measured for 1–3 at variable temperatures (4.5–300 K). Compound 1 has the copper center in a 4+2 geometry with the equatorial plane formed through the three N-donors of the DPA and an azido group which acting as a monodentate ligand. The 1-D chain is generated via the axial O,O′-bridging perchlorato groups where the intra-chain Cu⋯Cu distance is 6.9416(16) Å. In complex 2, the Cu center is ligated by the four N-donor atoms of Ldpdmen amine ligand and two N atoms of the EE bridging azido groups in a cis-coordinated asymmetric EE bonding fashion. The intra-chain Cu⋯Cu distance in this complex is 5.7949(15) Å.