Synthesis, structural characterization and magnetic studies of two Cu(II)-azide based one-dimensional polymeric chains derived from reduced Schiff base ligands

Abstract

This article describes syntheses, structural characterizations and magnetic studies of two new Cu(II)-azido based coordination polymers. The complexes, [Cu4(L1)2(N3)6]∞ (1) and [Cu4(L2)2(N3)6]∞ (2) have been synthesized by using Cu(ClO4)2·6H2O, reduced Schiff base ligands (HL1−2) and NaN3 in 1:1:2 M ratios. HL1 and HL2 are the condensation products of salicylaldehyde with N-ethyl-1,2-ethylenediamine and N,N-dimethyl-1,3-propanediamine, respectively. Structural analysis shows that both complexes have similar tetrameric Cu(II) building units in which Cu(II) ions are linked by phenoxo oxygen atoms and two different bridging azido linkages (µ1,1-N3− and µ1,1,3-N3−). An azide co-ligand is also attached with one of the Cu centres through terminal mode. The Cu(II) ions occupy distorted penta-coordinated square pyramidal geometry in complexes 1 and 2. Magnetic susceptibility measurements in the range of 300 K–2 K exhibit the presence of antiferromagnetic interactions between Cu(II) centeres of both complexes 1 and 2.