Ligand mediated structural diversity of copper(II)-azido moiety: synthesis, structure and magnetic study

Abstract Two copper azido complexes [Cu4(L1)4(µ1,1-N3)3(N3)] (1) and [{Cu2(L2)(N-benzylen)(µ1,1-N3)3(µ1,1,3-N3(N3)]n (2) have been synthesized by the reaction of aqueous solution of sodium azide to a methanolic solution of copper perchlorate hexahydrate and corresponding Schiff-base ligands. Schiff bases HL1 and HL2 act as blocking coligands are derived from the 1:1 condensation of N-benzyl ethylenediamine with Salicyldehyde and 2-hydroxy-5-chloroacetophenone respectively (N-benzylen is the N-benzyl ethylenediamine). These two complexes are characterized by the elemental analysis, FT-IR, single crystal X-ray diffraction, powder XRD and also TGA. Single crystal X-ray structural study reveals that complex 1 is the only single μ1,1- azido bridged chain tetramer to the best of our knowledge and complex 2 is a mixed ligand azido bridged one dimensional chain which also represents the unique example containing three types of azido bonding modes µ1,1-N3, µ1,1,3-N3 and terminal N3 present simultaneously. Magnetic susceptibility measurements between 4.5K to 300K showed that complex 1 and complex 2 are antiferromagnetic and ferromagnetic in nature, respectively.