Synthesis, X-ray structure, spectroscopic and magnetic properties of [Cu(DACO)(μ-1,1-N 3)(μ-1,3-N 3)] n and [Cu(DACO)(μ-NCS)(NCS)] n (DACO=1,5-diazacyclooctane)

Abstract

Two new one-dimensional copper(II) complexes bridged by azide and thiocyanate, [Cu(DACO)(μ-1,1-N 3)(μ-1,3-N 3)] n ( 1) and [Cu(DACO)(μ-NCS)(NCS)] n ( 2), where DACO=1,5-diazacyclooctane, have been synthesized and characterized. Single crystal X-ray diffraction analysis reveals that the bridging azido groups in complex 1 are coordinated alternately in the single end-to-end and single end-on models, giving an alternate chain, the unbridged N 3 − groups acted as the terminal ligands. In complex 2, the strictly alternating copper ions and thiocyanates produce a chain in which the metallic centers are connected through single end-on-end NCS − groups. The central copper(II) ions in both complexes are penta-coordinated and situated in a distorted square-pyramid environment. Low temperature magnetic susceptibility indicates that complex 1 shows an antiferromagnetic behavior with the value for exchange coupling constant J is −4.06 cm −1, and g=2.038; while the complex 2 exhibits a weak ferromagnetic interactions between the copper ions with J=1.04 cm −1 and the corresponding g=2.03. Moreover, the two complexes have also been characterized on the basis of elemental analysis, IR and UV–vis spectroscopy.