Synthesis, X-ray structure, spectroscopic and magnetic properties of [Cu(DACO)(μ-1,1-N3)(μ-1,3-N3)]n and [Cu(DACO)(μ-NCS)(NCS)]n (DACO=1,5-diazacyclooctane)

Two new one-dimensional copper(II) complexes bridged by azide and thiocyanate, [Cu(DACO)(μ-1,1-N3)(μ-1,3-N3)]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 N3− 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.