1D coordination polymer of copper(II) containing μ-1,1,3 azido ligand with alternating ferro–antiferromagnetic interactions

Abstract

Single crystals of the copper(II) chain of formula [(μ-1,1,3-N₃)₂{Cu₂(ampy)₂(N₃)₂}]n (ampy=1-(2-aminoethyl)pyrrolidine) were prepared and characterized by X-ray diffraction methods. The copper(II) possesses the pseudo-octahedral environment with a terminal azido, one substituted alicyclic diamine and the remaining coordination occupied by N atoms of the unusual μ-1,1,3-N₃ bridging azido ligand. The magnetic behavior was investigated in the temperature range 2.0–300 K and show ferro-antiferromagnetic alternating chain. The fit of the experimental data with the expression derived for an alternating S=1/2 chains based on the exchange Hamiltonian H=−∑^N−1_i−1[JAF] gave the best parameters J_AF=−2.80, J_FM=0.15 cm^-1, α=0.054, g=2.15 and R=1.2×10^-5, which are consistent with a dominant antiferromagnetic coupling.