Structure and magnetic properties of the weak ferromagnet bis(1-(2-chloroethyl)-tetrazole)bis(nitrato)copper(II)

The novel mononuclear complex [Cu(teec)2(NO3)2] with teec=1-(2-chloroethyl)tetrazole, has been prepared from 1 equiv. copper(II) nitrate with 2 equiv. of teec. The X-ray structure shows the formation of a mononuclear complex with hexa-coordinated copper(II) ions. The teec ligands are positioned in trans orientation with a distorted axial geometry. Two of the CuO bonds of the chelating nitrate anions are significantly longer than the other two CuO bonds (1.99 vs. 2.48 Å). Linear-chain packing of the mononuclear units is reflected in very weak, linear ferromagnetic chains with θ=0.30 K and C=0.44 cm3 K mol−1. The spectral properties are in accord with the structural and magnetic data.