Dinuclear nickel(II) complexes with a tridentate nitrito bridge and terminal thiocyanato ligands.: Crystal structure and magnetic properties

The mu-(eta(1)-N : eta(2)-O,O)-nitrito dinuclear compounds [Ni-2(mu-NO2)(NCS)(3)(Medpt)(2)]. H2O 1 and [Ni-2(mu-NO2)(NCS)(3)(dpt)(2)] 2, and the mononuclear nitrito compounds [Ni(NO2)(NCS)(Medpt)] 3 and [Ni(NO2)(NCS)(Medien)] 4, where Medpt = bis(3-aminopropyl)methylamine, dpt = bis(3-aminopropyl)amine and Medien = bis(2-aminoethyl)methylamine, have been synthesized and characterised. The crystal structures of 1-4 have been determined by single-crystal X-ray analysis. The thiocyanate ligand appears to stabilise the tridentate co-ordination mode of the nitrito ligand. The magnetic behaviour of the dinuclear compounds 1 and 2 was recorded between 300 and 4 K, showing antiferromagnetic coupling in both cases. The magnetic susceptibility data were fitted by the expression for a dinuclear nickel(II) compound giving the parameters J = -12.8 cm(-1), g = 2.17 and J = -12.2 cm(-1), g = 2.27 for 1 and 2 respectively.