CRYSTAL-STRUCTURE AND MAGNETIC-PROPERTIES OF [NI(TERPY)(N3)2]2.2H2O,A NICKEL(II) DINUCLEAR COMPLEX WITH FERROMAGNETIC INTERACTION

The crystal structure of dimeric [Ni(C15H11N3)(N3)2]2·2H2O has been determined at room temperature. Crystal data are as follows: P21/a, Z=2, a=15.628(3), b=9.798(2), c=10.322(2) Å, β=92.32(2)°, R=0.049 for 1137 reflections. The complex consists of isolated centrosymmetric [Ni(terpy)(N3)2]2·2H2O dimeric units, where the two metallic centers are linked through the N-end of two azide bridging groups. The Ni(II) atom displays a distorted octahedral coordination, being linked to three N atoms from the terpyridine ligand and three N atoms of three azide ligands. Magnetic susceptibility measurements have shown the existence of ferromagnetic exchange between nickel centers (J=+20.1 cm-1, D=-12.5 cm-1). The magnetic behavior of this and others related complexes is discussed and some magneto-structural trends are given. © 1990.