Ni(2,2':6',2''-terpyridine) 2 : a high-spin octahedral formal Ni(0) complex.

We have synthesised and characterised the complex Ni(tpy) 2 (tpy = 2,2':6',2''-terpyridine). This formally Ni(0) complex is paramagnetic both in the solid state and in solution ( S = 2). The crystal structure shows an octahedral geometry, with molecules arranged in independent dimers involving π-stacking between pairs of complexes. Magnetic measurementes and DFT calculations suggest the existence of temperature-dependent intermolecular antiferromagnetic coupling in the solid state.