New unexpected coordination mode of azide acting as a bridging ligand between nickel(II) ions. Synthesis, crystal structure and magnetic properties of [Ni(N3)2(2,2-dimethylpropane-1,3-diarnme)] n , and infinite bidimensional polymer

The reaction between aqueous solutions of Ni(ClO4)2, NaN3 and 2,2-dimethylpropane-1,3-diamine (dmpd) gives blue crystals of the title compound which presents the N3– in a new coordination mode (end-to-end with respect to two NiII and end-on to another NiII), the crystal structure of which reveals a new infinite bidimensional sheet with anomalous magnetic behaviour at low temperature.