2D and 3D coordination polymers based on 2,2?-bipyrimidine and cyanide bridging ligands incorporating coordinated and guest ammonia molecules. Synthesis, crystal structures, magnetic properties and thermal analysis of [Ni(CN)4] - Colacio, E; Lloret, F; Navarrete, M; Romerosa, A; Stoeckli-Evans, H; Suarez-Varela, J (New Journal of Chemistry, 2005)