Extended network via hydrogen bond linkages of coordination compounds: synthesis, crystal structure and thermal behaviour of the complexes [M(L)2(NO3)2] (MII=Cu, Co) and [Ni(L)2(H2O)2][(NO3)2] (L=malonamide)

A series of monomeric complexes of general formula [MII(L)2(NO3)2] (MII=Cu, Co) (1), (2, 3), and [NiII(L)2(H2O)2][(NO3)2] (4) with L=malonamide have been isolated and characterized by single crystal X-ray structure. The crystalline structures for all compounds show multi-dimensional arrays or networks structures created by two types of hydrogen-bonding interactions. The first, between hydrogen atoms of the amide moiety and oxygen atoms of malonamide NH(malonamide)⋯O(malonamide) forming two-dimensional arrays. The second type, between the hydrogen atoms of the amide moiety and the oxygen atoms of the nitrate molecules NH(malonamide)⋯O(nitrate) generating three-dimensional arrangements. Nevertheless, for the Ni compound two contacts between the oxygen atoms of water molecules and oxygen atoms of nitrate moiety O(water)⋯O(nitrate) are present too. All the compounds have been characterized through thermogravimetric (TG) and calorimetric analyses (DSC).