Synthesis, structure, and thermal properties of two new inorganic-organic framework compounds: Hexaaqua(mu(2)-1,2,4,5-benzenetetracarboxylato)-bis(N,N '-1,10-phenathroline)dicobalt(II) dihydrate and hexaaqua(mu(2)-1,2,4,5-benzenetetracarboxylato)-bis(N,N

Abstract

Two binuclear complexes [Co-2(C10H2O8)(C12H8N2)(2) (H2O)(6)]center dot 2H(2)O (1) and [Ni-2(C10H2O8)(C10H9N3)(2)(H2O)(6)]center dot 4H(2)O (2) were synthesized and their structures were determined by X-ray structure analysis. In both structures metal centres are in deformed octahedral environments and they are linked by bis-monodentately coordinated 1,2,4,5-benzenetetracarboxylate ligands as bridging units. In the packing arrangements of both compounds, binuclear units are connected by hydrogen bonds forming 2D pseudo-layers, strengthened by face-to-face pi-pi stacking interactions. The pseudolayers further construct 3D in organic-organic frameworks via system of hydrogen bonds. The complexes were also characterized by IR spectroscopy, TG and DSC analysis. Dehydration processes and thermal stability of the complexes are discussed. The dehydration enthalpies are calculated and the possible decomposition mechanisms are assumed.