A New Three-Dimensional Supramolecular Framework with an Unprecedented (5,6)-Connected Topology

A new complex, [Co(HL)(2)(H2O)(4)]center dot H2O (1) (H2L=5-carboxy-1-carboxymethyl-2-oxidopyridinium), was synthesized and characterized by X-ray single-crystal diffraction, elemental analysis, and IR spectra. The crystal is monoclinic, space group P2(1)/c with a=0.512 69(2) nm, b=2.275 31(1) nm, c=1.003 95(6) nm, beta=98.015(3)degrees, V= 1.159 7(1) nm(3), Z=2, M-r=541.29, F(000)=558, D-c=1.550 g.cm(-3),mu=0.816 min(-1), the final R=0.044 5 and wR=0.142 1 for 2 015 observed reflections (I>2 sigma(I)). Complex 1 can be considered constructed from 2D layers, which consist of left- and right-handed helical chains and further linked into a 3D supramolecular architecture by hydrogen bonds. Topology analysis reveals that complex 1 shows an unprecedented 3D binodal (5,6)-connected topology. CCDC: 733550.