Self-assembly of a Co(II) dimer through H-bonding of water molecules to a 3D open-framework structure

Reaction of pyridine-2,4,6-tricarboxylic acid (ptcH3) with Co(NO3)2.6H2O in presence of 4,4′-bipyridine (4,4′-bpy) in water at room temperature results in the formation of [Co2(ptcH)2(4,4′-bpy) (H2O)4]·2H2O, (1). The solid-state structure reveals that the compound is a dimeric Co(II) complex assembled to a 3D architecture via an intricate intra- and inter-molecular hydrogen-bonding interactions involving water molecules and carboxylate oxygens of the ligand ptcH2-. Crystal data: monoclinic, spacegroup P21/c, a = 11·441(5) å,b = 20·212(2) å,c = 7·020(5) å, Β = 103·77(5)°,V= 1576-7(1) å3,Z = 2,R1 = 00363,wR2 = 0·0856,S = 1·000.