Structure diversity of a series of new coordination polymers based on a C3-symmetric tridentate ligand with rosette architecture

4,4',4 ''-[1,3,5-Benzenetriyltris(carbonylimino)]trisbenzoic acid (H3L). a C-3-symmetric ligand, was found to self-assemble into an interesting core-rosette structure driven by intermolecular hydrogen-bonding interactions. Reactions of this ligand with Zn2+, Co2+ and Cd2+ under solvothermal conditions resulted in the formation of four new coordination polymers with interesting structural motifs: [Zn-2(L)(OH)(H2O)(DMF)]center dot DMF center dot H2O (1), [Co-3(L)(2)(DMF)(H2O)]center dot DMF center dot 3CH(3)OH (2), [Co-1.5(L)(H2O)(DMF)]center dot DMF (3), and [Cd-1.5(L)(H2O)(DMF)]center dot DMF (4). Single-crystal structural analysis revealed that complex 1 exhibits a rare example of twofold interpenetrating two-dimensional CdI2-type structure with tetranuclear Zn-4(mu(3)-OH)(2)(COO)(6)(H2O)(DMF) serving as secondary building unit (SBU), whereas in 2, the mu(3)-oxo-tricobalt basic carboxylate SBUs are connected by L3- ligands, leading to a twofold interpenetrating three-dimensional (3,6)-net framework. The isomorphous complexes 3 and 4 each has a (4,4)-grid layered architecture in which the SBU is a linear Co-3/Cd-3 cluster. The four coordination polymers were all further characterized by IR, thennogravimetric and powder X-ray diffraction (PXRD). (C) 2011 Elsevier Ltd. All rights reserved.