Helical ribbons of cadmium(II) and zinc(II) dicarboxylates with bipyridyl-like chelates - Syntheses, crystal structures and photoluminescence

Four mixed-ligand complexes of [M(mpa)(phen)](n), [M = Cd (1) or Zn (2) and mpa = m-phthalate and phen = 1,10-phenanthroline] and [M-2(mpa)(2)(2,2'-bpy)(2)](n), [M = Zn (3) or Cd (4) and 2,2'-bpy = 2,2'-bipyridine] have been synthesized and their crystal structures have been established by single-crystal X-ray diffraction. They all consist of one-dimensional ribbons featuring dinuclear units. Both 1 and 2 crystallize isomorphously in the monoclinic space group P2/c and feature helical chains. While 3 and 4 crystallize in the triclinic space group P (1) over bar. The one-dimensional ribbons are assembled into three-dimensional networks by pi-pi stacking interactions. They all show strong blue photoluminescence and are stable in air up to ca. 402, 371, 365 and 370 degreesC, respectively. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.