3,11,19-trithia[3.3.3]pyridinophane: Structural diversity in its transition metal complexes

The pyridine-containing aza-thia macrocycle 3,11,19-trithia-[3.3.3]pyridinophane (10) and its complexes with Ni-II, Pd-II, Cu-I, Ag-I and Hg-II were synthesised and their crystal structures were determined. The Ni-II and Hg-II complexes (11, 12) are mononuclear with 10 serving as an unusual quinquedentate ligand. The Cu-I. complex 13 is also mononuclear with 10 being tetra-coordinated to a tetrahedral Cu-I. Palladium(II) forms a binuclear complex 14 which exists as an inorganic zwitterion and both Pd-II metal ions adopt the expected square-planar geometry with facial coordination. Silver(I) forms one-dimensional coordination polymers (15 and 16) with 10 and these exhibit two different coordination modes, namely tetrahedral and trigonal planar. It was found that the macrocycle 10 did not show any selectivity among a series of metal ions. The electronic and redox properties of several complexes were studied. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).