Cadmium-porphyrin coordination networks:: Rich coordination modes and three-dimensional four-connected CdSO4 and (3,5)-connected hms nets

Functionalized tetraarylporphyrin molecules have been widely used as ligands for the design of supramolecular coordination arrays. Even though a large number of porphyrin coordination compounds have been synthesized, three-dimensional networks are still less common. Here we report the hydrothermal synthesis and structure characterizations of four cadmium-porphyrin compounds based on meso-tetra(4-pyridyl)porphyrin (H2TPyP). In these structures, both cadmium and porphyrin exhibit rich coordination chemistry. The porphyrin molecule displays four types of coordination modes in which each porphyrin molecule bonds to one, two, four, and five cadmium sites. The Cd2+ site shows equally diverse coordination modes and exists in five different coordination environments. The porphyrin molecules are connected through Cd2+ cations or Cd-3(SC2H2OH)(2)(4+) clusters into molecular (Cd-TPyP-1), two-dimensional (Cd-TPyP-4), and three-dimensional networks (Cd-H2TPyP-2 and Cd-TPyP-3). Three-dimensional frameworks are of particular interest because they adopt interesting and rare framework topologies (cds and hms types).