Synthesis and structures of cadmium(II) complexes of a series of multinucleating N/S donor ligands

The coordination chemistry of a series of bis-bidentate ligands with cadmium(II) ions has been investigated. The ligands, containing two N,S-donor chelating (pyrazolyl/thioether) fragments, have afforded complexes of a variety of structural types (dinuclear M2L2 'mesocate' complexes, a one-dimensional chain coordination polymer and a simple mononuclear complex) according to whether the bisbidentate ligands act as bridges spanning two metal ions, or a tetradentate chelate to a single metal ion. The p-phenylene and m-biphenyl spaced ligands L-1 and L-3 form dinuclear M2L2 Complexes where the ligands are arranged in a 'side-by-side' fashion. In contrast the m-phenylene spaced ligand L-2 forms a one-dimensional coordination polymer where the ligands adopt a highly folded conformation. The 1,8-naphthalene spaced ligand L-4 adopts a tetradendate chelating mode and affords a simple mononuclear complex. (C) 2007 Elsevier Ltd. All rights reserved.