Conformationally locked mixed aza–thioether macrocycles: synthesis and structures of complexes of PdII, PtII and RhIII of 2,5,8-trithia[9](2,9)-1,10-phenanthrolinophane

Abstract

The complexation of the mixed aza–thioether crown 2,5,8-trithia[9](2,9)-1,10-phenanthrolinophane (L) with Pd^II, Pt^II and Rh^III has been investigated. The single-crystal structures of [PdL][PF₆]₂ and [PtL][PF₆]₂ confirm [N₂S₂ + S] co-ordination in both complexes with the ligand adopting a folded conformation. Carbon-13 NMR spectroscopic studies, carried out in the solid state as well as in solution, indicated that only one form of each complex is present in solution, having [N₂S₂ + S] co-ordination at Pd^II and Pt^II and octahedral co-ordination [N₂S₃ + Cl^–] at Rh^III in [RhL(Cl)]²⁺. The redox properties of [ML][PF₆]₂ (M = Pd or Pt) in MeCN are reported.