Facile one-step synthesis of a thia-bridged bis-1,10-phenanthroline macrocycle

An efficient one-pot synthesis of a macrocyclic ligand, consisting of two 1,10-phenanthroline nuclei bridged by sulfur, is described. A spectrophotometric investigation reveals the isolated compound to be the mono-trifluoroacetate salt. Symmetrical NH- and S-bridged tetradentate ligands were also synthesized by the new method.