2,2′:6′,2″-Terpyridine-4′(1′H)-thione : a missing link in metallosupramolecular chemistry

The compound 2,2`: 6`,2 ``-terpyridine-4`(1`H)-thione 1 has been prepared and structurally characterised; in both the solid state and in solution, the thione tautomer is dominant. Compound 1 is a key entry into 4`-sulfur-functionalised tpy ligands and a representative alkylation with an electrophilic Frechet dendrimer is presented and the structural characterisation of the new ligand 4 reported. Oxidation of 1 yields bis(2,2`: 6`,2 ``-terpyridin- 4`-yl) disulfide 2 which is a novel homoditopic tpy ligand and which forms a tetranuclear [ 4 + 4] iron (II) metallomacrocycle. Structural characterisation of 2 and preliminary data for the iron complex are presented.