Synthesis and cryptate complexes of azathia macropolycyclic ligands based on 12-membered N₂S₂ and 15-membered N₂S₃ macrocyclic subunits

The cyclindrical macrotricyclic ligands 4,16-dioxa-10,22,27,32-tetrathia-1,7,13,19-tetra-aza-tricyclo[17.5.5.5 ^7,13]tetratriacontane (L²) and 4,19-dioxa-10,13,25,28,33,38-hexathia 1,7,16,22-tetra-aza-tricyclo[20.8.5.5^7,16]tetracontane (L⁷) have been synthesised by high-dilution condensation of macrocyclic ligands containing 12-membered N₂S₂ and 15-membered N₂S₃ subunits, following different reaction sequences. The macrocycles 4,10-dimethyl-1,7-dithia-4,10-diazacyclododecane and 7,13-dimethyl-1,4,10-trithia-7,13-diazacyclopentadecane and the macrotricycles L² and L⁷ form respectively mono- and di-nuclear complexes with Cu^II, Ni^II, and Ag^I. The reduced Cu^I and Ni^I complexes are strongly stabilized whilst the dinuclear complexes function as dielectronic receptors, exchanging two electrons in a single wave.