Syntheses of a series of S6 thioether cages and their coordination chemistry with Ag+

Abstract

The syntheses of four S₆-cages with different cavity sizes are described. In regard of potential applications for radioimmunotherapy with ¹¹¹Ag, their coordination behaviour towards Ag(I) was evaluated by studies of their reactivity in solution and of their crystal structures. All cages reacted differently with Ag(I). Whereas S₆-cages based on 3,8,12,17,20,25-hexathiabicyclo[8.8.8]-hexacosane (14) and on 5,9,17,21,28,31-hexathiabicyclo[11.11.11]pentatriacontane (18) showed only external Ag(I) coordination, successive adaptation of the cage size, yielded ligand 24, based on 4,7,13,21,24,25-hexathiabicyclo[8.8.8]hexacosane, which gave a complex with internal-peripheral Ag(I) binding.