Dalton Transactions

PAPER Michael Schmittel et al. Reversible cargo shipping between orthogonal stations of a nanoscaff old upon redox input The sterically shielded terpyridine 5 was prepared, both as a new ligand and as part of the four-station nanoscaffold 2. Mixing of terpyridine 5, the parent phenanthroline 4 and the shielded phenanthroline 3 in the presence of Zn 2+ (1 : 1 : 1 : 1) furnished quantitatively the inverse HETTAP complex [Zn(4)(5)] 2+ by self-sorting, while in the presence of Cu + the HETPHEN complex [Cu(3)(4)] + was preferred (89%). Due to the akin coordination preferences of Cu 2+ and Zn 2+ , the above self-sorting was implemented for Cu + /Cu 2+ on nanoscaffold 2, the latter equipped with the binding motifs of 3 (PhenAr 2) and 5 (TerpyAr 2). When 2 was reacted with Cu + and phenanthroline (4) in a 1 : 2 : 2 ratio, only the PhenAr 2 stations became involved in complex formation (= Cu 1 phen). In contrast, upon oxidative formation of Cu 2+ , ligand 4 was exclusively moved to the TerpyAr 2 stations (Cu 1 terpy). Electrochemical oxidation–reduction prompted the cargo to be shipped reversibly on a subsecond time scale between the two different stations of 2.