Cobalt(III) Metallacryptates and Their Guest Cation-Exchange in Solution Monitored by Co NMR.

One-pot reactions of the catechol-scaffolding aroylbis(,-diethylthiourea) HL with mixtures of CoCl and MCl (M = Cs, Rb, K, Tl, or NH) or with a Co(NO)/TlNO mixture lead to the self-assembly of a series of cationic Co(III) metallacryptates of the general formula [M ⊂ {Co(L)}] (M = Cs, Rb, K, Tl, or NH). Crystalline PF salts were obtained after workup with (-BuN)(PF), and the single-crystal structures of all five metallacryptates have been determined. Depending on the nature of the guest cations, the directional interactions between guest cations and the metallacryptand {Co(L)} are either weak coordination contacts or hydrogen bonds.