Tuning Binding of Rubidium Ions to Planar and Curved Negatively Charged π Surfaces

摘要: Two new rubidium salts of the bowl-shaped corannulene monoanion radical C20H10•– (1•–), [Rb(15-crown-5)2+][C20H10–] (2) and [Rb(dicyclohexano-18-crown-6)+][C20H10–] (3), have been synthesized structurally characterized in this work. An excess 15-crown-5 ether provided full encapsulation ion [Rb(15-crown-5)2]+, which precluded metal-directed π interactions with anionic surface solid-state structure 2. The use more sterically demanding dicyclohexano-18-crown-6 prevented formation polymeric chains previously seen 18-crown-6 favored isolation discrete contact pair 3. Complex 3 is built on a convex η6 coordination Rb+ to C20H10•–, reaffirming exo-binding preference ions toward singly charged bowl. A salt planar coronene C24H12•– (4•–), [Rb(18-crown-6)+][C24H12–] (5), has also prepared reveal binding mo...