Site-selective cation-π interaction as a way of selective recognition of the caesium cation using sumanene-functionalized ferrocenes.

The first sumanene-ferrocene probes for efficient and selective caesium cation (Cs+) recognition are reported. The working mechanism of the sumanene moiety as the sensing unit was based on the site-selective cation-π interaction in its neutral state. The interactions with Cs+ were characterized by high association constant values together with low limits of detection.