A new type of C-pivot lariat monoaza-crown ether 1b containing a 15-crown-5 ring and two pyrene moieties on the sidearms was found to be a highly sensitive and selective fluorescent chemosensor toward Ca2+ in the presence of Na+, K+, Mg2+, and Ca2+.

No abstract

Monoazacryptand [20.18.18] (1), monoaza-15-crown-5 (2a), and monoaza-18-crown-6 (2b) with a partially fl uorinated sidearm were newly prepared and their transport abilities were estimated in a supported liquid membrane containing a mixture of 2-(perfl uorohexyl) ethyl alcohol and 2-(perfl uorooctyl) ethyl alcohol. In competitive passive transport of K + , Na + , and Li + under neutral conditions, the K + selectivity increased in the order: ionophore 2a