New crown spirobenzopyrans as light- and ion-responsive dual-mode signal transducers

A new class of crown spirobenzopyrans were designed and synthesized. The crown spirobenzopyrans showed thermally irreversible photochromism only in the presence of alkali-metal cations accompanying cation-selective coloring efficiency. Thus, the new crown spirobenzopyrans could transmit information of two different simultaneous stimuli (ion and photon) to changes in their optical properties. The dual-mode signal transducer molecules developed here can be considered to perform ''AND'' gate type signal transduction based on photochromism of artificial receptors. Molecular recognition abilities and photochromic properties of the new crown spirobenzopyrans were characterized by use of NMR and FAB mass spectroscopies.