Alkaline earth metal-sensing anthracene fluorophore-hosts

Abstract

Novel anthracene fluorophore-hosts 1–4, bonding through an ester or ether linkage to a crown ether or polyether side-arm, have been synthesized. Addition of an alkaline earth metal cation to a host solution causes a unique fluorescence intensity change. That is, the hosts bonding through an ester linkage, compounds 1 and 3, give fluorescence quenching, whereas the hosts bonding through an ether linkage, compounds 2 and 4, give fluorescence enhancement. The host having a crown ether side-arm, compound 2, recognises calcium cations more strongly than barium cations, in contrast to the host having a polyether side-arm, compound 4, which prefers barium cations to calcium cations.