Fluorescent ionophoric compounds with a cryptand/crown-ether portion and a coumarin portion, their preparation and their use for measuring metal cation concentrations

摘要

A fluorescent ionophoric compound, comprising: a complexing moiety for selective binding of an ion; and a fluorescing moiety that contains close-lying nπ*and ππ* excited states, wherein the compound has a wavelength of maximum absorbance of at least about 350 nm and a wavelength of maximum emission of no more than about 500 nm, wherein the compound is capable of ion dependent out-of-plane puckering and wherein the ππ* state of the fluorescing moiety is sufficiently high in energy that ion dependent mixing dominates non-radiative coupling to the ground state.;Especially a fluorescent ionophoric compound having the general formula: wherein:T is O or N, with the proviso that when T is O, q is 0 and n is 0 to 2, and when T is N, q is 1 and m and n are independently 0 or 1;each R² independently is a sterically non-interferring group;R³ is selected from suitable electron withdrawing and non-electron withdrawing groups;R¹ is selected from suitable electron withdrawing and polarizable groups; andZ is O or NR⁵, where R⁵ is hydrogen or a hydrocarbyl-containing group. The compound, which exhibits good photostability, can be incorporated into cation-sensing composite structures by means of convenient points of covalent attachment.