“…Two BODIPY R -APTRA derivatives were synthesized, namely, the caesium salts of 4,4-difluoro-8-(3-hydroxy-4-aminophenyl-N,N,O-triacetate)-3,5-dimethyl-4-bora-3a,4a-diaza-s-indacene (12) and 4,4-difluoro-8-(3-hydroxy-4-aminophenyl-N,N,Otriacetate)-3,5-bis-(4-methoxyphenyl)-4-bora-3a,4a -diazas -indacene (13). Absorption, excitation and emission spectra of these indicators were measured at 20 • C in 100 mM KCl aqueous buffered solution, pH 7.20, as a function of Ca 2+ concentration.…”