A small molecule multi-FRET platform from benzotrifuranone

Reported is the preparation and photophysical investigation of the first molecular multi-FRET system from the benzotrifuranone (BTF) scaffold. The step-conservative synthetic approach to the representative target exploits the sequential aminolysis reactivity of BTF, together with CuAAC, for installation of three optically complementary chromophores, naphthalene, pyrene, and coumarin (1). Studied in parallel are two sets of three single- and double-dye comparator molecules. The fluorescence emission of the target is characterized by ∼80% energy transfer efficiency and ∼170 nm pseudo-Stokes shift. The design should accommodate other chromophore sets and covalent attachment of the dye triad to surfaces and/or substrates for applications in the materials or life sciences. •Benzotrifuranone scaffold efficiently functionalized with three unique chromophores.•Few other molecular reagents known that allow sequential chromophore introduction.•Multi-dye molecule shows high FRET efficiency and large pseudo-Stokes shift.