Tailoring the properties of boron-dipyrromethene dyes with acetylenic functions at the 2,6,8 and 4-B substitution positions

Substitution of F-Bodipy with alkynylaryl residues at boron, at the pyrrolic core or at the meso position, provides unique tri-, tetra-, and pentasubstituted dyes. Substitution at the (pyrrolic) 2,6-positions provides substantial red shifts with quantum yields in the 40-90% range and excited-state lifetimes of 3-7 ns. ON/OFF fluorescence switching can be produced by protonation of dibutylamino subunits.