Functional dyes: bipyridines and bipyrimidine based boradiazaindacene

The synthesis of molecules bearing pyridine, 2,2′-bipyridine or 2,2′-bipyrimidine donor units appended with one or two highly luminescent indacene fragments was undertaken by using two distinct pathways. The first used direct condensation of krytopyrrole with the corresponding aldehydes. The second, and more universal is based on a Pd cross-coupling reaction between an iodo functionalized BODIPY and the corresponding stable ethynyl derivatives. All compounds are strongly luminescent in solution with quantum yields as high as 70%. Interlocking of two 6,6′-BODIPY substituted bipyridines around a single copper(I) center is observed by proton NMR and cyclic voltammetry. These synthetic routes have made a variety of functionalized dyes available for studies of their optical properties in the presence of incoming cations, of their coordination chemistry and as light emitting solid state materials.