Luminescence spectral properties of dendritic oligothiophenesilane macromolecules

The luminescence spectral properties of oligothiophenesilane dendrite macromolecules were studied. It was found that the chromophores responsible for the formation of the absorption and luminescence spectra were dendrimer fragments separated by silicon atoms; all the chromophores are equally involved in the formation of the absorption spectra of dendritic macromolecules of the zero, first, second, and third generations. It was shown that for dendrites of the first, second, and third generations, the luminescence spectrum is mainly formed by the chromophore fragments lying in the internal layers of the dendritic macromolecule due to the induction resonance energy transfer of electronic excitation from peripheral to internal chromophore fragments. The conclusion was drawn that synthesis of dendritic macromolecules with internal chromophore fragments possessing a high quantum yield of fluorescence can give actively luminescing nanosized objects with the molar extinction coefficient proportional to the number of fragments ɛmax ≈ 106 l/(mol cm). These compounds can find wide application in transducers for converting various types of ionizing radiation into optical radiation in electroluminescent devices.