A new blue light-emitting oligofluorene glass: synthesis, characterization and photophysical properties

The synthesis, electrochemical, thermal and spectroscopic properties of the oligoaminofluorene derivative 9,9-didecyl-N,N-bis(9,9-didecyl-7-N,N-diphenylaminofluoren-2-yl)-N,N-diphenylfluorene-2,7-diamine (4), an organic glass, were investigated in solvents of differing polarity at room and 77 K temperature, including quantum yield and lifetime. The oligomer exhibited a glass transition near room temperature and was thermally stable to ca 400degreesC. Intramolecular interactions between the fluorenyl chromophores were investigated. The relatively complex nature of the emission band of 4 was characterized by reduced anisotropy and two components in its fluorescence decay at room temperature. Emission spectra of 4 at 77 K exhibited a single component in its fluorescence decay and a dependence on the excitation wavelength at the red edge of the absorption band. A spectroscopic model of 4 is proposed to explain the observed spectral behavior of this potentially important electroluminescent material. Copyright (C) 2003 John Wiley Sons, Ltd.