Ferrocene and triphenylamine appended boranils

Abstract

Boranils containing ferrocene and triphenylamine groups were synthesized and well characterized by IR, $$^{1}\hbox {H}$$ , $$^{13}\hbox {C}$$ , $$^{11}\hbox {B}$$ and $$^{19}\hbox {F}$$ NMR and ESI-MS spectrometry. UV-Vis absorption, steady-state and time-resolved fluorescence techniques were employed to study their photophysical properties. The presence of electron rich substituents caused significant alterations in their absorption and emission spectra. As compared to the parent boranil compound ( $$\lambda _{\mathrm{abs}} = 342 \hbox { nm}$$ ), boranil-triphenylamine and boranil-ferrocene conjugates exhibited red shifted absorption maxima ( $$\lambda _{\mathrm{abs}} = 384$$ , 375 nm, respectively). The boranil-triphenylamine and boranil-ferrocene conjugates displayed red shifted emission spectra ( $$\lambda _{\mathrm{em}} = 524$$ , 489 nm, respectively), as compared to the parent boranil ( $$\lambda _{\mathrm{em}} = 471 \hbox { nm}$$ ). Also, large Stokes shifts ( $$6217{-}6958 \hbox { cm}^{-1}$$ ) were observed for both the conjugates in solution phase. SYNOPSIS Synthesis and optical properties of boranils containing ferrocene and triphenylamine groups are reported. The presence of substituents caused significant bathochromic shifts in their absorption and emission spectra. As compared to the parent boranil compound, boranil-triphenylamine and boranil-ferrocene conjugates exhibited 32–41 nm red shifted absorption spectra, and 18–53 nm red shifted emission spectra in solution. Also, large Stokes shifts (6200–6900 $$\hbox { cm}^{-1}$$ ) were observed for both the conjugates in solution.