Synthesis and Properties of Symmetrical Donor or Acceptor Unit Conjugate Linked BODIPY Derivatives

Four novel symmetrical 4,4'-difluoro-4-bora-3a,4a-diaza-sindacene(BODIPY) derivatives were synthesized.These BODIPY derivatives bear different donor or acceptor units as conjugate bridge,and the BODIPYs meso-position substituted by thiophene or benzene as the termini groups.The structures of all the compounds were identified by 1H NMR,13C NMR and MS techniques.The photophysical properties of these compounds were measured by the UV-Vis absorption and the fluorescence emission spectrophotometer.And the electrochemical properties were investigated by the cyclic voltammetry.The results of absorption spectra confirmed that these BODIPYs had a characteristic absorption peak,and the conjugate bridges had little influence on the intramolecular charge-transfer(ICT) interaction neither used as donor nor acceptor.On the other hand,meso-position substituentes have a weak influence on the ICT interaction in the BODIPYs,and meso-position thiophene substituted ones have raised more intensive ICT than the meso-position benzene substituted ones.Both the absorption spectra and cyclic voltammetry data indicate that BODIPYs with mesothiophene substitutuents possess a lower oxidation potential and a narrower band gap than those meso-position benzene ones.