Polydiphenylenephthalide: Optical Spectroscopy and DFT Calculations

  • Alexander KUKHTA B. I. Stepanov Institute of Physics
  • Iryna KUKHTA Institute of Chemistry of New Materials
  • Sergey SALAZKIN Institute of Element Organic Compounds RAS
Keywords: polydiphenylenphthalide, fluorescence, spectroscopy, DFT calculations, helical structure


The results of spectral and luminescent studies of polydiphenylenphthalide (PDF) solutions and thin films as well as molecule structure and its energy levels DFT modelling within the Gaussian-03 software package are presented. It is shown that structural unit (diphenylenephthalide) can form four polymer conformations with a similar energy gap. The most probable polymer conformation is the spiral cis-form with phthalide groups turned in opposite directions. At long-wave optical transition the electronic density moves on a chain of a molecule from diphenyl part to somehow distant phthalide one. Fluorescence excitation spectra reveal a transition band on a long-wave tail of the absorption spectrum. Spectral and time measurements of the luminescence allow to assume the presence of conformation transformations of PDF molecule under its optical excitation.