Tuning Photoinduced Intramolecular Electron Transfer by Electron Accepting and Donating Substituents in Oxazolones


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Ozturk G., Karabıyık H., Aygün M., Alp S., Ozcelik S.

JOURNAL OF FLUORESCENCE, vol.23, no.4, pp.733-744, 2013 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 23 Issue: 4
  • Publication Date: 2013
  • Doi Number: 10.1007/s10895-013-1198-6
  • Journal Name: JOURNAL OF FLUORESCENCE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.733-744
  • Keywords: Solvatochromism, Photoinduced Intramolecular Electron Transfer (PIET), Stokes shift, Hypsochromic shift, Bathochromic shift, Azlactone, STATE DIPOLE-MOMENTS, PHOTOPHYSICAL PROPERTIES, FLUORESCENCE EMISSION, DIFFERENT SOLVENTS, HARTREE-FOCK, CROWN-ETHERS, LASER-DYES, AB-INITIO, SOLVATOCHROMISM, ABSORPTION
  • Dokuz Eylül University Affiliated: Yes

Abstract

The solvatochromic and spectral properties of oxazolone derivatives in various solvents were reported. Fluorescence spectra clearly showed positive and negative solvatochromism depending on substituents. The solvatochromic plots and quantum chemical computations at DFT-B3LYP/6-31 + G(d,p) level were used to assess dipole moment changes between the ground and the first excited singlet-states. The electron accepting nitro substituent at the para-position increased the pi-electron mobility, however, the 3,5-dinitro substituent decreased the pi-electron mobility as a result of inverse accumulation of the electronic density as compared with that of its ground state. Experimental and computational studies proved that the photoinduced intramolecular electron transfer (PIET) is responsible for the observed solvatochromic effects. We demonstrate that PIET can be finely tailored by the position of the electron accepting and donating substituents in the phenyl ring of the oxazolone derivatives. We propose that the photoactive CPO derivatives are new molecular class of conjugated push-pull structures using azlactone moiety as the pi-conjugated linker and may find applications in photovoltaic cells and light emitting diodes.