Photophysical properties of an asymmetrical 2,5-diarylidene-cyclopentanone dye possessing electron donor and acceptor substituents
2010; Elsevier BV; Volume: 982; Issue: 1-3 Linguagem: Inglês
10.1016/j.molstruc.2010.08.016
ISSN1872-8014
AutoresChristopher A. Zoto, Robert E. Connors,
Tópico(s)Nonlinear Optical Materials Studies
ResumoSpectroscopic and photophysical properties have been measured in a variety of solvents for (2E,5E)-2-(p-cyanobenzylidene)-5-(p-dimethylaminobenzylidene)-cyclopentanone (I), an asymmetrically substituted 2,5-diarylidene-cyclopentanone known to have potential for applications utilizing two-photon absorption (TPA). Compound I was synthesized by a simple procedure utilizing DIMCARB catalyst. Absorption and fluorescence maxima have been correlated with the ET(30) solvent polarity scale. Theoretical TD-DFT calculations and Lippert–Mataga analysis demonstrate the internal charge transfer (ICT) nature of the S0 → S1 excitation. Radiative and nonradiative decay constants have been determined from fluorescence quantum yields and lifetimes. Substantial variation with solvent in the rate of nonradiative decay is interpreted in terms of a competition between internal conversion and intersystem crossing.
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