Fluorescence emission studies of 4-(2-furylmethylene)-2-phenyl-5-oxazolone embedded in polymer thin film and detection of Fe3+ ion
ABSTRACT The photophysical and photochemical properties of azlactone derivative 4-(2-furylmethylene)-2-phenyl-5-oxazolone (PFO) were examined in solvents of tetrahydrofuran (THF), acetonitrile (ACN) and dichloromethane (DCM) and in solid matrix of polyvinyl chloride (PVC).The PFO dye embedded in plasticized PVC matrix has been used in monitoring Fe3+. The PFO dye exhibited satisfactory fluorescence emission based optical response to Fe3+ with a detection limit of 3.8 × 10−6 M. The sensor composition exhibited a dynamic response to Fe3+ in the concentration range of 6 × 10−6–6 × 10−4 M. The sensor is fully reversible within the dynamic range and the response time (τ90) is approximately 2 min under batch conditions. The reproducibility of the sensor membrane was investigated by alternately changing the solution of 2 × 10−5 M Fe3+ and BES buffer (10−3 M, pH = 7.0), and relative standard deviation was calculated as 0.4% (n = 7). pH dependence is negligible in the pH range of 4.0–11.0. The cross sensitivity of PFO to Co2+, Ni2+, Zn2+ and Cu2+ was also tested and evaluated.
Article: Tuning Photoinduced Intramolecular Electron Transfer by Electron Accepting and Donating Substituents in Oxazolones.[show abstract] [hide abstract]
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 π-electron mobility, however, the 3,5-dinitro substituent decreased the π-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 π-conjugated linker and may find applications in photovoltaic cells and light emitting diodes.Journal of Fluorescence 03/2013; · 2.11 Impact Factor