Abstract
The mechanism of deactivation of the electronic excitation energy of 2-N-piperidino-5-(2′,2′-dicyanovinyl)thiophene is studied by the methods of fluorescence and quantum chemical calculations. The increase in the fluorescence quantum yield from 0.0004 in n-hexane at room temperature to 1 in an EPA mixture at 77 K is determined by an increase in the viscosity (rigidity) of the medium hindering the rotation of molecular fragments. The efficient nonradiative process in a molecule with the probability ≤2.5×1011 s−1 results mainly from rotation about the C12–C13 bond and the transition to an intermediate state with a low-lying energy level.
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Translated from Optika i Spektroskopiya, Vol. 91, No. 1, 2001, pp. 67–73.
Original Russian Text Copyright © 2001 by Bondarev, Knyukshto, Masalov, Dzilinski.
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Bondarev, S.L., Knyukshto, V.N., Masalov, N.V. et al. Viscosity effect on the fluorescent and conformational properties of 2-N-piperidino-5-(2′,2′-dicyanovinyl)thiophene. Opt. Spectrosc. 91, 59–65 (2001). https://doi.org/10.1134/1.1388325
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DOI: https://doi.org/10.1134/1.1388325