Influence of the spacer on the photoreactivity of flurbiprofen-tyrosine dyads

I. Vayá (1) , T. Gustavsson (2, 3) , D. Markovitsi (2, 3) , M. A. Miranda (1) , M. C. Jiménez (1)

1 Instituto de Tecnologia Quimica UPV-CSIC - Universidad Politecnica de Valencia
2 LIDYL - Laboratoire Interactions, Dynamiques et Lasers (ex SPAM)
3 DICO - Dynamique et Interactions en phase Condensée

The photoreactivity of diastereomeric dyads containing (S)- or (R)-flurbiprofen (FBP) and (S)-Tyr, either directly linked (1) or separated by a cyclic spacer (3) has been investigated. The main feature is a remarkable intramolecular quenching of FBP fluorescence, especially in 1. The process is clearly configuration dependent, being more efficient for the (R,S)- diastereomer in 1 and for the (S,S)- analogue in 3. Noteworthy, exciplex emission is detected in the 380–500 nm region in the case of 3. Fluorescence decay kinetics from the femtosecond to the nanosecond time-domains provides evidence for the dynamic nature of the quenching. In agreement with the steady-state and time-resolved observations, molecular modelling points to a more favourable geometric arrangement of the two interacting chromophores in 1 than in 3.

Mots clés: Exciplex; Fluorescence quenching; Fluorescence upconversion; Laser flash photolysis; Time-correlated single photon counting

Domaines: Chimie théorique et/ou physique

I. Vayá, T. Gustavsson, D. Markovitsi, M. A. Miranda, M. C. Jiménez. Influence of the spacer on the photoreactivity of flurbiprofen-tyrosine dyads. Journal of Photochemistry and Photobiology A: Chemistry, 2016, 322–323, pp.95-101. ⟨10.1016/j.jphotochem.2016.03.006⟩. ⟨hal-01326998⟩