ZB 08 -Dynamics of photoinduced bimolecular reactions (G.Angulo)


Ultrafast intermolecular energy transfer in heavy water ,

Author(s): Piatkowski, L. and Eisenthal, K. B. and Bakker, H. J. ,
Title: Ultrafast intermolecular energy transfer in heavy water ,
Abstract: We report on a study of the vibrational energy relaxation and resonant vibrational (Forster) energy transfer of the OD vibrations of D2O and mixtures of D2O and H2O using femtosecond mid-infrared spectroscopy. We observe the lifetime of the OD vibrations of bulk D2O to be 400 +/- 30 fs. The rate of the Forster energy transfer is measured via the dynamics of the anisotropy of the OD vibrational excitation. For a solution of 0.5% D2O in H2O, resonant energy transfer is negligible, and the anisotropy shows a single exponential decay with a time constant of 2.6 +/- 0.1 ps, representing the time scale of the molecular reorientation. With increasing concentration, the anisotropy decay becomes faster and non-exponential, showing the increased contribution of resonant energy transfer between the OD vibrations. We determine the Forster radius of the OD vibration of HDO in H2O to be r0 2.3 +/- 0.2 A.
Pages: 9033-9038 ,
Journal: Phys. Chem. Chem. Phys. ,
Publisher: The Royal Society of Chemistry ,
Volume: 11 ,
Year: 2009
URL: http://dx.doi.org/10.1039/B908975F ,
DOI: 10.1039/B908975F ,