Êtes-vous un étudiant de l'EPFL à la recherche d'un projet de semestre?
Travaillez avec nous sur des projets en science des données et en visualisation, et déployez votre projet sous forme d'application sur Graph Search.
Rotationally resolved spectra in the 5 nu (1) region of (CH3OH)-C-13 reveal strong vibrational splittings, which by analogy to (CH3OH)-C-12, we assign to a resonance between 5 nu (1) and 4 nu (1)+nu (2). Accordingly, the vibrational dynamics on a subpicosecond time scale are similar for the two isotopomers. Comparison of the secondary structure of the first-order states resulting from this strong resonance shows a distinct difference in the two isotopomers. While the C-12 species exhibits sharp secondary structure for the lower energy band resulting from weak coupling to the remaining bath of dark states, the C-13 species shows an equally complex pattern of couplings for both first-order states. The difference between the two isotopic species arises from the relative position of key dark background states. Despite a vibrational density of states of 100 per cm(-1), only a small number of states seem to determine the secondary structure, and the difference in the positions of these states relative to the first-order states results in a difference in the vibrational dynamics on a picosecond time scale. What one might consider as statistical intramolecular energy transfer appears to occur on significantly longer time scales. (C) 2000 American Institute of Physics. [S0021-9606(00)02046-8].
Pierre Vandergheynst, Felix Naef, Cédric Gobet, Francesco Craighero, Mohan Vamsi Nallapareddy
Jacques Fellay, Konstantin Popadin, Dmitry Knorre