title: Structural dynamics in floppy systems: ultrafast conformeric motions in Rydberg-excited triethylamine.
abstract: Rotations about its three carbon-nitrogen bonds give triethylamine a complex, 3-dimensional potential energy landscape of conformeric structures. Electronic excitation to Rydberg states prepares the molecule in a high-energy, nonequilibrium distribution of such conformers, initiating ultrafast transitions between them. Time-resolved Rydberg electron binding energy spectra, observed using photoionization-photoelectron spectroscopy with ultrashort laser pulses, reveal these time-evolving structures. The time-dependent structural fingerprint spectra are assigned with the aid of a computational analysis of the potential energy landscape. Upon 209 nm electronic excitation to the 3p Rydberg state, triethylamine decays to 3s with a 200 fs time constant. The initially prepared conformer reacts to a mixture of structures with a time constant of 232 fs and settles into a final geometry distribution on a further subpicosecond time scale. The binding energy of the Rydberg electron is found to be an important determinant of the conformeric energy landscape.
authors.affiliation: Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
authors.forename: Sanghamitra
authors.initials: S
authors.lastname: Deb
authors.forename: Brian A
authors.initials: BA
authors.lastname: Bayes
authors.forename: Michael P
authors.initials: MP
authors.lastname: Minitti
authors.forename: Peter M
authors.initials: PM
authors.lastname: Weber
mesh_terms: D002082:Butylamines / Q000737:chemistry; D005021:Ethylamines / Q000737:chemistry*; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation; D009038:Motion; D013057:Spectrum Analysis; D013816:Thermodynamics
chemical_list: D002082:Butylamines; D005021:Ethylamines; C522349:N,N-dimethyl-2-butanamine; C016162:triethylamine