title: Laser-induced fluorescence of free diamondoid molecules.
abstract: We observe the fluorescence of pristine diamondoids in the gas phase, excited using narrow band ultraviolet laser light. The emission spectra show well-defined features, which can be attributed to transitions from the excited electronic state into different vibrational modes of the electronic ground state. We assign the normal modes responsible for the vibrational bands, and determine the geometry of the excited states. Calculations indicate that for large diamondoids, the spectral bands do not result from progressions of single modes, but rather from combination bands composed of a large number of Δv = 1 transitions. The vibrational modes determining the spectral envelope can mainly be assigned to wagging and twisting modes of the surface atoms. We conclude that our theoretical approach accurately describes the photophysics in diamondoids and possibly other hydrocarbons in general.
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany. robert.richter@tu-berlin.de.
authors.forename: Robert
authors.initials: R
authors.lastname: Richter
authors.forename: Merle I S
authors.initials: MI
authors.lastname: Röhr
authors.forename: Tobias
authors.initials: T
authors.lastname: Zimmermann
authors.forename: Jens
authors.initials: J
authors.lastname: Petersen
authors.forename: Christoph
authors.initials: C
authors.lastname: Heidrich
authors.forename: Ramon
authors.initials: R
authors.lastname: Rahner
authors.forename: Thomas
authors.initials: T
authors.lastname: Möller
authors.forename: Jeremy E
authors.initials: JE
authors.lastname: Dahl
authors.forename: Robert M K
authors.initials: RM
authors.lastname: Carlson
authors.forename: Roland
authors.initials: R
authors.lastname: Mitric
authors.forename: Torbjörn
authors.initials: T
authors.lastname: Rander
authors.forename: Andrea
authors.initials: A
authors.lastname: Merli