title: Far-infrared spectra of the tryptamine A conformer by IR-UV ion gain spectroscopy.
abstract: We present far infrared spectra of the conformer A of tryptamine in the 200 to 500 cm-1wavenumber range along with resonant photoionization spectra of the far-infrared excited conformer A of tryptamine. We show that single-far-infrared photon excited tryptamine has highly structured resonance enhanced multi-photon ionization spectra, revealing the mode composition of the S1-state. Upon multiple-far-infrared photon absorption, the resonance enhanced multi-photon ionization spectrum broadens allowing ion gain spectroscopy to be performed. In the ion gain spectrum we detect the fundamental far-infrared modes but also combination and overtone bands with high efficiency. The implications to dip spectroscopy using a free electron laser compared to more conventional light sources are discussed.
authors.affiliation: Heinrich-Heine-Universität Institut für Physikalische Chemie, D-40225 Düsseldorf, Germany. mschmitt@uni-duesseldorf.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Schmitt
authors.affiliation: Radboud University, Institute for Molecules and Materials, Felix Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands. a.rijs@science.ru.nl wim.van.der.zande@asml.com.
authors.forename: Frans
authors.initials: F
authors.lastname: Spiering
authors.affiliation: Radboud University, Institute for Molecules and Materials, Felix Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands. a.rijs@science.ru.nl wim.van.der.zande@asml.com.
authors.forename: Vitali
authors.initials: V
authors.lastname: Zhaunerchyk
authors.affiliation: Radboud University, Institute for Molecules and Materials, Felix Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands. a.rijs@science.ru.nl wim.van.der.zande@asml.com.
authors.forename: Rienk T
authors.initials: RT
authors.lastname: Jongma
authors.affiliation: Radboud University, Institute for Molecules and Materials, Felix Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands. a.rijs@science.ru.nl wim.van.der.zande@asml.com.
authors.forename: Sander
authors.initials: S
authors.lastname: Jaeqx
authors.affiliation: Radboud University, Institute for Molecules and Materials, Felix Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands. a.rijs@science.ru.nl wim.van.der.zande@asml.com.
authors.forename: Anouk M
authors.initials: AM
authors.lastname: Rijs
authors.affiliation: Radboud University, Institute for Molecules and Materials, Felix Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands. a.rijs@science.ru.nl wim.van.der.zande@asml.com.
authors.forename: Wim J
authors.initials: WJ
authors.lastname: van der Zande