title: Catalytically Triggered Energy Release from Strained Organic Molecules: The Surface Chemistry of Quadricyclane and Norbornadiene on Pt(111).
abstract: We have investigated the surface chemistry of the polycyclic valence-isomer pair norbornadiene (NBD) and quadricyclane (QC) on Pt(111). The NBD/QC system is considered to be a prototype for energy storage in strained organic compounds. By using a multimethod approach, including UV photoelectron, high-resolution X-ray photoelectron, and IR reflection-absorption spectroscopic analysis and DFT calculations, we could unambiguously identify and differentiate between the two molecules in the multilayer phase, which implies that the energy-loaded QC molecule is stable in this state. Upon adsorption in the (sub)monolayer regime, the different spectroscopies yielded identical spectra for NBD and QC at 125 and 160 K, when multilayer desorption takes place. This behavior is explained by a rapid cycloreversion of QC to NBD upon contact with the Pt surface. The NBD adsorbs in a η2:η1geometry with an agostic Pt-H interaction of the bridgehead CH2subunit and the surface. Strong spectral changes are observed between 190 and 220 K because the hydrogen atom that forms the agostic bond is broke. This reaction yields a norbornadienyl intermediate species that is stable up to approximately 380 K. At higher temperatures, the molecule dehydrogenates and decomposes into smaller carbonaceous fragments.
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.
authors.forename: Udo
authors.initials: U
authors.lastname: Bauer
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Mohr
authors.affiliation: Lehrstuhl für Theoretische Chemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.
authors.forename: Tibor
authors.initials: T
authors.lastname: Döpper
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Bachmann
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Späth
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Düll
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schwarz
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.
authors.forename: Olaf
authors.initials: O
authors.lastname: Brummel
authors.affiliation: Lehrstuhl für Theoretische Chemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.
authors.forename: Lukas
authors.initials: L
authors.lastname: Fromm
authors.affiliation: Lehrstuhl für Organische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Henkestrasse 42, 91054, Erlangen, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Pinkert
authors.affiliation: Lehrstuhl für Theoretische Chemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Görling
authors.affiliation: Lehrstuhl für Organische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Henkestrasse 42, 91054, Erlangen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hirsch
authors.affiliation: Lehrstuhl für Anorganische und Allgemeine Chemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany.
authors.forename: Julien
authors.initials: J
authors.lastname: Bachmann
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.|Erlangen Catalysis Resource Center (ECRC), Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Steinrück
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.|Erlangen Catalysis Resource Center (ECRC), Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Libuda
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058, Erlangen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Papp
keywords: DFT calculations; IR spectroscopy; catalysis; photoelectron spectroscopy; surfaces and interfaces