title: Electronic Spectra of Protonated Fluoranthene in a Neon Matrix and Gas Phase at 10 K.
abstract: Four electronic systems with origin bands at 759.5, 559.3, 476.3, and 385.5 nm are detected in a 6 K neon matrix following deposition of mass-selected protonated fluoranthene C16H11(+) produced from a reaction of neutral vapor and ethanol in a hot-cathode ion source. Two cationic isomers are identified as the carriers of these band systems. The 559.3, 476.3, and 385.5 nm absorptions are assigned to 4,3,2 (1)A' ← X (1)A' transitions of isomer E(+) (γ-) and the 2 (1)A' ← X (1)A' system at 759.5 nm is of isomer C(+) (α-) of protonated fluoranthene on the basis of theoretical predictions. The electronic spectrum of E(+) was also recorded in the gas phase using a resonant 1 + 1 two-photon excitation-dissociation technique in an ion trap at vibrational and rotational temperatures of 10 K. The 3,2 (1)A' ← X (1)A' transitions have origin band maxima at 558.28 ± 0.01 and 474.92 ± 0.01 nm. Both the 2 (1)A' and 3 (1)A' excited states have a distinct vibrational pattern with lifetimes on the order of 1 ps.
authors.affiliation: Department of Chemistry, University of Basel , Klingelbergstr. 80, CH-4056 Basel, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Chakraborty
authors.affiliation: Department of Chemistry, University of Basel , Klingelbergstr. 80, CH-4056 Basel, Switzerland.
authors.forename: C A
authors.initials: CA
authors.lastname: Rice
authors.affiliation: Department of Chemistry, University of Basel , Klingelbergstr. 80, CH-4056 Basel, Switzerland.
authors.forename: F-X
authors.initials: FX
authors.lastname: Hardy
authors.affiliation: Department of Chemistry, University of Basel , Klingelbergstr. 80, CH-4056 Basel, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Fulara
authors.affiliation: Department of Chemistry, University of Basel , Klingelbergstr. 80, CH-4056 Basel, Switzerland.
authors.forename: J P
authors.initials: JP
authors.lastname: Maier