Electronic spectrum of the protonated diacetylene cation (H2C4H+)

Katherine J Catani; Giel Muller; Pavol Jusko; Patrice Theulé; Evan J Bieske; Christophe Jouvet

doi:10.1063/1.4990572

Electronic spectrum of the protonated diacetylene cation (H₂C₄H⁺)

J Chem Phys. 2017 Aug 28;147(8):084302. doi: 10.1063/1.4990572.

Authors

Katherine J Catani¹, Giel Muller¹, Pavol Jusko², Patrice Theulé³, Evan J Bieske¹, Christophe Jouvet³

Affiliations

¹ School of Chemistry, The University of Melbourne, Victoria 3010, Australia.
² Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
³ CNRS, Aix Marseille Université, Physique des Interactions Ioniques et Moléculaires (PIIM) UMR 7345, 13397 Marseille Cedex, France.

PMID: 28863531
DOI: 10.1063/1.4990572

Abstract

The B̃¹A₁←X̃¹A₁ electronic band system of the protonated diacetylene cation (H₂C₄H⁺) is measured over the 230-295 nm range by photodissociating H₂C₄H⁺ ions stored in a cryogenic ion trap and by photodissociating H₂C₄H⁺ tagged with Ar and N₂ in a tandem mass spectrometer. The B̃¹A₁←X̃¹A₁ band system has an origin at 34 941 cm^-1 for H₂C₄H⁺, 34 934 cm^-1 for H₂C₄H⁺-Ar, and 34 920 cm^-1 for H₂C₄H⁺-N₂. The spectra of H₂C₄H⁺, H₂C₄H⁺-Ar, and H₂C₄H⁺-N₂ display similar vibronic structure, which is assigned using ab initio calculations to progressions in two symmetric a₁ C-C stretch vibrational modes (ν₆ and ν₄), with band spacings of 860 and 1481 cm^-1, respectively.