Cryogenic Photochemical Synthesis and Electronic Spectroscopy of Cyanotetracetylene

Urszula Szczepaniak (1, 2) , Robert Kołos (2) , Marcin Gronowski (2) , Michèle Chevalier (1) , Jean-Claude Guillemin (3) , Michał Turowski (2) , Thomas Custer (2) , Claudine Crépin (1)

1 ISMO - Institut des Sciences Moléculaires d'Orsay
2 Institute of Physical Chemistry
3 ISCR - Institut des Sciences Chimiques de Rennes

HC9N is a molecule of astrochemical interest. In this study, it was produced in cryogenic Ar and Kr matrices from UV-photolyzed diacetylene/cyanodiacetylene mixtures. Its strong phosphorescence was discovered and served for the identification of the compound. Vibrationally resolved phosphorescence excitation spectra gave insight into excited singlet electronic states. Two electronic systems were observed around 26 000-34 000 cm(-1) and 35 000-50 000 cm(-1). Energies of the second excited singlet and the lowest triplet state were derived from analysis of these systems. Vibrational and electronic spectroscopic features were assigned with the assistance of density functional theory calculations. Some trends concerning the electronic spectroscopy of HC2n+1N family molecules are presented.

Domaines: Autre

Urszula Szczepaniak, Robert Kołos, Marcin Gronowski, Michèle Chevalier, Jean-Claude Guillemin, et al.. Cryogenic Photochemical Synthesis and Electronic Spectroscopy of Cyanotetracetylene. Journal of Physical Chemistry A, 2017, 121 (39), pp.7374-7384. ⟨10.1021/acs.jpca.7b07849⟩. ⟨hal-01617947⟩