title: Photoionization and pyrolysis of a 1,4-azaborinine: retro-hydroboration in the cation and identification of novel organoboron ring systems.
abstract: The photoionization and dissociative photoionization of 1,4-di-tert-butyl-1,4-azaborinine by means of synchrotron radiation and threshold photoelectron photoion coincidence spectroscopy is reported. The ionization energy of the compound was determined to be 7.89 eV. Several low-lying electronically excited states in the cation were identified. The various pathways for dissociative photoionization were modeled by statistical theory, and appearance energies AE0K were obtained. The loss of isobutene in a retro-hydroboration reaction is the dominant pathway, which proceeds with a reverse barrier. Pyrolysis of the parent compound in a chemical reactor leads to the generation of several yet unobserved boron compounds. The ionization energies of the C4 H6 BN isomers 1,2- and 1,4-dihydro-1,4-azaborinine and the C3 H6 BN isomer 1,2-dihydro-1,3-azaborole were determined from threshold photoelectron spectra.
authors: Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg (Germany).
authors: Fabian
authors: F
authors: Holzmeier
authors: Melanie
authors: M
authors: Lang
authors: Patrick
authors: P
authors: Hemberger
authors: Andras
authors: A
authors: Bodi
authors: Marius
authors: M
authors: Schäfer
authors: Rian D
authors: RD
authors: Dewhurst
authors: Holger
authors: H
authors: Braunschweig
authors: Ingo
authors: I
authors: Fischer
keywords: heterocycles; high-temperature chemistry; ionization potentials; kinetics; photoelectron spectroscopy