La atom reaction with isoprene is carried out in a laser-vaporization molecular beam source. The reaction yields an adduct as the major product and C - C cleaved and dehydrogenated species as the minor ones. La(C5H8), La(C2H2), and La(C3H4) are characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectra of all three species exhibit a strong origin band and several weak vibronic bands corresponding to La-ligand stretch and ligand-based bend excitations. La(C5H8) is a five-membered metallacycle, whereas La(C2H2) and La(C3H4) are three-membered rings. All three metallacycles prefer a doublet ground state with a La 6s1-based valence electron configuration and a singlet ion. The five-membered metallacycle is formed through La addition and isoprene isomerization, whereas the two three-membered rings are produced by La addition and insertion, hydrogen migration, and carbon-carbon bond cleavage.
|Journal of Chemical Physics
|Published - May 21 2018
Bibliographical noteFunding Information:
We are grateful for the financial support from the National Science Foundation Division of Chemistry (Chemical Structure, Dynamics, and Mechanisms, Grant No. CHE-1362102). We also acknowledge additional support from the Kentucky Science and Engineering Foundation.
© 2018 Author(s).
ASJC Scopus subject areas
- Physics and Astronomy (all)
- Physical and Theoretical Chemistry