title: Spectroscopic Characterization of Nonconcerted [4 + 2] Cycloaddition of 1,3-Butadiene with Lanthanacyclopropene To Form Lanthanum-Benzene in the Gas Phase.
abstract: The reaction between La atoms and 1,3-butadiene is carried out in a laser-vaporization molecular beam source. Metal-hydrocarbon species with formulas La(CnHn) (n = 2, 4, and 6) and La(CmHm+2) (m = 4 and 6) are observed with time-of-flight mass spectrometry and characterized with mass-analyzed threshold ionization spectroscopy. A lanthanum-benzene complex [La(C6H6)] is formed by 1,3-butadiene addition to lanthanacyclopropene [La(C2H2)] followed by molecular hydrogen elimination. Lanthanacyclopropene is an intermediate generated by the primary reaction between La and 1,3-butadiene. Two other intermediates produced by the La + 1,3-butadiene reaction are La[η4-(1-buten-3-yne)] [La(C4H4)] and 1-lanthanacyclopent-3-ene [La(C4H6)]. The La(benzene) complex exhibits distinctive metal-ligand bonding from that of the three intermediates as shown by the adiabatic ionization energies and ground electron configurations.
authors.affiliation: Department of Chemistry, University of Kentucky , Lexington, Kentucky 40506-0055, United States.
authors.forename: Dilrukshi
authors.initials: D
authors.lastname: Hewage
authors.affiliation: Department of Chemistry, University of Kentucky , Lexington, Kentucky 40506-0055, United States.
authors.forename: Wenjin
authors.initials: W
authors.lastname: Cao
authors.affiliation: Department of Chemistry, University of Kentucky , Lexington, Kentucky 40506-0055, United States.
authors.forename: Jong Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology , Harbin 150080, China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Wang
authors.affiliation: MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology , Harbin 150080, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Chemistry, University of Kentucky , Lexington, Kentucky 40506-0055, United States.
authors.forename: Dong-Sheng
authors.identifier: http://orcid.org/0000-0001-9842-4343
authors.initials: DS
authors.lastname: Yang