We report the first example of metal-mediated acetylene bicyclopentamerization to form naphthalene in the gas phase. The bicyclic aromatic compound was observed in a complex with La. The La(naphthalene) complex was formed by the reaction of laser-ablated La atoms with acetylene molecules in a molecular beam source and was characterized by mass-analyzed threshold ionization spectroscopy. The bicyclo-oligomerization reaction occurs through sequential acetylene additions coupled with dehydrogenation. Three intermediates in the reaction have been identified: lanthanacyclopropene [La(C2H2)], La(cyclobut-1-en-3-yne) [La(C4H2)], and La(benzyne) [(La(C6H4)]. The metal-ligand bonding in the three intermediates is considerably different from that in the La(naphthalene) complex, as suggested by accurately measured adiabatic ionization energies.
|Number of pages||4|
|Journal||Journal of the American Chemical Society|
|State||Published - Mar 2 2016|
Bibliographical noteFunding Information:
We are grateful for the financial support from the National Science Foundation, Division of Chemistry (Chemical Structure, Dynamics, and Mechanisms, Grant CHE-1362102). We also acknowledge additional support from the Kentucky Science and Engineering Foundation. We thank Jack Selegue for helpful discussions about possible reaction pathways for the cyclopentamerization of acetylene.
© 2016 American Chemical Society.
ASJC Scopus subject areas
- Chemistry (all)
- Colloid and Surface Chemistry