Orientation of benzene in supersonic expansions, probed by IR-laser absorption and by molecular beam scattering.
This work represents the first experimental demonstration that planar molecules tend to travel as a "frisbee" when a gaseous mixture with lighter carriers expands into a vacuum, the orientation being due to collisions. The molecule is benzene, the prototype of aromatic chemistry. The demonstration is via two complementary experiments: interrogating benzene by IR-laser light and controlling its orientation by selective scattering on rare gas targets. The results cast new light on the microscopic mechanisms of collisional alignment and suggest a useful way to produce intense beams of aligned molecules, permitting studies of steric effects in gas-phase processes and in surface catalysis.
Pirani
F
F
Dipartimento di Chimica and Dipartimento di Ingegneria Civile ed Ambientale, Università di Perugia, 060123-Perugia, Italy.
Cappelletti
D
D
Bartolomei
M
M
Aquilanti
V
V
Scotoni
M
M
Vescovi
M
M
Ascenzi
D
D
Bassi
D
D