Theoretical and infrared spectroscopic investigation of the O(2) (-).benzene and O(4) (-).benzene complexes.
The infrared spectra of the O(2) (-).benzene and O(4) (-).benzene complexes are determined by means of Ar predissociation spectroscopy. Several transitions due to CH stretch fundamentals and various combination bands are observed in the 2700-3100 cm(-1) region. The experimental results are interpreted with the aid of electronic structure calculations. A comparison of the calculated and experimental spectra reveals that the spectrum of O(2) (-).benzene most likely arises from an isomer where the superoxide molecule binds preferentially to one CH group of benzene. In contrast, the spectrum of O(4) (-).benzene yields a CH pattern remarkably similar to that displayed by the C(2nu) X(-).benzene (X=halogen) complexes, consistent with a structure with two CH groups equally involved in the bonding. The lower energy vibrational fundamental transitions of the O(4) (-) anion are recovered with a slight redshift in the O(4) (-).benzene spectrum, establishing that this charge-delocalized dimer ion retains its identity upon complexation.
Schneider
Holger
H
JILA, NIST, and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA.
Weber
J Mathias
JM
Myshakin
Evgeniy M
EM
Jordan
Kenneth D
KD
Bopp
Joseph
J
Herden
Tobias
T
Johnson
Mark A
MA