Excited State of Lanthanum Dioxide Dong-Sheng Yang, Department of Chemistry, University of Kentucky 40134
A MO2 molecule may be in a linear or bent structure. A linear structure could have a D∞h symmetry (OMO, dioxide) or C∞v (MOO, superoxide), whereas a bent structure could have a C2v symmetry (OMO, dioxide; M(O2), peroxide) or C s (MOO, superoxide). Our spectral and computational analysis shows that MO 2 (M = La) produced in a laservaporization cluster beam source has a bent C 2v structure in an excited state at the energy of 3.40 eV. The excited state of LaO2 is 4 B 2 formed by transferring tw o La electrons to O atoms and has a valence electron configuration consisting of O 2pand La 6s-based orbitals.
656 92
122 0-0
(a) Experiment (b) OLaO(3B2 ← 4B2)
(c) La(O2) (3A2 ← 4A2)
(d) La(O2) (1A1 ← 2A1) (e) LaOO (1Σ+ ← 2Σ+)
40000
40500
41000
Wavenumber (cm-1)
41500
