Is the FeO2(-) anion bent or linear?
FeO(2)(-) anions were produced by co-condensation of laser-ablated iron atoms and electrons with dioxygen in excess argon at 6 K. A photosensitive absorption at 870.6 cm(-1) is assigned to the antisymmetric OFeO stretching vibration (nu(3)) of the inserted FeO(2)(-) anion trapped in solid argon. On the basis of the observed nu(3) vibrational frequencies for Fe(16)O(2) and Fe(18)O(2), the anion is estimated to be linear. Due to the severe symmetry-breaking problems of the reference wave function, calculations with single-reference methods, including various DFT and post-HF methods, are unreliable for this molecule. However, the state-averaged multireference MRCI method, which incorporates both dynamical and nondynamical correlations, predicted that the anion has a linear doublet ground state, consistent with the experimental observations.
Li
Zhen Hua
ZH
Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, People's Republic of China. lizhenhua@fudan.edu.cn
Gong
Yu
Y
Fan
Kangnian
K
Zhou
Mingfei
M