The ground state and electronic spectrum of CUO: a mystery
Björn O Roos1, Per-Olof Widmark, Laura Gagliardi
1Department of Theoretical Chemistry, Chemical Center, POB 124, S-221 00 Lund, Sweden. Bjorn.Roos@teokem.lu.se
Abstract:
Results are presented from a theoretical study of the lower electronic states of the CUO molecule. Multiconfigurational wave functions have been used with dynamic correlation added using second order perturbation theory. Extended basis sets have been used, which for uranium were contracted including scalar relativistic effects. Spin orbit interaction has been included using the state-interaction approach. The results predict that the ground state of linear CUO is phi2 with the closed shell sigma(+)0 state 0.5 eV higher in energy. This is in agreement with matrix isolation spectroscopy, which predicts phi2 as the ground state when the matrix contains noble gas atoms heavier than Ne. In an Ne matrix, the experiments indicate, however, that CUO is in the sigma(+)0 state. The change of ground state due to the change of the matrix surrounding CUO cannot be explained by the results obtained in this work and remains a mystery.
Related Concept Videos
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
Electron Configurations
The relative energies of the subshells determine the order in which atomic orbitals are filled (1s, 2s, 2p, 3s, 3p, 4s,...
UV–Vis Spectroscopy: Molecular Electronic Transitions
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
The Aufbau Principle and Hund's Rule
Electron Configuration of Multielectron Atoms


