Laser-induced fluorescence experimental spectroscopy and theoretical calculations of uranium monoxide

Abstract

As a model molecule of actinide chemistry, UO molecule plays an important role in understanding the electronic structure and chemical bonding of actinide-containing species. We report a study of the laser-induced fluorescence spectra of the U16O and U18O using two-dimensional spectroscopy. Several rotationally resolved excitation spectra were investigated. Accurate molecular rotational constants and equilibrium internuclear distances were reported. Low-lying electronic states information was extracted from high resolution dispersed fluorescence spectra and analyzed by the ligand field theory model. The configuration of the ground state was determined as U2+(5f37s)O2-. The branching ratios, and the vibrational harmonic and anharmonic parameters were also obtained. Radiative lifetimes were determined by recording the time-resolved fluorescence spectroscopy. Transition dipole moments were calculated using the branching ratios and the radiative lifetimes. These findings were elucidated by using quantum-chemical calculations, and the chemical bonding was also analyzed. The findings presented in this work will enrich our understanding of actinide-containing molecules.

Low-lying electronic states of osmium monoxide OsO

“…Roos and Malmqvist [19] have shown that the scalar relativistic multi-reference perturbation theory plus SI is applicable to not only d-block elements but also actinides, and therefore may be the most feasible scheme for studying the electronic spectra of uranium monoxide. [31] Theoretical results show that the ground Λ-S and Ω states of OsO are 1 Σ + and 3 Π 2 , respectively. Based on the theoretical spectroscopic constants and transition dipole moments between Ω states, seven emission bands have been preliminarily assigned.…”

Optical spectroscopy of CrO and electronic states of the Cr group metal monoxides

“…The accurate description of the electronic states of the transition metal monoxides is of fundamental importance for optimizing the computational methods and programs in modern quantum chemistry, [1][2][3] characterizing the properties of the bonding between metal and oxide, [4][5][6][7] and probing stellar compositions and evolution. [8][9][10][11] The open atomic d-shell of the transition metal atoms would result in many molecular low-lying electronic states with high spin multiplicity.…”