US 2 and SUO molecules have been prepared by laser ablation of the solid materials and reaction of the elements during condensation in solid argon, which give the same absorptions as earlier U atom reactions with sulfur vapor and sulfur dioxide. The antisymmetric stretching mode of US 2 shifts from 438.7 cm -1 in solid argon to 442.3 cm -1 in solid neon, which shows that the same electronic state is trapped in both matrix environments. Density functional calculations find a bent ( 3 B 2 ) ground state for the US 2 molecule, and CASSCF/CASPT2 calculations reveal a multiconfigurational mixture of (5fI) 1 (5fδ) 1 -type states, whereas the most stable state for UO 2 is a linear structure of the (5fI)(7s) type. The bent triplet ground state SUO molecule exhibits similar multireference character with the U-O stretching mode at 857.1 cm -1 in solid argon. The linear SUO molecule computed at the CASPT2 level is only 2 kcal/mol above the bent structure. A detailed analysis of the bonding in US 2 and SUO is provided and compared to the better known UO 2 molecule.
- Density functional calculations
- Energy decomposition
- Matrix isolation
ASJC Scopus subject areas
- Inorganic Chemistry