Theoretical studies on ClOO — electronic spectra, ionization potential, and electron affinity

摘要

Vertical excitation energies and oscillator strengths of doublet and quartet states of ClOO, covering doublet statesnup to 7.5 eV and quartet states up to 9 eV, were obtained by multireference configuration interaction calculations. Strong absorptionsnfrom the X2A″ ground state are predicted at 186 and 235 nm. Experimentally, a maximum has been found nearn248 nm. The grouping of excited states, with twelve low-lying doublet states and three low-lying quartet states, is explainednby the interaction of the 2P ground state of Cl with the p*2 states 3Sg–, 1Dg, and 1Sgn+ of O2. Potential energy curves fornCl–O separation at fixed O–O distance and ClOO angle show the lower states to be repulsive (with the exception of thenground state), and higher states to have minima due to avoided crossings. The lowest Rydberg states are expected aroundn8.5 eV. Adiabatic ionization potentials (IP) and electron affinities (EA) of ClOO were obtained by density functional andncoupled cluster methods, with values of 11.60–11.79 eV for IP and 3.56–3.79 eV for EA.