On the ultraviolet absorption of nitrous oxide and its van der Waals complexes

The possibility of simultaneous characterization of N2O and N2O van der Waals complexes in supersonic jet expansions is demonstrated for neat N2O samples. Room temperature and jet-cooled spectra of the Rydberg transitions 3pπ1Δ ←← X1Σ+ and 3pσ1Π ←← X1Σ+ are presented. Theoretical calculations support the assignment of the Rydberg transitions used. For stagnation pressures above 2 bar, a hitherto unreported broad spectral feature at 84 650 cm−1 is observed, where calculations predict absorption of the (N2O)2 dimer essentially due to excitation of the 4sσ and 3pπ Rydberg orbitals. Consequences for the use of N2O as a precursor for O(1D) atoms in reactive scattering experiments are discussed.