DETERMINATION OF THE BINDING ENERGY AND STRUCTURE OF VAN DER WAALS COMPLEXES OF OXYGEN WITH XENON Xe_n – O₂(n = 1,2)

Interest in van der Waals complexes of oxygen with xenon is due to the alleged participation of such

complexes in providing anesthetic action of xenon in medicine The work is devoted to the measurement of the

intermolecular binding energy in van der Waals complexes of oxygen with xenon in Xen-O₂. Van der Waals complexes

of oxygen with xenon were generated in a pulsed molecular beam. The velocity map imaging technique

was used to measure the energy distribution and the angular distribution anisotropy over the recoil directions of

oxygen atoms arising in the photodissociation of these complexes in the Xe_n-O₂+hν→ Xen+O+O process. The angular

distribution over the recoil directions of oxygen atoms with respect to the direction of the polarization of the

exciting radiation indicates the dominant contribution of T-shaped complexes, in which xenon atoms are oriented

perpendicular to the axis of the O₂ molecule. At a low xenon content in the expanding gas mixture, the dominant

contribution is provided by T-shaped Xe-O₂ complexes with van der Waals binding energy of 156 ± 11 cm‑1.

With an increase in the xenon concentration, the T-shaped complexes with higher binding energy appear. It is concluded

that these complexes have structure Xe₂-O₂. This assignment is confirmed by the measured velocity map

of Xe+ ions which indicates the presence of dimers Xe₂ in molecular beam at these conditions. The energy of the

van der Waals binding of O2 with Xe₂ in Xe₂-O₂ complex was determined to be 314 ± 30 cm‑1, and the structure

of these complexes was also proposed.