FORMATION OF POTASSIUM OXIDE CLUSTERS BY SEEDED SUPERSONIC EXPANSION

Binary oxygen potassium clusters were generated by seeded supersonic e xpansion of a gaseous mixture of potassium, argon and molecular oxygen . Clusters of composition KxO (x = 5, 7, 9) and KxO2 (x = 5-7, 9) were detected for the first time. Their ionization potentials are smaller than 3.67 eV. Scattering experiments with H2O as target molecules indi cate that K3O and K-4 have much more compact ground state structures t han the planar aggregates K-3 and K-4.