Photoionization of (H2)2 and the clusters of O2 molecules

Photoionizationof (H{sub 2}){sub 2} and clusters of O{sub 2} are investigated in a molecular beam experiment. No evidence was found for the existence of stable (H{sub 2}){sub 2}{sup +}. Photoionization spectra of (H{sub 2}){sub 2}+h{nu}{yields} {yields} H{sub 3}{sup +} + H + e is quite similar to that of H{sup 2} +h{nu} {yields} H{sub 2}{sup +} + e, yet the appreciable differences in some features of spectra suggests that there is a competition between the autoionization and vibrational predissociation of vibronically excited (H{sub 2}){sub 2}. From the photoionization thresholds of (O{sub 2}){sub n}, n = 1-5, it is concluded that (O{sub 2}){sub 2}{sup +} is bound by 0.26 ± 0.02 eV, but the additional binding energies for higher clusters of O{sub 2}{sup +} are much smaller; just about what one would expect from a charge induced dipole interaction