(2+1) REMPI spectra of the I2-Kr and I2-N2 van der Waals complexes and the (2+1′) ZEKE-PFI photoelectron spectrum of I2+-Kr

We present (2 + 1) mass-resolved resonance-enhanced multiphoton ionisation (REMPI) spectrum of the [(2) Pi(3/2)](c)5d; Ohm(g) (Ohm = 0,2) Rydberg states of the I-2-Kr van der Waals complex. Anharmonic progression in the I-2 ... Kr van der Waals stretching mode have been observed with <(omega)over tilde>(e) values of 49 +/- 2 and 47 +/- 2 cm(-1) for the [(2) Pi(3/2)](c)5d; Ohm = 0(g) and [(2) Pi(3/2)](c)5d; Ohm = 2(g) states, respectively. The [(2) Pi(3/2)](c)5d; Ohm = 2(g) state of I-2-Kr has been used as an intermediate in a two-colour (2 + 1') zero kinetic energy pulsed-field ionisation (ZEKE-PFI) photoelectron study of the (X) over tilde(2) Pi(3/2,g) state of the I-2(+)-Kr ionic complex. The adiabatic ionisation energy was determined to be 74248 +/- 3 cm(-1). An anharmonic vibrational progression in the I-2(+)... Kr van der Waals stretching mode was observed giving a value of <(omega)over tilde>(e) = 55 +/- 2 cm(-1) for the (X) over tilde(2) Pi(3/2,g) state of the complex. The [(2) Pi(1/2)](c)6s; Ohm = 1(g) Rydberg state of the I-2-N-2 van der Waals complex has also been observed using REMPI spectroscopy. Anharmonic progressions in the I-2 ... N-2 van der Waals stretching mode have been observed with <(omega)over tilde>(e) = 71 +/- 2 cm(-1). Comparisons are made between the spectroscopic data obtained for the Rydberg states of I-2-Kr and I-2-N-2 with the analogous Rydberg states in I-2-Ar.