Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.651594
Title: High resolution photoelectron spectroscopy of small molecules
Author: Goode, Jon G.
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 1995
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Abstract:
The gerade Rydberg states of jet-cooled iodine have been thoroughly investigated in the region between 53000 and 70000 cm-1 using mass resolved (2+1) resonantly enhanced multiphoton ionisation (REMPI) spectroscopy. All the nd Rydberg states were found to be heavily perturbed through vibronic coupling with ion-pair states in contrast to most of the ns Rydberg states which were found to be unperturbed. The characterisation of these Rydberg states provided the basis for a comprehensive study of the two spin-orbit components of the ground state of the cation using two colour (2+1') ZEKE-PFI photoelectron spectroscopy. The ZEKE-PFI spectrum recorded for the lower spin-orbit state exhibits non Franck-Condon behaviour in contrast to that recorded for the upper spin-orbit state. This was interpreted in terms of an autoionisation mechanism involving Rydberg states converging on the upper spin-orbit component. Several new Rydberg states of the iodine-argon van der Waals complex have been investigated using mass resolved (2+1) REMPI spectroscopy in the region between 53000 and 69000 cm-1. The complex spectra exhibit anharmonic vibrational progressions in the I2 Ar van der Waals stretching mode in combination with the I2 stretching progression. The I2 Ar stretching frequencies and binding energies were found to increase with the principal quantum number of the Rydberg state which is consistent with a progressive strengthening of the van der Waals bond. This agrees with the expected reduction in effective shielding of the ion core by the Rydberg electron as it is excited into higher principal quantum number orbits. A (2+1') ZEKE-PFI investigation of the van der Waals complex cation revealed a very small binding energy increase in the ion compared to that determined for the n=8 Rydberg state. This small increase indicates that for Rydberg orbitals with n≥8 the effective shielding of the ionic core by the Rydberg electron is minimal.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.651594  DOI: Not available
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