Multiphoton ionisation spectroscopy of ethyl iodide and deuteriated ethyl iodide in the region of the 6s Rydberg transitions. Evidence of molecular field splitting of spin–orbit degenerate states

Electronic excitation and oscillator strength of ethyl iodide by VUV photoabsorption and electron energy loss spectroscopy

“…Tentative assignments in the spectral region corresponding to electronically excited states involving electron transitions from the highest occupied molecular orbital into the 6s Rydberg orbital have been made by comparison with the high resolution photoelectron spectrum related to the HOMO. The suggested splitting of the E level into AЈ and AЉ components 12 is not observed. The present analysis shows methyl iodide, and consequently the C 3v approximation, to be a good model for the interpretation of higher alkyl iodides such as ethyl iodide.…”

“…This has been previously interpreted in terms of the splitting of the E states into AЈ and AЉ. 12 However, such a doubling is not observed around peak 17, which has been assigned to the transition to E(3), nor for the 7sa 1 Rydberg state region ͓see Fig. 4͑b͔͒.…”

“…This part of the spectrum has been interpreted as arising from the transition of a lone-pair iodine electron to the Rydberg orbital 6sa 1 . [9][10][11][12]14 The 0-0 transitions to the E(1) and the E(3) states have been assigned to peaks 3 and 17, respectively, these being the most intense in this region; also, their energy separation, 0.56 eV, is close to the spin-orbit splitting of the ion. The vibrational structure built on E(1) ͑peak 3͒ is interpreted by comparison with the PES spectrum.…”

“…Spectra in the region of the first Rydberg transition have been recorded using resonant enhanced multiphoton ionization and a molecular jet. 12 They have been interpreted in terms of the E(1) and E(2) states for the lowest energy region ͑6.15-6.42 eV͒, each split into the AЈ and AЉ components in the C s point group by 0.0299 eV and 0.0233 eV, respectively. Over the 6.69 eV-6.95 eV region, these workers placed the electronic origin of the A 1 state at a higher energy than that of E(3), and reported a splitting of 0.0285 eV for the AЈ and AЉ components.…”