Observation of the three lowest Ω=1 ion-pair states of ICl using double-resonance ionisation nozzle-cooled spectroscopy

✍ Scribed by R.J. Donovan; T. Ridley; K.P. Lawley; P.J. Wilson

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 343 KB
• Volume: 205
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(93)89216-5

✦ Synopsis

The observation of a new ion-pair state of ICI, the H' 1 ( 'D2), is reported. Existing vibrational constants for the Gl (sP,) and p 1 ( 'P, ) states have been extended to cover the range u' = O-63 and v' =O-I 37 respectively.

1. Introdoction

In two recent papers [ 1,2], we have shown how double-resonance ionisation nozzle-cooled spectroscopy (DRINCS) can be used to identify new molecular states in what would otherwise be a congested spectral region. Specifically, low vibrational levels of the third cluster ion-pair state f'O,+ ( 'Dt) of I2 and f O+ ( 'Dz) of ICI were excited via the intermediate B state in both molecules. In the present Letter we shall demonstrate how three molecular states can be simply characterised in one series of experiments. For this we have chosen to populate the three lowest energy Q= 1 states of ICI via the intermediate A state. Previous room-temperature double-resonance experiments have been used to investigate the S= 1 states of the first two clusters. The pl ( 3P2) state has been characterised [ 31 up to u' = 78 and the Gl (3P, ) up to [ 41 V' = 7. We report here the first observation of the corresponding third tier state, labelled H' I( rD1), and present vibrational constants valid up to U' = 18. Additionally, vibrational data on the B and G states have been extended up to v' = 137 and V' = 63 respectively.