Jd. Howe et al., OBSERVATION OF THE SCL RADICAL BY RESONANCE-ENHANCED MULTIPHOTON IONIZATION SPECTROSCOPY, Journal of the Chemical Society. Faraday transactions, 91(5), 1995, pp. 773-780
Citations number
19
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
We report the first observation of any excited electronic state of the
SCI radical. SCI (X (II)-I-2) radicals are produced by photolysis of
SCl2 vapour at near-UV wavelengths around 343 nm, and detected by mult
iphoton ionisation spectroscopy, resonance enhanced at the two-photon
energy by a Rydberg state of (II)-I-2 electronic symmetry. We suggest
that this state derives from an electronic configuration involving a 4
p pi Rydberg electron built on the (3) Sigma-ground-state ion core. An
alysis of the (partially) rotationally resolved resonance-enhanced mul
tiphoton ionisation (REMPI) spectra seems most fully consistent with a
ll transitions originating exclusively from X (II3/2)-I-2 levels of bo
th the (SCl)-S-32-Cl-35 and (SCl)-S-32-Cl-37 isotopomers and yields th
e term value for the newly identified (II)-I-2 state (v(0) = 58 220 +/
- 20 cm(-1)) measured relative to the lower (X (II3/2)-I-2) Spin-orbit
component of the ground state. The excited state is shown to have a b
ond length ca. 13% shorter than that of the ground-state neutral. Para
llel REMPI-photoelectron spectroscopy (PES) studies yield values of 9.
57 +/- 0.01 eV for the first ionisation energy (E(i)) of SCI (measured
relative to the lower, (II3/2)-I-2, spin-orbit component of the groun
d state), and 685 +/- 30 cm(-1) for the vibrational level separation i
n the ground-state ion (ca. 19% higher than that of the corresponding
energy interval in the ground-state neutral).