Abstract
The Ã2A1-X̃2B1 electronic transition of the jet-cooled stibino (SbH2 and SbD2) free radical has been observed for the first time using laser induced fluorescence (LIF) detection. The radicals were produced by a pulsed electric discharge through a mixture of stibine (SbH3 or SbD3) in high pressure argon at the exit of a pulsed molecular beam valve. SbH2 exhibits only three LIF bands, assigned as 21 0, 00 0, and 20 1, with a fluorescence lifetime (τ), which decreases from ∼50 ns for 00 to <10 ns for 21. LIF transitions to the 00 (τ ∼ 2 µs), 21 (τ ∼ 400 ns), and 22 (τ ∼ 75 ns) upper vibronic states of SbD2 were also observed. High-resolution spectra exhibited large spin-rotation splittings and small resolved antimony hyperfine splittings due to a substantial Fermi contact interaction in the excited state. The experimentally determined rotational constants gave effective molecular structures of r0 ″ = 1.724(2) Å, θ0 ″ = 90.38(7)° and r0 ' = 1.693(6) Å, θ0 ' = 120.6(3)°. The ground state bending vibrational levels up to eight quanta (6404 cm-1) in SbH2 and 12 quanta (6853 cm-1) in SbD2 were measured from dispersed fluorescence spectra. All indications are that SbH2 undergoes a dissociative process at low vibrational energies in the excited electronic state.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
