Photodetachment-photoelectron spectroscopy of disulfanide: the ground and first excited electronic state of HS2 and DS2

Abstract

Photodetachment-photoelectron spectra of HS(2)(-) and DS(2)(-) are presented. The obtained electron affinities (EA (HS(2)) = 1.916 +/- 0.015 eV and EA (DS(2)) = 1.918 +/- 0.015 eV) are in good agreement with earlier results (S. Moran and G. B. Ellison, J. Phys. Chem., 1988, 92, 1794). Photodetachment into the neutral ground state of the radicals HS(2) and DS(2) leads to excitation of the S-S stretching mode, whereas photodetachment into the first excited state causes a S-S-H bending and a weak S-H stretching motion. Additionally, weak peaks of S(2) were observed in the spectra of HS(2) and DS(2), leading to the conclusion that photodetachment with 2.77 eV (448 nm) causes dissociation of HS(2)(-) and DS(2)(-) into S(2)(-) and H/D. Taking 2.77 eV as an upper limit for D(0)(S(2)(-)-H) a lower limit for Delta(f)H(0)(HS(2 (g))) of 100.8 kJ mol(-1) is obtained which is an improvement on the literature value of 107.145 +/- 10.46 kJ mol(-1).

Franck–Condon profiles in photodetachment-photoelectron spectra of and based on vibrational configuration interaction wavefunctions

“…This is in good agreement with the experimental findings of Entfellner et al. 1 Excitations of the S-S stretching mode ν 3 are strongly suppressed due to the almost equal S-S bond length in the initial and final electronic state. The FCF of the 3 1 0 transition is only about 1/60 (1/15) of the FCF of 0 0 0 in HS (DS ).…”

“…In most cases deviations with respect to the experimental values 1 are significantly larger which we attribute to the large For both species the computed main spectral feature of this transition is a pronounced progression 3 n 0 in the S-S stretching mode ν 3 that extends (visibly) up to about n ′ = 5. This progression has also been identified by Entfellner et al 1 in the experimental low resolution photodetachment-photoelectron spectrum, with the progression extending as well up to about n ′ = 5. The FCFs of the 3 1 0 and 3 2 0 transition are the largest of the spectrum, with the former being less than 5 % (less than 13%) larger than the latter in HS 2 (in DS 2 ).…”

Direct Access to the Dipole-Forbidden n π ∗ T 1 State of p-Benzoquinone by Photodetachment Photoelectron Spectroscopy

“…Already in 1976 Lineberger and co-workers investigated the T 1 state of NH by performing photodetachment photoelectron spectroscopy (PD-PES) on NH − anions [16]. Although it has been well observed for many exotic molecules [17][18][19][20][21][22] and metal clusters [23][24][25][26][27][28][29] that triplet and other excited neutral states can be reached by PD-PES, excited states of closed shell molecules were sparsely in the focus of such experiments [30][31][32][33][34][35].…”

Design Near-threshold Photoelectron Imaging Spectrometer Based on UV Laser Induced Photoelectron Emission Anion Source

“…Owing to its high brightness (laser pulse ∼10 ns and laser energy ∼1 mJ of 355 or 266 nm), high intensity (>10 10 electrons/pulse·cm 3 ) and small divergence angle of photoelectron beam (<15 • , very small area), the source is suitable to yield high stable, relatively cold and intense anion beams which are of great interest for anion photodetachment photoelectron spectroscopy researches. Boesl group combined this source with anion TOF photoelectron spectroscopy to study EAs and electronic structures for small anion molecules [13,14]. However, it is still difficult to obtain accurate electron affinities (EAs) and vibrational structures (such as CH 3 S − , S 2 − ) due to the properties of low detection efficiency of low-energy electrons and limited electron energy resolution (∼10 meV) of this conventional photoelectron energy spectroscopy.…”