Vibrational State-Selective Resonant Two-Photon Photoelectron Spectroscopy of AuS^– via a Spin-Forbidden Excited State

Abstract

Vibrational state-selective resonant two-photon photoelectron spectra have been obtained via a triplet intermediate state ((3)Σ(-)) of AuS(-) near its detachment threshold using high-resolution photoelectron imaging of cryogenically cooled AuS(-) anions. Four vibrational levels of the (3)Σ(-) excited state are observed to be below the detachment threshold. Resonant two-photon absorptions through these levels yield vibrational state-selective photoelectron spectra to the (2)Σ final state of neutral AuS with broad and drastically different Franck-Condon distributions, reflecting the symmetries of the vibrational wave functions of the (3)Σ(-) intermediate state. The (3)Σ(-) excited state is spin-forbidden from the (1)Σ(+) ground state of AuS(-) and is accessed due to strong relativistic effects. The nature of the (3)Σ(-) excited state is confirmed by angular distributions of the photoelectron images and quantum calculations.

Perspective: Electrospray photoelectron spectroscopy: From multiply-charged anions to ultracold anions

“…Eight vibrational levels (v ′ = 0-7) were observed for the 3 Σ − excited state using resonant two-photon detachment spectroscopy. 127 Four long-lived levels (v ′ = 0-3) were boundstates below the detachment threshold, and four short-lived levels (v ′ = 4-7) were found to be above the detachment threshold and underwent autodetachment. The four bound vibrational levels allowed vibrational state-selective PE images to be obtained by resonant two-photon detachment via the 3 Σ − excited state.…”

Activity coefficients of individual ions in LaCl3from the II+IW theory

“…A well-known experimental fact in the world of electrolytes is that the activity coefficient (the excess chemical potential) depends on the electrolyte concentration non-monotonically; it decreases near infinite dilution according to the Debye-Hückel (DH) limiting law [1], goes through a minimum, and increases at high concentrations close to saturation. Many theoretical works tried to explain this behavior from various empirical modifications [2][3][4][5][6][7][8][9] of the DH theory [1] to advanced statistical mechanical approaches based on the model of charged hard spheres immersed in an implicit-water dielectric solvent [5,6,[10][11][12][13][14][15][16][17][18][19][20].…”

“…In another recent paper, the concentration dependent dielectric constant was built into the model in the Poisson-Fermi theory of Liu and Eisenberg [8].…”

Vibrational state-selective autodetachment photoelectron spectroscopy from dipole-bound states of cold 2-hydroxyphenoxide: o − HO(C6H4)O−

“…[1][2][3][4][5][6][7][8] Valence excited electronic states of anions are also not usually accessible. [9][10][11][12][13][14][15][16] However, the existence of dipole-bound states (DBSs) near the detachment threshold of anions significantly expands the scope of vibrational autodetachment spectroscopy. A molecule with a large enough dipole moment (>2.5 D) can weakly attract an electron and form a DBS of the corresponding anion in the dipolar field, which was first predicted theoretically [17][18][19][20] and has been observed experimentally.…”