dorsal/arxiv
View SchemaElectron Photodetachment from Aqueous Anions. III. Dynamics of Geminate Pairs Derived from Photoexcitation of Mono- vs. Poly- atomic Anions
| Authors | Rui Lian, Dmitri A. Oulianov, Robert A. Crowell, Ilya A. Shkrob, ; Xiyi Chen, Stephen E. Bradforth |
|---|---|
| Categories | |
| ArXiv ID | physics/0501112 |
| URL | https://arxiv.org/abs/physics/0501112 |
| DOI | 10.1021/jp0610113 |
Abstract
Photostimulated electron detachment from aqueous inorganic anions is the simplest example of solvent-mediated electron transfer. Here we contrast the behavior of halide anions with that of small polyatomic anions, such as pseudohalide anions (e.g., HS-) and common polyvalent anions (e.g., SO32-). Geminate recombination dynamics of hydrated electrons generated by 200 nm photoexcitation of aqueous anions (I-, Br-, OH-, HS-, CNS-, CO32-, SO32-, and Fe(CN)64-) have been studied. Prompt quantum yields for the formation of solvated, thermalized electrons and quantum yields for free electrons were determined. Pump-probe kinetics for 200 nm photoexcitation were compared with kinetics obtained at lower photoexcitation energy (225 nm or 242 nm) for the same anions, where possible. Free diffusion and mean force potential models of geminate recombination dynamics were used to analyze these kinetics. These analyses suggest that for polyatomic anions (including all polyvalent anions studied) the initial electron distribution has a broad component, even at relatively low photoexcitation energy. There seem to be no well-defined threshold energy below which the broadening of the distribution does not occur, as is the case for halide anions. Direct ionization to the conduction band of water is the most likely photoprocess broadening the electron distribution. Our study suggests that halide anions are in the class of their own; electron photodetachment from polyatomic, especially polyvalent, anions follows a different set of rules.
{
"annotation_id": "c796b73e-dd47-4070-9dfb-2f59b6d6299a",
"date_created": "2026-03-02T18:00:56.441000Z",
"date_modified": "2026-03-02T18:00:56.441000Z",
"file_hash": "fc7fe07722eef04883f3fc15848b0e581ce9f04c99f60fcd6e7773c25bab2454",
"private": false,
"record": {
"abstract": "Photostimulated electron detachment from aqueous inorganic anions is the\nsimplest example of solvent-mediated electron transfer. Here we contrast the\nbehavior of halide anions with that of small polyatomic anions, such as\npseudohalide anions (e.g., HS-) and common polyvalent anions (e.g., SO32-).\nGeminate recombination dynamics of hydrated electrons generated by 200 nm\nphotoexcitation of aqueous anions (I-, Br-, OH-, HS-, CNS-, CO32-, SO32-, and\nFe(CN)64-) have been studied. Prompt quantum yields for the formation of\nsolvated, thermalized electrons and quantum yields for free electrons were\ndetermined. Pump-probe kinetics for 200 nm photoexcitation were compared with\nkinetics obtained at lower photoexcitation energy (225 nm or 242 nm) for the\nsame anions, where possible. Free diffusion and mean force potential models of\ngeminate recombination dynamics were used to analyze these kinetics. These\nanalyses suggest that for polyatomic anions (including all polyvalent anions\nstudied) the initial electron distribution has a broad component, even at\nrelatively low photoexcitation energy. There seem to be no well-defined\nthreshold energy below which the broadening of the distribution does not occur,\nas is the case for halide anions. Direct ionization to the conduction band of\nwater is the most likely photoprocess broadening the electron distribution. Our\nstudy suggests that halide anions are in the class of their own; electron\nphotodetachment from polyatomic, especially polyvalent, anions follows a\ndifferent set of rules.",
"arxiv_id": "physics/0501112",
"authors": [
"Rui Lian",
"Dmitri A. Oulianov",
"Robert A. Crowell",
"Ilya A. Shkrob",
"; Xiyi Chen",
"Stephen E. Bradforth"
],
"categories": [
"physics.chem-ph"
],
"doi": "10.1021/jp0610113",
"title": "Electron Photodetachment from Aqueous Anions. III. Dynamics of Geminate Pairs Derived from Photoexcitation of Mono- vs. Poly- atomic Anions",
"url": "https://arxiv.org/abs/physics/0501112"
},
"schema_id": "dorsal/arxiv",
"source": {
"execution_id": "fce12085-2985-4e37-a662-9687bb213c51",
"id": "arXiv Dataset IDs",
"type": "Model",
"variant": "snapshot-2026-03-01",
"version": "0.1.0"
},
"user_id": 1000002
}