Photoelectron anisotropy and channel branching ratios in the detachment of solvated iodide cluster anions

Richard Mabbs, Eric Surber, Andrei M Sanov

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Photoelectron spectra and angular distributions in 267 nm detachment of the I -ṡAr, I -ṡH 2O, I -ṡCH 3I, and I -ṡCH 3CN cluster anions are examined in comparison with bare I - using velocity-map photoelectron imaging. In all cases, features are observed that correlate to two channels producing either I( 2P 3/2) or I( 2P 1/2). In the photodetachment of I - and I -ṡAr, the branching ratios of the 2P 1/2 and 2P 3/2 channels are observed to be ≈0.4, in both cases falling short of the statistical ratio of 0.5. For I -ṡH 2O and I -ṡCH 3I, the 2P 1/2 to 2P 3/2 branching ratios are greater by a factor of 1.6 compared to the bare iodide case. The relative enhancement of the 2P 1/2 channel is attributed to dipole effects on the final-state continuum wave function in the presence of polar solvents. For I -ṡCH 3CN the 2P 1/2 to 2P 3/2 ratio falls again, most likely due to the proximity of the detachment threshold in the excited spin-orbit channel. The photoelectron angular distributions in the photodetachment of I -, I -ṡAr, I -ṡH 2O, and I -ṡCH 3CN are understood within the framework of direct detachment from I -. Hence, the corresponding anisotropy parameters are modeled using variants of the Cooper-Zare central-potential model for atomic-anion photodetachment. In contrast, I -ṡCH 3I yields nearly isotropic photoelectron angular distributions in both detachment channels. The implications of this anomalous behavior are discussed with reference to alternative mechanisms, affording the solvent molecule an active role in the electron ejection process.

Original languageEnglish (US)
Article number054308
JournalThe Journal of Chemical Physics
Volume122
Issue number5
DOIs
StatePublished - 2005

Fingerprint

Iodides
Photoelectrons
detachment
iodides
Anions
Angular distribution
photoelectrons
Anisotropy
methylidyne
anions
anisotropy
photodetachment
angular distribution
Wave functions
Orbits
Imaging techniques
falling
ejection
Molecules
Electrons

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Photoelectron anisotropy and channel branching ratios in the detachment of solvated iodide cluster anions. / Mabbs, Richard; Surber, Eric; Sanov, Andrei M.

In: The Journal of Chemical Physics, Vol. 122, No. 5, 054308, 2005.

Research output: Contribution to journalArticle

@article{f1d4eb6caede451a946525dc2176a7ad,
title = "Photoelectron anisotropy and channel branching ratios in the detachment of solvated iodide cluster anions",
abstract = "Photoelectron spectra and angular distributions in 267 nm detachment of the I -ṡAr, I -ṡH 2O, I -ṡCH 3I, and I -ṡCH 3CN cluster anions are examined in comparison with bare I - using velocity-map photoelectron imaging. In all cases, features are observed that correlate to two channels producing either I( 2P 3/2) or I( 2P 1/2). In the photodetachment of I - and I -ṡAr, the branching ratios of the 2P 1/2 and 2P 3/2 channels are observed to be ≈0.4, in both cases falling short of the statistical ratio of 0.5. For I -ṡH 2O and I -ṡCH 3I, the 2P 1/2 to 2P 3/2 branching ratios are greater by a factor of 1.6 compared to the bare iodide case. The relative enhancement of the 2P 1/2 channel is attributed to dipole effects on the final-state continuum wave function in the presence of polar solvents. For I -ṡCH 3CN the 2P 1/2 to 2P 3/2 ratio falls again, most likely due to the proximity of the detachment threshold in the excited spin-orbit channel. The photoelectron angular distributions in the photodetachment of I -, I -ṡAr, I -ṡH 2O, and I -ṡCH 3CN are understood within the framework of direct detachment from I -. Hence, the corresponding anisotropy parameters are modeled using variants of the Cooper-Zare central-potential model for atomic-anion photodetachment. In contrast, I -ṡCH 3I yields nearly isotropic photoelectron angular distributions in both detachment channels. The implications of this anomalous behavior are discussed with reference to alternative mechanisms, affording the solvent molecule an active role in the electron ejection process.",
author = "Richard Mabbs and Eric Surber and Sanov, {Andrei M}",
year = "2005",
doi = "10.1063/1.1839861",
language = "English (US)",
volume = "122",
journal = "Journal of Chemical Physics",
issn = "0021-9606",
publisher = "American Institute of Physics Publising LLC",
number = "5",

}

TY - JOUR

T1 - Photoelectron anisotropy and channel branching ratios in the detachment of solvated iodide cluster anions

AU - Mabbs, Richard

AU - Surber, Eric

AU - Sanov, Andrei M

PY - 2005

Y1 - 2005

N2 - Photoelectron spectra and angular distributions in 267 nm detachment of the I -ṡAr, I -ṡH 2O, I -ṡCH 3I, and I -ṡCH 3CN cluster anions are examined in comparison with bare I - using velocity-map photoelectron imaging. In all cases, features are observed that correlate to two channels producing either I( 2P 3/2) or I( 2P 1/2). In the photodetachment of I - and I -ṡAr, the branching ratios of the 2P 1/2 and 2P 3/2 channels are observed to be ≈0.4, in both cases falling short of the statistical ratio of 0.5. For I -ṡH 2O and I -ṡCH 3I, the 2P 1/2 to 2P 3/2 branching ratios are greater by a factor of 1.6 compared to the bare iodide case. The relative enhancement of the 2P 1/2 channel is attributed to dipole effects on the final-state continuum wave function in the presence of polar solvents. For I -ṡCH 3CN the 2P 1/2 to 2P 3/2 ratio falls again, most likely due to the proximity of the detachment threshold in the excited spin-orbit channel. The photoelectron angular distributions in the photodetachment of I -, I -ṡAr, I -ṡH 2O, and I -ṡCH 3CN are understood within the framework of direct detachment from I -. Hence, the corresponding anisotropy parameters are modeled using variants of the Cooper-Zare central-potential model for atomic-anion photodetachment. In contrast, I -ṡCH 3I yields nearly isotropic photoelectron angular distributions in both detachment channels. The implications of this anomalous behavior are discussed with reference to alternative mechanisms, affording the solvent molecule an active role in the electron ejection process.

AB - Photoelectron spectra and angular distributions in 267 nm detachment of the I -ṡAr, I -ṡH 2O, I -ṡCH 3I, and I -ṡCH 3CN cluster anions are examined in comparison with bare I - using velocity-map photoelectron imaging. In all cases, features are observed that correlate to two channels producing either I( 2P 3/2) or I( 2P 1/2). In the photodetachment of I - and I -ṡAr, the branching ratios of the 2P 1/2 and 2P 3/2 channels are observed to be ≈0.4, in both cases falling short of the statistical ratio of 0.5. For I -ṡH 2O and I -ṡCH 3I, the 2P 1/2 to 2P 3/2 branching ratios are greater by a factor of 1.6 compared to the bare iodide case. The relative enhancement of the 2P 1/2 channel is attributed to dipole effects on the final-state continuum wave function in the presence of polar solvents. For I -ṡCH 3CN the 2P 1/2 to 2P 3/2 ratio falls again, most likely due to the proximity of the detachment threshold in the excited spin-orbit channel. The photoelectron angular distributions in the photodetachment of I -, I -ṡAr, I -ṡH 2O, and I -ṡCH 3CN are understood within the framework of direct detachment from I -. Hence, the corresponding anisotropy parameters are modeled using variants of the Cooper-Zare central-potential model for atomic-anion photodetachment. In contrast, I -ṡCH 3I yields nearly isotropic photoelectron angular distributions in both detachment channels. The implications of this anomalous behavior are discussed with reference to alternative mechanisms, affording the solvent molecule an active role in the electron ejection process.

UR - http://www.scopus.com/inward/record.url?scp=22944443263&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=22944443263&partnerID=8YFLogxK

U2 - 10.1063/1.1839861

DO - 10.1063/1.1839861

M3 - Article

VL - 122

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 5

M1 - 054308

ER -