Using the Diphosphanyl Radical as a Potential Spin Label: Effect of Motion on the EPR Spectrum of an R1(R2)P--PR1 Radical

Cataldo, Laurent; Dutan, Cosmina; Misra, Sushil K.; Loss, Sandra; Grützmacher, Hansjörg; Geoffroy, Michel

doi:10.1002/chem.200401276

Scientific article

English

Using the Diphosphanyl Radical as a Potential Spin Label: Effect of Motion on the EPR Spectrum of an R1(R2)P--PR1 Radical

Contributors

Cataldo, Laurent; Dutan, Cosmina; Misra, Sushil K.; Loss, Sandra; Grützmacher, Hansjörg; Geoffroy, Michel

Published in

Chemistry, vol. 11, no. 11, p. 3463-3468

Publication date

2005

Abstract

The EPR spectrum of the novel radical Mes*(CH3)PPMes* (Mes*=2,4,6-(tBu)3C6H2) was measured in the temperature range 100-300 K, and was found to be drastically temperature dependent as a result of the large anisotropy of the 31P hyperfine tensors. Below 180 K, a spectrum of the liquid solution is accurately simulated by calculating the spectral modifications due to slow tumbling of the radical. To achieve this simulation, an algorithm was developed by extending the well-known nitroxide slow-motion simulation technique for the coupling of one electron spin to two nuclear spins. An additional dynamic process responsible for the observed line broadening was found to occur between 180 K and room temperature; this broadening is consistent with an exchange between two conformations. The differences between the isotropic 31P couplings associated with the two conformers are shown to be probably due to an internal rotation about the PP bond.

Keywords

EPR spectroscopy
Internal rotation
Phosphorus
Radicals
Spin labeling

UNIGE affiliation entities

Faculté des sciences / Section de chimie et biochimie / Département de chimie physique

UNIGE research groups

Groupe Geoffroy

Citation (ISO format)

CATALDO, Laurent et al. Using the Diphosphanyl Radical as a Potential Spin Label: Effect of Motion on the EPR Spectrum of an R1(R2)P--PR1 Radical. In: Chemistry, 2005, vol. 11, n° 11, p. 3463–3468. doi: 10.1002/chem.200401276

Article (Published version)

Identifiers

PID : unige:3277
DOI : 10.1002/chem.200401276

Journal ISSN

0947-6539

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Creation

21/09/2009 16:22:39

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21/09/2009 16:22:39

Update

14/03/2023 15:14:10

Status update

14/03/2023 15:14:10

Last indexation

29/10/2024 12:14:09

Using the Diphosphanyl Radical as a Potential Spin Label: Effect of Motion on the EPR Spectrum of an R1(R2)P--PR1 Radical

Contributors

Published in

Publication date

Abstract

Keywords

UNIGE affiliation entities

UNIGE research groups

Citation (ISO format)

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Journal ISSN

Technical informations

Creation

First validation

Update

Status update

Last indexation