Electron Spin Resonance Analysis of the Nitroxide Spin Label 2,2,6,6-Tetramethylpiperidone-N-Oxyl (Tempone) in Single Crystals of the Reduced Tempone Matrix

The nitroxide spin label Tempone (2,2,6,6-tetramethylpiperidone-N-oxyl) can be reduced with ascorbic acid to give a nonparamagnetic species. Single crystals of reduced Tempone serve as a suitable host matrix to orient trace quantities of Tempone for ESR analysis. In these crystals the majority of th...

ver descrição completa

Na minha lista:
Detalhes bibliográficos
Main Authors: Snipes, Wallace, Cupp, James, Cohn, Gerald, Keith, Alec
Formato: Artigo
Idioma:English
Publicado em: 1974
Assuntos:
Articles
Acesso em linha:https://ncbi.nlm.nih.gov/pmc/articles/PMC1334484/
https://ncbi.nlm.nih.gov/pubmed/4359744
Tags: Adicionar Tag
Sem tags, seja o primeiro a adicionar uma tag!
id pubmed-1334484
record_format dspace
spelling pubmed-13344842006-01-26 Electron Spin Resonance Analysis of the Nitroxide Spin Label 2,2,6,6-Tetramethylpiperidone-N-Oxyl (Tempone) in Single Crystals of the Reduced Tempone Matrix Snipes, Wallace Cupp, James Cohn, Gerald Keith, Alec Biophys J Articles The nitroxide spin label Tempone (2,2,6,6-tetramethylpiperidone-N-oxyl) can be reduced with ascorbic acid to give a nonparamagnetic species. Single crystals of reduced Tempone serve as a suitable host matrix to orient trace quantities of Tempone for ESR analysis. In these crystals the majority of the Tempone molecules are well-oriented, but a smaller fraction of the molecules tumble freely to give an isotropic electron spin resonance (ESR) spectrum. ESR transitions for the oriented molecules are saturated at much lower microwave power levels than for the tumbling molecules. For the oriented molecules, an analysis of the anisotropy of the spectroscopic splitting factor (g) gives principal values of g(1) = 2.0094, g(2) = 2.0061, g(3) = 2.0021. The hyperfine coupling tensor is nearly axially symmetric, with principal values (in gauss) of A(1) = 6.5, A(2) = 6.7, A(3) = 33.0. Within experimental error, the principal axis systems for the g tensor and the hyperfine tensor are identical. Comparison of the average values of g and A with the isotropic values of these parameters for Tempone in solvents of different polarity suggests a method for choosing the most appropriate tensor elements to be used for spin label experiments in various solvent systems. 1974-01 /pmc/articles/PMC1334484/ /pubmed/4359744 Text en
institution US National Library of Medicine
collection PubMed Central
language English
format Article
topic Articles
spellingShingle Articles
Snipes, Wallace
Cupp, James
Cohn, Gerald
Keith, Alec
Electron Spin Resonance Analysis of the Nitroxide Spin Label 2,2,6,6-Tetramethylpiperidone-N-Oxyl (Tempone) in Single Crystals of the Reduced Tempone Matrix
description The nitroxide spin label Tempone (2,2,6,6-tetramethylpiperidone-N-oxyl) can be reduced with ascorbic acid to give a nonparamagnetic species. Single crystals of reduced Tempone serve as a suitable host matrix to orient trace quantities of Tempone for ESR analysis. In these crystals the majority of the Tempone molecules are well-oriented, but a smaller fraction of the molecules tumble freely to give an isotropic electron spin resonance (ESR) spectrum. ESR transitions for the oriented molecules are saturated at much lower microwave power levels than for the tumbling molecules. For the oriented molecules, an analysis of the anisotropy of the spectroscopic splitting factor (g) gives principal values of g(1) = 2.0094, g(2) = 2.0061, g(3) = 2.0021. The hyperfine coupling tensor is nearly axially symmetric, with principal values (in gauss) of A(1) = 6.5, A(2) = 6.7, A(3) = 33.0. Within experimental error, the principal axis systems for the g tensor and the hyperfine tensor are identical. Comparison of the average values of g and A with the isotropic values of these parameters for Tempone in solvents of different polarity suggests a method for choosing the most appropriate tensor elements to be used for spin label experiments in various solvent systems.
author Snipes, Wallace
Cupp, James
Cohn, Gerald
Keith, Alec
author_facet Snipes, Wallace
Cupp, James
Cohn, Gerald
Keith, Alec
author_sort Snipes, Wallace
title Electron Spin Resonance Analysis of the Nitroxide Spin Label 2,2,6,6-Tetramethylpiperidone-N-Oxyl (Tempone) in Single Crystals of the Reduced Tempone Matrix
title_short Electron Spin Resonance Analysis of the Nitroxide Spin Label 2,2,6,6-Tetramethylpiperidone-N-Oxyl (Tempone) in Single Crystals of the Reduced Tempone Matrix
title_full Electron Spin Resonance Analysis of the Nitroxide Spin Label 2,2,6,6-Tetramethylpiperidone-N-Oxyl (Tempone) in Single Crystals of the Reduced Tempone Matrix
title_fullStr Electron Spin Resonance Analysis of the Nitroxide Spin Label 2,2,6,6-Tetramethylpiperidone-N-Oxyl (Tempone) in Single Crystals of the Reduced Tempone Matrix
title_full_unstemmed Electron Spin Resonance Analysis of the Nitroxide Spin Label 2,2,6,6-Tetramethylpiperidone-N-Oxyl (Tempone) in Single Crystals of the Reduced Tempone Matrix
title_sort electron spin resonance analysis of the nitroxide spin label 2,2,6,6-tetramethylpiperidone-n-oxyl (tempone) in single crystals of the reduced tempone matrix
publishDate 1974
url https://ncbi.nlm.nih.gov/pmc/articles/PMC1334484/
https://ncbi.nlm.nih.gov/pubmed/4359744
_version_ 1760296096941211648

Registos relacionados