Ion complexation induced high-spin associations of spin-labeled crown ethers

A reevaluation

Sei Hum Jang, Christine Mitchell, James E. Jackson, Bart Kahr

Research output: Contribution to journalArticle

Abstract

Between 1978 and 1989, Mukai and coworkers demonstrated that a series of spin-labeled benzo-15-crown-5 derivatives gave triplet ESR spectra in ethanol glasses in the presence of diamagnetic alkali and alkaline earth ions. They proposed that the high-spin coupling resulted from a pair of radicals being brought into close contact by a 1:2 complexation of metal ions with the crown ether moieties. The work of Mukai and his colleagues represents an early example of high-spin coupling induced in radical pairs that assemble around diamagnetic metal ions. Herein, we describe ion binding experiments with simple stable free radicals such as TEMPO and galvinoxyl that lack the crown moiety. The triplet state species that we observe require the possibility of unforeseen mechanisms for previously reported high-spin associations in spin labeled crown ethers.

Original languageEnglish (US)
Pages (from-to)139-145
Number of pages7
JournalMolecular Crystals and Liquid Crystals Science and Technology Section A: Molecular Crystals and Liquid Crystals
Volume272
StatePublished - 1995

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Crown Ethers
Crown ethers
Complexation
Metal ions
ethers
Ions
Alkalies
Free radicals
Free Radicals
Paramagnetic resonance
ions
Ethanol
Earth (planet)
Derivatives
metal ions
Glass
Experiments
free radicals
atomic energy levels
alkalies

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

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abstract = "Between 1978 and 1989, Mukai and coworkers demonstrated that a series of spin-labeled benzo-15-crown-5 derivatives gave triplet ESR spectra in ethanol glasses in the presence of diamagnetic alkali and alkaline earth ions. They proposed that the high-spin coupling resulted from a pair of radicals being brought into close contact by a 1:2 complexation of metal ions with the crown ether moieties. The work of Mukai and his colleagues represents an early example of high-spin coupling induced in radical pairs that assemble around diamagnetic metal ions. Herein, we describe ion binding experiments with simple stable free radicals such as TEMPO and galvinoxyl that lack the crown moiety. The triplet state species that we observe require the possibility of unforeseen mechanisms for previously reported high-spin associations in spin labeled crown ethers.",
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T1 - Ion complexation induced high-spin associations of spin-labeled crown ethers

T2 - A reevaluation

AU - Jang, Sei Hum

AU - Mitchell, Christine

AU - Jackson, James E.

AU - Kahr, Bart

PY - 1995

Y1 - 1995

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AB - Between 1978 and 1989, Mukai and coworkers demonstrated that a series of spin-labeled benzo-15-crown-5 derivatives gave triplet ESR spectra in ethanol glasses in the presence of diamagnetic alkali and alkaline earth ions. They proposed that the high-spin coupling resulted from a pair of radicals being brought into close contact by a 1:2 complexation of metal ions with the crown ether moieties. The work of Mukai and his colleagues represents an early example of high-spin coupling induced in radical pairs that assemble around diamagnetic metal ions. Herein, we describe ion binding experiments with simple stable free radicals such as TEMPO and galvinoxyl that lack the crown moiety. The triplet state species that we observe require the possibility of unforeseen mechanisms for previously reported high-spin associations in spin labeled crown ethers.

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