Aftereffects in zeolite-encapsulated 57Co-complexes

Z. Homonnay, G. Vankó, A. Vértes, A. Nath, H. Spiering, P. Gütlich

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Tris(2,2′-bipyridyl)-57CoII and bis(2,2′:6′,2″-terpyridine)-57CoII complexes were synthesised in the supercages of zeolite-Y in order to study the effect of molecular isolation on the aftereffects of the 57Co(EC)57Fe decay. As compared to the regular crystalline salts of the complex ions where, according to the emission Mössbauer spectra, the most abundant species is low-spin FeII, the molecular isolation in the zeolite resulted in a larger fraction of low-spin FeIII and a varying amount of high-spin Fe2+ species. In the investigated temperature range, 20 K to 295 K, the majority of the changes was observed above 80 K. In the case of tris(2,2′-bipyridyl)-57CoII-Y, the most characteristic change occurred in valence states, while for bis(2,2′:6′,2″-terpyridine)-57CoII-Y, the temperature dependence of the spin states was more prominent. The change in the low spin valence states is explained partly by donor-acceptor properties of the zeolite lattice. The variation in the high spin fraction is explained by radiation damage of the ligand sphere and/or fragmentation of the complex ion followed by incomplete recombination in the supercage. Molecular isolation itself did not seem to increase the chance of fragmentation (as a consequence of charge neutralization following Auger ionization) of these highly conjugated complex molecules.

Original languageEnglish
Pages (from-to)331-339
Number of pages9
JournalHyperfine Interactions
Volume113
Issue number1-4
Publication statusPublished - 1998

Fingerprint

Zeolites
2,2'-Dipyridyl
Radiation damage
Ions
Ionization
isolation
Ligands
Salts
Crystalline materials
Temperature
Molecules
fragmentation
valence
radiation damage
ions
emission spectra
salts
ionization
temperature dependence
ligands

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials
  • Nuclear and High Energy Physics
  • Physical and Theoretical Chemistry

Cite this

Aftereffects in zeolite-encapsulated 57Co-complexes. / Homonnay, Z.; Vankó, G.; Vértes, A.; Nath, A.; Spiering, H.; Gütlich, P.

In: Hyperfine Interactions, Vol. 113, No. 1-4, 1998, p. 331-339.

Research output: Contribution to journalArticle

Homonnay, Z, Vankó, G, Vértes, A, Nath, A, Spiering, H & Gütlich, P 1998, 'Aftereffects in zeolite-encapsulated 57Co-complexes', Hyperfine Interactions, vol. 113, no. 1-4, pp. 331-339.
Homonnay, Z. ; Vankó, G. ; Vértes, A. ; Nath, A. ; Spiering, H. ; Gütlich, P. / Aftereffects in zeolite-encapsulated 57Co-complexes. In: Hyperfine Interactions. 1998 ; Vol. 113, No. 1-4. pp. 331-339.
@article{699c8615e2f2462d9f37be552ae8b37c,
title = "Aftereffects in zeolite-encapsulated 57Co-complexes",
abstract = "Tris(2,2′-bipyridyl)-57CoII and bis(2,2′:6′,2″-terpyridine)-57CoII complexes were synthesised in the supercages of zeolite-Y in order to study the effect of molecular isolation on the aftereffects of the 57Co(EC)57Fe decay. As compared to the regular crystalline salts of the complex ions where, according to the emission M{\"o}ssbauer spectra, the most abundant species is low-spin FeII, the molecular isolation in the zeolite resulted in a larger fraction of low-spin FeIII and a varying amount of high-spin Fe2+ species. In the investigated temperature range, 20 K to 295 K, the majority of the changes was observed above 80 K. In the case of tris(2,2′-bipyridyl)-57CoII-Y, the most characteristic change occurred in valence states, while for bis(2,2′:6′,2″-terpyridine)-57CoII-Y, the temperature dependence of the spin states was more prominent. The change in the low spin valence states is explained partly by donor-acceptor properties of the zeolite lattice. The variation in the high spin fraction is explained by radiation damage of the ligand sphere and/or fragmentation of the complex ion followed by incomplete recombination in the supercage. Molecular isolation itself did not seem to increase the chance of fragmentation (as a consequence of charge neutralization following Auger ionization) of these highly conjugated complex molecules.",
author = "Z. Homonnay and G. Vank{\'o} and A. V{\'e}rtes and A. Nath and H. Spiering and P. G{\"u}tlich",
year = "1998",
language = "English",
volume = "113",
pages = "331--339",
journal = "Hyperfine Interaction",
issn = "0304-3843",
publisher = "Springer Netherlands",
number = "1-4",

}

TY - JOUR

T1 - Aftereffects in zeolite-encapsulated 57Co-complexes

AU - Homonnay, Z.

AU - Vankó, G.

AU - Vértes, A.

AU - Nath, A.

AU - Spiering, H.

AU - Gütlich, P.

PY - 1998

Y1 - 1998

N2 - Tris(2,2′-bipyridyl)-57CoII and bis(2,2′:6′,2″-terpyridine)-57CoII complexes were synthesised in the supercages of zeolite-Y in order to study the effect of molecular isolation on the aftereffects of the 57Co(EC)57Fe decay. As compared to the regular crystalline salts of the complex ions where, according to the emission Mössbauer spectra, the most abundant species is low-spin FeII, the molecular isolation in the zeolite resulted in a larger fraction of low-spin FeIII and a varying amount of high-spin Fe2+ species. In the investigated temperature range, 20 K to 295 K, the majority of the changes was observed above 80 K. In the case of tris(2,2′-bipyridyl)-57CoII-Y, the most characteristic change occurred in valence states, while for bis(2,2′:6′,2″-terpyridine)-57CoII-Y, the temperature dependence of the spin states was more prominent. The change in the low spin valence states is explained partly by donor-acceptor properties of the zeolite lattice. The variation in the high spin fraction is explained by radiation damage of the ligand sphere and/or fragmentation of the complex ion followed by incomplete recombination in the supercage. Molecular isolation itself did not seem to increase the chance of fragmentation (as a consequence of charge neutralization following Auger ionization) of these highly conjugated complex molecules.

AB - Tris(2,2′-bipyridyl)-57CoII and bis(2,2′:6′,2″-terpyridine)-57CoII complexes were synthesised in the supercages of zeolite-Y in order to study the effect of molecular isolation on the aftereffects of the 57Co(EC)57Fe decay. As compared to the regular crystalline salts of the complex ions where, according to the emission Mössbauer spectra, the most abundant species is low-spin FeII, the molecular isolation in the zeolite resulted in a larger fraction of low-spin FeIII and a varying amount of high-spin Fe2+ species. In the investigated temperature range, 20 K to 295 K, the majority of the changes was observed above 80 K. In the case of tris(2,2′-bipyridyl)-57CoII-Y, the most characteristic change occurred in valence states, while for bis(2,2′:6′,2″-terpyridine)-57CoII-Y, the temperature dependence of the spin states was more prominent. The change in the low spin valence states is explained partly by donor-acceptor properties of the zeolite lattice. The variation in the high spin fraction is explained by radiation damage of the ligand sphere and/or fragmentation of the complex ion followed by incomplete recombination in the supercage. Molecular isolation itself did not seem to increase the chance of fragmentation (as a consequence of charge neutralization following Auger ionization) of these highly conjugated complex molecules.

UR - http://www.scopus.com/inward/record.url?scp=0005305189&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0005305189&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0005305189

VL - 113

SP - 331

EP - 339

JO - Hyperfine Interaction

JF - Hyperfine Interaction

SN - 0304-3843

IS - 1-4

ER -