An iron(ii) spin-crossover metallacycle from a back-to-back bis-[dipyrazolylpyridine]

Laurence J. Kershaw Cook, Julie Fisher, Lindsay P. Harding, Malcolm A. Halcrow

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

The syntheses of 4-mercapto-2,6-di(pyrazol-1-yl)pyridine (bppSH) and bis[2,6-di(pyrazol-1-yl)pyrid-4-yl]disulfide (bppSSbpp) are reported. In contrast to previously published "back-to-back" bis-[2,6-di(pyrazol-1-yl)pyridine] derivatives, which form coordination polymers with transition ions that are usually insoluble, bppSSbpp yields soluble oligomeric complexes with iron(ii) and zinc(ii). Mass spectrometry and DOSY data show that [{Fe(μ-bppSSbpp)}n]2n+ and [{Zn(μ-bppSSbpp)}n]2n+ form tetranuclear metallacycles in nitromethane solution (n = 4), although 1H NMR and conductivity measurements imply the iron compound may undergo more fragmentation than its zinc congener. Both [{Fe(bppSH)2]2+ and [{Fe(μ-bppSSbpp)}n]2n+ exhibit thermal spin-crossover in CD3NO2 solution, with midpoint temperatures near 245 K. The similarity of these equilibria implies there is little cooperativity between the iron centres in the metallacyclic structures.

LanguageEnglish
Pages9417-9425
Number of pages9
JournalDalton Transactions
Volume44
Issue number20
DOIs
Publication statusPublished - 28 May 2015

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Zinc
Iron
Iron Compounds
Disulfides
Mass spectrometry
Polymers
Nuclear magnetic resonance
Ions
Derivatives
Temperature
nitromethane
Hot Temperature
pyridine
2,6-bis(pyrazol-1-yl)pyridine

Cite this

Kershaw Cook, Laurence J. ; Fisher, Julie ; Harding, Lindsay P. ; Halcrow, Malcolm A. / An iron(ii) spin-crossover metallacycle from a back-to-back bis-[dipyrazolylpyridine]. In: Dalton Transactions. 2015 ; Vol. 44, No. 20. pp. 9417-9425.
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An iron(ii) spin-crossover metallacycle from a back-to-back bis-[dipyrazolylpyridine]. / Kershaw Cook, Laurence J.; Fisher, Julie; Harding, Lindsay P.; Halcrow, Malcolm A.

In: Dalton Transactions, Vol. 44, No. 20, 28.05.2015, p. 9417-9425.

Research output: Contribution to journalArticle

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