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

12 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.

Original languageEnglish
Pages (from-to)9417-9425
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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