Effect of the counter-anion on the spin-transition properties of a family of Fe(ii) tetrazole complexes, [Fe(i4tz)6]X2 (X = ClO4, PF6, SbF6, BF4)

Myrvete Tafili-Kryeziu, Matthias Weil, Takahiro Muranaka, Azzedine Bousseksou, Miki Hasegawa, Akimitsu Jun, Wolfgang Linert

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The monodentate ligand 1-isobutyl-1H-tetrazole (i4tz) was used to synthesize a series of iron(ii) spin-crossover (SCO) complexes with the general formula [Fe(i4tz)6]X2, where X = ClO4 (1), PF6 (2), SbF6 (3), or BF4 (4). Upon cooling, magnetic susceptibility measurements of compounds1, 2 and3 show a reversible one-step spin crossover (SCO) behaviour between HS (S = 2) and LS (S = 0) states without hysteresis. The ClO4 compound shows a gradual spin transition at T1/2 = 208 K at a considerably higher temperature than the other compounds. The larger anions PF6 (T1/2 = 114 K) and SbF6 (T1/2 = 116 K) show more gradual transitions, and a “frozen-in effect” was observed after fast cooling. The crystal structure of [Fe(i4tz)6](SbF6)2 (3) was determined at 296, 200 and 100 K, revealing a reversible first-order phase transition between 200 and 100 K, accompanied by a triplication of the unit cell volume at 100 K. Temperature-dependent vibration and electronic spectroscopic measurements of compound1 were compared with the magnetic susceptibility measurements.

Original languageEnglish
Pages (from-to)15796-15804
Number of pages9
JournalJournal of the Chemical Society. Dalton Transactions
Volume42
Issue number44
DOIs
Publication statusPublished - Oct 22 2013
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)

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