Issue 44, 2013

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)

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 compounds 1, 2 and 3 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 compound 1 were compared with the magnetic susceptibility measurements.

Graphical abstract: 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−)

Supplementary files

Article information

Article type
Paper
Submitted
26 Aug 2013
Accepted
31 Aug 2013
First published
03 Sep 2013

Dalton Trans., 2013,42, 15796-15804

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)

M. Tafili-Kryeziu, M. Weil, T. Muranaka, A. Bousseksou, M. Hasegawa, A. Jun and W. Linert, Dalton Trans., 2013, 42, 15796 DOI: 10.1039/C3DT52339J

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements