Structural phase transition to disorder low-temperature phase in [Fe(ptz)(6)](BF4)(2) spin-crossover compounds

Beitrag in einer Fachzeitschrift


Details zur Publikation

Autor(en): Kusz J, Zubko M, Neder R, Guetlich P
Zeitschrift: Acta Crystallographica Section B: Structural Science
Verlag: WILEY-BLACKWELL
Jahr der Veröffentlichung: 2012
Band: 68
Seitenbereich: 40-56
ISSN: 0108-7681


Abstract


In the spin-crossover compound [Fe(ptz)(6)](BF4)(2) (where ptz=1-n-propyltetrazole) six different phases are observed. When a single crystal is slowly cooled from high temperatures to those below 125 K, the reflections broaden into diffuse maxima and split into two maxima along the c* direction [Kusz, Gutlich & Spiering (2004). Top. Curr. Chem. 234, 129-153]. As both maxima are broad along the c* direction, the short-range order exists only along the c direction and in the ab plane the structure remains long-range ordered. In this disordered phase additional satellite reflections appear. Upon heating above 135 K, the diffuse maxima return to their previous shape and this process is completely reversible. Rapidly cooled samples, on the other hand, do not show such splitting and the symmetry remains R (3) over bar, despite a jump in lattice parameters. We use a special technique to analyse the disorder model of the slowly cooled samples, which consists of layered domains shifted in the hexagonal ab plane. The low-spin disordered phase was solved in a novel approach to accommodate the very unusual twinning and refined in the non-standard space group C (1) over bar. In contrast to the ordered low-spin phase, the Fe ion is in a non-centrosymmetric coordination polyhedron and two of the six propyl groups change their conformation.



FAU-Autoren / FAU-Herausgeber

Neder, Reinhard Prof. Dr.
Professur für Allgemeine Mineralogie/Kristallographie


Autor(en) der externen Einrichtung(en)
Johannes Gutenberg-Universität Mainz
University of Silesia in Katowice / Uniwersytet Śląski w Katowicach


Zitierweisen

APA:
Kusz, J., Zubko, M., Neder, R., & Guetlich, P. (2012). Structural phase transition to disorder low-temperature phase in [Fe(ptz)(6)](BF4)(2) spin-crossover compounds. Acta Crystallographica Section B: Structural Science, 68, 40-56. https://dx.doi.org/10.1107/S0108768111053298

MLA:
Kusz, Joachim, et al. "Structural phase transition to disorder low-temperature phase in [Fe(ptz)(6)](BF4)(2) spin-crossover compounds." Acta Crystallographica Section B: Structural Science 68 (2012): 40-56.

BibTeX: 

Zuletzt aktualisiert 2018-10-08 um 15:39