title: Low-spin state structure of [Fe(chloroethyltetrazole)6](BF4)2 obtained from synchrotron powder diffraction data.
abstract: The complex [Fe(teec)6](BF4)2 (teec = chloroethyltetrazole) shows a two-step complete spin-crossover transition in the temperature range 300-90 K. Time-resolved synchrotron powder diffraction experiments have been carried out in this temperature range, and crystal structure models have been obtained from the powder patterns by using the parallel tempering technique. Of these models, the low-spin state structure at 90 K has been refined completely with Rietveld refinement. Its structural characteristics are discussed in relation to the high-spin state model and other spin-crossover compounds. The complex shows a remarkable anisotropic unit-cell parameter contraction that is dependent on the applied cooling rate. In addition, the possible important implications for the interpretation of spin-crossover behavior in terms of structural changes are discussed.
authors.affiliation: University of Amsterdam, Faculty of Science, van't Hoff Institute for Molecular Sciences, Laboratory of Crystallography, Valckenierstraat 65, 1018XE Amsterdam, The Netherlands. eva@science.uva.nl
authors.forename: Eva
authors.initials: E
authors.lastname: Dova
authors.forename: René
authors.initials: R
authors.lastname: Peschar
authors.forename: Masaki
authors.initials: M
authors.lastname: Takata
authors.forename: Eiji
authors.initials: E
authors.lastname: Nishibori
authors.forename: Henk
authors.initials: H
authors.lastname: Schenk
authors.forename: Arno F
authors.initials: AF
authors.lastname: Stassen
authors.forename: Jaap G
authors.initials: JG
authors.lastname: Haasnoot