Related Experiment Video
Updated: Mar 7, 2026

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
Gradual Thermal Spin-Crossover Mediated by a Reentrant Z' = 1 → Z' = 6 → Z' = 1 Phase Transition
Rafal Kulmaczewski1, Oscar Cespedes2, Malcolm A Halcrow1
1School of Chemistry, University of Leeds , Woodhouse Lane, Leeds LS2 9JT, U.K.
Abstract:
The Fe[BF4]2 complex of the Schiff base podand tris[4-(thiazol-4-yl)-3-aza-3-butenyl]amine exhibits gradual thermal spin-crossover with T1/2 ≈ 208 K in the solid state. A weak discontinuity in the magnetic susceptibility curve at 190 K is associated with a reentrant symmetry-breaking transition involving a trebling of the unit cell volume (from P21/c, Z = 4, to P21, Z = 12). The intermediate phase contains six independent cations in puckered layers of low-spin, and high-spin or mixed-spin, molecules with an overall 30% high-spin population at 175 K.
Related Concept Videos
Phase Transitions
Phase Transitions
Phase Transitions: Vaporization and Condensation
Phase Transitions: Melting and Freezing
Phase Transitions: Sublimation and Deposition
Thermal Sigmatropic Reactions: Overview
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in 1,5-hexadiene, referred...

