Related Experiment Video
Updated: Jun 2, 2025
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Broken Symmetry and Elastic Frustration in Isostructural MnIII Spin Crossover Crystals
Conor T Kelly1, Vibe B Jakobsen1, Ross Jordan2
1School of Chemistry, University College Dublin, Belfield, Dublin 4, D04 N2E5, Ireland.
Abstract:
Symmetry breaking spin state transitions in two of three isostructural salts of MnIII spin crossover cations, [MnIII(3-OMe-5-NO2-sal2323)]+, with heavy anions are reported. The ReO4 - (1) salt undergoes two-step spin crossover which is coupled with a re-entrant symmetry breaking structural phase transition between a high temperature phase (S=2, C2/c), an intermediate ordered phase (S=1/S=2, P21/c), and a low temperature phase (S=1, C2/c). The AsF6 - (2) complex undergoes an abrupt transition between a high temperature phase (S=2, C2/c) and a low temperature ordered phase (S=1/S=2, P ). The SbF6 - (3) complex undergoes a gradual transition between a high temperature phase (S=2, P ) and a low temperature spin state ordered phase (S=1/S=2, P- ). Correlation of the volume of the anion and the T1/2 of the transitions in these complexes and three analogous complexes with similar anions, BF4 - (4), ClO4 - (5), PF6 - (6), reveals an increase in T1/2 upon increasing the anion volume. We rationalise that the volume of the anions used modulates the elastic interactions between the MnIII sites in the lattice, with increasing elastic frustration with the larger anions resulting in a two-stepped transition for 1 and the stabilisation of the mixed (HS:LS) state to low temperature for 2 and 3.
More Related Videos
09:06Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
07:24Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
Related Concept Videos
02:52Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:37Metallic Solids
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...