Regulation of Multistep Spin Crossover Across Multiple Stimuli in a 2-D Framework Material

Abstract

S1. Synthesis and characterisation S2. Thermogravimetric analysis (TGA) S3. Differential scanning calorimetry (DSC) S4. Powder X-ray diffraction S5. Single crystal X-ray diffraction S6. Magnetic susceptibility S7. Elastic model S8. References S2 S1. Synthesis and characterisation General ProceduresAll materials were available commercially and used as received (iron(II) perchlorate was handled carefully and in small amounts to avoid any potential explosions). Metal cyanides are toxic and should be used with care and in small amounts.

Pressure-Induced Hysteretic and Abrupt Spin Transition in Amine Functionalized Isoquinoline-Based Two-Dimensional FeII Hofmann Frameworks

“…The upfront synthetic processes and adaptable metal–ligand combinations of 2D and 3D Hofmann-type Fe II coordination polymers are among the most extensively investigated SCO materials. − They often show abrupt spin transitions, sometimes with a substantial hysteresis, and are extremely sensitive to changes in temperature, pressure, and light exposure. − Even though several Hofmann-type compounds have had the impact of pressure on the spin transition behavior, still there is not enough experimental evidence to draw broad conclusions about how the spin state affects the magnetic properties of these compounds.…”

The joint effect of elasticity, interaction energy and entropy on behavior of pressure- and temperature-induced electronic bistability in a family of two-dimensional Hofman-like coordination polymers

“…[14][15][16][17] The interest in integrating the SCO phenomenon in practical devices has recently boosted the emergence of many new materials, [18][19][20][21] as well as advances in the usual physical methods at high pressures, e.g. optical, 22,23 Raman, 24,25 infrared, 26 X-ray spectroscopy, [27][28][29][30] magnetic measurements 31 and methods of their analyses. 5 2D and 3D Hofmann-type Fe(II) coordination polymers are among the more widely studied SCO materials due to their facile synthetic methods and flexible metal-ligand combinations.…”

“…18,19,21,32 They typically exhibit sharp spin transitions, in some cases accompanied by relatively large hysteresis, and are very sensitive to temperature and pressure changes and light irradiation. [31][32][33][34][35] Although the effect of pressure on the spin transition has been studied for a series of Hoffman-type compounds, to date, the volume of experimental data is not sufficient to draw general conclusions about the influence of the state of spins on the different properties of these compounds.…”

Bidirectional photoswitchability in an iron(III) spin crossover complex: Symmetry-breaking and solvent effects

“…Moreover, light irradiation sometimes allows access to hidden spin states that are not accessible thermally (Figure 1b). While common in coordination polymers, [40][41][42][43][44][45] we are aware of only one mononuclear complex were this has been observed. 36 where the different alcohols result in symmetry-breaking SCO or non-symmetry breaking and gradual SCO, respectively.…”