Single‐Crystal X‐Ray Diffraction Study of Pressure and Temperature‐Induced Spin Trapping in a Bistable Iron(II) Hofmann Framework

Abstract

High‐pressure single‐crystal X‐ray diffraction has been used to trap both the low‐spin (LS) and high‐spin (HS) states of the iron(II) Hofmann spin crossover framework, [FeII(pdm)(H2O)[Ag(CN)2]2⋅H2O, under identical experimental conditions, allowing the structural changes arising from the spin‐transition to be deconvoluted from previously reported thermal effects.

Spin crossover in the Prussian blue analogue FePt(CN)6induced by pressure or X-ray irradiation

“…This is similar in magnitude to what was reported for other SCO complexes based on nitrogen-coordinated Fe II . 3,36 The critical pressure agrees with the results from ref. 28 at 0.9(1) GPa.…”

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.…”

High-pressure single-crystal diffraction at the Australian Synchrotron

“…High-pressure single-crystal diffraction techniques have been well developed for the investigation of materials over a wide range of scientific disciplines. Recent examples of materials where structure elucidation has been performed at pressure include spin-crossover complexes (Turner et al, 2020), molecular magnets (Etcheverry-Berrios et al, 2020), pharmaceuticals (Oswald et al, 2010), molecular and framework porous materials (McKellar & Moggach, 2015), gases (Lundegaard et al, 2009), pure metals (McMahon & Nelmes, 2006), alloys (Perez-Albuerne et al, 1966), proteins (Librizzi et al, 2018) and molecules associated with planetary science (Cable et al, 2021). A range of high-pressure single-crystal diffraction apparatuses have been developed over the years for investigating these materials, including high-pressure capillary pressure cells for both laboratory diffractometers (Yufit & Howard, 2005) and for use at central facilities (McMonagle et al, 2020) for exploring the effect of lower pressures (< 2000 atm) on soft materials (McMonagle et al, 2022).…”