Light-Induced Excited Spin-State Trapping: A Methodological Approach

Abstract

Light-Induced spin state state switching has been widely studied over the last 40 years, exploring the different time and size scales. This exploration was performed by using a wide range of techniques which are still growing in resolution and accuracy to face the challenge of the increasing complexity of the studied materials (multifunctionnality, nanoparticles, thin films, single domain, single molecule…). All these techniques are well described in various papers and reviews emphasizing their specificities and richness. The aim of the chapter is to discuss most of these techniques from a methodological point of view in order to be aware of all the cautions to take while using them. The most usual techniques used to induce and record the light-induced spin crossover will be described, complemented by a series of recommendations to be in the best conditions for such measurements. The informations that could be extracted or not from these techniques will also be presented in order to have the right level of interpretation.

Substrate driven Spin Crossover in a Fe(II) scorpionate complex.

“…We checked by performing a photomagnetic experiment on bulk microcrystalline powder within a SQUID magnetometer equipped with a dedicated setup. 78,79 Some very limited photoconversion (a few %, see Figure S29 in Supplementary Information) was observed using either 532 or 650 nm laser light, but relaxation was observed to be quite fast, with a T(LIESST) about 14K. No significant reverse-LIESST effect was observed when irradiating at 830 nm.…”

High temperature spin crossover behaviour of mononuclear bis-(thiocyanato)iron(ii) complexes with judiciously designed bidentate N-donor Schiff bases with varying substituents

“…Irradiation is applied on a thin layer of compound and the relaxation temperature T (LIESST) is recorded according to the already reported protocol. 33,34,40 Furthermore, the magnetic data up to 500 K (for 1-3) were recorded using a Microsense EZ7 vibrating sample magnetometer with the 150-1000 K EV1-LNA temperature control option. Samples were weighed in aluminium capsules that were wrapped closed and glued to a 3 mm ∅ quartz rod with a double-face Scotch tape.…”