Spin-transition chemical compounds and temperature threshold crossing display devices comprising an active medium which contains at least one of those compounds

摘要

A chemical spin transition compound comprises a matrix consisting of molecules each forming a metal-ligand complex and at least one anion, also at least one molecule of water linked to the ligand by hydrogen bonding. The metal comprises a metallic ion with an electronic configuration d4, d5, d6 or d7 : the ligand is a substituted 1,2,4-triazole, the substituting radical comprising an OH- group and the anion is an organic derivative combining a tosylate and nitrate. Also claimed is the method of preparation and use.