Bright Solvent-Free Luminescent Liquid with Magnetism Composed of a Thiocyanate Complex of Ce(III)

Ionic liquids composed of a thiocyanate complex of Ce(III) exhibit bright cyan photoluminescence with a quantum yield close to 40% in addition to paramagnetism. The morphology of a droplet of ionic liquid changes in response to solvent vapor as a stimulus. The emission lifetime and thermal property are characterized. The Weiss temperature is evaluated from the magnetic property measurements, which indicates that antiferromagnetic exchange interaction exists between Ce(III) ions. Insight into the characteristics of the electronic transitions in the Ce(III) complex is obtained using quantum chemical calculations. Thiocyanate complexes of Ce(III) are demonstrated as promising building blocks to produce solvent-free luminescent functional materials.