Enhanced solid-state phosphorescence of organoplatinum π-systems by ion-pairing assembly.

Anion binding and ion pairing of dipyrrolyldiketone Pt complexes as anion-responsive π-electronic molecules resulted in photophysical modulations, as observed in solid-state phosphorescence properties. Modifications to arylpyridine ligands in the Pt complexes significantly impacted the assembling behaviour and photophysical properties of anion-free and anion-binding (ion-pairing) forms. The Pt complexes, in the presence of guest anions and their countercations, formed various anion-binding modes and ion-pairing assembled structures depending on constituents and forms (solutions and crystals).