Luminescent Mechanochromism of a Platinum Complex with Four Monodentate Ligands Governed by Intramolecular Interactions Between Ligands.

A platinum complex equipped with 3-methylbenzofuryl groups was prepared and its crystal structure and emission properties were investigated. This platinum complex has two distinctly emissive polymorphs: a blue-emissive polymorph with low intensity and a brightly green-emissive polymorph. Upon mechanical stimulation, the blue-emitting phase is converted to green-emitting powder through a crystal-to-crystal phase transition. Structure analyses indicated that intramolecular interactions between ligands control the phase-transition behavior and the emission properties.