Two-step phosphorescent mechanochromism due to intramolecular deformation

Abstract

A triphosphine-supported Pt₂Cu heterotrinuclear complex (1) constrained with 3,6-di-tert-butyl-1,8-diethynyl-9H-carbazole exhibits two-step phosphorescent mechanochromism due to intramolecular deformation. The stepwise phosphorescent mechanochromism following green → yellow → orange-red corresponds exactly to the phosphorescent emission observed in crystal morphs 1·4THF (green), 1·3acetone (yellow), and 1·4CH₂Cl₂ (orange-red), respectively, with different degrees of intramolecular deformation, as demonstrated by X-ray crystallography.