Polymorphic Copper Iodide Anions: Luminescence Thermochromism and Mechanochromism of (PPh)[CuI].

The photoluminescent stimuli-responsive properties of two crystalline polymorphs with the formula (PPh)[CuI] are reported. Distinct luminescence properties are exhibited by these ionic copper iodide compounds with blue or yellow emission, and original luminescence thermochromism and mechanochromism are demonstrated. While one polymorph displays contrasted temperature-dependent emission properties, the other shows great modification of its emission upon mechanical solicitation.