From homonuclear to heteronuclear: a viable strategy to promote and modulate phosphorescence
Numerous mononuclear platinum(II) complexes are non-emissive or weakly emissive under ambient conditions, but the corresponding Pt–M (M = Cu(I), Ag(I), Au(I), etc.) heteronuclear assemblies could become intensely luminescent because of the inhibition of non-radiative relaxation and the promotion of intersystem crossing from singlet to triplet state through Pt–M intermetallic interactions. To this end, the fabrication of specifically structured Pt–M complexes by the use of slightly luminescent homonuclear Pt(II) precursors provides a promising approach to switching on phosphorescence as well as modulating emission energy and colour. This feature article is aimed at providing some typical examples for attaining highly phosphorescent Pt–M heteronuclear complexes using homonuclear Pt(II) precursors, focusing on the assembly strategy, the correlation of emissive properties to the structures, and the application of phosphorescence in sensing and light-emitting devices.