Accessing the long-lived near-IR-emissive triplet excited state in naphthalenediimide with light-harvesting diimine platinum(II) bisacetylide complex and its application for upconversion

Room temperature near-IR phosphorescence of naphthalenediimide (NDI) was observed with N boolean AND N Pt(II) bisacetylide complex (Pt-NDI) in which the NDI was connected to Pt(II) center via acetylide. Pt-NDI shows intense absorption of visible light and long-lived NDI-localized excited state ((IL)-I-3) (tau(T) = 22.3 mu s). Pt-NDI was used as a triplet sensitizer for upconversion.