Controlled Synthesis of PdII and PtII Supramolecular Copolymer with Sequential Multiblock and Amplified Phosphorescence

Abstract

Summary Supramolecular copolymers constitute a fundamental new class of functional materials attracting burgeoning interest, but examples that display phosphorescence and long-lived excited states are rare. Herein, we describe the synthesis of sequential phosphorescent multi-block supramolecular copolymers in one and multiple dimensions using pincer PtII and PdII complexes as building blocks by manipulating out-of-equilibrium self-assemblies via the living supramolecular polymerization approach. Doping a small amount of PtII complexes (2 mol %) into the PdII assemblies significantly boosted the emission efficiency and radiative decay rate constant (Φem = 3.7%, kr = 1.8 × 104 s−1 in PdII assemblies; Φem = 76.2%, kr = 58.6 × 104 s−1 in PtII-PdII co-assemblies), which is ascribed to an external heavy-atom spin-orbital coupling effect arising from the doped PtII complex with a delocalized 3[dσ∗→π∗] excited state. The findings on PtII and PdII supramolecular copolymers with controlled sequences and greatly enhanced phosphorescence efficiencies open the door to new photofunctional and responsive luminescent metal-organic supramolecular materials.