Structural Softness–Rigidity Mediation Enables Multicolor Emission and Long‐Lived Phosphorescence in Hf/Zr Halides

Abstract

ABSTRACT Multicolor fluorescence, typically favored by soft environments, and phosphorescence, which relies on rigid lattices to stabilize triplet excitons, are fundamentally incompatible and hard to coexist within a single material. Here, we report a crown–ether–directed lattice assembly that integrates [HfCl 6 ] 2‒ /[ZrCl 6 ] 2‒ octahedra and DB18C6@M(K + /Rb + ) supramolecular, yielding four unknown organic–inorganic hybrid Hf/Zr halides. Notably, (DB18C6@K) 2 (CH 3 CN) 2 HfCl 6 achieves an exceptional room‐temperature phosphorescence (RTP) quantum yield (Φ p ) of 54.43%, a long lifetime of 0.8 s, and a visually discernible afterglow persisting up to 6 s. Moreover, these materials exhibit excitation–dependent multicolor emission, producing green and blue–white outputs under 302 and 365 nm irradiation, respectively. This unique multimodal luminescence originates from the synergistic interplay between the balanced soft‐rigid lattice provided by the crown‐ether framework and heavy – atom Hf/Zr centers, which facilitates intersystem crossing, enabling both efficient RTP and tunable multichannel pathways. It has been confirmed by the high–pressure synchrotron angle–dispersive x–ray diffraction and Raman results. Overall, this work establishes a heavy–atom–based structural mediation which may offer a generalizable route to high‐efficiency, multichannel, and stimuli‐responsive RTP materials.