Green Synthesis and Flexibilization Engineering of (ECMP)₂MnBr₄ for Smart Textile‐Integrated Luminescence

Abstract 0D hybrid manganese halides represent an emerging class of luminescent materials, yet their practical application has been hindered by the intrinsic trade‐off between optical performance and mechanical flexibility. Here, a green synthesis of 0D (ECMP) 2 MnBr 4 crystal is reported, exhibiting unprecedented triple‐mode emission (photoluminescence, X‐ray scintillation, and mechanoluminescence) through rationally designed highly symmetric [MnBr 4 ] 2− tetrahedra, achieving near‐unity photoluminescence quantum yield (98.97%), record‐low X‐ray detection limit (15.62 nGy air s −1 ) and multi‐stimuli responsiveness (rubbing, squeezing, stretching). The material's ultralow electron‐phonon coupling ( S = 1.438) and defect‐suppressing π–π stacking enable exceptional environmental stability and closed‐loop recyclability via solvent‐mediated recrystallization. Innovatively, (ECMP) 2 MnBr 4 is first integrated into thermoplastic polyurethane via wet‐spinning, simultaneously retaining single‐crystal emission intensity and achieving remarkable elasticity (>1000% strain) for deformation‐resistant wearable applications. This work establishes a new design paradigm for sustainable multifunctional optoelectronics, with immediate applications in wearable displays, high‐resolution X‐ray imaging, and self‐powered optical sensors.