Vinylene-Linked Helical Covalent Organic Frameworks

Macroscopic helices with single-handedness represent the manifestation of chirality across multiple length scales, yet their realization in covalent organic frameworks (COFs) remains synthetically challenging. Here, we report the first synthesis of vinylene-linked helical COFs (V-heliCOFs) via an unprecedented Siegrist olefination strategy. This strategy enables the formation of highly uniform, single-handed macroscopic COF helices with micrometer-scale dimensions, overcoming the longstanding reliance on reversible imine chemistry. The resulting V-heliCOFs exhibit emergent circularly polarized luminescence (CPL), achieving a record-high luminescent dissymmetric factor (|g_lum|) of 1.1 × 10^-1 alongside a solid-state photoluminescence quantum yield (PLQY) of up to 45.7%, the highest reported among chiral COF-based materials. Systematic comparisons across molecular, framework, and macroscopic levels reveal that this exceptional chiroptical activity arises from the synergistic coupling of the emissive vinylene-linked conjugated framework with the well-defined macroscopic helical architecture, collectively enabling efficient chirality transfer and amplification. This work establishes a new synthetic pathway for crystalline COF helices and highlights hierarchical covalent assembly as a powerful strategy for designing high-performance chiroptical materials.