Manipulating Large Luminescent Shift from Red to Near-Infrared by Pressure via Charge-Transfer States in Covalent Organic Frameworks

• • Py-BO-COF achieves a piezochromic shift of 187 nm and sensitivity of 44.52 nm GPa−1, outperforming most COF/MOF systems and enabling high-contrast pressure sensing in the NIR region. • • The COFs exhibit fully reversible and repeatable emission switching over multiple cycles with no degradation, ensuring long-term operational stability for mechanical sensors and storage devices. • • The red-shift mechanism is attributed to reduced interlayer distance and enhanced coplanarity, which modulate charge-transfer states, providing a design principle for pressure-responsive materials. • • The study demonstrates that donor-acceptor structured 2D COFs can achieve NIR emission (>700 nm) under pressure, overcoming the limitation of visible-range shifts in conventional piezochromic materials.