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Supramolecular polymer networks (SPNs), crosslinked by noncovalent bonds, have emerged as reorganizable and recyclable polymeric materials with unique functionality. However, poor stability is an imperative challenge faced by SPNs, because SPNs are susceptible to heat, water, and/or solvents due to the dynamic and reversible nature of noncovalent bonds. Herein, the design of a noncovalent cooperative network (NCoN) to simultaneously stabilize and reinforce SPNs is reported, resulting in an ultrastable, superrobust, and recyclable SPN. The NCoN is constructed by multiplying the H‐bonding sites and tuning the conformation/geometry of the H‐bonding segment to optimize the multivalence cooperativity of H‐bonds. The rationally designed H‐bonding segment with high conformational compliance favors the formation of tightly packed H‐bond arrays comprising higher‐density and stronger H‐bonds. Consequently, the H‐bonded crosslinks in the NCoN display a covalent crosslinking effect but retain on‐demand dynamics and reversibility. The resultant ultrastable SPN not only displays remarkable resistance to heat up to 120 °C, water soaking, and a broad spectrum of solvents, but also possesses a superhigh true stress at break (1.1 GPa) and an ultrahigh toughness (406 MJ m−3). Despite the covalent‐network‐like stability, the SPN is recyclable through activating its reversibility in a high‐polarity solvent heated to a threshold temperature. [ABSTRACT FROM AUTHOR]

Purely organic molecules exhibiting near‐infrared (NIR) emission possess considerable potential for applications in both biological and optoelectronic technological domains, owing to their inherent advantages such as cost‐effectiveness, biocompatibility, and facile chemical modifiability. However, the repertoire of such molecules with emission peaks exceeding 750 nm and concurrently demonstrating high photoluminescence quantum efficiency (PLQE) remains relatively scarce due to the energy gap law. Herein, we report two open‐shell NIR radical emitters, denoted as DMNA‐Cz‐BTM and DMNA‐PyID‐BTM, achieved through the strategic integration of a donor group (DMNA) onto the Cz‐BTM and PyID‐BTM frameworks, respectively. We found that the donor‐acceptor molecular structure allows the two designed radical emitters to exhibit a charge‐transfer excited state and spatially separated electron and hole levels with non‐bonding characteristics. Thus, the high‐frequency vibrations are effectively suppressed. Besides, the reduction of low‐frequency vibrations is observed. Collectively, the non‐radiative decay channel is significantly suppressed, leading to exceptional NIR PLQE values. Specifically, DMNA‐Cz‐BTM manifests an emission peak at 758 nm alongside a PLQE of 55 %, whereas DMNA‐PyID‐BTM exhibits an emission peak at 778 nm with a PLQE of 66 %. Notably, these represent the pinnacle of PLQE among metal‐free organic NIR emitters with emission peaks surpassing 750 nm. [ABSTRACT FROM AUTHOR]