Key Words:High resolution transmission electron microscopy;Carbon - Coenzymes - Condensation reactions - Conjugated polymers - Energy gap - Photocatalysis - Pore structure
Abstract:The synthesis of fully conjugated sp<sup>2</sup>-carbon covalent organic frameworks (COF) is extremely challenging given the difficulty of the formation of very stable carbon-carbon double bonds (-C=C-). Here, we report the successful preparation of a 2D COF (TP-COF) based on triazine as central planar units bridged by sp<sup>2</sup>-carbon linkers through the -C=C- condensation reaction. High-resolution-transmission electron microscopy (HRTEM) clearly confirmed the tessellated hexagonal pore structure with a pore center-to-center distance of 2 nm. Powder X-ray diffraction (PXRD) together with structural simulations revealed an AA stacking mode of the obtained layered structure. TP-COF turned out to be an excellent semiconductor material with a LUMO energy of −3.23 eV and a band gap of 2.36 eV. Excitingly, this novel sp<sup>2</sup>-carbon conjugated TP-COF exhibited unprecedented coenzyme regeneration efficiency and can significantly boost the coenzyme-assisted synthesis of l-glutamate to a record-breaking 97 % yield within 12 minutes.<br/> © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Volume:58
Issue:16
Translation or Not:no
