2024-01-282024-01-28 23:18浏览数:86次
Chiral transfer amidst one-dimensional linear polymers and twodimensionalnetwork covalent organic frameworks: Striking a finebalance between helicity and crystallinity Abstract: The current landscape of chiral covalent organic frameworks (COFs) predominantly centered on constructing asymmetricmolecular-scale chirality, often introducing an inherent contradiction to the COF symmetry and limiting diversity. Herein, weovercome these challenges by achieving chiral transfer between one-dimensional (1D) imine linear polymers (LPs) and twodimensional (2D) network β-ketoenamine COFs composed of achiral monomers. We successfully synthesize several 1D imineLPs with mesoscopic helical chirality, comprising achiral C2-symmetric terephthalaldehyde and diamine linkers in a chiralsupramolecular transcription system. Leveraging the irreversible tautomerism mechanism within the linker replacementapproach, terephthalaldehyde (TPA) units in these helical 1D LPs are substituted with C3-symmetric 1,3,5-triformylphloroglucinol(TP), yielding the corresponding 2D network β-ketoenamine COFs. Crystallinity and helicity of the resultant β-ketoenamine COFsintimately hinge on reaction conditions, including the aldehyde stoichiometry of Tp and TPA, as well as the quantity andconcentration of the catalyst employed. Under optimized conditions, the nucleation and growth were precisely governed,achieving a harmonious equilibrium of crystallinity and helicity within the generated 2D network β-ketoenamine COFs, even withcovalent bond rupture, recombination, and topological transition (from [C2 + C2] to [C3 + C2]). Impressively, the ground statechirality inherent to helical 1D LPs seamlessly transfers to helical 2D network β-ketoenamine COFs. This study not only offersnew perspectives on the development of chiral functional COFs, but also provides fresh insights into the precise control of COFs'microscopic morphology. Xinlin Zha, Mengjuan Zuo, Guilin Xu, Zhong Yan, Haining You, Yi Xiong, Ying Liu, Yingying Li, Liyan Yang,Ke Liu, Mufang Li, Tao Zhao, and Dong Wang. Chiral transfer amidst one-dimensional linear polymers and twodimensionalnetwork covalent organic frameworks: Striking a finebalance between helicity and crystallinity . Nano Research. (2024). |