Full-Dimensional Control of Covalent Organic Frameworks Through Repulsion-Torsion Effect: Prominent 1D Above 2D and 3D Structures.

Exploring the impact of different dimensions on the properties and functions of covalent organic frameworks (COFs) has always been a key goal, as this can provide feedback to assist in the design of advanced COFs. However, this goal has never been performed simultaneously in one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) COFs, due to the difficulty of dimensional control. Herein, for the first time, we synthesized three novel COFs with different dimensions, from similar composition by manipulating the conformation of the molecular building blocks through repulsion-torsion effect. Impressively, the strong repulsion-torsion effect transformed the planar building block into a non-planar building block, resulting in the construction of 2D and 3D COFs, respectively. Moreover, when we consciously reduced the repulsion-torsion effect, the resulting intramolecular conformation struggled to meet the requirements for the formation of 2D and 3D structures, ultimately generating a rare 1D COF. Further research indicated the charge transfer efficiency and photocatalytic performance of the resulting COFs followed a dimensional order of 1D > 3D > 2D. This phenomenon was attributed to the unique in-plane and out-of-plane double rotational restriction (IODRR) effect in the 1D structure, which stabilized the aromatic framework and thus greatly reduced the carrier recombination probability and energy loss.