Enhanced Photoconductivity of Metal–Organic Frameworks by Regulating <i>π</i>‐Stacking Pathways on Their Skeletons

Photoconductivity properties of metal–organic frameworks (MOFs) have recently become a cutting‐edge area of research. Enhancing photoconductivity through skeleton tuning, which can intuitively construct the relationship between MOF structures and photoconductivity properties, is desirable but still challenging. Herein, the photoconductivity enhancement of metal–organic frameworks (MOFs) through regulating π stacking pathways on their skeletons is reported. By using amino group functionalization or lengthening the dicarboxylic acid ligand to change the interpenetration, the distance between adjacent conjugated planes along the a‐axis of FJU‐67/68/69 increases from 4.433 to 5.031 Å, indicating that the π – π interactions gradually decrease, accompanied by a decrease in the on–off ratio of the photocurrent from 8.67 to 0. The spin density diagram after illumination based on density‐functional‐theory calculation for FJU‐67 shows its electron conduction pathway, closely related to the π – π interaction composed of the deprotoned 2,7‐bis(3,5‐dimethyl) dipyrazol‐1,4,5,8‐naphthalene tetracarboxydiimide (NDI) and the benzene ring. The in situ light‐illumination single‐crystal X‐ray diffraction of FJU‐67 verifies a minor enhancement of π – π interactions. This corresponds to a decrease in the distance between the centers of adjacent conjugated planes from 4.433 to 4.425 Å in its framework under 405 nm light irradiation.