Erasable Photopatterning of Stilbene‐Based Metal‐Organic Framework Films

Abstract

The development of photosensitive materials for erasable photopatterning is of significant interest in anti-counterfeiting and information storage applications. Herein two kinds of stilbene-based metal-organic framework (MOF) films with layer by layer method for studying photopatterning is reported. The resulting 2D Zn 2 (sdc) 2 MOF film (sdc = 4,4′-stilbenedicarboxylate) exhibits excellent photosensitive features with a very short photoconversion time (<35 s) while the 3D MOF Zn 4 O(sdc) 6 film does not have the property due to the fact that only parallel and short distance arrangement of olefin groups in the adjacent MOF layers can trigger [2+2] photocycloaddition. Furthermore, the Zn 2 (sdc) 2 film indicates obvious reversible fluorescent photoswitch behavior between yellow and blue fluorescence emission, which can achieve high-efficient, erasable photopatterning with various sizes (ca. 20 microns to decimeter). This study not only develops a new kind of photosensitive crystalline network film but also provides erasable photopatterning from macroscopic to microscopic in optical applications.

Chiral Liquid Crystalline Metal–Organic Framework Thin Films for Highly Circularly Polarized Luminescence

“…The XRD pattern of Zn 2 (sdc) 2 thin film shows three sharp diffraction peaks at 5.4, 10.8, and 16.2° (Figure c), corresponding to (100), (200), and (300), respectively . The XRD patterns of LC/MOF, S-LC/MOF, and R-LC/MOF thin films are consistent with the data of Zn 2 (sdc) 2 thin film, which indicates that the skeleton of MOF was not destroyed after loading and polymerization with CLC (Figure S3).…”

Recent advances in photoresponsive fluorescent materials based on [2+2] photocycloaddition reactions

“…Rare examples were reported to develop effective strategies for controlling the stacking patterns of fluorophores facilitating [2+2] photocycloaddition reaction, but it was demonstrated that this intermolecular photoreaction can efficiently take place when the stacking patterns of the fluorophores were arranged in a right way using DNA or MOF-controlled assembly (Fig. 22), 115,116 and thus more efforts should be devoted to regulating molecular packing of fluorophores in a controllable manner.…”

Chemistry of Materials Nanoarchitectonics for Two-Dimensional Films: Langmuir–Blodgett, Layer-by-Layer Assembly, and Newcomers

“…Gu and co-workers fabricated two types of stilbene-based MOF films by the LbL method and investigated their optical patterning. 116 The aim was to develop a new type of highly sensitive MOF film triggered by [2 + 2] photocycloaddition. The photosensitivity varied greatly depending on the structure of the MOF.…”

“…The grain boundaries, structural defects, and orientation of the films were studied by a combination of microscopic analysis techniques and electrical measurements, demonstrating an “in-plane self-limiting and self-repairing” growth mechanism. Gu and co-workers fabricated two types of stilbene-based MOF films by the LbL method and investigated their optical patterning . The aim was to develop a new type of highly sensitive MOF film triggered by [2 + 2] photocycloaddition.…”