Affiliation:
1. School of Chemistry and Chemical Engineering Nanjing University of Science and Technology Nanjing 210094 P. R. China
2. College of Material Science and Chemical Engineering Ningbo University of Technology 201 Fenghua Road Ningbo 315211 P. R. China
3. State Key Laboratory of Coordination Chemistry Nanjing University Nanjing 210023 P. R. China
Abstract
AbstractDesigning single‐component fluorochromic metal–organic frameworks (MOFs) with multiple stages presents a significant challenge in the field of functional and smart MOFs. In this study, this challenge is successfully addressed by designing and synthesizing a novel ligand called cyclooctatetrathiophene‐tetrapyridine (COTTTP), and incorporating it into 3D MOFs known as Zn/Cd‐COTTTP. By exploiting the intrinsic properties of COTTTP, specifically its ability to undergo geometry changes from a bent form to a more planar form, both COTTTP as an individual molecule and the resulting Zn/Cd‐COTTTP MOFs exhibit similar fluorochromic behavior. This behavior manifests as a color change from yellow to orange to red. Characterization techniques such as single crystal X‐ray diffraction, Fourier transform infrared spectroscopy, solid‐state UV–vis and near‐infrared spectroscopy, and X‐ray photoelectron spectroscopy are employed to investigate and confirm the geometry change of COTTTP within the MOF structures. Furthermore, the introduction of an auxiliary rigid ligand to the system is explored, which effectively restricts the geometry change of COTTTP and subsequently diminishes the fluorochromic behavior. This work sheds new light on the design and application of smart porous materials, particularly in the realm of single‐component fluorochromic MOFs. The successful incorporation of COTTTP and the understanding of its geometry change provide insights into the development of functional and responsive MOFs for various applications.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Jiangsu Province
Fundamental Research Funds for the Central Universities
Nanjing University of Science and Technology