A zinc porphyrin-based halogen-bonded organic framework with the heavy atom effect as a highly efficient photocatalyst for oxidative coupling of amines

Abstract

Understanding the influence of connection knots on the properties of organic frameworks is pivotal in exploring their functions and potential applications. In this study, we demonstrate the design and preparation of a novel porphyrin-based halogen-bonded organic framework, XOF-ZnTPP, utilizing [N⋯I⁺⋯N] halogen bonds. XOF-ZnTPP has been comprehensively characterized, revealing a well-defined orderly crystalline structure. This framework exhibits pronounced photophysical activity and an enhanced yield of singlet oxygen (¹O₂), compared with the monomeric precursor, ZnTPP. This increase in ¹O₂ generation is mainly attributed to the heavy atom effect, among the unique structural features of the framework, supported by DFT calculations. Moreover, XOF-ZnTPP demonstrates superior catalytic efficacy in the aerobic oxidative coupling of amines with outstanding recyclability and stability. This research offers insights into the impact of the connection motifs on organic frameworks, which may help to extend their functions and applications.