Engineering the electronic and optical properties of 2D porphyrin-paddlewheel metal-organic frameworks

Abstract Metal-organic frameworks (MOFs) are promising photocatalytic materials due to their high surface area and tuneability of electronic structure. We discuss here how engineer the band structures optical properties a family two-dimensional porphyrin-based MOFs, consisting M -tetrakis(4-carboxyphenyl)porphyrin ( -TCPP, where = Zn or Co) metal (Co, Ni, Cu Zn) paddlewheel clusters, with aim optimising behaviour in solar fuel synthesis reactions (water-splitting and/or CO 2 reduction). Based on density functional theory (DFT) time-dependent DFT simulations hybrid functional, we studied three types composition/structural modifications: (a) varying centre at porphyrin modify alignment; (b) partially reducing unit chlorin, which leads stronger absorption visible light; (c) substituting benzene bridging between paddlewheel, by ethyne butadiyne bridges, modifying linker charge transfer behaviour. Our work offers new insights improve porphyrin- paddlewheel-based MOFs.