Tetrabenz[ a , c , h , j ]anthracene-Bridged Carbaporphyrin Dimer

A new carbaporphyrin dimer ( 8 ) featuring a π-extended polycyclic aromatic hydrocarbon (PAH) bridge, namely, tetrabenz[ a, c, h, j ]anthracene (TBA), was synthesized and characterized. Single-crystal X-ray structure analysis revealed that 8 exhibits an overall nearly planar configuration. 1 H NMR spectroscopy and nucleus-independent chemical shift (NICS) calculations demonstrated reduced paratropicity in the two carbaporphyrin(1.1.1.0) subunits compared to the previously reported dibenzo[ g, p ]chrysene (DBC)-bridged analogue. The local aromaticity of the individual benzene rings of the TBA bridge is found to be disrupted by the fusion of the carbaporphyrin(1.1.1.0) units as well. Furthermore, 8 could coordinate with Cu(III) and Ag(III) ions to form bis-metal complexes. Metal coordination enhanced molecular planarity, and the bis-metallic complexes maintained antiaromatic characteristics. This research elucidates the regulatory role of the π extension of the PAH bridge on the (anti)aromatic character and coordination behavior of carbaporphyrin dimers, providing valuable insights for the design of novel PAH–porphyrin hybrid functional molecular systems.