Triply N‐Confused Hexaphyrins(1.1.1.1.1.0) Synthesized From N‐Confused Hexaphyrin(2.1.1.1.1.1): Aromaticity Modulation, Metal Coordination, and Photothermal Conversion

Antiaromatic compounds exhibit intriguing structures, reactivity, and physicochemical properties. To address the challenge in developing stable antiaromatic porphyrinoids, a vinylene bridge and an α,β′‐linked pyrrole unit were used to synthesize a 28π Möbius aromatic N‐confused oxohexaphyrin(2.1.1.1.1.1) ( 1 ). Subsequent oxidative C β –C β fusion afforded a stable Hückel antiaromatic formally triply N‐confused oxohexaphyrin(1.1.1.1.1.0) ( 2 ) as a hybrid of 24 and 28π systems with two peripheral NH moieties, enabling further C–N fusion with the adjacent C 6 F 5 moiety under basic conditions to yield the corresponding N‐confused dioxohexaphyrin(1.1.1.1.1.0) ( 3 ), which shows Hückel antiaromaticity with a modulated circuit. Coordination of various metals within the distinct coordination cavities afforded two mono‐rhenium complexes 3‐Re‐1 (NNη 2 ‐coordinated) and 3‐Re‐2 (NNO‐coordinated) along with a mono‐Pd complex 3‐Pd‐1 (CNNO‐coordinated) with modulated antiaromaticity. On this basis, the heterobimetallic complex 3‐O‐Pd‐Re was synthesized with the conjugation and antiaromaticity disrupted by further oxygenation. Notably, these compounds display distinctive near‐infrared (NIR) absorption, enabling pronounced photothermal conversion under 1064 nm laser irradiation with efficiencies up to 61.4%. This work composes an effective post‐fusion approach for developing multiply N‐confused porphyrinoids with tunable antiaromaticity and distinctive coordination properties to achieve efficient NIR photothermal conversion behavior.