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Meso-Modified Porphyrinoids: Stimuli-Driven Conformational Plasticity, Modulation of π-Conjugation, and Bis-Rh(I)
Rampal Vishwakarma1, Mainak Das2, A Srinivasan1
1School of Chemical Sciences, National Institute of Science Education and Research (NISER), An OCC of Homi Bhabha National Institute, Bhubaneswar 752050, Odisha, India.
Abstract:
Topology and the extent of π-electron delocalization govern the (anti)aromatic behavior in macrocycles. We report meso-carbon-amended porphyrinoids with ortho-benzannulation at the periphery for rigidity and vinylogous linkages for flexibility. This design enables stimuli-responsive conformational plasticity and tunable (anti)aromaticity, manifesting as moderate Hückel antiaromaticity in freebases, weak Möbius aromaticity upon protonation, and nonaromaticity through bis-Rh(I) complexation, resulting in foldameric structures with η2 coordination and panchromatic absorption. Thus, this design reveals topology-property relationships in π-conjugated macrocycles.
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