Navigating the Bio‐Inspired Structure‐Function Landscape: Spectroscopy Driven Finding of Hidden Radical Oxidation in Co‐porphyrinic Porous Organic Polymer

ABSTRACT The conventional synthesis of acetophenone via the Friedel‐Crafts reaction is a highly waste‐intensive process. Consequently, the development of more sustainable and efficient alternatives is important. In this regard, radical oxidation represents a promising, environmentally benign route for acetophenone production. In this work, we designed a cobalt porphyrin‐based metalated porous organic polymer ( Co@POR‐POP ), a highly active catalytic system, offering a potentially viable and cleaner approach to acetophenone production, utilizing styrene as the starting material. The catalyst exhibits a high surface area (BET = 650 m ² g ⁻¹ ) with bimodal pores, and delivers more than 90% yield of acetophenone under ambient conditions with excellent selectivity. Synchrotron‐based XAFS spectroscopy study revealed a square‐planar Co‐N ₄ coordination environment with coordination number (CN) ≈4 and Co─N bond distance of ∼1.93 Å, with no evidence of Co–Co scattering, confirming the presence of isolated active sites. In situ EPR spectroscopy investigation displayed g _⊥ = 2.049 and g _∥ = 1.985 with hyperfine couplings A _⊥ = 49.8 MHz and A _∥ = 46.16 MHz, alongside an organic radical signal at g = 2.003. Spin‐trapping with DMPO detected both hydrogen (•H) and styrene (•C) radicals, validating a radical‐mediated mechanism. DFT calculations established a thermodynamically favourable pathway with an overall energy drop of −4.5 eV, supported by spin density localization at the Co centre and significant d‐π orbital overlap facilitating O ₂ activation. Overall, this work presents a new avenue of exploring novel organic transformation reactions using metalated porous organic polymer, opening scope for further investigations in this domain.