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The synthesis and reactivity of $N$-bridged diiron macrocyclic complexes have been a topic of increasing interest in recent years since the observation of particular catalytic properties of these complexes. Herein, we report a preparation of a novel heteroleptic μ-nitrido diiron complex with unsubstituted phthalocyanine and octapropylporphyrazine macrocycles. This complex reacts with $m$-chloroperbenzoic acid to form high-valent diiron oxo species showing strong oxidizing properties. The formation and structure of the transient oxo species was investigated by cryospray collision induced dissociation MS/MS technique. Analysis of fragmentation pattern showed that the attachment of oxo moiety occurred at either iron phthalocyanine or at iron porphyrazine site with slight preference for the phthalocyanine iron site. The catalytic properties of the heteroleptic μ-nitrido diiron complex were evaluated in the oxidative transformation of hexafluorobenzene and perfluoro(allylbenzene).

$N$-bridged diiron porphyrinoid complexes are powerful oxidation biomimetic catalysts. Their use as oxidation catalysts is quite recent, as it started approximately one decade ago. Many mechanistic works and elucidation of properties are conducted on simple derivatives which are not functionalized, preventing their covalent incorporation into advanced materials, even though it would expand their scope of applications. With the ultimate purpose to produce $N$-bridged diiron porphyrinoid complexes that can be incorporated into advanced functionalized materials and thereby increase the range of their utilization, we have explored synthetic strategies to prepare di- and octafunctionalised $N$-bridged diiron porphyrin complexes, either with hydroxyl or propargyl functions, which have been selected for their versatility. The considerations taken into account for the synthetic strategies are detailed and the complexes are fully characterized.

Transformation of organofluorine compounds by oxidation pathways is rare in chemistry and biology since C-F bonds formed by the most electronegative element should react with electron-deficient oxidizing species. Recently, we have shown that $\mu$-nitrido diiron phthalocyanine complexes efficiently catalyze oxidative defluorination of poly- and perfluoroaromatics by H₂O₂. Herein, we studied their more biologically relevant porphyrin counterpart, $\mu$-nitrido diiron(III,IV) tetraphenylporphyrin complex (TPP)Fe${}^{\text{III}}(\mu$N)Fe${}^{\text{IV}}$(TPP) in stoichiometric and catalytic reactions with a series of fluorinated aromatic compounds under oxidation conditions. The addition of hexafluorobenzene to (TPP)Fe${}^{\text{III}}(\mu$N)Fe${}^{\text{IV}}$(TPP) in the presence of $t$-butylhydroperoxide led to the formation of high-valent $\mu$-nitrido diiron(IV,IV) porphyrin cation radical complex [TPP)Fe${}^{\text{IV}}(\mu$ -N)Fe${}^{\text{IV}}$(TPP${}^{+•}$]F₂. This complex was isolated and its structural and electronic properties were investigated by spectroscopic methods (EXAFS, XANES, EPR, UV-vis). Replacement of ${}^t$BuOOH with H₂O₂ oxidant resulted in the catalytic defluorination of selected heavily fluorinated aromatic compounds with high conversions (25–84%), TON (1768–3535), and defluorination degrees (71–84%). The scope of oxidative defluorination with (TPP)Fe${}^{\text{III}}(\mu$N)Fe${}^{\text{IV}}$(TPP) was extended to perfluorinated olefins exemplified by perfluoroallylbenzene. The perfluorinated double bond was more reactive compared with perfluorinated aromatic moiety providing C₆F₅CF₂COOH and C₆F₅COOH products. The properties of $\mu$-nitrido diiron tetraphenylporphyrin in homogeneous and heterogeneous catalytic defluorination were compared with those of its phthalocyanine counterpart.