The Corrole Radical

Abstract

The reaction of 5,10,15-trimesitylcorrole (H3 cor) with tungsten hexachloride and tungsten hexacarbonyl resulted in the unexpected formation of the 3,17-dichloro-5,10,15-trimesitylcorrole radical (H2 cor*) as an air-stable product. X-ray crystallography proved the planarization of the corrole radical structure, which was rationalized by the reduced steric hindrance of two versus three hydrogen atoms inside the N4 cavity. Although the aromaticity was lost, no specific changes in C-C or C-N bond distances could be observed. The regioselectivity of the two-fold chlorination is the result of the nucleophilic attack of chloride ions to an oxidized corrole macrocycle, and is supported by DFT results. The corrole radical acts as a dianionic ligand and allows the insertion of the divalent zinc(II) cation, which usually does not form neutral corrole complexes.

Rhenium(v)–oxo corrolazines: isolating redox-active ligand reactivity

“…These features are characteristic of a corrole, 19 porphyrazine, 20 and corrolazine π-radical. 9–10,18 Spectral titration showed one equiv of oxidant was required for complete formation of the π-radical cation complex (Fig.…”

Spontaneous Formation of an Air‐Stable Radical upon the Direct Fusion of Diphenylmethane to a Triarylporphyrin

“…[6] Time-dependent DFT calculations at the UB3LYP/6-31G(d) level [12] predicted that the lowest-energy transitions of 7Ni and 7FB are HOMO-SOMO transitions. [6] Time-dependent DFT calculations at the UB3LYP/6-31G(d) level [12] predicted that the lowest-energy transitions of 7Ni and 7FB are HOMO-SOMO transitions.…”

“…[1] Organic radicals exhibit characteristic electrochemical, optical, and magnetic properties derived from an unpaired electron, which encourages their use in the fields of molecular conductors, [2] spin-based batteries, [3] magnetic bistable materials, [4] and bioimaging. [6] During our studies on p-expanded fused porphyrins,w e have explored heteroatom-embedded Ni II porphyrins,such as 1Ni (nitrogen-embedded), [7] 2Ni (boron-embedded), [8] and 3Ni (silicon-embedded) [9] (Scheme 1). In recent years,ithas been demonstrated that porphyrinoids are effective platforms to stabilize radicals owing to extensive spin delocalization.…”

meso-N-Methylation of a porphyrinoid complex: activating the H-atom transfer capability of an inert ReV(O) corrolazine

“…The unalkylated Re V (O) complex is unreactive toward electron- and hydrogen-atom donors, whereas alkylated 1 undergoes one-electron reduction to give an air-stable 19π-electron radical complex. The stabilization of organic radicals with extended porphyrinoid π systems has been the focus of much effort, 9b, 10 and reduced 1 is a rare example of such a species. A PCET mechanism is indicated from kinetic and thermodynamic analyses of the reaction of 1 with H-atom donors.…”

“…[8c,14] However, a similarly red-shifted band at 915 nm was recently reported for a P V porphyrazine π-radical complex. [10b] The new 920 nm species can be quantitatively converted back to 1 by titration with the one-electron oxidant Cp 2 Fe + PF 6 − (Fig. S11, ESI † ).…”