One-Pot Synthesis of a bis-Pocket Corrole through a 14-fold Bromination Reaction.

A one-pot protocol, effecting 14-fold bromination with elemental bromine, has afforded copper ß-octabromo-meso-tris(2,6-dibromo-3,5-dimethoxyphenyl)corrole, a new bis-pocket metallocorrole. The Cu complex underwent smooth demetalation under reductive conditions, affording the free corrole ligand, which in turn could be readily complexed to MnIII and AuIII. A single-crystal X-ray structure was obtained for the MnIII complex.

Ligand noninnocence in FeNO corroles: insights from ß-octabromocorrole complexes.

The first FeNO octabromocorroles have been synthesized including four ß-octabromo-meso-tris(p-X-phenyl)corrole derivatives Fe[Br8TpXPC](NO) (X = CF3, H, CH3, OCH3) and the ß-octabromo-meso-tris(pentafluorophenyl)corrole complex, Fe[Br8TPFPC](NO). The last complex, which proved amenable to single-crystal X-ray structure determination, exhibits the geometry parameters: Fe-N(O) 1.643(8) Å, N-O 1.158(9) Å, and a FeNO angle of 176.4(6)°. The more electron-deficient complexes exhibit increased instability with respect to NO loss and also higher infrared NO stretching frequencies (νNO). Interestingly, DFT calculations and IR marker bands indicate a noninnocent {FeNO}(7)-(corrole˙(2-)) formulation for all FeNO corroles, both ß-H8 and ß-Br8, with essentially the same degree of corrole radical character. Instead, an electron-deficient corrole appears to exert a field effect resulting in reduced Fe-to-NO backdonation, which accounts for both the increased instability with respect to NO loss and the higher νNO's.

Cryptic noninnocence: FeNO corroles in a new light.

Multiple lines of evidence, including electronic absorption spectroscopy, infrared spectroscopy, and broken-symmetry DFT calculations, indicate that the well-known FeNO corroles, long assumed to be {FeNO}(6) complexes, are in fact better described as {FeNO}(7)-(corrole˙(2-)).