388075-97-6

Upstream product

• 7647-01-0 hydrogenchloride 
• 388076-00-4 μ-oxo-bis[meso-(triphenylcorrolato)iron(IV)] 

Downstream Products

• 1610623-60-3 C₃₇H₁₅Br₈FeN₄⁽¹⁺⁾*Cl^(1-) 

Relevant academic research and scientific papers

Chloroiron meso-triphenylcorrolates: Electronic ground state and spin delocalization

Four chloroiron meso-triphenyl-substituted corrolates have been synthesized and studied by 1H NMR spectroscopy. As in the case of the β-pyrrole-octaalkylcorrolatoiron chloride complexes studied previously [Inorg. Chem. 39 (2000) 3466], these complexes were also found to be S=3/2 Fe(III) corrolate(2-·) π-cation radical species, where the macrocycle radical electron is antiferromagnetically coupled to the metal electrons to give an overall S=1 complex. This conclusion is based upon the large alternating-sign contact shifts observed for the meso-phenyl protons. The 1H isotropic shifts of the pyrrole-H of these chloroiron-triphenylcorrolate complexes are similar to those of the chloroiron tri-(pentafluorophenyl)corrolate complex reported previously and said to be a S=1 Fe(IV) complex bound to a simple corrolate(3-) ligand [Inorg. Chem. 39 (2000) 2704]. The 19F NMR spectrum of the latter complex shows that it has small (negative) phenyl-F isotropic shifts for all phenyl-F, which might suggest that this single compound has a different electronic structure than all other chloroiron corrolates investigated thus far. However, there have as yet been very few NMR investigations of paramagnetic metal macrocycles having fluorine substituents, and thus it is premature to conclude that the small phenyl-F isotropic shifts are definitive proof of small spin density at the meso positions of the corrolate ring. It is concluded that pyrrole-H chemical shifts alone cannot differentiate the two possible electron configurations, simple S=1 Fe(IV) (Corr3-) and antiferromagnetically coupled S=3/2 Fe(III) (Corr2-·), and that based on the 1H investigations reported in this and two previous papers, all chloroiron corrolates reported thus far, with the exception of one, have the electron configuration S=3/2 Fe(III) (Corr2-·), in which the corrolate unpaired electron is antiferromagnetically coupled to the three metal electrons, yielding an overall spin for the complex, S=1. The electron configuration of the one exception, the strongly electron-withdrawing tri-(pentafluorophenyl)corrolate complex of iron chloride, cannot as yet be definitively assigned.

Iron(IV)-Corrole Catalyzed Stereoselective Olefination of Aldehydes with Ethyl Diazoacetate

Iron(IV)-corrole complexes were first investigated as catalysts for olefination of aldehydes with ethyl diazoacetate in the presence of triphenylphosphine. Efficient olefination of aromatic aldehydes with high trans-selectivity was observed, showing iron corrole is a new kind of promising catalyst for olefination reaction. Transformation of the phosphazine to ylide by iron(IV) corrole was proved to be the key step in the present system.

β-Nitro derivatives of iron corrolates

Two different methods for the regioselective nitration of different meso-triarylcorroles leading to the corresponding β-substituted nitrocorrole iron complexes have been developed. A two-step procedure affords three Fe(III) nitrosyl products-the unsubstituted corrole, the 3-nitrocorrole, and the 3,17-dinitrocorrole. In contrast, a one-pot synthetic approach drives the reaction almost exclusively to formation of the iron nitrosyl 3,17-dinitrocorrole. Electron-releasing substituents on the meso-aryl groups of the triarylcorroles induce higher yields and longer reaction times than what is observed for the synthesis of similar triarylcorroles with electron-withdrawing functionalities, and these results can be confidently attributed to the facile formation and stabilization of an intermediate iron corrole π-cation radical. Electron-withdrawing substituents on the meso-aryl groups of triarylcorrole also seem to labilize the axial nitrosyl group which, in the case of the pentafluorophenylcorrole derivative, results in the direct formation of a disubstituted iron μ-oxo dimer complex. The influence of meso-aryl substituents on the progress and products of the nitration reaction was investigated. In addition, to elucidate the most important factors which influence the redox reactivity of these different iron nitrosyl complexes, selected compounds were examined by cyclic voltammetry and thin-layer UV-visible or FTIR spectroelectrochemistry in CH2Cl2.

Electrochemical and electronic absorption spectroscopic studies of substituent effects in iron(IV) and manganese(IV) corroles. Do the compounds feature high-valent metal centers or noninnocent corrole ligands? Implications for peroxidase compound I and II intermediates

We report here an electrochemical and optical spectroscopic study of new Fe(IV) and Mn(IV) meso-triarylcorrole complexes. The complexes studied are three Fe(IV)Cl, three Mn(IV)Cl, and three dimeric Fe(IV)-OFe(IV) meso-tris(p-X-phenyl)corrole complexes, where X = CH3, H, and CF3. The first oxidation potentials of the Fe(IV)Cl and Mn(IV)Cl corrole complexes are considerably higher than those of the corresponding Fe(IV) corrole ??-oxo dimers, suggesting that the corrole ligands in the chloride complexes are already oxidized to a radical-like state. This is consistent with the suggestion by Walker and co-workers (ref 12) that the iron center in an (octaalkylcorrolato)FeIVCl complex is best described as intermediate spin (S = 3/2) and that it is antiferromagnetically coupled to a corrole ??-radical. We have attempted to clarify the nature of this antiferromagnetic coupling by means of DFT calculations and propose that it results from an metal(dz2)-corrole( b1 ) orbital interaction. In contrast, the corrole ligand in the Fe(IV) corrole ??-oxo dimers does not seem to have radical character. The optical spectra of the Fe(IV)Cl and Mn(IV)Cl corrole derivatives exhibit distinctive split Soret bands, one arm of which is strongly substituent sensitive. This behavior contrasts with that of free-base corroles and porphyrins and of typical metalloporphyrins whose optical spectra are relatively substituent-insensitive. We qualitatively assign this substituent-sensitive feature to a transition with significant ligand-to-metal charge-transfer character.