Copper corroles

Copper corrole is a diamagnetic copper(III) complex which at higher temperatures exists in the triplet state and is then best formulated as a copper(II) corrole-n-radical. 

Copper Corrole Oxidation States Experiment and Theory... 

Fig. 13 The crystal structure of a highly saddled copper [3-octabrominated corrole complex (left) and the predicted saddling angles for a number of mero-triaryl-substituted copper corroles. Reprinted with permission from [171]. Copyright 2010 American Chemical Society...

Johnson AW, Grigg R, Shelton G (1971) Structures and thermal rearrangements of alkylated palladium and copper corroles. J Chem Soc C Organic 12 2287-2294... 

Will S, Lex J, Vogel E, Schmickler H, Gisselbrecht JP, Haubtmann C, Bernard M, Gross M (1997) Nickel and copper corroles well-known complexes in a new light. Angew Chem Int Ed Engl 36 357-361... 

Ou Z, Shao J, Zhao H, Ohkubo K, Wasbotten IH, Fukuzumi S, Ghosh A, Kadish KM (2004) Spectroelectrochemical and ESR studies of highly substituted copper corroles. J Porphyr Phthalocyanines 8 1236—1247... 

Broring M, Bregier F, Tejero EC, Hell C, Holthausen MC (2007) Revisiting the electronic ground state of copper corroles. Angew Chem Int Ed 46 445 448... 

Pierloot K, Zhao H, Vancoillie S (2010) Copper corroles the question of non-innocence. Inorg Chem 49 10316-10329... 

Alemayehu A, Gonzalez E, Hansen LK, Ghosh A (2009) Copper corroles are inherently saddled. Inorg Chem 48 7794—7799... 

Capar C, Thomas KE, Ghosh A (2008) Reductive demetalation of copper corroles first simple route to free-base P-octabromocorroles. J Porphyr Phthalocyanines 12 964-967... 

Figure 3.5. Electronic absorption spectra of a series of copper corroles with systematically varying substituents.

It was found that addition of hydroxide anion in dimethylformamide or dimethylsulfoxide to metal(II) corrole complexes results in the appearance of much sharper absorption bands relative to the starting compounds. These findings were considered consistent with the idea that an anionic, 18 Jt-electron aromatic corrole complex (e.g., 2.119) is formed as the result of what appears to be a formal deprotonation process (Scheme 2.1.25). That deprotonation actually occurs was inferred from acid-base titrations involving nickel(II) and copper(II) corroles. The conclusion that these species are anionic aromatic compounds came from an appreciation that their electronic spectra resemble those recorded for divalent metallo-porphyrins. In any event, the anion that results was found to be quenched upon acidification, regenerating the corresponding non-aromatic metallocorroles. ... 

As hinted at previously, Vogel and coworkers have recently offered an alternative interpretation of what occurs when corroles are reacted with divalent metals." This work, which has been largely focused on nickel and copper, has served to call into question the structural and metal oxidation state assignments not only of the... 

The reaction of corrole 2.82 with copper(II) acetate was also found to produce a neutral complex that is spectroscopically identical to that previously described. In this case, however, the complex that results was assigned structure 2.181, wherein oxidation of the metal center from + 2 to +3 appears to have occurred (Scheme 2.1.58). This is in marked contrast to the two previous structural assignments (i.e.. 

A single crystal X-ray diffraction analysis of this abovementioned N(21)-methyl copper(II) corrole 2.215 confirmed the site of methylation to be at N(21). This same structure also revealed a rather distorted molecule with the N-methylated pyrrole ring being twisted out of the mean plane of the remaining pyrrolic portions of the macrocycle. Thus, this X-ray structure was seminal in its time. It provided both a... 

Attempts to insert copper(II) into either A(21)-allyl or A(22)-allyl corroles using Cu(OAc)2 as the metal source led only to the formation of N-unsubstituted copper(II) corroles. On the other hand, heating AT(21)-allyl or A(22)-allyl corroles with Ni(OAc)2 led to no reaction whatsoever. (The starting materials were isolated... 

Subsequent to the submission of this manuscript, a communication detailing the interpretation of copper (II) and nickel (II) corrole as II radical cations was published by Vogel et al Another report in the calix[3]-indole area also appeared. 

Group 11. Paramagnetic (1H, 15N) NMR spectra were used to study a Cu -IDA (=iminodiacetic acid) complex localised on a protein surface. H and 13C NMR spectra were reported for copper(II) bis-benzimidazole complexes.1225 Variable temperature H NMR spectra of copper complexes of p-octafluorinated triarylcorroles reveal a thermally-accessible paramagnetic excited state, i.e. a Cu11 corrole 7i-cation radical.1226 Copper(II) forms of stellacyanin from Rhus vernicifera were characterised by H NMR.1227... 

Abstract The transition metal complexes of the non-innocent, electron-rich corrole macrocycle are discussed. A detailed summary of the investigations to determine the physical oxidation states of formally iron(IV) and cobalt(IV) corroles as well as formally copper(III) corroles is presented. Electronic structures and reactivity of other metallocorroles are also discussed, and comparisons between corrole and porphyrin complexes are made where data are available. The growing assortment of second-row corrole complexes is discussed and compared to first-row analogs, and work describing the synthesis and characterization of third-row corroles is summarized. Emphasis is placed on the role of spectroscopic and computational studies in elucidating oxidation states and electronic configurations. 

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