444987-83-1

Upstream product

• 12093-10-6 ferrocenecarboxaldehyde 
• 142-71-2 copper diacetate 
• 107798-98-1 5-phenyldipyrromethane 
• 6046-93-1 copper(II) acetate monohydrate 

Downstream Products

• 444987-87-5 (2,3,7,8,12,13,17,18-octabromo-5,10,15-triphenylcorrolato)copper 

Relevant academic research and scientific papers

5,10,15-triferrocenylcorrole complexes

Complexes of 5,10,15-triferrocenylcorrole were synthesized from the crude free-base corrole product obtained by the reaction of ferrocenyl aldehyde and pyrrole. Direct formation of the complex in this manner leads to an increase of the reaction yield by protecting the corrole ring toward oxidative decomposition. The procedure was successful and gave the expected product in the case of the copper and triphenylphosphinecobalt complexes, but an unexpected result was obtained in the case of the nickel derivative, where metal insertion led to a ring opening of the macrocycle at the 5 position, giving as a final product a linear tetrapyrrole nickel complex bearing two ferrocenyl groups. The purified 5,10,15-triferrocenylcorrole complexes have been fully characterized by a combination of spectroscopic methods, electrochemistry, spectroelectrochemistry, and density functional theory calculations. Copper derivatives of 10-monoferrocenyl- and 5,15-diferrocenylcorrole were prepared to investigate how the number and position of the ferrocenyl groups influenced the spectroscopic and electrochemical properties of the resulting complexes. A complete assignment of resonances in the 1H and 13C NMR spectra was performed for the cobalt and nickel complexes, and detailed electrochemical characterization was carried out to provide additional insight into the degree of communication between the meso-ferrocenyl groups on the conjugated macrocycle and the central metal ion of the ferrocenylcorrole derivatives.

Observations on the Mechanochemical Insertion of Zinc(II), Copper(II), Magnesium(II), and Select Other Metal(II) Ions into Porphyrins

Building on a proof of concept study that showed the possibility of the mechanochemical insertion of some M(II) metals into meso-tetraphenylporphyrin using a ball mill as an alternative to traditional solution-based methods, we present here a detailed study of the influence of the many experimental variables on the reaction outcome performed in a planetary mill. Using primarily the mechanochemical zinc, copper, and magnesium insertion reactions, the scope and limits of the type of porphyrins (electron-rich or electron-poor meso-tetraarylporphyrins, synthetic or naturally occurring octaalkylporphyrins, and meso-triphenylcorrole) and metal ion sources suitable for this metal insertion modality were determined. We demonstrate the influence of the experimental metal insertion parameters, such as ball mill speed and reaction time, and investigated the often surprising roles of a variety of grinding agents. Also, the mechanochemical reaction conditions that remove zinc from a zinc porphyrin complex or exchange it for copper were studied. Using some standardized conditions, we also screened the feasibility of a number of other metal(II) insertion reactions (VO, Ni, Fe, Co, Ag, Cd, Pd, Pt, Pb). The underlying factors determining the rates of the insertion reactions were found to be complex and not always readily predictable. Some findings of fundamental significance for the mechanistic understanding of the mechanochemical insertion of metal ions into porphyrins are highlighted. Particularly the mechanochemical insertion of Mg(II) is a mild alternative to established solution methods. The work provides a baseline from which the practitioner may start to evaluate the mechanochemical metal insertion into porphyrins using a planetary ball mill.

Improved syntheses of β-octabromo-meso-triarylcorrole derivatives

In spite of significant applications as starting materials for a variety of metallocorrole derivatives, free-base β-octabromo-meso-triarylcorroles continue to be viewed as inaccessible. The reasons range from the need for tedious column-chromatographic pu

Electronic absorption, resonance Raman, and electrochemical studies of planar and saddled copper(III) meso-triarylcorroles. Highly substituent-sensitive Soret bands as a distinctive feature of high-valent transition metal corroles

We present here a first systematic study of substituent effects in metallocorroles, based on electronic absorption, resonance Raman (RR), and infrared (IR) spectroscopic studies and electrochemical measurements on 10 copper(III) meso-triarylcorroles, CuIII[β-Y8TArC], where the β-substituent Y = H or Br and the meso-aryl group Ar = C6F5 or p-X-C6H4 and X = CF3, H, CH3, and OCH3. The results afford a number of significant inisights. (1) The RR (and IR) results show that at least two and possibly more high-frequency bands in the 1400-1550 cm-1 region exhibit significant frequency downshifts on β-octabromination and, thus, qualify as structure-sensitive marker bands. DFT geometry optimizations indicate that the saddled conformation should be clearly preferred for the β-octabromo-meso-triarylcorrole derivatives studied and that β-octabromination results in expansion of a number of skeletal bond distances of the corrole macrocycle, consistent with observed frequency downshifts. (2) Electrochemical measurements on planar CuIII[TArC] derivatives have shown that the para substituents on the meso-aryl groups exert a strong influence on the half-wave potentials for oxidation (ρox = ΔE1/2ox/Δ(3σ) = 95 mV), suggesting that oxidation involves removal of an electron from the corrole "b1" HOMO, which has significant amplitudes at the meso postions and crudely resembles a porphyrin a2u HOMO in shape. In contrast, the Hammett ρox is much lower for the nonplanar CuIII[Br8TArC] derivatives and we suggest that this ultimately results from a b1-to-a2 HOMO reversal which in turn stems from a metal (dx2-y2)-corrole ("b1") orbital interaction that becomes symmetry-allowed under a saddle distortion of the corrole macrocycle. In contrast to what has been observed for metallotetraphenylporphyrins, β-octabromination dramatically raises the half-wave potential for one-electron oxidation of the triarylcorrole derivatives studied. This appears to be due to the fact that both the "a2" and "b1" HOMOs of a corrole (in C2v notation) have significantly higher amplitudes at the β positions, compared to a porphyrin a2u HOMO. Thus, although many metallocorroles are significantly more easily oxidizable than analogous metalloporphyrins, certain β-octahalogeno-meso-triarylcorrole derivatives can indeed be extremely electron deficient and oxidation resistant and may, therefore, find use as rugged catalysts or reagents under highly oxidizing conditions. (3) Finally, the Soret absorption maxima of high-valent metallotriarylcorroles exhibit a uniquely sensitive dependence on the substituents on the meso-aryl groups. Thus, on going from CuIII[T(p-CF3-P)C] (T(p-CF3-P)C = meso-tris((p-trifluoromethyl)phenyl)corrolato) to CuIII[T(p-OM-P)C] (T(p-OM-P)C = meso-tris(p-methoxyphenyl)corrolato), the Soret maximum red shifts by 26 nm, from 407 to 433 nm. Similarly, on going from CuIII[Br8T(p-CF3-P)C] (Br8T(p-CF3-P)C = β-octabromo- meso-tris((p-trifluoromethyl)phenyl)corrolato) to CuIII[Br8T(p-OM-P)C] (Br8T(p-CF3-P)C = β-octabromo-meso- tris(p-methoxyphenyl)corrolato), the Soret maximum red shifts by 34 nm, from 434 to 468 nm. Time-dependent DFT calculations suggest that this substituent dependence reflects significant ligand-to-metal charge-transfer character of certain transitions in the Soret region. The optical spectra of free-base and non-high-valent transition metal tetrapyrroles, in general, do not exhibit a similar substituent dependence.