Ruffling and doming: Structural and redox studies on meso-aryl and β-alkyl chromyl(V)corroles

Abstract

Chromyl(V) complexes of eleven different meso-aryl- and [Formula: see text]-alkylcorrole ligands have been prepared and characterized by analytical, spectroscopical, electrochemical and structural means. All seven new complexes show the expected optical spectra of chromyl(V) corroles with the Soret band situated slightly above (meso-arylcorroles) or below ([Formula: see text]-alkylcorrole) 400 nm, and with an isotropic room temperature EPR signal for the [Formula: see text] ion Cr(V) at about [Formula: see text]. Cyclic voltammetry evidences two or three quasi-reversible one-electron redox steps, which are characterized as two ligand-centered processes and one metal-centered process based on spectroelectrochemical measurements and a Hammett analysis. Chemical reduction to a chromyl(IV) corrolate was successfully performed using NaHg and NEt3. Citric acid, however, produces a different reduction product, for which an isocorrole structure is proposed. Six chromyl(V) corroles could be analysed by seven single crystal diffraction analyses. The obtained molecular data prove the presence of remarkably similar CrN4O coordination units independent of the corrole substitution pattern, and of macrocyclic conformations which can be understood as comprised mainly of a doming mode, a more or less pronounced saddling mode, and one out of two different and dominating ruffling modes.

PorphyStruct: A Digital Tool for the Quantitative Assignment of Non‐Planar Distortion Modes in Four‐Membered Porphyrinoids

“…Chromyl corroles . Besides the phosphorus(V) corroles, ruffling modes have also been reported in the literature for chromyl corroles with the small Cr(V) central atom [7i] . A PorphyStruct analysis of 7 structures (6 x meso ‐triaryl, 1x β ‐octaalkyl substitution) with the minimal basis succeeds only in two cases, so that the extended basis is used again.…”

“…Besides the phosphorus(V) corroles, ruffling modes have also been reported in the literature for chromyl corroles with the small Cr(V) central atom. [7i] A PorphyStruct analysis of 7 structures (6 x meso ‐triaryl, 1x β ‐octaalkyl substitution) with the minimal basis succeeds only in two cases, so that the extended basis is used again. The compounds reveal a D oop value for the overall distortion of 0.39–0.68, and significant doming modes of 0.19–0.44 Å, with the octaalkyl compound being the most distorted species.…”

Synthesis, Characterization, and the N Atom Transfer Reactivity of a Nitridochromium(V) Complex Stabilized by a Corrolato Ligand

“…Oxo-[5,10,15-tris( p -cyanophenyl)corrolato]chromium(V), 1 , was synthesized by following a literature-reported method. 39 (Saloph)Mn V (N) was prepared by following a literature-reported method. 41 5,10,15-Tris(4-cyanophenyl)corrole was prepared according to a literature-reported protocol.…”

“…38c We have reported here the synthesis of a new nitrido(corrolato)chromium(V) complex, namely, [nitrido{5,10,15-tris( p -cyanophenyl)corrolato}chromium(V)] − , 3 ( Scheme 1 ). An oxo[5,10,15-tris( p -cyanophenyl)corrolato]chromium(V) complex, 1 , 39 has been used as a precursor complex, and the synthesis of a new nitrido(corrolato)chromium(V) complex was achieved via using nitrido(salophen)manganese(V) [salophen = N , N ′ - o -phenylenebis(salicylidene-iminato) dianion] as a nitrogen atom transfer reagent ( Scheme 2 ). The nitrido{5,10,15-tris( p -cyanophenyl)corrolato}chromium(V) complex, 3 , has been fully characterized via various spectroscopic techniques.…”

Corroles and Hexaphyrins: Synthesis and Application in Cancer Photodynamic Therapy

“…The A 3 -type chromyl(V) triarylcorrole complexes 53 were prepared from the corresponding free base corroles in moderate yields by metalation with chromium oxide in refluxing toluene ( Scheme 20 ) [ 57 ]. Even though having high similarity in electronic and structural properties, complexes 53 show some differences in redox potentials, which were associated with the inductive effect of the substituents at the 4 position of the aryl groups.…”