Photoinduced Electron Transfer in an Amine–Corrole–Perylene Bisimide Assembly: Charge Separation over Terminal Components Favoured by Solvent Polarity

Abstract

An assembly has been synthesised that consists of four units: a meso-substituted corrole (C3), perylene bisimide (PI), and two electron-rich triphenylamine (DPA) units. PI is connected through a 1,4-phenylene bridge to C3, whereas the two DPA units are linked to C3 through a diphenyl ether linkage, which is used for the first time to connect the various moieties. Various synthetic strategies were elaborated, and the chosen one afforded the final system in six steps in an overall yield of 6 %. The resulting assembly, made of three different units, was named a "triad". Excitation of the corrole (C3) or perylene bisimide (PI) units led to the charge-separated state DPA-C3(+)-PI(-) with a rate k>10(11) s(-1) in benzonitrile and dichloromethane (CH(2) Cl(2) ) or with k of the order of 10(10) s(-1) in toluene. The latter charge-separated state decayed to the ground state with a rate k=1.8×10(9) s(-1) in toluene. In the polar solvents benzonitrile and dichloromethane, recombination to the ground state competes with a charge shift to form the distal charge-separated state, DPA(+)-C3-PI(-), the formation of which occurs with a yield of 50 %. Recombination to the ground state of DPA(+)-C3-PI(-) occurs with a rate k=5×10(7) s(-1) in CH(2)Cl(2) and k=2×10(7) s(-1) in benzonitrile.

meso‐Ester Corroles

“…The CVs recorded for corroles 4 and 9 are shown as typical examples in Figure 3. All corresponding oxidation and reduction half‐wave potential values ( E 1/2 ) are listed in Table 3 together with those of 5,10,15‐trispentafluorophenylcorrole ( Tpfc ), 5,10,15‐tris(4‐methylphenyl)corrole ( TTc ),37 and 10‐(4‐methylphenyl)‐5,15‐(pentafluorophenyl)corrole ( C3 ) measured under the same experimental conditions 38. Each CV features two irreversible reduction waves and up to three irreversible oxidation waves (Figure 3).…”

“…as typical examples in Figure3.A ll corresponding oxidation and reduction half-wave potentialv alues (E 1/2 )a re listed in Ta ble 3t ogether with those of 5,10,15-trispentafluorophenylcorrole (Tpfc), 5,10,15-tris(4-methylphenyl)corrole (TTc), [37] and 10-(4-methylphenyl)-5,15-(pentafluorophenyl)corrole (C3)m ea-sured under the same experimental conditions. [38] Each CV features two irreversible reduction waves and up to three irreversible oxidation waves (Figure 3). Previous studies of the electrochemical properties of corrole free bases have shown that their redox behavior is rather complicated because the starting compounds, written as CorH 3 ,u ndergo facile gain or loss of inner protons.…”

“…Previous studies of the electrochemical properties of corrole free bases have shown that their redox behavior is rather complicated because the starting compounds, written as CorH 3 ,u ndergo facile gain or loss of inner protons. [37][38][39] Consequently,t he effect of meso-ester substituents on the redox properties of corrole are analyzed herein through the values of the half-wave potentials of the first oxidation and reduction processes, which produce, according to Equations (1) and (2), the corresponding radical[ C CorH 2 ], protonated [CorH 4 ] + ,o rd eprotonated [CorH 2 ] À forms that can be further oxidized or reduced. [37][38][39] For each compound, we also measured the half-wavep otentialv alue of the oxidation wave observed when reversing the scan in ap ositive direction immediately after the first reduction process that produced the anion [CorH 2 ] À (Figure 3).…”

Green and Red Fluorescent Dyes for Translational Applications in Imaging and Sensing Analytes: A Dual‐Color Flag

“…The most‐studied green dyes are fluoresceins, Oregon green 488 and 514, perylene diimide, the rhodamine green family, chlorophyll, and eosin . Red dyes typically come from rhodamines, porphyrins, and corroles …”

Functional Arrays for Light Energy Capture and Charge Separation

“…However, for this assembly a very efficient light energy collection on the corrole chromophore was detected; for details, see the original paper 61. Next, the structure DPA‐C3‐PI was synthesized (Figure b), which was somehow similar to the previous case but missing the extended conjugation of the terminal aromatic amine electron donor 62. This increases the HOMO–LUMO gap of the unit and makes it easier to oxidize.…”