Corrole–Porphyrin Conjugates with Interchangeable Metal Centers

Abstract

Oligoporphyrinoid materials composed of two or three tetrapyrrolic macrocycles have been synthesized by either mono‐ or disubstitution (SNAr) of a phenolic Zn‐AB3‐porphyrin on a meso‐dichloropyrimidinyl‐substituted Cu‐AB2‐corrole. Selective metallation/demetallation sequences were carried out on these mixed corrole–porphyrin conjugates to afford multichromophoric systems with variable metal centers. The absorption spectra of the free‐base corrole–porphyrin systems were essentially additive, which demonstrates that only weak intercomponent interactions take place in these assemblies and therefore they can be regarded as supramolecular systems. Photophysical studies of the free‐base conjugates showed that these species are highly fluorescent, with fluorescence occurring from the lowest‐energy singlet state of the porphyrin subunit(s), which is (are) the lowest‐energy state(s) of the assemblies. Pump‐probe transient absorption spectroscopy experiments demonstrated that very efficient (>95 %) corrole‐to‐porphyrin singlet–singlet energy transfer takes place in these pyrimidinyl‐bridged multichromophoric systems by a coulombic mechanism with rate constants on the picosecond timescale.

Absorption and Fluorescence Features of an Amphiphilic meso-Pyrimidinylcorrole: Experimental Study and Quantum Chemical Calculations

“…Synthetic strategies from the literature were used. [36][37][38][39][40] A mixture of p-octylbenzaldehyde (1) and BF3⋅OEt2 (3 µL, 0.043 equiv) in dichloromethane (50 mL) was added dropwise over 2 h to a stirred solution of pyrimidinyldipyrromethane 2 (600 mg, 1,17 mmol) in dichloromethane (400 mL), under N2. The mixture was shielded from light and further stirred overnight at room temperature.…”

Engaging Copper(III) Corrole as an Electron Acceptor: Photoinduced Charge Separation in Zinc Porphyrin–Copper Corrole Donor–Acceptor Conjugates

“…Osuka and co‐workers reported the preparation of β , β ‐linked corrole dimers by using Suzuki–Miyaura cross‐coupling (after regioselective Ir‐catalyzed direct borylation), whereas Gryko has disclosed the preparation of a meso–meso ‐corrole–porphyrin dyad containing an amide and imide spacer . In recent years, we have focused on the synthesis and functionalization of corrole . One such example involves a high yielding preparation of a bis‐porphyrin–corrole triad employing nucleophilic aromatic substitution of the pyrimidinyl‐substituted corroles involving phenolic porphyrins .…”

“…[28,29] In recent years, we have focused on the synthesis and functionalization of corrole. [30][31][32][33][34][35][36][37][38] One such example involves ah igh yieldingp reparation of ab is-porphyrin-corrole triad employing nucleophilic aromatic substitution of the pyrimidinylsubstituted corroles involving phenolic porphyrins. [30] The first report of the application of the click reactioni nt etrapyrrole chemistry was made by Collman and Chidsey in 2006.…”

Corrole‐Decorated Porphyrin Dendrimer and Its Selective Metallation

“…Both porphyrins and corroles form stable chelates with many elements,18 but their affinity to divalent metal ions is very different: large for porphyrins and virtually zero for corroles 10b. This knowledge was used for selective metallation of the inner core of 5 , whose treatment with zinc(II) acetate provided the Zn‐ 5 complex in which zinc(II) is only chelated by the central porphyrin core (Scheme ).…”