The oxidation of 10-10' singly linked corrole dimers with DDQ at low concentration in CHCl3 afforded meso-meso, β-β, β-β triply linked 2H-corrole dimers (with two inner NH groups in each corrole unit), which exhibited characteristic (1) H NMR and absorption spectra attributable to their nonaromatic electronic networks. These 2H-corrole dimers were reduced with NaBH4 to aromatic 3H-corrole dimers, which were unstable and easily oxidized back to the 2H-corrole dimers upon exposure to air. Bis(zinc(II)) complexes of the 2H-corrole dimers were synthesized and characterized as rare examples of nonaromatic zinc(II) corrole complexes.

A singly linked corrole dimer was synthesized by condensation of a dipyrromethane-1-carbinol with 1,1,2,2-tetrapyrroethane. Oxidation of the dimer gave doubly linked corrole dimers 9 and 10 as the first examples of fused corrole dimers involving a meso-meso linkage. Dimers 9 and 10 exhibit characteristic (1)H NMR spectra, absorption spectra, excited-state dynamics, and two-photon absorption (TPA) values, which indicate the nonaromatic nature of 9 and the aromatic nature of 10. Interestingly, 9 is fairly stable despite its unusual 2H-corrole structure, which has been ascribed to the presence of two direct connections between the individual corrole units.

5,10-Bis(pentafluorophenyl)corrole (5) and 5,15-bis(pentafluorophenyl)corrole (9) have been synthesized as meso-free corroles by rational synthetic routes. Both the structures of these corroles have been unambiguously revealed by X-ray diffraction analysis and their optical and electrochemical properties have been studied. Chlorination and oxidative dimerization of 5 and 9 have been explored, which revealed a marked different reactivity of the free meso-positions in 5 and 9. 10-Chlorinated corrole 11 was effectively prepared by the reaction of 9 with Palau'chlor in the presence of 1 % pyridine whereas 5-chlorinated corrole 12 was obtained in a trace amount from similar chlorination of 5. 5,5'-Linked corrole dimer 13 was produced by reaction of 5 with AgNO2 in a good yield, whereas 10,10'-linked corrole dimer 14 was formed in a moderate yield by the reaction of 9 with [bis(trifluoroacetoxy)iodo]benzene. Observed large electronic interaction between the two corroles in 13 as compared with that in 14 has been ascribed mainly to conformational flexibility of the former, which allows more coplanar conformation.

We report the chemical synthesis and characterization of the stable 5,15-bis(pentafluorophenyl)-10-(trimethylsilylethynyl)corrole which serves as a precursor for the subsequent in situ sila-Sonogashira-cross-coupling reaction and metalation with copper(II) acetate. Under ambient conditions and a common catalyst system the reaction with 1-iodopyrene occurred within five hours. Due to the direct conjugation of the 18p-electronic system of the corrole macrocycle over the alkynyl group to the pyr-ene moiety the optical transitions in the Soret (B-) band Q-band region are significantly altered. The copper corrole exhibited complex hyperfine and superhyperfine structure in the EPR spectrum. The assignment of the EPR spectrum reveals the existence of an axial [CuII-cor •? ] species. Graphical abstract

The oxidation of 10-10' singly linked corrole dimers with DDQ at low concentration in CHCl 3 afforded mesomeso, b-b, b-b triply linked 2H-corrole dimers (with two inner NH groups in each corrole unit), whichexhibited characteristic 1 HNMR and absorption spectra attributable to their nonaromatic electronic networks.T hese 2H-corrole dimers were reduced with NaBH 4 to aromatic 3H-corrole dimers,w hich were unstable and easily oxidized backt ot he 2H-corrole dimers upon exposure to air.B is(zinc(II)) complexes of the 2H-corrole dimers were synthesized and characterized as rare examples of nonaromatic zinc(II) corrole complexes. Scheme 1. Porphyrin tapes (2), porphyrin-hexaphyrin hybrid tapes (4), and fused corrole dimers (5 and 6).