A one-pot reaction of 5,14-bis(mesityl)-norcorrolatonickel(II) with isoamyl nitrite under mild reaction conditions resulted in the consecutive formation of 3-nitro-, 3,12-dinitro- and 3,16-dinitro-, 3,7,12-trinitro-, and 3,7,12,16-tetranitro-norcorrolatonickel(II) in 50–80 % yield. The substituted macrocycles retained their antiaromatic character. The observed regioselectivity of the substitution was analyzed by comparing the relative energies of the DFT energy-optimized models of the radical or arenium cationic intermediates that can be formed upon reaction with NO₂. The nitrated systems were characterized by high-resolution mass spectrometry, NMR and UV/Vis spectroscopy, X-ray diffraction analysis, cyclic voltammetry, and DFT calculations. A significant and systematic cathodic shift of the redox couples was observed to correlate with an increasing number of the NO₂ group. A decrease of the LUMO energies in the tri- and tetra-nitrated products stabilizes mono- and bis-reduced complexes of these ligands. The reduction takes place on the macrocycle rather than on the metal ion leading to the consecutive formation of stable paramagnetic monoanion radicals and water-soluble diamagnetic dianions with an aromatic character, which were revealed by ESR and ¹H NMR measurements, respectively. The electronic structures of the reduced forms were analyzed by extensive TD-DFT calculations.

Embedding endohdedral metallofullerenes (EMFs) into electron donor–acceptor systems is still a challenging task owing to their limited quantities and their still largely unexplored chemical properties. In this study, we have performed a 1,3-dipolar cycloaddition reaction of a corrole-based precursor with Sc₃N@C₈₀ to regioselectively form a [5,6]-adduct (1). The successful attachment of the corrole moiety was confirmed by mass spectrometry. In the electronic ground state, absorption spectra suggest sizeable electronic communications between the electron acceptor and the electron donor. Moreover, the addition pattern occurring at a [5,6]-bond junction is firmly proven by NMR spectroscopy and electrochemical investigations performed with 1. In the electronically excited state, which is probed in photophysical assays with 1, a fast electron-transfer yields the radical ion pair state consisting of the one-electron-reduced Sc₃N@C₈₀ and of the one-electron-oxidized corrole upon its exclusive photoexcitation. As such, our results shed new light on the practical work utilizing EMFs as building blocks in photovoltaics.

5,14-Dimesitylnorcorrolatonickel(II) was hydrogenated under mild conditions (room temperature, 1 atm H₂, THF solution, 5 min.) in the presence of Raney nickel to yield nonaromatic derivatives that were isolated and characterized by NMR spectroscopy, UV/Vis spectrophotometry, HRMS, cyclic voltammetry, and X-ray diffraction analysis. The major hydrogenation product, 1,2,3,7,8,9-hexahydronorcorrolatonickel(II), underwent dimerization in the presence of p-chloranil to give a nonsymmetrically linked 2,3′-bis(norcorrole) system that can adopt eight different oxidation states over a redox potential window of 3 V and has a HOMO–LUMO gap of 0.92 V.

The reaction involving 4-phenyl-octahydro-pyrano[2,3-d]pyrimidine-2-thione, ethyl chloroacetate and the appropriate aromatic aldehyde yielded 2-arylmethylidene-5-phenyl-5a,7,8,9a-tetrahydro-5H,6H-pyrano[2,3-d][1,3]thiazolo[3,2-a]pyrimidin-3(2H)-ones. The 1,3-dipolar cycloaddition of 2-arylmethylidene-5-phenyl-5a,7,8,9a-tetrahydro-5H,6H-pyrano[2,3-d][1,3]thiazolo[3,2-a]pyrimidin-3(2H)-ones with azomethine ylide generated by a decarboxylative route from sarcosine and acenaphthenequinone afforded 4′-aryl-1′-methyl-5″-phenyl-5a″,7″,8″,9a″-tetrahydro-2H,5″H,6″H-dispiro[acenaphthylene-1,2′-pyrrolidine-3′,2″-pyrano[2,3-d][1,3]thiazolo[3,2-a]pyrimidine]-2,3″-diones in moderate yields. The structures of the products were determined and characterized thoroughly by NMR, MS, IR, elemental analysis, and X-ray crystallographic analysis.