Search

A library of novel π-extended porphyrin-hexabenzocoronene (HBC) architectures is presented. Two distinct synthetic pathways were utilized to obtain either phenyl- or HBC-fused compounds. Absorption experiments reveal the species' exciting photophysical and optoelectronic properties. Depending on the degree of π-extension, the number of porphyrins, and their relative position, a decisive change in shape, panchromatic broadening, and red-shifting of the absorption curves is observed. Theoretical studies give more profound insight into the molecule's electronic structures, showing vast decreases in HOMO-LUMO energy gaps., (© 2024 The Author(s). Chemistry - A European Journal published by Wiley-VCH GmbH.)

Partially β-substituted and meso-tetrakis(pentafluorophenyl)-substituted [22]pentaphyrins 11 and 12 were synthesized by acid-catalyzed condensation of a meso-C 6 F 5 -substituted tripyrrane dicarbinol with β-alkylated dipyrromethanes. These [22]pentaphyrins are stable, allowing their characterization by NMR and UV/Vis spectroscopies, and X-ray crystallography, and display strong aromaticity due to 22π-electronic circuits. In methanol, β,β-diethoxycarbonylated pentaphyrin 12 underwent an N-fusion reaction to give N-fused pentaphyrin 13, which exhibits crystal polymorphism between Hückel and Möbius structures, depending upon the recrystallization solvent., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The chlorination of β-halo or β,β-dihaloporphyrins with 2-chloro-1,3-bis(methoxycarbonyl)guanidine (Palau'Chlor) proceeded selectively at the neighboring unsubstituted meso position to afford meso,β-dihalo or meso,β,β-trihaloporphyrins. Such oligohaloporphyrins are useful platforms for constructing more-elaborate porphyrin-based extended π systems. For example, meso-chloro-β,β-diiodoporphyrin participated in an efficient single-step synthesis of a diphenylamine-fused porphyrin. In addition, meso-chloro-β-iodoporphyrin was transformed in stepwise fashion into an efficiently conjugated meso-to-meso,β-to-β doubly butadiyne-linked porphyrin dimer, a system which was previously difficult to access without such haloporphyrin precursors., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Treatment of N-substituted 2-(methylamino)naphthoquinones 3 and -anthracene-1,4-diones 4 with S2Cl2 and DABCO in chlorobenzene gave the corresponding 2,3-dihydronaphtho[2,3-d][1,3]thiazole-4,9-diones 1 and 2,3-dihydroanthra[2,3-d][1,3]thiazole-4,11-diones 2 by triethylamine addition, in high to moderate yields. The DABCO replacement for N-ethyldiisopropylamine in the reaction of anthracene-1,4-diones 4 led unexpectedly to the corresponding 2-thioxo-2,3-dihydroanthra[2,3-d][1,3]thiazole-4,11-diones 10. The reaction of 3H-spiro[1,3-thiazole-2,1'-cyclohexanes] 1d, 2d with Et3N in chlorobenzene under reflux yielded 2,3,4,5-tetrahydro-1H-carbazole-6,11-diones 15, 16, i.e., ring contraction and fusion products. A plausible mechanism was proposed for the formation of the products.