Search

9,10-Quinoxaline-fused porphycenes 1a-H2 and 1b-H2 were synthesized by intramolecular McMurry coupling. As a result of the annulation of the quinoxaline moiety on the porphycene skeleton, 1a-H2 and 1b-H2 display absorption and fluorescence in the near infra-red (NIR) region. Additionally, the quinoxaline moieties of 1a-H2 and 1b-H2 act as electron-withdrawing groups, introducing lower reduction potentials than for pristine porphycene. The protonation occurred at the nitrogen atoms in the cavity of freebase porphycenes and at the quinoxaline moieties for their nickel complexes to give diprotonic species.

An insoluble thin film of a coronene diimide (CDI) derivative was fabricated from a soluble precursor of perylene diimide (PDI) by photoirradiation. We prepared a 1,7-diarylated PDI (TPPDI) that can be converted into a coronene diimide (TP-CDI) derivative via a Scholl-type photocyclization reaction. This reaction was accompanied by structural changes from a twisted structure to a π-extended planar molecule. It was found that this photoconversion reaction occurs for both solution-based and thin-film-based reactants investigated by the changes of UV-vis absorption spectra and 1H NMR spectra. The photocyclization reactions were found to proceed smoothly in polar solvents. In the thin-film state, the solvent vapor annealing method is a key process for achieving photoconversion reaction. Additionally, the fabrication of multi-layered thin films was achieved without undesirable dissolution of the underlying layers because of different solubilities of TP-PDI and TP-CDI. [ABSTRACT FROM AUTHOR]

An oxidative ring-closure reaction of a tetranaphthylpyrene derivative led to the synthesis of a 56 all-carbon conjugated tetrabenzoperipentacene. In the single-crystal Xray structure, three molecules make a triple-layered cluster by p-stacking, wherein each layer rotates by 120°, and is thus considered a petit b-graphite. As for the optical properties, the Stokes shift is extremely small (10 cm-1), thus indicating its remarkably rigid framework. The tetrabenzoperipentacene exhibits reversible five-electron oxidation waves in cyclic voltammetry, and is regarded as a counterpart to the fullerene C60 in terms of stable multicharge-storage nanocarbon materials. [ABSTRACT FROM AUTHOR]

Linearly π-expanded novel tetraanthroporphyrins with and without aromatic rings at the meso-positions were prepared quantitatively for the first time from the corresponding precursors by a retro-Diels−Alder reaction. [ABSTRACT FROM AUTHOR]

Sterically congested tetraarylpyrenes exhibited emission in both solution and the solid state. The monocationic species of pyrene 1 could be isolated because of the reasonably protected system. The aromaticity of 1 relocates from the biphenyl part to the naphthalene unit upon two-electron oxidation. [ABSTRACT FROM AUTHOR]

A p-i-n organic photovoltaic cell with tetrabenzoporphyrin (BP), a BP-C60 dyad and PCBM for the p-, i- and n-layers, respectively, gave a better fill factor and power conversion efficiency than the corresponding p-i-n cell having a 1 : 1 blend film of BP and PCBM as the i-layer. [ABSTRACT FROM AUTHOR]