Substituent Effects at the 5,10-Positions of Dianilinotripyrrins on Their Dimerization Themodynamics.

Control of the association behavior by molecular design is one of the most essential benefits in artificial supramolecular systems. 1,14-Dianilinotripyrrin has recently emerged as a novel conjugated molecule which forms a double helix in non-polar solvents with the aid of multiple interstrand hydrogen bonding interactions. In this work, we investigated the substituent effects at the 5,10-positions of tripyrrin on their association thermodynamics.

Development of the Peripheral Functionalization Chemistry of meso-Free Corroles.

In contrast to the extensive development of the meso-functionalization of porphyrins, that of corroles had rarely been explored until the development of practical synthetic methods for meso-free corroles in 2015. The ready availability of meso-free corroles opened up meso-functionalization chemistry of corroles, giving rise to successful synthesis of various meso-substituted corroles such as meso-halogen, meso-nitro, meso-amino, meso-oxo, and meso-iminocorroles as well as meso-meso-linked corrole dimers and corrole tapes. In some cases, 2NH corroles exist as stable or transient radical species.

Synthesis of 8,12-Dibromocorrole and Its Transformation to Antiaromatic 8,10-Fused Iminoisocorrole with a Polarized Resonance Contribution.

8,12-Dibromo-5,15-bis(pentafluorophenyl)corrole and its Ag(III) complex were prepared via intramolecular oxidative coupling of a 8,12-dibromobilane precursor. The Ag(III) complex was allowed for further transformation via Suzuki coupling reaction. Thus, 2-aminophenyl group was coupled at one of the β-positions, and subsequent demetalation followed by oxidation with MnO afforded 8,10-fused iminoisocorrole in good yields.

-Oxoisocorroles: Tunable Antiaromaticity by Metalation and Coordination of Lewis Acids as Well as Aromaticity Reversal in the Triplet Excited State.

The corrole derivative -oxoisocorrole has been theoretically predicted to be antiaromatic, despite its formally cross conjugated electronic system. In this study, this prediction has been experimentally proven by the facile preparation of -oxoisocorrole via the oxidation of a free corrole with MnO and its comprehensive characterization using NMR, UV/vis absorption, FT-IR, and transient-absorption spectroscopy, cyclic voltammetry, and X-ray diffraction analysis. Furthermore, the free base -oxoisocorrole was metalated by treatment with Ni(acac), PdCl(PhCN), and Zn(OAc) to give the corresponding metal complexes.

Single- and double-helices of α,α'-dibenzylaminotripyrrin: solution and solid state studies.

The dimeric association of α,α'-di(benzylamino)tripyrrin in chloroform was found to be 40 times less effective than that of previously reported α,α'-dianilinotripyrrin, which, however, led us to observe the co-crystal structure of single and double helix forms. Attachment of chiral phenylethylamines on the same tripyrrin platform was also performed to induce helical chirality.

Singly, Doubly, and Triply Linked Corrole Oligomers: Synthesis, Structures, and Linking Position Dependent Properties.

Direct covalent connections of porphyrinoids have been demonstrated as an effective way to expand their π-electronic networks and perturb their optical and electrochemical properties. Covalent connections are also useful for studies on the precise electronic interaction between two porphyrinoid units. However, the chemistry of covalently linked corrole oligomers lags far behind that of the porphyrin counterparts in spite of the importance of corrole as a ring-contracted porphyrinoid.

Synthesis of -Diarylaminocorroles via SAr Reactions.

A corrole is a tetrapyrrolic macrocycle known as a ring-contracted porphyrinoid. Despite the progress of the synthetic chemistry of -aryl-substituted corroles since the early 2000s, -heteroatom-substituted corroles have been scarcely reported. Herein we report that the SAr-type substitution reaction of a -chlorocorrole silver complex with diphenylamine or carbazole in the presence of NaH as a base produced -aminocorroles.

Bis-copper(II) Complex of Triply-linked Corrole Dimer and Its Dication.

Copper complexes of corroles have recently been a subject of keen interest due to their ligand non-innocent character and unique redox properties. Here we investigated bis-copper complex of a triply-linked corrole dimer that serves as a pair of divalent metal ligands but can be reduced to a pair of trivalent metal ligands. Reaction of triply-linked corrole dimer 2 with Cu(acac) (acac=acetylacetonate) gave bis-copper(II) complex 2Cu as a highly planar molecule with a mean-plane deviation value of 0.

The First Silicon(IV) Corrole Complexes: Synthesis, Structures, Properties, and Formation of a μ-Oxo Dimer.

The first Si corrole complexes were synthesized in good yields by treatment of meso-triarylcorroles with tetrachlorosilane in 1,2-dichloroethane at 60 °C. The central silicon atom possesses a square-pyramidal coordination geometry with slightly longer Si-N bond lengths as compared with those of known triazacorrole Si complexes. The Si corrole complexes exhibit sharp and blue-shifted absorption spectra and larger fluorescence quantum yields as compared with the corresponding free-base corroles.

meso-Cumulenic 2H-Corroles from meso-Ethynyl-3H-corroles.

Alkynyl-substituted 3H-corrole 9 a was converted to [3]cumulenic 2H-corrole 10 a by treatment with trimethylsilyl chloride (TMSCl), and 1,3-butadiyne-bridged 3H-corrole dimer 11 b was transformed into [5]cumulene-bridged 2H-corrole dimer 12 b by oxidation with PbO . Both 10 a and 12 b were metalated to form Zn complexes 10 a-Zn and 12 b-Zn. The structures of 10 a-Zn and 12 b-Zn show planar conformations with bond-length alternations that are analogous to those of tetraaryl [n]cumulenes.