Effective π-Extension of Carbazole-Based Thiaporphyrins by Peripheral Phenylethynyl Substituents

Conformationally Restricted and Three-dimensionally Extended Carbazole-Incorporating Expanded Porphyrinoids

Condensation of 3,6-(1-phenyl-1-(2-pyrroyl)methyl)carbazole with pentafluoroaldehyde and subsequent oxidation with DDQ gave a carbazole-incorporating octaphyrin(1.1.1.0.1.1.1.0) analogue, 7, which was shown to exists as locked conformers 7a and 7b. Both conformers were...

Carbenaporphyrins: No Longer Missing Ligands in N-Heterocyclic Carbene Chemistry

The synthesis of an NHC-containing porphyrinoid ligand is presented. The formally antiaromatic 20 πe- macrocyclic framework can be obtained via a 1,3-dipolar cycloaddition ("click-reaction") to form two triazole moieties which were alkylated to the respective triazolium macrocycle. Deprotonation of the ligand precursor with lithium bases to the respective dilithio carbenaporphyrin complex and transmetallation to scandium lead to complexes that exhibit orange fluorescence. Optical property combined with TD-DFT studies verify an aromatic character for each heterocyclic moiety rather than an antiaromatic macrocycle in the ligand precursor as well as in the complexes. While the geometric features of the carbenaporphyrin ligand strongly resemble those of porphyrin, DFT calculations reveal a stronger electron-donating ability of the new ligand.

Synthesis and electronic properties of carbazole-based core-modified diporphyrins showing near infrared absorption

Directly linked carbazole-based core-modified diporphyrin D2 and fused diporphyrin F2 were synthesized. These diporphyrins showed significant electronic interactions and conjugation allowing for redshifted near infrared (NIR) absorption and small HOMO-LUMO gaps as confirmed by NIR absorption spectroscopy, cyclic voltammetry (CV) measurements, and DFT calculations.

Synthesis and Chiroptical Properties of Chiral Carbazole-Based BODIPYs

A series of carbazole-based boron dipyrromethenes (BODIPYs) 2 a-g bearing binaphthyl units have been synthesized by the Et₂ AlCl-mediated reaction of the corresponding BODIPY difluorides 1 a-g with 1,1'-binaphthalene-2,2'-diol. Substituents such as halogen, nitrile, and amino groups were tolerated under the reaction conditions, and the reaction of the phenylethynyl-substituted 1 h gave (R,R)-3 h bearing two binaphthyl units. The chiroptical properties of these dyes with different substituents were investigated by UV/Vis, CD, fluorescence, and circularly polarized luminescence (CPL) spectroscopy. The CD spectra showed Cotton effects in the absorption region of the BODIPY moieties. In addition, they showed CPL both in solution and in the solid state. Interestingly, several dyes recorded higher g_lum values in the solid state, probably due to intermolecular interactions. Because (R,R)-3 h recorded relatively low g_lum values, the diastereomer (R,S)-3 h was prepared. The (R,S) diastereomer showed intense CPL, which suggests a synergetic effect of the two binaphthyl groups. Finally, chiral carbazole-based BODIPY dimers have been synthesized for the first time and their chiroptical properties were investigated. They showed redshifted fluorescence and CPL, which reached the near-IR (NIR) region in the solid state.

Carbazole-containing porphyrinoid and its oligomers

A novel carbazole-containing porphyrinoid 4H and its oligomers 6H and 7H were synthesized for the first time via the Suzuki-Miyaura cross-coupling reaction. The structures of 4H, 4Pd, 6H, and 6Zn were finally confirmed by X-ray analysis. The exciton coupling strength (628 cm^-1) in 4Zn, 6Zn, and 7Zn was found to be larger than that of the directly-linked porphyrin arrays (570 cm^-1), extending their absorption spectra to the NIR region as well as enhancing the extinction coefficients.

Synthetic aspects of carbazole containing porphyrins and porphyrinoids

Porphyrins are tetrapyrrolic aromatic macrocycles and ubiquitous in nature. They are excellent dyes with strong absorption in the visible region (400–700 nm) and they exhibit decent fluorescence in the red region (620–900 nm). Carbazole is a nitrogen-containing electron rich aromatic heterocycle which can be linked to porphyrins and other chromophores. This review provides an overview of the different synthetic strategies that have been employed to prepare carbazole-substituted porphyrins and carbazole-fused porphyrinoids and similar systems. It also shows that how the substitution of carbazole occurs on the porphyrin core can alter its optical and electronic features. Introduction of carbazole moieties in the porphyrin ring resulted in fused porphyrinoids with changed aromaticity and significantly altered electronic features of the molecules.

Synthesis of chiral carbazole-based BODIPYs showing circularly polarized luminescence

Chiral carbazole-based BODIPYs with a binaphthyl unit were synthesized via an Al-mediated reaction. Et2AlCl was found to be a convenient reagent for the reaction to give the chiral BODIPYs in high yields. It has been shown for the first time that these chiral carbazole-based BODIPYs show circularly polarized luminescence (CPL) both in solution and in the solid state.

Synthesis and electronic properties of π-expanded carbazole-based porphyrins

Peripheral π-expansion of carbazole-based porphyrins was achieved for the first time by the Pt-catalyzed cyclization and the incorporation of a benzocarbazole unit.

Synthesis of carbazole-based BODIPY dimers showing red fluorescence in the solid state

Carbazole-based BODIPY dimers 2a–g were synthesized via direct arylation.

Carbazole-based BODIPYs with ethynyl substituents at the boron center: solid-state excimer fluorescence in the VIS/NIR region

Carbazole-based BODIPYs 1–6 with several different substituents at the boron atom site were synthesized.

Synthesis and Functionalization of Porphyrins through Organometallic Methodologies

This review focuses on the postfunctionalization of porphyrins and related compounds through catalytic and stoichiometric organometallic methodologies. The employment of organometallic reactions has become common in porphyrin synthesis. Palladium-catalyzed cross-coupling reactions are now standard techniques for constructing carbon-carbon bonds in porphyrin synthesis. In addition, iridium- or palladium-catalyzed direct C-H functionalization of porphyrins is emerging as an efficient way to install various substituents onto porphyrins. Furthermore, the copper-mediated Huisgen cycloaddition reaction has become a frequent strategy to incorporate porphyrin units into functional molecules. The use of these organometallic techniques, along with the traditional porphyrin synthesis, now allows chemists to construct a wide range of highly elaborated and complex porphyrin architectures.

Phenanthrylene-butadiynylene and Phenanthrylene-thienylene Macrocycles: Synthesis, Structure, and Properties

A series of macrocycles consisting of 9,10-substituted phenanthrenes connected by butadiynylene linkers in positions 3 and 6 has been described as well as their transformation into the corresponding phenanthrylene-thienylene macrocycles. Structure and properties of the macrocycles, such as self-association in solution and optical and electrochemical properties, were studied and reported in a comparative manner with respect to the effects of the different sizes and shapes of the macrocycles and the character and length of their side chains.

Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds: Synthetic Routes, Properties, and Applications

Two-dimensionally extended, polycyclic heteroaromatic molecules (heterocyclic nanographenes) are a highly versatile class of organic materials, applicable as functional chromophores and organic semiconductors. In this Review, we discuss the rich chemistry of large heteroaromatics, focusing on their synthesis, electronic properties, and applications in materials science. This Review summarizes the historical development and current state of the art in this rapidly expanding field of research, which has become one of the key exploration areas of modern heterocyclic chemistry.

Effects of cyano, ethynyl and ethylenedioxy groups on the photophysical properties of carbazole-based porphyrins

The synthesis and photophysical properties of cyano and ethynyl substituted carbazole-based porphyrins were investigated.

Synthesis of carbazole-based hetero-core-modified porphyrins

Annulation reaction of a 1,1′-(1,3-butadiyne)-8,8′-(2,5-thiophene)-bridged carbazole dimer 10 provided the carbazole-based isophlorines 11a–11c and 12. The oxidation of 12 generated the corresponding 21-selena-23-thiaporphyrin 13.