Meso-β Doubly Linked Zn(II) Porphyrin Trimers: Distinct anti-versus-syn Effects on Their Photophysical Properties

Synthesis of NiII porphyrin-NiII 5,15-diazaporphyrin hybrid tapes

NiII porphyrin (P) and NiII 5,15-diazaporphyrin (DAP) hybrid tapes were synthesized by Suzuki-Miyaura cross-coupling reactions of meso- or β-borylated P with β-brominated DAP followed by intramolecular oxidative fusion reactions. Meso-β doubly linked hybrid tapes were synthesized by oxidation of singly linked precursors with DDQ-FeCl3. Synthesis of triply linked hybrid tapes was achieved by oxidation with DDQ-FeCl3-AgOTf with suppression of peripheral β-chlorination. In these tapes, DAP segments were present as a 20π-electronic unit, but their local antiaromatic contribution was trivial. Remarkably, these hybrid tapes were stable and exhibited extremely enhanced absorption bands in the NIR region and multiple reversible redox waves. A pentameric hybrid tape showed a remarkably sharp and red-shifted band at 1168 nm with ε = 5.75 × 105 M-1 cm-1. Singly linked P-DAP dyads were oxidized with DDQ-FeCl3 to give stable radicals, which were oxidized further to afford dimeric hybrid tapes possessing a nitrogen atom at the peripheral-side meso-position.

Functionalization of Porphyrins Using Metal-Catalyzed C–H Activation

The review is devoted to the C–H functionalization of porphyrins. Porphyrins exhibit the properties of organic semiconductors, light energy converters, chemical and electrochemical catalysts, and photocatalysts. The review describes the iridium- and palladium-catalyzed direct functionalization of porphyrins, with more attention given to the results obtained in our laboratory. The development and improvement of synthetic methods that do not require preliminary modification of the substrate with various functional groups are extremely important for the preparation of new organic materials based on porphyrins. This makes it possible to simplify the synthetic procedure, to make the synthesis more economical, environmentally safe, and simple to perform.

meso-to-meso 2,5-Pyrrolylene bridged zig-zag porphyrin arrays

meso-to-meso 2,5-Pyrrolylene bridged zig-zag porphyrin arrays have been synthesized via a stepwise Suzuki-Miyaura cross coupling reaction. Both the dimeric and trimeric structures of Zn^II porphyrin were confirmed by X-ray diffraction analysis. DFT calculations indicate that the porphyrin oligomers are all in zig-zag conformations. The UV/Vis absorption and emission spectra of these porphyrin oligomers were red-shifted as the number of their porphyrin units increased.

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.

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.

Conjugated porphyrin arrays: synthesis, properties and applications for functional materials

Conjugated porphyrin arrays that possess delocalised electronic networks have, for the most part, been assembled by using alkene or alkyne type bridging units or by directly connecting individual porphyrin chromophores with multiple bonds to form fused porphyrin arrays.

Switchable regioselectivity in the PIFA–BF3·Et2O mediated oxidative coupling of meso-brominated Ni(ii) porphyrin

A simple and efficient method has been developed for the switchable synthesis of directly linked meso-brominated Ni(ii) porphyrin dimers through PIFA–BF₃·Et₂O mediated oxidative coupling.

Higher Order Acenes and Fused Acenes with Near-infrared Absorption and Emission

Higher order acenes and fused acenes represent two outstanding classes of building blocks to achieve near-infrared absorbing and emitting materials. Appropriate chemical modification and functionalization will lead to significant improvements in solubility and stability, thus making their applications practically possible. This short review summarizes the recent developments of the two types of polycyclic aromatic compounds mentioned above based on their physical and optical properties including absorption, emission, quantum yield, solubility, and stability.