Pentagon-Rich Caged Carbon Catalyst for the Oxygen Reduction Reaction in Acidic Electrolytes.

The interaction between electron spin and oxygen molecules in non-platinum catalysts, particularly carbon catalysts, significantly influences the catalytic performance of the oxygen reduction reaction (ORR). A promising approach to developing high-performance catalysts involves introducing five-membered ring structures with spin into graphitic carbons. In this study, we present the successful synthesis of cage-like cubic carbon catalysts enriched with pentagon structures using pentagon ring-containing C and a NaCl template.

Storing electrons from H for transfer to CO, all at room temperature.

We present an Ir complex that extracts electrons from H at room temperature and stores them as a H-derived energy carrier (HEC) at room temperature. Furthermore, we demonstrate that this complex reduces CO to a metal-CO species at room temperature, and present the first electrospray ionisation mass spectrum for this compound.

H-driven reduction of CO to formate using bacterial plasma membranes.

Bacterial membranes shield the intracellular compartment by selectively allowing unwanted substances to enter in, which in turn reduces overall catalytic efficiency. This report presents a model system using the isolated plasma membranes of Citrobacter sp. S-77 that harbor oxygen-stable [NiFe]hydrogenase and [Mo]formate dehydrogenase, which are integrated into a natural catalytic nanodevice through an electron transfer relay.

2D Coordination Network of Trioxotriangulene with Multiple Redox Abilities and Its Rechargeable Battery Performance.

A three-fold symmetric trioxotriangulene derivative with three pyridyl groups as coordinating sites was designed and synthesized. In a cyclic voltammetry measurement, the trioxotriangulene skeleton exhibited a multi-stage redox ability from neutral radical to radical tetra-anion species. In the zinc complex of monoanion species, three pyridyl groups coordinated to the zinc ion to build up a two-dimensional coordination network with a cavity larger than 12 Ã… in diameter.

Redox behaviour of the β-dihydroporphycene cobalt complex: study on the effect of hydrogenation of the ligand.

The dihydrogenated porphycene cobalt(ii) complex was synthesized and electrochemical experiments were carried out. The one-electron reduction of the complex proceeded at the central metal to afford the Co(i) species; in contrast, for the non-hydrogenated porphycene cobalt(ii) complex, the one-electron reduction gave the ligand reduced radical anion species. The reactivity of the one-electron reduced species with alkyl halides showed clear differences between the complexes.

Cobalt-Carbon Bond Formation Reaction via Ligand Reduction of Porphycene-Cobalt(II) Complex and Its Noninnocent Reactivity.

The interesting redox properties and reactivity of metalloporphycene have been studied for decades; however, the detailed experimental investigation on the reactivity and reaction mechanism under inert condition combined with theoretical calculations had not been performed so far. In this study, the novel reactivity of the reduced form of the cobalt porphycene with alkyl halides to form cobalt-carbon (Co-C) bonds was revealed. Under electrochemical reductive conditions, not the central cobalt, but the ligand was reduced and reacted with alkyl halides to afford the cobalt-alkyl complexes under N atmosphere in a glovebox.

An Azulene-Fused Tetracene Diimide with a Small HOMO-LUMO Gap.

A newly prepared tetraazulene-fused tetracene diimide (TA-fused TDI) showed absorption in the near-IR region owing to the effective extension of the π-conjugated system as well as a large two-photon absorption cross-section (σ =2140 GM) at 950 nm. Four reversible reduction processes and n-type semiconductivity were also confirmed as attractive electronic properties of this compound.

A Stable Organic π-Radical of a Zinc(II)-Copper(I)-Zinc(II) Complex of Decaphyrin.

A Zn(II) -Cu(I) -Zn(II) heterotrimetal complex of decaphyrin was synthesized by stepwise metalations: metalation of a [46]decaphyrin with Zn(II) ions to produce a 46π decaphyrin bis(Zn(II) ) complex and its subsequent metalation with Cu(II) ion. In the second metalation step, it has been shown that Cu(II) ion is reduced to a Cu(I) ion in the complex and a dianionic bis(Zn(II) ) containing [46]decaphyrin ligand is oxidized to the corresponding monoanionic [45]decaphyrin ligand, indicating a non-innocent nature of the decaphyrin ligand. Despite the radical nature, the heterotrimetal complex is fairly stable under ambient conditions and exhibits almost no intermolecular magnetic interaction, owing to extensive delocalization of an unpaired electron in the large π-conjugated circuit of decaphyrin moiety.

Solvent- and temperature-dependent conformational changes between Hückel antiaromatic and Möbius aromatic species in meso-trifluoromethyl substituted [28]hexaphyrins.

We investigated the photophysical properties of figure-eight-like meso-hexakis(trifluoromethyl) [26]- and [28]hexaphyrins(1.1.1.

Neutral radical and singlet biradical forms of meso-free, -keto, and -diketo hexaphyrins(1.1.1.1.1.1): effects on aromaticity and photophysical properties.

We have investigated the electronic structures and photophysical properties of 5,10,20,25-tetrakis(pentafluorophenyl)-substituted hexaphyrin(1.1.1.

A stable non-Kekulé singlet biradicaloid from meso-free 5,10,20,25-tetrakis(pentafluorophenyl)-substituted [26]hexaphyrin(1.1.1.1.1.1).

A meso,meso-diketohexaphyrin was isolated and characterized as a chemically stable non-Kekulé singlet biradicaloid. Two unpaired electrons are seemingly delocalized on two tripyrrolic units separated by C=O bonds. These results underscore the potential of expanded porphyrins to achieve unique electronic states.

Multiple conformational changes of beta-tetraphenyl meso-hexakis(pentafluorophenyl) substituted [26] and [28]hexaphyrins(1.1.1.1.1.1).

Beta-tetraphenyl meso-hexakis(pentafluorophenyl) substituted [26]hexaphyrin is conformationally flexible between rectangular and figure-of-eight shapes and its two-electron reduced [28]hexaphyrin takes figure-of-eight conformations, which are changed, upon protonation, to twisted conformations with distinct Möbius aromaticity.

Homo- and heterobismetal complexes of 5-Hydroxy-10,15,25,30-tetrakis(pentafluorophenyl)-substituted [26]hexaphyrin(1.1.1.1.1.1).

Metalation of meso-free 5,10,20,25-tetrakis(pentafluorophenyl)-substituted [26]hexaphyrin(1.1.1.