鈴木 航

Gold (Au) exhibits distinct reactivities with O2 at the nanometer to atomic scales, whereas bulk Au is chemically inert. Since the discovery of catalytic reactivities in Au‐based materials, including nanoparticles, molecular complexes, and nanoclusters (AuNCs), mechanistic insights into the interaction and reductive activation of O2 by Au have been pursued by researchers. However, the atomic level understanding of the reaction mechanism remains elusive compared with that for other widely explored transition metalO2 systems. This paper briefly discusses recent progress in clarifying the reaction mechanisms of Au‐O2 chemistry for homogeneous molecular Au complexes and atomically precise AuNCs. We introduce our research on (1) O2‐activation by Au complexes without the distinct formation of conventional metal‐hydride species, and (2) the application of kinetic analyses to the reaction of thiolate‐protected AuNCs with O2 to quantify parameters like O2‐binding constants on the Au surface. These findings help elucidate both the Au‐O2 interaction and reductive activation of O2, which are essential in catalytic systems using O2 as a terminal oxidant that can contribute to the developments of eco‐friendly oxidation Au‐based catalysts with high performance.

Regioselective N-methylation of β-bromoporphyrins were achieved to prepare ²¹N,²³N-dimethylporphyrins (syn), which was stemmed from the steric factors of Br groups and the high basicity of syn.

Abstract The singlet exciton (S1) lifetime of nonfullerene acceptor (NFA) films is a crucial factor influencing their photovoltaic performances, as a longer S1 lifetime increases the exciton diffusion length. We previously reported that a NFA with a two-dimensionally π-extended thienoazacoronene (TAC) central core, S-TACIC, exhibits an exceptionally long S1 lifetime in the film. In this study, we examined the effects of replacing thiophene with selenophene on the photophysical and photovoltaic properties. Fluorescence decay measurements showed that the S1 lifetime of the selenophene-substituted TAC-based NFA (Se-TACIC) is longer in solution (500 ps) but significantly shorter in the film (<200 ps) compared to S-TACIC (220 ps in solution and 1,590 ps in film). When blended with the polymer donor PBDB-T, the Se-TACIC-based organic photovoltaic (OPV) device exhibited a lower power conversion efficiency (5.58%) than the S-TACIC-based one (9.92%), due to inferior photovoltaic parameters of the Se-TACIC-based OPV device.