フッ化物イオンによるπ-π相互作用に基づく会合状態の解離効果

Synthesis and properties of porphyrin-pyrene conjugated system connected by acetyleneπ-Expanded porpyrin oligomers have been attracting much attention from the viewpoint of creating novel electronic systems associated with delocalized π-electrons. To expand the π-systems, the method of connecting a porphyrin with another π-chromophore using acetylene linkage is frequently used, because the net electronic interaction is always achieved regardless of the conformation between the chromophores. With the aim of creating enhanced π-electron conjugated systems, we designed, prepared, and characterized novel pyrene-linked porphyrins connected by acetylene at the meso-position of porphyrin and the α-position of pyrene, both positions have large atomic coefficients. The coupling reaction between ethynylpyrene derivative 2 and dibromoporphyrin 3 gave 1 as a dark green stable solid. The electronic absorption spectrum of 1 is composed of two main bands: Q-band-like Band-I and Soret-band-like Band-II. Band-I and Band-II appear at 14300 cm-1 (700 nm) and 22600 cm-1 (442 nm), respectively. Compared with the absorption bands of ZnBDtBuPP, both Band-I and Band-II are shifted to the lower energy, reflecting the highly conjugated structure of 1. Furthermore, a weak and broadened absorption of ~1300 nm was observed in the near-infrared region, presumably due to intramolecular charge transfer transition