Charged Porphyrin Metal Complexes As Building Units of Ion-Pairing Assemblies and Materials

Abstract

π-Electronic ions with appropriate geometries and peripheral substituents provide assemblies through interactions between building subunits, resulting in fascinating electronic properties. Structures and properties of the assemblies can be controlled by the combined negatively and positively charged species in the assemblies. Thus far, diverse ion-responsive π-electronic systems and π-electronic ions have afforded dimension-controlled ion-pairing assemblies as crystals, supramolecular gels, and thermotropic liquid crystals (LCs).[1,2] Highly ordered arrangement of charged species has been found to be a key factor to exhibit the enhanced performance as fascinating electronic materials. In fact, ion pairs of porphyrin-AuIII complexes as π-electronic cations, prepared with the combination of various anions including a π-electronic anion, formed dimension-controlled assemblies as thermotropic liquid crystals, whose ionic components were highly organized by electrostatic and π–π stacking interactions.[3–5] References A recent review: Haketa, Y.; Maeda, H.Bull. Chem. Soc. Jpn. 2018, 91,420.Recent examples: a) Maeda, H.;Takeda, Y.; Haketa, Y.; Morimoto, Y.; Yasuda, N. Chem. Eur. J. 2018, 24, 8910; b) Kaname, S.; Haketa, Y.; Yasuda, N.; Maeda, H. Org. Lett. 2018, 20, 3268; c) Maeda, H.; Okubo, T.; Haketa, Y.; Yasuda, N. Chem. Eur. J. 2018, 24, 16176; d) Yamakado, R.; Ishibashi, H.; Motoyoshi, Y.; Yasuda, N.; Maeda, H. Chem. Commun. 2019, 55, in press.Haketa, H.; Bando, Y.; Sasano, Y.; Tanaka, H.; Yasuda, N.; Hisaki,I.; Maeda, H.to be submitted.Assemblies of anionic porphyrins: Sasano, Y.; Yasuda, N.; Maeda, H. to be submitted.As related species, chiral metal complexes of dipyrrins, with half structures of porphyrin, have exhibited long lifetime photo-excited triplet states: Hirata, G.; Kobayashi, Y.; Yasuda, N.; Maeda, H. to be submitted.