Ichiro Hisaki

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Steroidal bile acids and their derivatives exhibit characteristic inclusion behaviors in the crystalline state. Their crystals present varied assemblies due to asymmetric molecular structures, which relate to supramolecular properties through cooperative weak interactions. An overview indicates that the steroidal assemblies lie in an intermediate position(More)
Steroidal bile acids and over 50 of their derivatives serve as the hosts of inclusion crystals. These hosts each exhibit their own characteristic inclusion behaviors, which have been explored through more than 300 crystallographic data. The molecules with three-axial chirality combine in asymmetric fashion to form diverse assemblies, which have(More)
Achiral molecules can form aggregates with chirality. This depends on the relative position of the molecules, in other words, the tilt of the molecules (so-called supramolecular tilt chirality). In this paper, we describe supramolecular chirality appearing in a 2(1) column composed of symmetrical benzene molecules, which is formed in the host cavity of(More)
The supramolecular chirality of 1D ladder-type hydrogen-bond networks composed of primary ammonium carboxylates was determined based on topological considerations. Chirality in such networks is based on the absolute configuration of the primary ammonium cation, which arises from discrimination between the two oxygen atoms of the carboxylate anion. The(More)
A twofold helix (2(1) helix) is an essential motif in approximately 70% of organic crystals. Although handedness of 2(1) helix has not been discussed from a mathematical viewpoint, we noticed that the handedness can be defined by considering the molecular shape and manner of assembly. Herein we propose the supramolecular-tilt-chirality (STC) method to(More)
We have designed and synthesized a π-conjugated system that consists of a flexible and nonplanar π joint and two emissive rigid and planar wings. This molecular system exhibits respectively red, green, and blue (RGB) emission from a single-component luminophore in different environments, namely in polymer matrix, in solution, and in crystals. The flexible(More)
Highly twisted π-conjugated molecules have been attractive but challenging targets. We report here an efficient synthesis of highly twisted diporphyrins with 126° and 136° twist angles that involves an oxidative fusion reaction of planar aminoporphyrin precursors at room temperature. Repeated amination-oxidative fusion sequences provide a unidirectionally(More)