Tomoki Ogoshi

Condensation of 1,4-dimethoxybenzene (DMB) with paraformaldehyde in the presence of BF3.O(C2H5)2 gave novel para-bridged pentacyclic pillar DMB (DMpillar[5]arene). Moreover, para-bridged pentacyclic hydroquinone (pillar[5]arene) was prepared. Pillar[5]arene formed 1:1 host-guest complexes with dialkyl viologen and alkyl pyridinium derivatives. However, pillar[5]arene did not form complexes with the diadamantyl viologen derivative since a bulky adamantyl group was unable to thread the cavity of p

In 2008, we reported a new class of pillar-shaped macrocyclic hosts, known as "pillar[n]arenes". Today, pillar[n]arenes are recognized as key players in supramolecular chemistry because of their facile synthesis, unique pillar shape, versatile functionality, interesting host-guest properties, and original supramolecular assembly characteristics, which have resulted in numerous electrochemical and biomedical material applications. In this Review, we have provided historical background to macrocyc

This tutorial review summarizes the continuing exploration of three prominent water-soluble hosts: cucurbiturils, pillar[<italic>n</italic>]arenes and deep-cavity cavitands.

Water-soluble pillar[5]arene was synthesized by the introduction of carboxylate anions at both upper and lower rims. When cationic viologen salt was mixed with the water-soluble pillar[5]arene in aqueous media, a very stable 1:1 host-guest complex was formed.

Supramolecular assemblies are constructed from at least two molecules through various noncovalent bonding modes such as hydrogen bonding, cationic-anionic electrostatic interactions, aromatic interactions, metal-ligand bonding, hydrophobic-hydrophilic interactions, and charge-transfer interactions. Owing to the dynamic and reversible nature of these noncovalent bonds, the assembly and disassembly of these molecules are dynamic and reversible. Molecules self-assemble to form the most conformation

Macrocycles are an important player in supramolecular chemistry. In 2008, a new class of macrocycles, "pillar[n]arenes", were first discovered. Research efforts in the area of pillar[n]arenes have elucidated key properties, such as their shape, reaction mechanism, host-guest properties, and their versatile functionality, which has contributed to the development of pillar[n]arene chemistry and their applications to various fields. This Minireview describes how pillar[n]arene-based supramolecular

Abstract In 2008 we reported a new class of macrocyclic hosts that we named “pillararenes”. To date, pillar[5]arenes and pillar[6]arenes, containing five and six repeating units, respectively, have been synthesized. Pillar[5]arenes and pillar[6]arenes can accommodate 10 and 12 substituent groups, respectively. The position‐selective versatile functionalization of these substituents enables the preparation of various supramolecular assemblies. Here we discuss the synthesis and selective functiona

Hybrids of single-walled carbon nanotubes (SWNTs) and β-cyclodextrins (β-CDs) were prepared by π−π interaction between pyrene modified β-CDs and SWNTs. Moreover, chemically responsive supramolecular SWNT hydrogel was constructed using host−guest interactions by means of hybrids of SWNTs and β-CDs.

We monitored the progress of formation of dimethoxypillar[5]arene by size-exclusion chromatography. Surprisingly, the cyclization reaction completely finished in just 3 min. By improving the reaction conditions and purification process, we successfully obtained dimethoxypillar[5]arene in a short time and in high yield (71%) from commercially available reagents. By improving the deprotection reaction of the methoxy moieties, pillar[5]arene was isolated quantitatively. Single crystal X-ray analysi

Pillar[n]arenes, which we first synthesized and named in 2008, are new pillar-shaped macrocyclic hosts. Pillar[n]arene homologues with n = 5-10 have already been synthesized, but the cyclic pentamers, i.e., pillar[5]arenes, and cyclic hexamers, i.e., pillar[6]arenes, have been most widely used because these can be obtained in good yields. To date, nearly all pillar[n]arene-based supramolecular assemblies have been constructed using pillar[5]- and pillar[6]arene scaffolds. In this feature article

Abstract Polymer‐based room‐temperature‐phosphorescent (RTP) materials are attractive alternatives to low‐molecular‐weight organic RTP compounds because they can form self‐standing transparent films with high thermal stability. However, their RTP lifetimes in air are usually short (&lt;≈0.4 s). Here, the simple organic amorphous polymer, poly(styrene sulfonic acid) (PSS), exhibits an ultralong RTP lifetime in air when desiccated. The maximum lifetime is 1.22 s, which is three times that of previ

Enantiomers of bulky percyclohexylmethyl-substituted pillar[5]arene (Cy-C1-Pillar) were able to be separated by chiral column chromatography, and the separated enantiomers did not racemize. Even though modified with the bulky cyclohexylmethyl-substituents at both rims, Cy-C1-Pillar was able to capture a guest molecule.

A series of pillar[5]arene derivatives with alkyl groups of different length were synthesized. The new alkyl-substituted pillar[5]arene derivatives 1,4-bis(ethoxy)pillar[5]arene (C2), 1,4-bis(propoxy)pillar[5]arene (C3), 1,4-bis(butoxy)pillar[5]arene (C4), 1,4-bis(pentyloxy)pillar[5]arene (C5), 1,4-bis(hexyloxy)pillar[5]arene (C6), and 1,4-bis(dodecanoxy)pillar[5]arene (C12) were obtained by Lewis acid-catalyzed condensation of dialkoxybenzene monomers with paraformaldehyde. The conformational c

On the flipside: A planar chiral pseudo- [1]catenane based on pillar[5]arene, in which an alkyl chain is connected to one pillar[5]arene unit, has been synthesized. Capture and release of achiral guests and solvents trigger the inclusion and de-threading of the alkyl chain, which causes the inversion of planar chirality.