Host–Guest Complexation of Perethylated Pillar[5]arene with Alkanes in the Crystal State. Issue 34 (1st July 2015)

• Record Type: Journal Article
• Authors: Ogoshi, Tomoki; Sueto, Ryuta; Yoshikoshi, Kumiko; Sakata, Yoko; Akine, Shigehisa; Yamagishi, Tada‐aki
• Is Part Of: Angewandte Chemie international edition. Volume 54:Issue 34(2015)
• Page Start: 9849
• Page End: 9852
• Publication Date: 2015-07-01
• Subjects: alkanes -- crystals -- host–guest chemistry -- macrocyclic compound -- pillar[n]arenes; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201503489
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Activated perethylated pillar[5]arene crystals show an unexpected alkane‐shape‐ and ‐length‐selective gate‐opening behavior. Activated crystals were obtained upon removing solvents from perethylated pillar[5]arene crystals by heating. The activated crystals could quantitatively take up n ‐alkanes with carbon chains containing more than five carbon atoms as a consequence of their gate‐opening pressure. As the chain length of the n ‐alkanes increased, the gate pressure decreased. A transformation into a herringbone structure was induced when n ‐hexane was used as a guest. By contrast, cyclic and branched alkanes were not taken up and could not induce a crystal transformation because they were too large to fit in the cavities of the pillar[5]arene. Alkane‐shape‐selective molecular recognition of pillar[5]arenes in the solution state was translated into the vapor/crystal state. Abstract : Gate crashers : Activated perethylated pillar[5]arene crystals have been demonstrated to show selective gate‐opening behavior depending on alkane shape and length. The activated crystals could quantitatively take up n ‐alkanes with more than five carbon atoms, and n ‐hexane could even be stored under reduced pressure. In contrast, the gate‐opening behavior was not observed in the adsorption of cyclic and branched alkanes.