A Balance between van der Waals and Cation–π Interactions Stabilizes Hydrophobic Assemblies. Issue 36 (1st June 2018)

• Record Type: Journal Article
• Authors: Zhan, Yi‐Yang; Kojima, Tatsuo; Koide, Takuya; Tachikawa, Masanori; Hiraoka, Shuichi
• Is Part Of: Chemistry. Volume 24:Issue 36(2018)
• Page Start: 9130
• Page End: 9135
• Publication Date: 2018-06-01
• Subjects: hydrophobic effect -- nanostructures -- noncovalent interactions -- pi interactions -- self-assembly; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201801376
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: A thermally highly stable molecular self‐assembly (nanocube) in water, the decomposition temperature of which is 415 K, was developed by designing a gear‐shaped amphiphile (GSA) with an indented hydrophobic surface, even though the nanocube is stabilized only by van der Waals (vdW) and cation–π interactions as well as the hydrophobic effect. The introduction of an electron‐donating substituent in one of the benzene rings of the GSA increased the decomposition temperature by 12 K, which is due to the stronger cation–π interactions between the benzene ring and positively charged pyridinium rings and tighter molecular meshing between the GSAs in the nanocube. The position of the substituent introduced in the benzene ring greatly affects the thermal stability of the nanocubes, and this indicates that both vdW (molecular meshing) and cation–π interactions are crucial for improving the thermal stability of the hydrophobic assemblies. Abstract : Extreme thermal stability : A molecular assembly (nanocube) with a decomposition temperature of 415 K was developed, even though the factors that stabilize the nanocube are only very weak molecular interactions such as van der Waals and cation–π interactions as well as the hydrophobic effect (see figure).