Acoustic Alignment of a Supramolecular Nanofiber in Harmony with the Sound of Music.

Invited for this month's cover is the group of Prof. Akihiko Tsuda from Kobe University and Kobe City Collage of Technology. The cover picture shows the alignment of a supramolecular nanofiber, composed of an anthracene derivative, while the Kobe University Symphony Orchestra was playing classical music.

Acoustic Alignment of a Supramolecular Nanofiber in Harmony with the Sound of Music.

Audible sound with a low-frequency vibration brings about hydrodynamic alignment of a supramolecular nanofiber in solution. Design of the nanoscale molecules and molecular assemblies, which can sense a wide range of frequencies of the audible sound wave with high sensitivity, develops sound-driven molecular machines and sound-responsive nanomaterials, and is also interesting for investigation of unknown physical interactions between the molecules and audible sound vibrations. In this study, it was found that a supramolecular nanofiber, composed of an anthracene derivative AN, in an n-hexane solution aligned upon exposure to an audible sound wave at frequencies up to 1000 Hz, with quick responses to the sound and silence, and to amplitude and frequency changes of the sound wave.

A self-assembled helical anthracene nanofibre whose P- and M-isomers show unequal linear dichroism in a vortex.

An anthracene derivative, having benzamide substituents bearing optically active alkyl chains, in hexane forms one-handedly biased helical supramolecular nanofibres, which show unequal linear dichroism (LD) in right- and left-handed vortex flows.