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. These properties are of great advantage to sense dynamic changes of fluid flows, such as those induced by the sound of music. Music is composed of multiple complex sounds and silence, which characteristically change in the course of its playing time. When classical music was playing, the AN nanofiber aligned itself in harmony with the sound of the music. Time course linear dichroism spectroscopy revealed the dynamic acoustic alignments of the AN nanofiber in the solution upon playing the music. The sound vibrations of music, which generate acoustic streaming flows in liquid media, allowed shear-induced alignments of the nanofiber.

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. Read the full text of the article at 10.1002/cplu.201300400

Chlorine, phosgene, and trichloroacetyl chloride are some of the complex mixture of multiple products that is obtained from the oxidative photodecomposition of tetrachloroethylene. These toxic but important reagents in organic synthesis can generated and used in situ for practical syntheses of ureas, amides, carbonates, esters, carbamates, enaminones, and organochlorides.

The photochemical generation of elemental Br₂ from brominated methanes is reported. Br₂ was generated by the vaporization of carbon oxides and HBr through oxidative photodecomposition of brominated methanes under a 20 W low-pressure mercury lamp, wherein the amount and situations of Br₂ generation were photochemically controllable. Liquid CH₂Br₂ can be used not only as an organic solvent but also for the photoresponsive molecular storage of Br₂, which is of great technical benefit in a variety of organic syntheses and in materials science. By taking advantage of the in situ generation of Br₂ from the organic solvent itself, many organobromine compounds were synthesized in high practical yields with or without the addition of a catalyst. Herein, Br₂ that was generated by the photodecomposition of CH₂Br₂ retained its reactivity in solution to undergo essentially the same reactions as those that were carried out with solutions of Br₂ dissolved in CH₂Br₂ that were prepared without photoirradiation. Furthermore, HBr, which was generated during the course of the photodecomposition of CH₂Br₂, was also available for the substitution of the OH group for the Br group and for the preparation of the HBr salts of amines. Furthermore, the photochemical generation of Br₂ from CH₂Br₂ was available for the area-selective photochemical bleaching of natural colored plants, such as red rose petals, wherein Br₂ that was generated photochemically from CH₂Br₂ was painted onto the petal to cause radical oxidations of the chromophoric anthocyanin molecules.