Facile separation of cyclic aliphatic and aromatic vapors using crystalline thiacalixarene assemblies with preorganized channels.

Conventional distillation methods cannot separate compounds with similar boiling points, molecular sizes, and volumes, such as cyclohexane and benzene or methylcyclohexane and toluene, effectively. The corresponding cyclic aliphatic and aromatic hydrocarbons cannot be separated effectively using the same type of sorption material. We report that crystalline thiacalixarene assemblies featuring preorganized channel-like adsorption sites are capable of both separations.

Alkane Shape- and Size-Recognized Selective Vapor Sorption in "Channel-Like" Crystals Based on Thiacalixarene Assemblies.

Invited for the cover of this issue is the group of Manabu Yamada at Akita University and colleagues from Yamagata University and Vellore Institute of Technology. The image depicts two activated "channel-like" crystals, effectively adsorb branched and cyclic alkanes from linear, branched, and cyclic alkane vapors. Read the full text of the article at 10.

Alkane Shape- and Size-Recognized Selective Vapor Sorption in "Channel-Like" Crystals Based on Thiacalixarene Assemblies.

Alkanes composed of C-C and C-H show a low electric polarization, and therefore, there is only very weak interaction between alkanes and adsorbents. Thus, it is difficult to separate a specific alkane from a mixture of alkanes by adsorption. Here, two activated "channel-like" crystals generated from brominated thiacalix[4]arene propyl ethers, which adopt 1,3-alternate and partial cone conformations, recognize specific alkane vapors depending on alkane-shape and -size, sorting in three-type alkane guests such as linear, branched, and cyclic alkanes.