Organic chemistry

Combinatorial chemistry

Carborane

Stereochemistry

Computational chemistry

Chemistry

Hexane

Journal of the American Chemical Society

Herein, we describe how to utilize dihydrogen bond interactions to achieve alkane recognition and hexane isomer separation. A series of metallacycles based on carborane backbones are presented herein, revealing interdependent B–Hδ−···Hδ+–C proton–hydride interactions. The metallacycles take advantage of these dihydrogen bond interactions for the separation of hexane isomers. We show that the metallacycle 3a, bearing 1,4-di(4-pyridyl)benzene (DPB), can produce n-hexane with a purity of >99% in a single adsorption–desorption cycle from an equimolar mixture of all five isomers of hexane. The isomers 2-methylpentane and 3-methylpentane can be selectively absorbed by metallacycle 4a, which bears 1,2-di(4-pyridyl)ethylene (DPE). The size of the metallacycle, C–H···π interactions, and particularly B–Hδ−···Hδ+–C interactions are the main forces governing the extent of hexane recognition. This work provides a promising principle for the design of supramolecular coordination complexes (SCCs) for the separation of alkanes.

Dihydrogen Bond Interaction Induced Separation of Hexane Isomers by Self-Assembled Carborane Metallacycles