The separation of high-purity linear alkanes from a mixture of linear and branched alkanes is of great importance to the oil and gas industry for the improvement of the gasoline quality. Herein, we investigate the methylene-bridged trianglamines (M-TA) as supramolecular adsorbents for the selective separation of linear alkane isomers. This selectivity depends on the host–guest complexation arising from the size matching between the trianglamines cavity and the linear guest molecules. Moreover, M-TA are highly recyclable with almost no loss of efficiency showing a promising prospect in industrial applications. We believe that the tailored design of host supramolecular entities as smart and selective recognition units for energy-intensive separations will be the preferred future approch towards environmentally friendly and sustainable processes in industrial operations.