A polymerized calix[6]arene monolayer having gas permeation selectivity that exceeds Knudsen diffusion.

A polymerized monolayer of 5,11,17,23,29,35-hexamercaptomethyl-37,38,40,41,42-hexakis-(1-n hexadecyloxy)calix[6]arene (1) has been synthesized on the surface of an ca. 15 mum-thick film derived from poly[1-(trimethylsilyl)-1-propyne] (PTMSP). This monolayer exhibits a permeation selectivity toward He and SF6 that exceeds Knudsen diffusion. Analogous membranes made from a calix[6]arene that contains amidoxime headgroups (i.e., 2) showed Knudsen diffusion characteristics.