Calix[n]arene derivatives for gas storage

Abstract

The calix[n]arenes are versatile inclusion compounds (Scheme 1) comprise of cyclic, polyphenolic compounds that can be tailored synthetically by altering X, Y, R and n. In solid state, we found simple calixarenes are quite interesting for example separation of hydrogen from mixture of gases so our attention turned into the closely related calixarenes for sorption studies.

With this little back ground on calixarenes and their uses in solid state, we designed and synthesized tert-butylsulfonylcalix[4]arene and Tetra-p-tert-butyl-tetramethoxysulfonylcalix[4]arene from tert-butylthiacalix[4]arene by oxidizing in the presence H2O2 or NaBO3 in exceptional yield.

Furthermore, asymmetric bridging of two calix[4]arene molecules to form a calixarene tubes with a larger and easily accessible cavity was also attempted to synthesize. Finally, H1NMR spectral and X- ray crystallographic modeling studies was done to reveal the conformational characteristics of the synthesized compounds.