Solution conformation and inversion barrier in p-tert-butyl-25,27-dihydroxycalix[4]arene

Spectroscopic data indicate that the solution conformation of the dihydroxycalix[4]arene 3 (1,3-alternate) is intramolecularity hydrogen bonded and is different from the crystallographic conformation of its MeOH solvate (1,2-alternate).