title: Restricted rotation of tert-butyl groups in sterically crowded methylene-functionalized calix[4]arenes.
abstract: The crowded methylene-functionalized calix[4]arenes 4 and 5 display restricted rotation of the tert-butyl substituents at the bridges. At low temperatures, separate signals were observed for the methyls of these groups in the (1)H NMR spectra.
authors.affiliation: Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Lev
authors.initials: L
authors.lastname: Kuno
authors.forename: Silvio E
authors.initials: SE
authors.lastname: Biali