FORMATION OF DISCRETE, FUNCTIONAL ASSEMBLIES AND INFORMATIONAL POLYMERS THROUGH THE HYDROGEN-BONDING PREFERENCES OF CALIXARENE ARYL AND SULFONYL TETRAUREAS

Derivatives of the calix[4]arenes in the cone conformation featuring e ither aryl urea or sulfonyl urea functions on their larger (upper) rim s dimerize through hydrogen bonding to give molecular capsules. The ca psules act as hosts that reversibly bind smaller molecule guests in or ganic media. Heterodimers form when both aryl and sulfonyl ureas are p resent, and the heterodimers form exclusively with respect to the homo dimers. The heterodimerization encodes information at the molecular le vel and allows the predictable formation of discrete aggregates of nan ometer dimensions. Evidence for the reversible assembly of these struc tures is provided by H-1 NMR, guest encapsulation studies, and gel per meation chromatography. Covalent attachment of these calixarene aryl a nd sulfonyl ureas at their smaller (lower) rims leads to polymeric ass emblies in which the informational content is preserved.