ENCAPSULATION OF GUEST MOLECULES INTO A DENDRITIC BOX

Dendrimers are well-defined, highly branched macromolecules that emana te from a central core and are synthesized through a stepwise, repetit ive reaction sequence. The synthesis and characterization of dendritic boxes, based on the construction of a chiral shell of protected amino acids onto poly(propyleneimine) dendrimers with 64 amine end groups, is reported here. Nuclear magnetic resonance-relaxation and optical da ta show that a dense shell with solid-phase character is formed. Guest molecules were captured within the internal cavities of the boxes whe n these boxes were constructed in the presence of guest molecules. The diffusion of guest molecules out of the boxes into solution was unmea surably slow because of the close packing of the shell. These monomole cular dendritic containers of 5-nanometer dimensions with physically l ocked-in guest molecules were characterized spectroscopically.