Supramolecular polymer chemistry: self-assembling dendrimers using the DDA.AAD (GC-like) hydrogen bonding motif.
Heterocyclic unit 2 containing complementary donor-donor-acceptor (DDA) and acceptor-acceptor-donor (AAD) hydrogen bonding arrays at an angle of about 60 degrees was designed to self-assemble into a hexamer. To investigate whether this unit could self-assemble dendrimers, the 2,8-diamino-2-N-ethylpyrimido-(4,5-b)(1,8)naphthyridine-3H-4-one subunit was synthesized with a first (2a), second (2b), and third generation (2c) Fréchet-type dendron attached to the 8-amino group. The synthesis of 2a-c was accomplished in 11 steps beginning with 2,6-diaminopyridine and the corresponding dendron bromide. Studies using (1)H NMR, size exclusion chromatography (SEC), and dynamic light scattering (DLS) support the cooperative formation of cyclic hexamers in apolar solvents. The stability of the self-assembled dendrimers is dependent on the size of the attached dendron, and mixing studies with 2a-c indicate their usefulness in constructing dynamic combinatorial libraries.
Ma
Yuguo
Y
Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Kolotuchin
Sergei V
SV
Zimmerman
Steven C
SC
D002850:Chromatography, Gel; D020650:Combinatorial Chemistry Techniques; D006860:Hydrogen Bonding; D007700:Kinetics; D008027:Light; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D018716:Molecular Mimicry; D009287:Naphthyridines / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012542:Scattering, Radiation
D046911:Macromolecular Substances; D009287:Naphthyridines; D011108:Polymers