Related Experiment Video
Updated: Jul 16, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Supramolecular polymer chemistry: self-assembling dendrimers using the DDA.AAD (GC-like) hydrogen bonding motif
Yuguo Ma1, Sergei V Kolotuchin, Steven C Zimmerman
1Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Abstract:
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.
Related Concept Videos
Molecular Models
Newman Projections
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as conformers.
Structure of Conjugated Dienes
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Diels–Alder Reaction: Characteristics of Dienes
Characteristics of the diene
Conformation
The simplest example of a diene is 1,3-butadiene, an acyclic conjugated π system. At room temperature, the molecule exists as a mixture of s-cis and s-trans conformers by virtue of rotation around the carbon–carbon single bond. Although the s-trans isomer is more stable, the...
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement

