pH‐Triggered Self‐Assembly of Zwitterionic Polyglycerol Dendrons into Discrete and Highly Stable Supramolecular Dendrimers in Water

Abstract

pH‐dependent dimerization: Zwitterionic polyglycerol dendrons self‐assemble into discrete and well‐defined dimers in water as shown by dynamic light scattering (DLS), gel permeability chromatography (GPC), and DOSY NMR spectroscopy. However, self‐assembly occurs only at neutral pH as either protonation or deprotonation destroys the self‐complementary zwitterionic binding motif in the core of the dendrimer. Hence, structure formation can be triggered back and forth by changing the pH of the solution.

Supramolecular Polymer Networks: Preparation, Properties, and Potential

“…In approaches that serve to derive fundamental physical-chemical understanding of supramolecular polymer networks, synthetic precursors are mostly used because chemical modification allows them to be tailored as desired. When it comes to further tailoring of supramolecular polymer materials for practical applications in the biological area, a popular class of precursor polymers are those that are water soluble, including poly(ethylene glycol) (PEG) [41,42], poly(vinyl alcohol) (PVA) [43][44][45], and polyglycerol [46][47][48]. However, several other synthetic precursors are only soluble in organic solvents.…”

Second‐Generation Supramolecular Dendrimer with a Defined Structure due to Orthogonal Binding

“…In addition to hydrogen bonds, coordinative bond formation [9,10] can also be used for the assembly of dendrimers or betaines. [11] A combination of coordinative bond formation for the core and hydrogen bonding for the next generation has been demonstrated by Hirsch and co-workers. [14] In this investigation we chose to combine two different hydrogen-bonding patterns for the first-and second-generation recognition domains: The isocyanuric acid/Hamilton [15] receptor pair, as used by Hirsch and co-workers, [13] and a linear, quadruple hydrogen-bonding dimer developed in our group.…”

“…This problem can be solved if different and orthogonal recognition events are chosen for each generation. In addition to hydrogen bonds, coordinative bond formation9, 10 can also be used for the assembly of dendrimers or betaines 11. A combination of coordinative bond formation for the core and hydrogen bonding for the next generation has been demonstrated by Hirsch and co‐workers 14…”

“…[8] Whole dendrons can also be connected by reversible interactions. [9][10][11][12] But reversible reactions can also be used in each generation. In 2005, Hirsch and co-workers [13] presented a supramolecular dendrimer in which the core, branching units, and outer-most units (caps) self-assemble through hydrogen bonds.…”

A Journey through 12 Years of Interacting Molecules: From Artificial Amino Acid Receptors to the Recognition of Biomolecules and Switchable [nl]Nanomaterials

“…The first approach was realized by embedding the zwitterion in a polyglycerol dendrimer. 66 Using click chemistry, we attached dendrons of different generations to the periphery of our zwitterion (Figure 25). The resulting hybrid molecules could dimerize, again in a pH-dependent manner, into well-defined and monodisperse dendrimers with a specific size and shape.…”