Synthesis of Large Dendrimers with the Dimensions of Small Viruses

Abstract

The dendrimer chemistry reported offers a route to synthetic target molecules with spherical shape, well-defined surface chemistries and dimensions that match the size of virus particles. The largest target, a generation 13 dendrimer comprising triazines linked by diamines, is stable across ranges of concentration, pH, temperature, solvent polarity and in the presence of additives. This dendrimer theoretically, presents 16384 surface groups and has a molecular weight exceeding 8.4 million Daltons. Transmission electron and atomic force microscopies, dynamic light scattering, and computation reveal a diameter of approximately 30 nm. The target is synthesized through an iterative divergent approach using a monochlorotriazine macromonomer providing two generations of growth per synthetic cycle. Fidelity in synthesis is supported by evidence from NMR spectroscopy, mass spectrometry, and high pressure liquid chromatography.

Bifunctional Phosphorus Dendrimers and Their Properties

“…This method also afforded layered dendrimers with an alternation of P=N-P=S and hydrazine functions [95]. Another development of this process consisted in using AB 5 branched monomers ( Figure 13) instead of the AB 2 monomers, either alone, or in alternation with AB 2 monomers. This methodology with AB 5 branched monomers permitted the preparation of a dendrimer of generation 3 bearing 750 phosphine terminal groups in only three steps, starting from a hexaaldehyde core [96].…”

“…Comparison of the properties of the Figure 13. Synthesis of layered dendrimers using two branched orthogonal monomers of type AB 2 and CD 2 , and structure of branched orthogonal monomers of type AB 5 and CD 5 , usable in the same process.…”

“…Each time a new layer of branching points is created, a new generation is obtained. High generations have been obtained in some cases: generation 9 for polyphenylene dendrimers [1], generation 10 for PAMAM dendrimers [2] and for polylysine dendrimers [3], generation 12 for phosphorhydrazone dendrimers [4], and recently generation 13 for triazine dendrimers [5]. In most cases, the internal structure has no specific function usable for further functionalization, and all the terminal functions are identical.…”

Solvent effects on the properties of hyperbranched polythiophenes

“…Dendrimers undergo changes in size, shape and flexibility as a function of increasing generation. [16][17][18][19] On the other hand, dendrons are monodisperse dendritic wedge-shaped structures that comprise a single function at the core and multifunctionality at the outer layer (periphery). Figure 1a illustrates the difference between dendrimers and dendrons structures.…”

Phosphorus dendrimers as supports of transition metal catalysts

“…If this sequence of reactions is absolutely quantitative, then the process can be used again, to afford the second generation, then the third, and so on. High generations have been attained for some dendrimers, generation 10 for PAMAM (polyamidoamine) dendrimers [4] and poly-L-lysine dendrimers [5], generation 12 for PPH (polyphosphorhydrazone) dendrimers [6], and very recently generation 13 for polytriazine dendrimers [7] and polyphenylene dendrimers [8]. Obtaining these high generations is a long process, but most of the properties of dendrimers can be attained with lower generations, most often not higher than generations 4 or 5.…”