Synthesis of Neutral, Water-Soluble Oligo–Ethylene Glycol-Containing Dendronized Homo- and Copolymers of Generations 1, 1.5, 2, and 3

Abstract

Oligo-ethylene glycol-containing dendronized monomers MG1, MG1.5, MG2, and MG3 were synthesized in a particularly easy fashion on the gram scale involving only few steps. Their corresponding homopolymers (PG1, PG1.5, PG2, and PG3) and copolymers (PG1co2, PG1co3, and PG2co3) were synthesized via free radical polymerization. All the polymers are soluble in water and also in organic solvents such as DCM, CHCl 3 , 1,4-dioxolane, DMF, and DMSO. Their glass transition temperatures (T g ) are in the range −68°C < T g < −48°C and thus rather low. All polymers show thermoresponsive behavior which was investigated by turbidity measurements. Interestingly, a 1:1 mixture of homopolymers PG1 and PG2 behaves identical with PG1 alone, while the collapse curve of copolymer PG1co2 is almost superimposable with that of PG2 alone. Thus, in the former case PG1 dominates the thermoresponsive behavior while in the latter this is done by the G2-dendrons in the copolymer. Finally, the polymer chains were visualized by AFM, confirming the rod-like behavior of these rigidified polymers.

Confined Microenvironments from Thermoresponsive Dendronized Polymers

“…One possible way to do so is tuning the number of OEG chains and their arrangement in each dendron. [ 56 ] Dendrons carrying two to six arms of OEG chains have already been prepared in our lab recently. Another possibility is the random or block copolymerization of two or several dendritic macromonomers with different dendron generations to tune thickness along polymer mainchains.…”

Main-chain scission of individual macromolecules induced by solvent swelling

“…In-depth investigations regarding charged DPs and the purposeful variation of structural parameters such as repeating unit spacing, dendron tether length, and peripheral substitution may deliver further insights into DP main-chain scission. Particularly the functionalization of DPs with groups providing LCST/UCST behavior will be of great interest 63. The knowledge of degradation tendencies may also prove synthetically useful in the preparation of g > 6, high P n DPs in the quest towards individual macromolecules of GDa molar mass.…”

Design, synthesis and cytotoxic activity of water-soluble quinones with dibromo-p-benzoquinone cores and amino oligo(ethylene glycol) side chains against MCF-7 breast cancer cells

“…Linear amine 2 was prepared in two steps from commercially available diethylene glycol monomethyl ether (DEGME) (Scheme 1). 29 The novel first-and second-generation amino oligoIJethylene glycol) dendrons 5 and 9 were derived from their hydroxyl analogues 3 and 7, 30 whereby the synthetic procedures reported herein feature several improvements in terms of efficacy and scale. The synthetic route towards the first-generation dendron 5 is delineated in Scheme 2.…”