Supramolecular structures of uracil-functionalized PEG with multi-diamidopyridine POSS through complementary hydrogen bonding interactions
作者:Jui-Hsu Wang、Oleksii Altukhov、Chih-Chia Cheng、Feng-Chih Chang、Shiao-Wei Kuo
DOI:10.1039/c3sm27968e
日期:——
In this study, we synthesized (i) a multi-diamidopyridine-functionalized polyhedral oligomeric silsesquioxane (MD-POSS) through nucleophilic substitution and click 1,3-cycloaddition reactions and (ii) both mono- and bis-uracil (U)-functionalized poly(ethylene glycol) derivatives (U–PEG and U–PEG–U, respectively) through Michael additions of U to acryloyl-functionalized PEG oligomers. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) revealed that supramolecular structures self-assembled from mixtures of MD-POSS and U–PEG and from MD-POSS and U–PEG–U. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy confirmed the presence of multiple hydrogen bonding interactions between the diaminopyridine groups of MD-POSS and the U groups of U–PEG and U–PEG–U. Because of these strong reversible intermolecular multiple hydrogen bonds, the POSS-based polymer-like supramolecular materials exhibited improved thermal properties upon increasing the MD-POSS content.
在本研究中,我们通过亲核取代和点击1,3-环加成反应合成了(i)一种多二酰胺吡啶功能化的多面体低聚倍半硅氧烷(MD-POSS),并通过迈克尔加成反应合成了(ii)单和双尿嘧啶(U)功能化的聚乙二醇衍生物(U–PEG和U–PEG–U)。透射电子显微镜(TEM)和动态光散射(DLS)揭示了从MD-POSS和U–PEG以及MD-POSS和U–PEG–U的混合物中自组装的超分子结构。傅里叶变换红外(FTIR)和核磁共振(NMR)光谱证实了MD-POSS的二氨基吡啶基团与U–PEG和U–PEG–U的尿嘧啶基团之间存在多重氢键相互作用。由于这些强可逆的分子间多重氢键,基于POSS的类聚合物超分子材料在增加MD-POSS含量时表现出改善的热性能。