Design of hydrophobic polyoxometalate hybrid assemblies beyond surfactant encapsulation.
Design of hydrophobic polyoxometalate hybrid assemblies beyond surfactant encapsulation.
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DOI：
10.1002/chem.200701629
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发表时间：
2008-03
期刊：
影响因子：
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通讯作者：
Yu-Fei Song;N. McMillan;D. Long;J. Thiel;Yulong Ding;Haisheng Chen;N. Gadegaard;L. Cronin
中科院分区：
文献类型：
--
作者：
Yu-Fei Song;N. McMillan;D. Long;J. Thiel;Yulong Ding;Haisheng Chen;N. Gadegaard;L. Cronin
Grafting of C-6, C-16 and C-18 alkyl chains onto the hydrophilic Mn-Anderson clusters (compounds 2-4) has been achieved. Exchange of the tetrabutyl ammonium (TBA) with dimethyldioctadecyl ammonium (DMDOA) results in the formation of new polyoxometalate (POM) assemblies (compounds 5-6), in which the POM cores are covalently functionalized by hydrophilic alkyl-chains and enclosed by surfactant of DMDOABr. As a result, we have been able to design and synthesize POM-containing hydrophobic materials beyond surfactant encapsulation. In solid state, scanning electron and transmission electron microscopy (SEM and TEM) studies of the TBA salts of compounds 3 and 4 show highly ordered, uniform, reproducible assemblies with unique segmented rodlike morphology. SEM and TEM studies of the DMDOA salts of compounds 5 and 6 show that they form spherical and sea urchin 3D objects in different solvent systems. In solution, the physical properties of compound 5 and 6 (combination of surfactant-encapsulated cluster (SEC) and surface-grafted cluster (SGC)) show a liquid-to-gel phase transition in pure chloroform below 0 degrees C, which are much lower than other reported SECs. By utilizing light scattering measurements, the nanoparticle size for compounds 5 and 6 were measured at 5 degrees C and 30 degrees C, respectively. Other physical properties including differential scanning calorimetry have been reported.
