Synthesis of Fine-Controlled Metallodendrimers
1.Introduction Dendrimers are highly branched organic macromolecules with successive layers or generations of branch units surrounding a central core.Organic inorganic hybrid versions have also been produced,by trapping metal ions or metal clusters within the voids of the dendrimers.Their unusual, tree-like topology endows these nanometre-sized macromolecules with a gradient in branch density from the interior to the exterior,which can be exploited to direct the transfer of charge and energy from the dendrimer periphery to its core. Here we show that tin ions,Sn2+,complex to the imines groups of a spherical polyphenylazomethine dendrimer in a stepwise fashion according to an electron gradient,with complexation in a more peripheral generation proceeding only after complexation in generations closer to the core has been completed.By attaching an electron-withdrawing group to the dendrimer core,we are able to change the complexation pattern,so that the core imines are complexed last.By further extending this strategy,it should be possible to control the number and location of metal ions incorporated into dendrimer structures,which might and uses as tailored catalysts or building blocks for advanced materials.
dendrimer metal complez metal-organic hybrid material
Kimihisa Yamamoto
Department of Chemistry,Keio University,Yokohama,223-8522 JAPA
国际会议
江苏镇江
英文
10-12
2008-10-15（万方平台首次上网日期，不代表论文的发表时间）