Synthesis and characterization of a novel alcohol-soluble ladderlike polysilsesquioxane containing side-chain with amino terminal groups

A novel kind of alcohol-soluble ladderlike polysilsesquioxane having side-chain with amino terminal groups (NH₂-T) was first prepared by reduction of nitro terminal groups on the side chains of ladderlike polynitrosilsesquioxane (NO₂-T) with a nearly 100% conversion rate. The parent polymer NO₂-T was synthesized by stepwise coupling polymerization. As starting monomer, 3-(4-nitrophenoxy)propyltrichlorosilane (M) was synthesized by hydrosilylation of the corresponding allylic derivative with trichlorosilane in the presence of dicyclopentadienylplatinum (II) chloride (Cp₂PtCl₂) catalyst in a high yield. A variety of characterization methods including FTIR, ¹H NMR, ¹³C NMR, ²⁹Si NMR, differential scanning calorimetry, thermogravimetric analysis, vapour pressure osmometry, and X-ray diffraction were combined to verify that NH₂-T had ladderlike structure. The alcohol-soluble ladderlike NH₂-T prepared has promising application in controlled release of catalysts and drugs, NLO materials, alignment layer in liquid crystal display, and as a precursor for further preparing advanced functional polymers and their supramolecular systems.