Nanostructuring of Hybrid Silicas:New Approach to Bridged Silsesquioxanes with Purine-Pyrimidine Base Pairs as Bridging Units

摘要

A new route to synthesize hybrid silica-based network with bridging organic units via molecular recognition is described.The hydrolysis of two monosilylated complementary base pairs,one bearing an adenine fragment and the other a thymine fragment leads to the formation of a powdered sample that has been characterized by Scanning Electron Microscopy(SEM),Powder X-ray Diffraction(PXRD)FTIR and solid state NMR(~1H,~(13)C and ~(29)Si).This last technique proved to be extremely powerful to directly demonstrate the occurrence of heteroassembly of the nucleobase-based silylated fragments,through the use of two-dimensional ~1H double-quanta MAS-NMR that could probe spatial proximities between the thymine NH groups and the adenine NH2 groups.