Synthesis of dendrimers with a N-Si-C framework

A novel family of air-stable dendrimers with a N-Si-C framework has been pr epared up to the fourth generation. The divergent synthesis starts with the hydrosilylation of the trisilazane N(SiMe(2)vinyl)(3) [0-G(vinyl)] by HSiM e2Cl, which gives the three-directional core molecule N(SiMe2CH2CH2SiMe2Cl) (3) [0-G(Cl)]. A 1-to-2 branching achieved by reacting the core molecule [0 -G(Cl)] with 3 equiv of KN(SiMe(2)vinyl)(2) affords the first generation de ndrimer [l-G(vinyl)]. By repeating the above two steps, the second [2-G(vin yl)], third [3-G(vinyl)], and four th generation [4-G(vinyl)] can be obtain ed. The compounds have been characterized by H-1, C-13, and Si-29 NMR spect roscopy, by elemental analysis, and up to the third generation by MALDI-TOF mass spectrometry. Gel permeation chromatography was used to prove the fou rth generation [4-G(vinyl)].