Progress toward limiting generation of dendritic ethynylsilanes (PhCC)4−nMenSi (n = 0–2)

Dendritic carbosilanes based on phenylethynylmethylsilanes (PhCC)_4−nMe_nSi (n = 0–2) as cores were synthesized. The building blocks of the dendrimers consist of double bonds ( PhCCHMeSi ) in the inner shell and triple bonds [(PhCC)₂MeSi ] on the outmost periphery. The synthetic methods used the iterative alkynylation and hydrosilation cycle, which was composed of lithium phenylacethylide and dichloromethylsilane. The limiting generation of the dendrimer for the four branching type (PhCC)₄Si at a core molecule has 32 phenylethynyl groups on the third generation, 48 for the three branching type (PhCC)₃MeSi on the fourth generation, and 64 for the two branching type (PhCC)₂Me₂Si on the fifth generation. The dendrimers were characterized by the use of NMR, Maldi mass, SEC, DSC, UV as well as elemental analysis. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2749–2759, 2000