First synthesis of a dihydrido functionalized double-cored oligosilane dendrimer

The reaction of (R2MeSi)(2)SiHCl (2) [R = SiMe3] with Na-K-alloy yields the double-cored dendritic oligosilane [(R2MeSi)(2)SiH](2) (4). The structure of 4 was obtained from X-ray diffraction data, which verify a total of 14 silicon atoms and a longest chain of six silicon atoms. The UV-Vis spectra of 4 and the structurally analogous [(R2MeSi)(2)SiMe](2) (5) exhibit absorption maxima (shoulders) at 269 nm (epsilon = 2.0 x 10(4)) and 276 nm (epsilon = 2.3 x 10(4)), respectively, which are the longest so far observed for alkyl substituted oligosilanes with hexasilane chains. (C) 2004 Published by Elsevier B.V.