抄録
Synthesis, structure, and electronic properties of silicon chains functionalized with hypervalent silicon moieties, polar substituents, or transition metal clusters are reported. Absorption spectra of pentacoordinate silicon oligomers reveal that the introduction of pentacoordinate silicon moieties into oligosilanes leads to a drastic change of the σSiSi-σ*SiSi excitation energies. 29Si NMR spectra have proved that the conformations of pentacoordinate oligosilanes are tightly locked even in room-temperature solution. UV-VIS spectra of polysilanes having polar substituents like (alkoxycarbonyl) methyl groups suggest that polar substituents effectively promote the σ-conjugation of the silicon backbones. Electron delocalization in (-Si-Ru-Ru-Si-C6H44-) n polymers was demonstrated by the absorption spectra. Solvent-sensitive structural deformation of the Si-Ru-Ru-Si unit leads to change of the optical properties.
