“…They exhibit intense σ−σ* electronic transitions in the near-UV region, − intermolecular charge transfer (CT) complexes involving permethylated oligosilanes have been reported, , and in photoexcited arylsilanes intramolecular CT emission originating from a 1 (σ,π*) charge transfer state has been observed. − Furthermore, rapid electron transfer between chromophores connected by silicon catenates was proposed . These properties find their origin in the occurrence of σ-conjugation along the silicon backbone, ,, the presence of polarizable valence electrons, low ionization potentials, , and σ−π interactions. − Because of these features Zyss and co-workers − investigated the second-order nonlinear optical activity, which is strongly related to the presence of intramolecular CT interactions, of donor−acceptor substituted silanes. Although moderate second-order nonlinear optical responses were found, it remained obscure whether CT between donors and acceptors takes place in oligo- and especially monosilylene-bridged compounds.…”