naphthyldisilanes originates from the intramolecularcharge-transferstate1(2pπ, 3dπ) produced by 2pπ*→ 3dπ charge transfer. The rearrangement (ϕr) and decrease (ϕR) quantum yields at 254 nm and the quantum yield (ϕct) for the charge-transfer emission for disilanylnaphthalenes decreased markedly with solvent polarity because of fast intersystem crossing (through the charge-transferstate) in competition with