Solvent and temperature effects on the chiral aggregation of optically active poly(dialkylsilane)s confined in microcapsules.

To obtain optically active polysilane aggregates consisting of an appropriate number of polysilane molecules, polysilane aggregates were prepared into poly(ureaurethane) microcapsules and their bisignate circular dichroism signals around 320 nm were observed at three different temperatures. The size of the aggregates and the chiroptical properties of polysilanes could be fixed by the preparation temperature. The memorized chiroptical property was eliminated only when the aggregation was disintegrated. This methodology is suitable to control the chiroptical properties of polysilanes.