Selective binding of unsaturated aliphatic hydrocarbons by a pillar[5]arene

The complexation behavior of unsaturated fatty hydrocarbons, i.e., 1,7-octadiyne and 1,7-octadiene, by a perethylated pillar[5]arene has been investigated, which was compared with that for saturated n-octane. It was found that the host-guest binding strength increased in accordance with the electron-negativity of the terminal carbon atom on the guests: alkyne > alkene > alkane.