5-(2-Methylthio-4-methylpyrimidin-5-yl) penta-2, 4-diyn-1-ol was synthesized by asymmetric coupling, and the corresponding diacetylene monomers were also prepared in good yields. These monomers could be dissolved in common organic solvents. The monomers can be polymerized in the solid state using heat, light or γ-radiation. In addition, micro-and macroscopic third-order susceptibilities were measured by the degenerate four-wave ...