Synthesis of linear and V-shaped oligo(phenylene ethynylene) derivatives: Geometric effects on photophysical properties

A series of linear and V-shaped oligo(phenylene ethynylene) derivatives 1-3 were synthesized through sequent Sonogashira coupling and propargyl alcohol deprotection reaction in high yields. The alkoxy chains (i.e., n-hexyloxy groups) were introduced to assure good solubility of compounds 1-3 in common solvents. The photophysical properties of 1-3 in solution depend strongly on the geometries of these compounds.