The third-order optical non-linearity of the phenylethynyl-substituted benzene system

Phenylethynyl substituted benzenes 1, 2 and 3 are synthesized by the Pd-coupling reaction of phenylacetylene with the corresponding bromobenzene; the third-order optical non-linearity [χ(3)(ω)] increases with the participation of π-conjugation through the triple bond as determined by the degenerate four-wave mixing (DFWM) method in a chloroform solution.