Synthesis and nonlinear properties of poly[1,4-bis(4-methylpyridinium)butadiyne triflate)]

1,4-Bis(4-methylpyridinium)butadiyne triflate (1), which was prepared from the reaction of 1,4- bis(4-pyridyl)butadiyne with methyl trifluoromethanesu lfonate, was found to be piled up along the c axis with two triflates as co unter anions. The UV irradiation and thermal treatment of 1 gave rise to 1, 4-topochemical polymerization to yield poly[1,4-bis(4-methylpyridinium) but adiyne triflate)]. The third-order nonlinear optical susceptibility (chi (( 3))) Of the polymer was determined by the degenerate four wave mixing (DFWM ) method to exhibit the remarkable high value of 2.2 x 10(-10) esu.