Synthesis and stability studies of Z-beta-(1-substituted-4-pyridinium)-alpha-cyano-4-styryldicyanomethanide nonlinear optical chromophores

Z-β-(1-substituted-4-pyridimum)-α-cyano-4-styryldicyanomethanide NLO chromophores have shown potential for use in electro-optic (EO) materials but have long been dismissed due to the low yields (15 to 30%) and long reaction times (5 to 14 days) associated with synthesis. The objectives were to make the chromophores available by a high-yield cost-effective pathway and to assess the stability of the chromophores to processing and device operating conditions.; By varying the ratio of reactants and with the use of an amine base, the synthesis was improved up to 97% with a reaction time of 14 hours. The chromophores in solution decomposed when exposed to oxygen, and were sensitive to white light and high temperatures. In doped polymer films using poly(ether sulfone) the chromophores were stable to oxygen and high temperatures, but were light-sensitive indicating that the materials would require protection from white light if used in EO devices. The mechanism of decomposition was established providing the information required to design a more stable chromophore.