Published online by Cambridge University Press: 21 February 2011
We have used DCM/polyimide guest-host films for a series of device demonstrations, including demonstrations of high speed, low voltage digital and analog switching. Although useful for such demonstrations, DCM tends to out diffuse at polyimide cure temperatures, motivating the search for related compounds with similar activity, transparency, processibility, and greater thermal stability. We have designed, synthesized, and characterized a series of chromophores with related molecular structures. Like DCM, all of these chromophores share the dicyanomethylene [>C=C(CN)2] acceptor group. Some of these compounds are conventional donor-acceptor chromophores, while others fall into the class of lambda-shaped donor-acceptor-donor (DAD) compounds. An acceptor-donor-acceptor (ADA) chromophore has also been prepared and characterized. The donor-acceptor analog studies utilize a variation on the Knoevenagel condensation reaction used to make DCM, substituting isophorone for 4-pyranone to avoid the formation of mixtures. These reactions lead to the DCI series of compounds. We will describe progress in our investigations of these series of compounds.