New processable, functionalizable polydiacetylenes

A new series of diacetylenes, 9-(arylamino)-5,7-nonadiynyl-N-(alkoxycarbony lmethyl) urethanes was synthesized based on three design paradigms: (1) the polydiacetylene (PDA) conjugated backbone, (2) one side group as a chromop hore, and (3) the remaining side group with components to promote solubilit y and processability. After exposure to Co-60 gamma-radiation, the resultin g polydiacetylenes were highly soluble in many common organic solvents. The se diacetylene monomers can be functionalized with ease not only before but after polymerization as well. Tricyanovinylation of diacetylene monomers f ollowed by polymerization gave insoluble polymers, possibly due to strong i nteractions involving tricyanovinyl groups. However, tricyanovinylation aft er polymerization gave polymers soluble in common organic solvents with 45- 55% degree of functionalization. The diazonium coupling reaction could also be carried out at the phenyl ring of the diacetylene monomer both before a nd after polymerization. In contrast to the intractable product from the di rect polymerization of the azodiacetylene, postpolymerization diazonium cou pling reaction yielded azobenzene-substituted polydiacetylene with good sol ubility in polar organic solvents. The degree of functionalization was in t he same range as that of tricyanovinylated PDA. The second-order NLO coeffi cient (d(33)) Of the poled tricyanovinylated PDA (via postpolymerization fu nctionalization) was found to be 33 pm/V at 1.136 mu m. The photorefractive response of the tricyanovinylated PDA was demonstrated by two-beam-couplin g measurements. The PDA-containing 4-[4-(carboxylic acid)phenylazo]aniline chromophores can directly be photomanipulated to form surface relief gratin gs.