SYNTHESIS, VAPOR GROWTH, POLYMERIZATION, AND CHARACTERIZATION OF THIN-FILMS OF NOVEL DIACETYLENE DERIVATIVES OF PYRROLE - THE USE OF COMPUTER MODELING TO PREDICT CHEMICAL AND OPTICAL-PROPERTIES OF THESE DIACETYLENES AND POLY(DIACETYLENES)

In the present work two diacetylene derivatives of pyrrole (compounds 1 and 2), which are predicted by semiempirical AM1 calculations to have very different properties, are synthesized; the polymerizability of these diacetylenes in the solid state is determined; and the results are compared to the computer predictions. Diacetylene 1 is novel in that the monomer is a liquid at room temperature; this may allow for the possibility of polymerization in the liquid state as well as the solid state. Thin poly(diacetylene) film are obtained from compound 1 by growing films of the monomer using vapor deposition and polymerizing with UV light; these films are then characterized. Interestingly, while the poly(diacetylene) from 1 does not possess good nonlinear optical properties, the monomer exhibits very good third-order nonlinear optical effects (e.g., phase conjugation) in solution. Dilute acetone solutions of the monomer 1 give intensity-dependent refractive indices (n2) on the order of 10(-6) esu (chi(3) values on the order of 10(-7) esu); these are 10(6) times better than for CS2.