Structure‐Conductivity Relationship of a Novel Semiconducting Diacetylene Polymer

SynopsisA family of nitrile-terminated diacetylene materials were synthesized. Samples were prepared in various forms and polymerization was performed photochemically and thermally. The resulting materials exhibited low molecular weights and were obtained in low yields. Although the diacetylene group had oligomerized, no evidence was.found in support of -C=Nchain formation. Thermochromism was exhibited by the irradiated 8-nitrile sample and a molecular interpretation of this chromic transition was discussed. Diffraction data implied that strong intermolecular interactions were present between adjacent nitrile groups in the low temperature phase. I t is suggested that stresses are built up during polymerization which cause the low degree of polymerization and yield.

Section: Introductionmentioning

confidence: 99%

Polymerization and characterization of nitrile‐terminated diacetylene materials

Grasso

Lando

1989

Solid‐state polymerization of diacetylene: 1,11,13,23‐tetracosatetrayne

Nezu

Lando

1995

The solid‐state polymerization of a diacetylene, 1,11,13,23‐tetracosatetrayne, was studied using x‐ray powder diffraction and electron diffraction. It is shown that the material exhibits polymorphism. Thermochromic transitions, which are generally observed for diacetylenes, are related to the particular crystalline phase using x‐ray powder diffraction. The unit cell dimensions and space group of one polymorph were determined by electron diffraction analysis: a = 20.83 Å, b = 4.84 Å, c = 10.08 Å, β = 92.4°, space group: P21/n. © 1995 John Wiley & Sons, Inc.

Synthesis and polymerization of coupled compounds of 1,11‐dodecadiyne

Nezu

Walsh

Meille

et al. 1995

The dimer, trimer, and tetramer of 1,11-dodecadiyne, HCC(CH2)8CCH, were synthesized. The solid-state polymerization of the dimer was investigated by infrared (IR) spectroscopy. IR bands due to the diacetylene moiety were identified through the comparison of the IR spectra of the dimer, trimer, and tetramer. The dimer was found to have two polymorphs, melt-crystallized and solution-crystallized. Both of the polymorphs undergo solid-state polymerization by exposure to gamma-ray or UV irradiation. The former has higher polymerizability for the diacetylene moiety than the latter. The solid-state polymerization of the terminal acetylene group was not observed. It is shown that the previously reported dimer structure in which both the diacetylene and terminal acetylene groups are polymerized to form an inherently electrically conducting polymer is incorrect