Amphiphilic diacetylenes of the type HCC(CH2)nCCCC(CH2)8COOH (n=6 and 12) were synthesized. The solid‐state polymerization of the bulk crystals, mono‐layers on the gas‐water interface, and multilayers were investigated. The diacetylene moieties underwent polymerization upon irradiation by UV or γ‐rays, showing different polymerizability depending on the material form. The polymerization of the terminal acetylene groups was not observed. Enhanced polymerizability and stability of the monolayers on subphases containing LiOH are explained by a proposed model of the monolayers. © 1995 John Wiley & Sons, Inc.

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

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.