title: Thermochromism and structural change in polydiacetylenes including carboxy and 4-carboxyphenyl groups as the intermolecular hydrogen bond linkages in the side chain.
abstract: We investigated the thermochromic behavior of polydiacetylenes including the carboxy and 4-carboxyphenyl groups as the side-chain substituents adjacent to the conjugated main chain, and then, the thermal stability and the thermochromism reversibility of the polymers were related to changes in the polymer conformations monitored by IR and Raman spectroscopies and powder X-ray diffractions. The polydiacetylenes with no or a phenylene spacer between the main chain and the carboxylic acid moiety were revealed to exhibit a thermal resistance for maintaining reversible thermochromism in a high temperature range, rather than polydiacetylenes with a conventional structure with a flexible alkylene spacer. The molecular stacking structures of the diacetylenes and the corresponding polymers in the crystals were discussed based on the results of an X-ray single-crystal structure analysis as well as the powder X-ray diffraction measurements.
authors.affiliation: Department of Applied Chemistry and Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Tanioku
authors.forename: Kimihiro
authors.initials: K
authors.lastname: Matsukawa
authors.forename: Akikazu
authors.initials: A
authors.lastname: Matsumoto
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D006860:Hydrogen Bonding; D015394:Molecular Structure; D000078789:Polyacetylene Polymer; D011108:Polymers / Q000737:chemistry*; D053279:Polyynes / Q000737:chemistry*
chemical_list: D000078789:Polyacetylene Polymer; D011108:Polymers; D053279:Polyynes; C082361:polydiacetylene