Influences of bulky aromatic head group on morphology, structure and color-transition behaviors of polydiacetylene assemblies upon exposure to thermal and chemical stimuli

The crystal engineering of radiation-sensitive diacetylene cocrystals and salts

“…The blue colour is due to p-p* transitions in the ordered, conjugated chain with the reorganisation of the chains controlling the degree of diacetylene polymerisation. 9 Additional external stimuli on the polymerised diacetylene (polydiacetylene) such as extended heating, [10][11][12] pH change, 10,[13][14][15][16] treatment with organic solvents, 10,17-21 mechanical stress, 22,23 and ligand-receptor interactions, 24,25 can cause the polydiacetylenes to exhibit a range of colours from blue, to red, to yellow. 15 These chromic changes can be explained by a conformational rearrangement within the polydiacetylene assembly Scheme 1 The topochemical parameters for diacetylene 1,4-addition polymerisation requires the tilt angle (q) of the monomers to be 45 , the C1-C4 0 distance (r) to be #3.8Å, and the translational repeat distance (d) to be #4.9Å to yield a polydiacetylene.…”

“…which disrupts the conjugated backbone, causing reduced overlap of the p orbitals, resulting in a widening of the HOMO-LUMO energy gap and hence the polydiacetylene absorbing light at a higher energy. 12,26,27 The commercially important diacetylene, 10,12-pentacosadiynoic acid (PCDA, 1), is used to provide a colourimetric change in practical chemosensors, [28][29][30][31][32][33] biosensors, 24,[34][35][36] and dosimeters. [37][38][39][40] Although PCDA is somewhat photoreactive, further tuning of its photoresponse is of considerable interest, especially for radiation dosimetry applications.…”

Aggregation‐Dependent Chromism and Photopolymerization of Aminoanthraquinone‐Substituted Diacetylenes

“…The periodic peaks corresponding to 2.7 nm (d/2), 1.8 nm (d/3), and 1.35 nm (d/4), depicted in the inset in Figure 4A, attest to the high degree of lamellar ordering in the Y‐phase. [ 29,55 ] In comparison, the SAXS pattern of the R‐phase displays a peak exhibiting a shorter d‐spacing of 2.1 nm (Figure 4A, red spectrum). Furthermore, the lack of higher‐order reflections in the SAXS pattern of the R‐phase suggests lower lamellar ordering.…”

“…[ 23–26 ] Diacetylenes displaying aromatic headgroups have attracted interest in recent years due to the distinctive morphologies, optical, and electronic properties of the polymerized systems. [ 24,27–29 ]…”

Properties and Applications of Stimuli-Responsive Diacetylenes

“…67 The increasing size of the PCDA derivatives also affects how the monomers pack in the solid state and, as a result, their color and the response time of the film to heat. 67 The morphology of the polydiacetylenes also changes with the different headgroups. When PCDA is structured as a vesicle, it has a spherical morphology, while PCDA-mBzA exhibits a large rodlike shape assembly (suggesting high molecular order), in contrast to PCDA-NPA, which exists as large irregularly shaped particles.…”