Structural and Chromatic Changes of Host Polydiacetylene Crystals during Intercalation with Guest Alkylamines

Abstract

Many kinds of conjugated polymers have been designed and synthesized due to their eminent properties, 1 such as use in organic light-emitting diodes, 2 third-order nonlinear optical properties, 3 and chemical or biochemical sensing. 4 Polydiacetylenes (PDAs) as one of the conjugated polymers have been investigated as the key materials changing their intrinsic blue-tored color and fluorescence properties in response to external stimuli or environmental perturbations. 5À7 The repeated color change of PDAs is expected to be used for various applications, but in most of the actual cases, their chromatic transition reversibly occurs under limited conditions. For example, poly-(10,12-pentacosadiynoic acid) [poly(12,8-DA-CO 2 H)] exhibited a partially reversible color change between the initial blue and the intermediate purple in the temperature range below 50°C, followed by an irreversible change to the final red one upon further heating. 8 When any strong interaction is introduced into the side chain of the PDAs, the PDAs exhibit a reversible color change over a wider temperature range. 9 Recently, we investigated the molecular packing structure and the solid-state polymerization behavior of diacetylene compounds containing a naphthylmethylammonium carboxylate in the side chain. 10 The PDAs with robust two-dimensional (2D) hydrogen bond networks directly bound to the main chain exhibited a reversible color change over a wide temperature range upon heating.We previously reported an intercalation system using organic layered host materials, which were obtained by the topochemical polymerization of alkylammonium muconates and sorbates. 11À14 For example, the ammonium muconate polymer crystals are converted into poly(muconic acid) (PMA) crystals by hydrolysis with HCl in an aqueous methanol or by thermolysis in the solid state, and the process is reversible. Some alkylamine molecules as the guests are intercalated into the PMA crystals dispersed in a methanol solution of the amine with stirring at room temperature. During the intercalation and its reverse reaction (i.e., deintercalation), the guest amines are inserted into the polymer crystals and reversibly removed from them. The transformation heterogeneously occurs because both the polymer crystals as the acid and the ammonium salts are insoluble in methanol as the dispersant. Nevertheless, intercalation proceeds with a high efficiency to achieve a high conversion. The PDAs are also one of the promising candidates as the polymer host compound for organic intercalation because they have a lamellar structure similar to the polymers obtained from 1,3-diene monomers. 15 In the present study, we synthesized three kinds of PDAs containing a carboxylic acid in the side chain with or without a phenylene or methylene spacer between the main chain and the carboxylic acid, i.e., poly(1,3-hexadecadiynyl-4-benzoic acid) [poly(12,Ph-DA-CO 2 H)], poly(2,4-heptadecadiynoic acid) [poly(12,0-DA-CO 2 H)], and poly-(12,8-DA-CO 2 H), as shown in Figure 1. We investigated the intercalatio...

A protective layer approach to solvatochromic sensors

“…In order to determine the feasibility of the turn-on solvatochromic sensor strategy described above, studies were carried out using the conjugated polydiacetylene (PDA) polymer252627282930313233343536373839 derived from 10,12-pentacosadiynoic acid (PCDA, CH 3 (CH 2 ) 11 C≡C−C≡C(CH 2 ) 8 COOH), which is a well-known solvatochromic material (Supplementary Fig. S1).…”

Polydiacetylenes – recent molecular advances and applications

“…59 Fig. Unlike most PDA investigations focusing upon vesicular PDA assemblies or thin lms, a recent report described the effect of alkylamine guest molecules upon the organization and properties of PDA crystals.…”

Constructing π-Electron-Conjugated Diarylbutadiyne-Based Polydiacetylene under Molecular Framework Controlled by Hydrogen Bond and Side-Chain Substituent Position

“…[6][7][8][9] In fact, PDAs are potential sensing materials because of their ability to undergo color change in response to various external stimuli such as temperature, [10][11][12] pH, [ 10,13 ] solvent, [ 14 ] and host-guest interactions. [15][16][17] It was reported that the preparation of PDAs by photo chemical polymerization requires the imbalance of electronic density distribution and assembly of diacetylene monomers in an appropriate arrangement to favor 1,4-addition polymerization. [ 1,2,18,19 ] In addition, the crystal structure parameters available for topotactic polymerization are the translational period ( d ) in the range of 4.7-5.2 Å and the tilt angle ( γ ) between the diacetylene rods close to 45°.…”