Conformation Control of a Conjugated Polymer through Complexation with Bile Acids Generates Its Novel Spectral and Morphological Properties

Abstract

Control of higher-order polymer structures attracts a great deal of interest for many researchers when they lead to the development of materials having various advanced functions. Among them, conjugated polymers that are useful as starting materials in the design of molecular wires are particularly attractive. However, an equilibrium existing between isolated chains and bundled aggregates is inevitable and has made their physical properties very complicated. As an attempt to simplify this situation, we previously reported that a polymer chain of a water-soluble polythiophene could be isolated through complexation with a helix-forming polysaccharide. More recently, a covalently self-threading polythiophene was reported, the main chain of which was physically protected from self-folding and chain-chain π-stacking. In this report, we wish to report a new strategy to isolate a water-soluble polythiophene and to control its higher-order structure by a supramolecular approach: that is, among a few bile acids, lithocholate can form stoichiometric complexes with cationic polythiophene to isolate the polymer chain, and the higher-order structure is changeable by the molar ratio. The optical and morphological studies have been thoroughly performed, and the resultant complex has been applied to the selective recognition of two AMP structural isomers.

Solubilization and Photostabilization in a Sodium Deoxycholate Hydrogel of a Neutral Conjugated Thiophene Oligomer and Polymer

“…Bile salts have been used to solubilize in aqueous solutions and in hydrogels; a large variety of molecules, such as ionic polymers, 32 photochromic molecules, 33 organic molecules, 34,35 and carbon nanotubes, 36,37 and bile salts, have been used in advanced material engineering. 38 Based on the self-assembly behavior of NaDC, we explored the ability of NaDC to solubilize and photochemically stabilize a neutral conjugated oligomer, oligo(3-hexylthiophene-co-1,4phenylene) (OTPh, Chart 1), at concentrations of the oligomer that are relevant for fluorescence studies.…”

“…However, the use of di- and trivalent metal cations can interfere with fluorescence. Bile salts have been used to solubilize in aqueous solutions and in hydrogels; a large variety of molecules, such as ionic polymers, photochromic molecules, organic molecules, , and carbon nanotubes, , and bile salts, have been used in advanced material engineering …”

Solubilization and Photostabilization in a Sodium Deoxycholate Hydrogel of a Neutral Conjugated Thiophene Oligomer and Polymer

“…The formation of gels can be facilitated with the addition of di-or trivalent cations. 31 Bile salts have been used to solubilize in aqueous solutions and in hydrogels a large variety of molecules, such as ionic polymers, 32 photochromic molecules, 33 organic molecules, 34,35 and carbon nanotubes, 36,37 and bile salts have been used in advanced material engineering. 38 Based on the self-assembly behavior of NaDC, we explored the ability of NaDC to solubilize and photochemically stabilize a neutral conjugated oligomer, oligo(3-hexylthiophene-co-1,4phenylene) (OTPh, Chart 1).…”