Synthesis of a Terpene-Based New Chiral Inducer and Preparation of an Asymmetric Polymer

Abstract

Abstract:A new chiral compound was synthesized based on L-borneol. A cholesteric liquid crystal (LC) electrolyte solution was prepared by adding it as a chiral inducer to a nematic LC. A chiral poly(3,4-ethylenedioxythiophene) (PEDOT*, * = asymmetry) film was prepared by electrochemical polymerization in the induced cholesteric LC. The PEDOT* film showed a maximum absorption band due to a π-π* transition in the UV-Vis absorption and bisignate Cotton effect in the reduced state in circular dichroism (CD). The CD spectrum indicates that PEDOT* backbones form right-handed helical aggregation. However, the maximum optical absorption band due to π-π* transition of the PEDOT* decreases and a new absorption band appears at long wavelengths upon oxidation due to generation of polarons as charge carriers. Bisignate Cotton effect disappears and broadly negative CD signal appears at long wavelengths in the oxidized state.

Supramolecular Helical Systems: Helical Assemblies of Small Molecules, Foldamers, and Polymers with Chiral Amplification and Their Functions

“…The helically assembled superstructures have been directly produced during the polymerization process, mostly by the Ziegler–Natta polymerization of acetylene or by the electrochemical polymerization of heteroaromatic compounds in chiral liquid crystalline phases. − Akagi and co-workers reported a series of hierarchically self-assembled helical fibrils consisting of π-conjugated polymers ( 484 – 493 in Chart ) with either a left- or right-handed twist direction that can be produced during the polymerization of the corresponding monomers in chiral nematic liquid crystalline phases (for example, see Figure , left) composed of achiral nematic liquid crystalline compounds ( 494 – 497 ) and chiral inducers ( 498 – 509 ). − Interestingly, the hierarchically self-assembled 484 fibrils can be converted to helical carbon thin films through iodine-doping followed by carbonization. − The doped 484 fibrils were almost completely carbonized at 800 °C and further graphitized by thermal treatment at 2600 °C. Surprisingly, the morphology of the original helical fibrous structure mostly remains after carbonization and graphitization (Figure ).…”

Improved Anisotropic Thermoelectric Behavior of Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate) via Magnetophoresis

“…Our experimental PEDOT:PSS samples exhibit broadly negative CD at non-normal incidence, which is derived from the polaron band and the partially coiled or helical structure of PEDOT:PSS. 37,38 We expect that the CD is only visible at non-normal angles of incidence because the polymer rods are aligned largely parallel to the plane of the substrate; therefore, in order to excite the polarons and tune into the handedness of the PSS moiety, light needs to illuminate the sample at an oblique angle. With magnetically treated samples, we observe a stronger CD measurement, indicating that strong paramagnetic polarons on the PEDOT chains are excited.…”

“…The magnetophoretic behavior of CPs remains largely overlooked and underexplored; however, several connections between prior efforts and our preliminary measurements are made. The helicity of PEDOT:PSS is associated with the broadly negative CD and paramagnetic response that we measure, − which depends on and is controlled by processing techniques. The connection to and relation between these properties and low-level magnetophoresis deserve further study.…”

Sustainable Composites from Waste Sulfur, Terpenoids, and Pozzolan Cements

“…In addition to naturally occurring plants, genetically engineered organisms have been designed to efficiently produce terpenoids [13][14][15][16][17], to the extent that techno-economic assessment suggests terpenoids are competitive with petrochemical olefins for some markets [18,19]. In durable structural materials, terpenoids have found use in more sustainable tars and bitumen for asphalt [20][21][22][23][24][25][26][27][28] and in sulfur cements/composite materials [8][9][10]. The sulfur used in sulfur cements is a byproduct of fossil fuel refining, which is annually produced in megaton quantities of unutilized material for valorization [29][30][31][32][33][34][35][36][37].…”