Origin of the Color of π-Conjugated Polymers: Poly(N-n-octyl-3-carbazoyl)acetylene Prepared with a [Rh(norbornadiene)Cl]2 Catalyst

Helix-sense-selective surface grafting polymerization for preparing optically active hybrid microspheres

Chiral hybrid micro/nanomaterials have attracted great interest and have been extensively studied due to their intriguing properties and promising applications which cannot be achieved with each of the single components.

Synthesis and characterization of poly(arylene ether ketone)s with 3,6-diphenyl-9H-carbazole pendants using C–N coupling reaction

3,6-Diphenyl-9 H-carbazole pendants are grafted herein to poly(arylene ether ketone)s (PAEKs) via the Ullmann C–N coupling reaction. To the best of our knowledge, this is the first time that PAEKs containing a carbazole pendant (Cz) have been synthesized through the Ullmann C–N coupling reaction. The high molecular weights of PAEK-Cz (PAEKs with 3,6-diphenyl-9 H-carbazole pendants) are inherited from their precursors, owing to the high reactivity of their monomers. The obtained PAEK-Cz- x polymers exhibit good solubility in most common organic solvents and excellent thermal stabilities, with the 5% weight loss temperatures for all products being above 598°C under a nitrogen atmosphere. The glass transition temperatures are all above 199°C and can be controlled by adjusting the feed ratio of monomers. The polymer membranes obtained by the casting method are tough and thus have strong potential for practical applications.

Influence of a hydrodynamic environment on chain rigidity, liquid crystallinity, absorptivity, and photoluminescence of hydrogen-bonding-assisted helical poly(phenylacetylene)

The chain rigidity, liquid crystallinity, absorptivity, and photoluminescence of a helical poly(phenylacetylene) derivative varied significantly depending on the solvent, owing to the conformational changes based on intramolecular hydrogen bonds.

Optically active hollow nanoparticles constructed by chirally helical substituted polyacetylene

Hollow nanoparticles were constructed by chirally helical substituted polyacetylene and they demonstrated intriguing optical activity and high stability.

Optically Active Porous Materials Constructed by Chirally Helical Substituted Polyacetylene through a High Internal Phase Emulsion Approach and the Application in Enantioselective Crystallization

This article reports the first optically active macroporous materials constructed by helical substituted polyacetylene and prepared by a high internal phase emulsion (HIPE) technique. The macroporous (∼3 μm) materials were fabricated simply through polymerization of the continuous phase in HIPEs. The porous structures of the resulting materials can be adjusted by varying the fraction of the dispersed phase. The obtained materials were characterized by regular pore morphology, high porosity, and low density. Circular dichroism and UV-vis absorption spectra demonstrated that the substituted polyacetylene forming the materials adopted chirally helical conformations, which endowed the materials with considerable optical activity. The optically active porous materials were used as chiral inducers and efficiently induced enantioselective crystallization of threonine and alanine racemates. l-Threonine and l-alanine were preferably induced to form crystals from the respective racemic solutions. The prepared materials open a new type of functional chiral materials with potential applications in asymmetric catalysis, chiral resolution, etc.

Configuration and conformation of poly(3-carbazolylacetylene) including cis and trans radicals revealed by ESR spectroscopy

π-Conjugated cis and trans radicals of poly(N-isobutyl-3-carbazolylacetylene) were stereospecifically prepared using the [Rh(norbornadiene)Cl]₂-NEt₃ catalyst, and their geometric structures were determined using the electron spin resonance (ESR) method.

Optically active helical polyacetylene/Fe3O4 composite microspheres: prepared by precipitation polymerization and used for enantioselective crystallization

The precipitation polymerization for constructing chiral, magnetic microspheres based on substituted polyacetylene and Fe₃O₄ nanoparticles: preparation and application in enantioselective crystallization.

New symmetrical conjugated thiophene-azomethines containing triphenylamine or carbazole units: Synthesis, thermal and optoelectrochemical properties

New oligo- and poly(azomethine)s containing 3,4-dicyanothiophene and triphenylamine or carbazole units were synthesized under condensation reaction conditions. Although the different amino group reactivity, a one-pot synthesis of symmetric conjugated oligoazomethines was possible by judicious choice of solvent and careful control of reagent stoichiometry. Different polycondensation strategies (in solution and bulk polymerization reactions) were applied in order to obtain soluble oligoazomethines and poly(azomethine)s. Their expected chemical structures were confirmed by 1H-NMR and Fourier transform infrared (FT-IR) characterization techniques. Electronic properties of the synthesized oligoazomethines were investigated in different solvents, using UV-Vis and photoluminescence spectroscopy (PL) and these revealed that there is a slight dependency between the solvent polarity and absorption wavelength, while the emissions peaks are shifted at higher wavelength with increasing the solvent polarity. The thermogravimetric and differential scanning calorimetry analysis showed a high thermal stability up to 350 °C and no glass transition temperature. Having in their structure electroactive sites, i.e., carbazole and triphenylamine units, cyclic voltammetry technique was used to investigate the oxido-reduction behavior and to determine the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels.