Synthesis and self‐organization properties of copolyurethanes based on perylenediimide and naphthalenediimide units

Abstract

A series of perylene and naphthalene diimide‐containing random copolyurethanes with different ratios of perylene/naphthalene diimide content was synthesized and characterized. Copolymerization improved the solubility of these rigid aromatic diimides, and the copolymers were soluble in common organic solvents like chloroform, tetrahydrofuran, and so forth. The absorption spectra of perylene‐based copolymers showed a red‐shifted peak at a wavelength of 557 nm corresponding to J‐type aggregates. For naphthalene copolymers, the quenching of fluorescence at higher naphthalene incorporation suggested the presence of aggregates because of the extensive π‐π stacking of the aromatic core. FTIR spectroscopic analysis showed that the hydrogen bonding tendency of the polymer decreased with increase in perylene/naphthalene incorporation. The fluorescence spectra of the perylene polymers were exactly a mirror image of the absorption spectra. The fluorescence spectra of the naphthalene polymers at higher naphthalene incorporation showed a red‐shifted excimer like emission peak, which was assigned as static excimers based on their excitation spectra. These polymers could exhibit two types of secondary interaction modes, namely, hydrogen bonding (via urethane linkage) and π‐stacking (via aromatic perylene or naphthalene units) thus highlighting the importance of polymer design in inducing self‐organization at both low and high incorporation of the rigid bisimide moieties. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1224–1235, 2009

Ammonium Transport Simulation in Horizontal Soil Columns from a Natural Inland Alkaline Wetland

“…In 2009, Asha synthesized and characterized a series of naphthalene diimide‐containing copolyurethanes with different ratios of naphthalene diimide. It was found that fluorescence quenching happened with higher naphthalene incorporation, which indicated the presence of aggregates in the structure due to extensive π ··· π stacking of the aromatic core 11b. A similar fluorescence quenching mechanism was also reported in metal‐organic compounds 12a–12c.…”

n-Type Field Effect Transistors Based on Rigid Rod and Liquid Crystalline Alternating Copoly(benzobisoxazole) Imides Containing Perylene and/or Naphthalene

“…The polyimides of perylene and naphthalene bisimides reported in the literature are however not very high because of the inherent low solubility of the formed polymer. 39 Therefore, the inherent viscosity of 0.2 dL/g reported here indicated reasonably high molecular weight and the perylene containing polymers were obtained as dark red powders. Supporting Information Figure S4 shows the TGA thermograms of the homo-and copolymers, and the 10% weight loss temperatures are given in Table 1.…”

Pi‐conjugated chain extenders for the synthesis of optoelectronic segmented polyurethanes

“…Such insolubilities have been reported 24,37 for these types of systems, and we expect to solve this problem in the future through the use of a more solubilizing soft segment. 26…”

“…In addition to preliminary synthetic work, we present the optical and thermal characterization of the resulting polymeric materials. Recent work has examined the incorporation of functional electronic units such as 3,4‐ethylenedioxythiophene (EDOT) monomer, rylene diimides, and oligophenylene vinylenes into polyurethane‐type materials 19, 24–26. The pi systems embedded within the macromonomers here consist of a series of telechelic oligothiophene diols and diamines as chain extenders for complex polymer synthesis.…”