Non-symmetrical three and two-core ring mesogens based on quinoxaline and benzimidazole derivatives: Supramolecular layers through amphoteric donating/accepting H-bonds
| Autor: | André H. de Oliveira, Fabrício G. Menezes, Jordan K. da Silva, Miguel A. F. de Souza, Rodrigo Cristiano, Welisson P. Silva, Julio Cezar de Oliveira Freitas |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
Benzimidazole 010405 organic chemistry Mesogen Organic Chemistry Supramolecular chemistry Mesophase 010402 general chemistry 01 natural sciences 0104 chemical sciences Analytical Chemistry Inorganic Chemistry chemistry.chemical_compound Crystallography Quinoxaline chemistry Liquid crystal Molecule Spectroscopy Alkyl |
| Zdroj: | Journal of Molecular Structure. 1180:399-405 |
| ISSN: | 0022-2860 |
| Popis: | Self-assembly-based molecular structures have proven to be highly relevant to the development of soft materials. This work reports the synthesis, thermal behavior and computational analysis of two novel heterocyclic compounds with a non-symmetrical shape bearing a single long alkyl (C12) chain. The compounds 2-(4-dodecyloxy-phenyl)-1H-benzoimidazole, 1, with three-ring core mesogen with a more linear shape, and 1-dodecyl-1,4-dihydro-quinoxaline-2,3-dione, 2, with a condensed two-ring core with a more compact discotic shape, were obtained in good yields and investigated by polarized optical microscopy (POM) and differential scanning calorimetry (DSC) analysis. Benzimidazole derivative 1 was found to present liquid crystalline property, with a mesophase range from 85 to 177 °C, as verified by POM and DSC, with a smectogenic polymorphism assigned as a SmB and a more organized unidentified SmX phase. On the other hand, although quinoxaline 2 did not show liquid crystal behavior, POM analysis indicated an interesting spherulitic packing pattern, typical of a columnar arrangement of the molecules by possible H-bond interactions. Computational results indicated that combining intermolecular hydrogen bonds and hydrophobic interactions lead to a non-planar lamellar model for benzimidazole 1, consistent with the smectic packing found in the liquid crystalline phase and a twist-type packing for compound 2, which is consistent with a spherulitic model. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect