In this article we describe research on the synthesis and characterization of a family of "Janus" amphiphiles composed of disaccharide head groups and alkaloid units joined together via a methylene linker, and bearing a lateral aliphatic chain of varying length. The condensed phases formed by self-organization of the products as a function of temperature were characterized by differential scanning calorimetry, thermal polarized light microscopy, and small angle X-ray scattering, allied with computational modelling and simulations. Structural studies on heating specimens from the solid showed that some homologues exhibited lamellar, columnar and bicontinuous mesophases, whereas the same homologues revealed different phase sequences on cooling from the amorphous liquid. We explore these unusual results, which are revealed via supercooling.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/chem.202403678 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The Unusual Mesophases and Properties Exhibited by a Family of Glycosteroids.
Chemistry
January 2025
Universite Claude Bernard Lyon 1, ICBMS, Bâtiment Lederer, 1 Rue Victor Grignard, F-69622, Villeurbanne, FRANCE.
In this article we describe research on the synthesis and characterization of a family of "Janus" amphiphiles composed of disaccharide head groups and alkaloid units joined together via a methylene linker, and bearing a lateral aliphatic chain of varying length. The condensed phases formed by self-organization of the products as a function of temperature were characterized by differential scanning calorimetry, thermal polarized light microscopy, and small angle X-ray scattering, allied with computational modelling and simulations. Structural studies on heating specimens from the solid showed that some homologues exhibited lamellar, columnar and bicontinuous mesophases, whereas the same homologues revealed different phase sequences on cooling from the amorphous liquid.
View Article and Find Full Text PDFProgramming liquid crystal elastomers for multistep ambidirectional deformability.
Science
December 2024
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
Ambidirectionality, which is the ability of structural elements to move beyond a reference state in two opposite directions, is common in nature. However, conventional soft materials are typically limited to a single, unidirectional deformation unless complex hybrid constructs are used. We exploited the combination of mesogen self-assembly, polymer chain elasticity, and polymerization-induced stress to design liquid crystalline elastomers that exhibit two mesophases: chevron smectic C (cSmC) and smectic A (SmA).
View Article and Find Full Text PDFStructural Rheology in the Development and Study of Complex Polymer Materials.
Polymers (Basel)
August 2024
A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 29 Leninsky Prospect, 119991 Moscow, Russia.
The progress in polymer science and nanotechnology yields new colloidal and macromolecular objects and their combinations, which can be defined as complex polymer materials. The complexity may include a complicated composition and architecture of macromolecular chains, specific intermolecular interactions, an unusual phase behavior, and a structure of a multi-component polymer-containing material. Determination of a relation between the structure of a complex material, the structure and properties of its constituent elements, and the rheological properties of the material as a whole is the subject of structural rheology-a valuable tool for the development and study of novel materials.
View Article and Find Full Text PDFMonodisperse nanosheet mesophases.
Sci Adv
June 2024
Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Article Synopsis
- * The research highlights how these nanosheets can form unique superstructured mesophases through tunable interactions, overcoming challenges posed by size variability in previous materials.
- * Various microscopy techniques were used to demonstrate the reversible nature of these mesophases, which can be controlled by factors like counter cations, nanosheet concentration, solvent choice, and temperature.
Mn(iii)-mediated C-P bond activation of diphosphines: toward a highly emissive phosphahelicene cation scaffold and modulated circularly polarized luminescence.
Chem Sci
October 2023
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210093 P. R. China
Transition metal mediated C-X (X = H, halogen) bond activation provides an impressive protocol for building polyaromatic hydrocarbons (PAHs) in C-C bond coupling and annulation; however, mimicking both the reaction model and Lewis acid mediator simultaneously in a hetero-PAH system for selective C-P bond cleavage faces unsolved challenges. At present, developing the C-P bond activation protocol of the phosphonic backbone using noble-metal complexes is a predominant passway for the construction of phosphine catalysts and P-center redox-dependent photoelectric semiconductors, but non-noble metal triggered methods are still elusive. Herein, we report Mn(iii)-mediated C-P bond activation and intramolecular cyclization of diphosphines by a redox-directed radical phosphonium process, generating phosphahelicene cations or phosphoniums with nice regioselectivity and substrate universality under mild conditions.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!