Chiral Supramolecular Assemblies from an Achiral Naphthalene Diimide Bearing a Urea Moiety. Issue 21 (2nd October 2018)

• Record Type: Journal Article
• Authors: Shaikh, Dada B.; Bhosale, Rajesh S.; La, Duong Duc; Al Kobaisi, Mohammad; Bhosale, Sidhanath V.; Bhosale, Sheshanath V.
• Is Part Of: Chemistry, an Asian journal. Volume 13:Issue 21(2018)
• Page Start: 3268
• Page End: 3273
• Publication Date: 2018-10-02
• Subjects: helical superstructures -- nanostructures -- naphthalene diimides -- self-assembly -- supramolecular chemistry; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.201801115
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: The ordering of organic molecules in a supramolecular self‐assembly determines their physical, chemical, and photonic properties. Here, we report the aggregation of two achiral naphthalene diimides (NDIs), in which phenyl moieties are linked to the NDI core via a urea subunit, leading to chiral supramolecular assemblies in THF/methylcyclohexane. Circular dichroism spectroscopic analysis of twisted ribbons deposited from solutions indicated a mixture of left‐ and right‐handed nanostructures for one NDI, whereas only left‐handed structures were observed for the other one. Furthermore, this study also shows the effect of large atoms such as iodine on the self‐assembly process, which governs and controls the helicity of the produced microstructures. The supramolecular assemblies were characterized by UV/Vis, fluorescence emission, CD, SEM, and XRD techniques. Abstract : Inspired by Mother Nature : A synthesis of two naphthalene diimides (NDIs) bearing urea functionalities is reported. These diimides assembled into supramolecular chiral helical superstructures in THF/methylcyclohexane with varying ratios. The self‐assembly was driven by the hydrogen bonding induced by the urea subunit, π–π stacking interactions between the NDI aromatic core and van der Waals interactions between alkyl chains. The left‐handed twisted supramolecular structures were confirmed by circular dichroism and SEM.