Circularly Polarized Luminescence from Chiral Supramolecular Polymer and Seeding Effect. Issue 56 (21st September 2020)

• Record Type: Journal Article
• Authors: Mukherjee, Anurag; Ghosh, Suhrit
• Is Part Of: Chemistry. Volume 26:Issue 56(2020)
• Page Start: 12874
• Page End: 12881
• Publication Date: 2020-09-21
• Subjects: aggregation -- chiral resolution -- chirality -- circular dichroism -- hydrogen bonds -- supramolecular polymerization; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202002056
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: H‐bonding driven J‐type aggregation and cooperative supramolecular polymerization of a sulfur‐substituted chiral naphthalene‐diimide (NDI)‐derivative ( S, S )‐NDI‐2 in decane leads to remarkable enhancement of fluorescence quantum yield (43.3 % from 0.5 % in the monomeric state) and intense CPL signal in the aggregated state with a high luminescence dissymmetry factor ( g lum ) of 4.6×10 −2 . A mixture of NDI‐2 with a structurally similar NDI‐derivative NDI‐1 (mixture of racemic ( S, S )‐ and ( R, R )‐ isomers and the achiral derivative) in 1:9 (NDI‐2/NDI‐1) ratio, when heated and slowly cooled to room temperature, showed no enhanced CD band, indicating lack of any preferential helicity. However, when a monomeric solution of the NDI‐1 in tetrahydrofuran (THF) was injected to preformed seed of NDI‐2 in decane, a prominent CD signal appeared, indicating chiral amplification resulting in induced CPL with high g lum value of 2.0×10 −2 from mostly (>98.5 %) diastereomeric mixture. Abstract : Seeding CPL : Supramolecular polymerization of a sulfur‐substituted naphthalene‐diimide (NDI) derivative ( S, S )‐NDI‐2 leads to the formation of highly fluorescent fibrillar nanostructures with the emergence of strong CPL signal and a very high luminescence dissymmetry factor ( g lum ) of 4.6×10 −2 . Seeded supramolecular polymerization with NDI‐2 as seed produced similarly intense CPL signal from a diastereomeric mixture of homologous NDI‐derivative (NDI‐1) via chirality induction.