Graphic summary. Credit: Journal of the American Chemical Society (2022). DOI: 10.1021 / jacs.2c00285
Compared to traditional materials with circularly polarized luminescence (CPL) activity, covalent organic frames (COF), a new type of crystalline porous material, have great potential due to their structural designability, versatility, functional adjustability. and chemical stability.
Currently, no COFs have been created with CPL activity and good crystallinity. 2D COFs with ultra-thin nanofull structures can effectively prevent the extinction of fluorescence caused by π-π stacking. Introducing chiral and luminescent functions to 2D COFs is an effective way to obtain CPL materials, but it is still a challenge.
In a study published in the Journal of the American Chemical SocietyZhang Jian, Professor Gu Zhigang, and colleagues at the Fujian Research Institute on the Structure of Matter at the Chinese Academy of Sciences have developed ultra-thin, chiral COF-induced chiral COF nanowires and reported on the its application in the field of circularly polarized luminescence.
The researchers first prepared CPL materials based on ultrafine COF nanosheets (NS) using a chiral-induced synthesis strategy. Chiral amines served as chiral inducers to give TfBpy COF with chirality and participated in TpBpy modification, inhibiting the extinction of fluorescence caused by π-π stacking to form ultrafine luminescent chiral COFs (chirCOFs) NS. The chirCOF R- / S-TpBpy NS obtained had strong chirality and an intense red CPL property with a | glum | of about 0.02.
They then postmodified the carboxyl containing green and blue fluorescent dye molecules to chirCOFs NS (chirCOFs / Dyes) to achieve a color-adjustable CPL.
Due to the chirality and energy transfer between the chirCOFs and dye groups, the chirCOFs / dyes obtained showed strong chirality and increased and adjustable photoluminescence, showing excellent CPL performance, adjustable and amplified with a | glum | of about 0.1, which was about five times stronger than that of the prepared chirCOF NS.
In addition, the researchers dispersed the corresponding NS chirCOFs in a polydimethylsiloxane (PDMS) matrix to form wafer-sized, highly transparent, and flexible COFs / PDMS films for practical CPL application.
This study opens a new strategy for preparing ultrafine NS chirCOFs with strong and adjustable chiral induction CPL and provides a new approach for the preparation of transparent, large and flexible COF composite films in chiral optical applications.
Researchers achieve chiral self-assembly and induction by photofunctional lanthanide tetrahedral cage guests. More information: Hao Chen et al, Chiral-induced ultrafine covalent organic frame nanosheets with circularly adjustable polarized luminescence, Journal of the American Chemical Society (2022). DOI: 10.1021 / jacs.2c00285 Provided by the Chinese Academy of Sciences
Citation: Ultrafine and Luminescent Covalent Organic Frame Nanoflugs Induced by Chiral Induced (2022, May 31) Retrieved May 31, 2022
This document is subject to copyright. Apart from any fair treatment for private study or research purposes, no part may be reproduced without the written permission. Content is provided for informational purposes only.