Hydrazone-linked luminescent covalent organic frameworks based on AIE-active unit for acid vapour sensing was written by Gong, Wei;Dong, Yujie;Liu, Chunyu;Shi, Hongliang;Yin, Maoxing;Li, Weijun;Song, Qingbao;Zhang, Cheng. And the article was included in Dyes and Pigments in 2022.Quality Control of Ethyl 2-hydroxybenzoate This article mentions the following:
Many two-dimensional (2D) covalent organic frameworks (COFs) exhibit weak fluorescence in the solid state or relatively strong fluorescence only in their suspensions. So it is significant to develop a COF with high luminescence in its as-synthesized solid-state for the better practical applications such as fluorescence sensor. We constructed a 2D COF of TPE-DHZ-COF with the hydrazone bond as the linkage and the monomers of triphenylbenzene (TPE) units with aggregation-induced emission (AIE) characteristics, and also synthesized an analog of TPB-DHZ-COF without AIE-active unit as a comparison. Compared with TPB-DHZ-COF, the COF with TPE unit show excellent solid-state luminescence properties, demonstrating that introducing of AIE-active unit in COF can significantly improve the solid-state luminescence performance of hydrazone-linked COFs. In addition, all of these COFs could weaken or quench their fluorescence when exposure to strong-acid vapor. We regarded the response of TPE-DHZ-COF to trifluoroacetic acid (TFA) vapor as the research object, and found that TPE-DHZ-COF exhibited a fast response speed, strong adsorption capacity, excellent stability and recycling performance in the detection of TFA vapor. These results indicated that COFs would be a good candidate in solid-state fluorescence sensing. In the experiment, the researchers used many compounds, for example, Ethyl 2-hydroxybenzoate (cas: 118-61-6Quality Control of Ethyl 2-hydroxybenzoate).
Ethyl 2-hydroxybenzoate (cas: 118-61-6) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Esters are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility.Quality Control of Ethyl 2-hydroxybenzoate
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics