Polymorph-Dependent Luminescence Response to Acid Vapors and Its Application in Safety Protection of File Information

Sensor with Strong Solid Emission for Fluorescence Colormetric Detection of 1, 4-Dioxane in Water and Vapor Based on the Keto-Enol Isomerisation

In this work, an easy prepared solid fluorescent sensor 3-(benzo[d]thiazol-2-yl)-1-hydroxy-4-oxo-3,4-dihydrophthalazine-6-carboxylic acid (BPCA) was designed and synthesized and the structure was proved by IR, UV-Vis, NMR, HRMS and elemental analysis, which displayed high selectivity and sensitivity for fluorescence colormetric from green to blue sensing 1, 4-dioxane in water, and the detection limit was obtained 0.009% and the stability constant was 7.4 × 104 M. Also, sensor BPCA was applied for the real-time monitoring 1, 4-dioxane vapor with apparent fluorescent color change from green to blue. The mild and specific chemical interaction between sensor BPCA and 1, 4-dioxane molecule allowed the sensor as portable chips to respond 1, 4-dioxane vapor with good selectivity over other common VOCs at room temperature. Also, the sensing mechanism based on the 1, 4-dioxane-induced keto-enol tautomerization of the phthalazine moiety was found and supported by DFT calculations. This sensor could serve as the basis of gas analyzers for detecting 1, 4-dioxane in the environment.

Unexpected synthesis, delayed emission and solid-state acidochromism of novel 2,7-naphthyridine derivatives obtained from 2-(3,5-diaryl-4H-pyran-4-ylidene)malononitrile

Two novel 2,7-naphthyridine derivatives are unexpectedly synthesized by the reaction of 2-(3,5-diaryl-4H-pyran-4-ylidene)malononitrile and benzylamine, and are achieved through different ring-closing mechanisms. These two derivatives with twisted molecular conformations display phosphorescence, thermally activated delayed fluorescence, and high contrast solid-state acidochromism due to special chemical structures.

Catalytic Annulation of Alkynyl 1,2-Diketone Leading to Hydroxy Spirocyclopenteneindenedione: An Organic Dye with Strong Crystallization-Induced Emission and Data Storage Application

An unprecedented cascade annulation between alkynyl 1,2-diketones and indene-1,3-diones is achieved for the first time, leading to a series of propeller-like large conjugated compounds in ≤99% yield. The products show strong crystallization-induced emission, with the colors changing from green to red. The fluorescence of the dye can be switched on and off by external acid/alkali stimuli, which can be utilized to develop a practical technology for rewritable information storage and security ink.