Dicyanomethylene-4H-pyran derivatives as well as preparation method and application thereof

Abstract

The invention particularly relates to dicyanomethylene-4H-pyran derivatives as well as a preparation method and an application thereof. The preparation method of the dicyanomethylene-4H-pyran derivatives comprises the following steps: (1) 2,6-dimethyl-4H-pyran-4-one 1 as a starting material is subjected to an addition-elimination reaction with malononitrile, and an intermediate 2 is obtained; (2) the intermediate 2 is subjected to an addition-elimination reaction with indolal with different alkyl chains, and the dicyanomethylene-4H-pyran derivatives are obtained. Indole structural units with different alkyl groups and dicyanomethylene-4H-pyran structural units are introduced into the field of organic solid luminescent materials, novel piezoluminescence color change materials are developed, and the derivatives play an important role in the field of photoelectricity. The provided method adopts a simple synthesis process, purification is easy, and the synthesized piezoluminescence materials are quite applicable to various fields of preparation of pressure sensors, anti-counterfeiting trademarks and the like and have good scientific research value and industrialized application potential.

Description

technical field [0001] The invention belongs to the field of organic synthesis and application, and specifically relates to dicyanomethylene-4H-pyran derivatives and their preparation methods and applications. Background technique [0002] Piezoluminescence of organic molecules is a class of "smart" materials. For the stimulation of external force, its solid-state fluorescent color can show obvious changes. And because of its potential applications in the fields of fluorescent sensors, data storage, security inks and optoelectronic devices, it has been valued by the scientific and industrial circles. (See literature: J. Am. Chem. Soc., 2005, 127, 11661-11665; Adv. Funct. Mater., 2007, 17, 3799-3807; Chem. Commun., 2013, 49, 273-275). [0003] The dicyanomethylene-4H-pyran unit has a longer emission wavelength and a high fluorescence quantum yield due to the ultrafast intramolecular fast charge transfer effect in its structure, and is an ideal choice for the construction of...

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Problems solved by technology

[0003] The dicyanomethylene-4H-pyran unit has a longer emission wavelength and a high fluorescence quantum yield due to the ultrafast intramolecular fast charge transfer effect in its structure, and is an ideal choice for the construction of red light materials. Excellent fluorophore, but so far, its derivatives are prone to fluorescence quenching due to the π-π stacking effect in the aggregated state, which limits their application as fluorescent materials in film-forming or solid-state forms (see literature: Chem.Commun., 2012, 48, 6073–6084), rare reports on piezoluminescent materials based on dicyanomethylene-4H-pyran units

[0004] Generally speaking, the introduction of alkyl chains into the conjugated backbone of organic fluorescent molecules is mainly to adjust the solubility of organic molecules in organic solvents in the future, but some recent studies have shown that the introduction of different alkyl chains may also affect the aggregation state of organic molecules. The luminescent properties of (see literature: J.Mater.Chem.C, 2016, 4, 1568–1578)

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