A multi-phase state force stimulation responsive luminescent material and preparation and application thereof

Abstract

The application provides a compound of formula I which can be used as a multi-phase state force stimulation responsive luminescent material, a preparation method and application thereof. When the luminescent material is used for real-time monitoring of deformation and stress conditions of a part, low response threshold and high contrast fluorescent response can be realized, under the action of pressure stimulation, fluorescent light can be turned on, under the action of friction stimulation, fluorescent color change can be realized, differential response to different forces can be realized, and multi-stage response can be realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of stimulus-responsive luminescent materials, and particularly relates to preparation and application of a multi-phase-state force-stimulated organic luminescent material. BACKGROUND

[0002] In the process of carrying out strength tests on parts for aero-engines, stress and strain of different parts of the parts need to be captured in time so as to monitor the deformation and stress of the parts in real time. Meanwhile, in the process of material-level or component-level mechanical tests, the stress and strain of each part of the test piece need to be fed back in real time so as to obtain the stress change of the test piece in the process of loading and unloading.

[0003] The stimulus-responsive luminescent material refers to a material whose luminescent color or intensity changes obviously under the stimulation of mechanical force, temperature, pH value and water vapor. When applied in a non-destructive pressure sensor, the force-stimulated luminescent material can change the luminescent wavelength or intensity according to the magnitude of the force stimulation, which enables the non-destructive pressure sensor to instantaneously and sensitively detect the extrusion of the bearing sheet surface.

[0004] The multi-phase-state force-stimulated organic luminescent material can be applied to the surface of a test piece. In the process of the test, different parts of the test piece are subjected to different forces, and the material presents different luminescent colors. Through high-speed photography or other recording means, a stress distribution cloud diagram of the test piece in different test stages can be obtained. Through the stress distribution cloud diagram, the strength test model of the test piece can be calibrated, and more accurate strength calculation results can be obtained after iteration.

[0005] After the test is completed, the most stressed parts of the test piece have obvious color difference from other parts, and these parts are the most dangerous parts leading to failure of the test piece. By calibrating the key parts, the strength calculation model can be verified, and the failure probability of the test piece can be evaluated.

[0006] The existing force-stimulated luminescent material has the problems of high response threshold and low contrast when used for monitoring the deformation and stress of the test piece in real time, and only fluorescence is turned on or fluorescence color is changed for monitoring, which cannot realize the differential response to different forces and cannot realize the multi-stage response. SUMMARY

[0007] In view of the problems in the prior art, the present application provides a multi-phase state force stimulation responsive luminescent material, which can realize low response threshold and high contrast fluorescent response when used for real-time monitoring of deformation and stress conditions of a part. Under the action of pressure stimulation, the luminescent material of the present application can realize fluorescent lightening, and further under the action of friction stimulation, can realize fluorescent color change, realize differential response to different forces, and realize multi-stage response.

[0008] Specifically, the present application provides a compound of formula I which can be used as a multi-phase state force stimulation responsive luminescent material:

[0009]

[0010] The present application also provides a method for preparing the compound of formula I, comprising the following steps:

[0011] (1) acylating nucleophilic substitution reaction of 4-bromo-2-nitrophenol with 4-methoxybutyryl chloride to generate a compound of formula II;

[0012]

[0013] (2) reduction and diazotization reaction of the compound of formula II to obtain a compound of formula III;

[0014]

[0015] (3) Sonogashira cross-coupling reaction of the compound of formula III with trimethylsilyl acetylene to obtain a compound of formula IV;

[0016]

[0017] (4) trimethylsilyl deprotection reaction of the compound of formula IV to obtain a compound of formula V;

[0018]

[0019] (5) Sonogashira cross-coupling reaction of the compound of formula V with 9,10-dibromoanthracene to obtain the compound of formula I.

[0020] In one or more embodiments, in step (1), the reaction solvent is dichloromethane, and the reaction is carried out in the presence of sodium hydride.

[0021] In one or more embodiments, step (2) is divided into two steps, wherein, in the first step, the reaction is first carried out in ethanol as the reaction solvent in the presence of stannous chloride, and then carried out in water as the reaction solvent in the presence of sodium hydroxide; and in the second step, the reaction solvent is acetonitrile and hydrochloric acid, and the second step is carried out in the presence of sodium nitrite and p-toluenesulfonyl cyanide.

[0022] In one or more embodiments, in step (3), the reaction solvent is triethylamine, and the reaction is carried out in the presence of triphenylphosphine, tetrakis(triphenylphosphine)palladium and cuprous iodide.

[0023] In one or more embodiments, in step (4), the reaction solvent is tetrahydrofuran, and the reaction is carried out in the presence of tetrabutylammonium fluoride.

[0024] In one or more embodiments, in step (5), the reaction solvent is a mixture of toluene and triethylamine, and the reaction is carried out in the presence of triphenylphosphine, tetrakis(triphenylphosphine)palladium and cuprous iodide.

[0025] The present application also provides a luminescent material, which is a crystal material obtained by recrystallization of a compound of formula I in a mixed solvent of dichloromethane and ethyl acetate.

[0026] The present application also provides a mechanical force sensing device, which comprises a test sample and a mechanoluminescent coating disposed on the surface of the test sample, wherein the mechanoluminescent coating comprises a compound of formula I or a luminescent material according to any one of the embodiments described herein.

[0027] The present application also provides the use of a compound of formula I or a luminescent material according to any one of the embodiments described herein in a mechanical force sensing device.

[0028] The present application also provides the use of a compound of formula I or a luminescent material according to any one of the embodiments described herein in the detection of part deformation or stress. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Photoluminescence spectra of the original sample, the slightly crushed sample and the completely ground sample of the D1 crystal of the present application.

[0030] Figure 2 Photos under 365 nm ultraviolet light of the original sample, the slightly crushed sample and the completely ground sample of the D1 crystal of the present application.

[0031] Figure 3 Crushing pressure scatter plot of the D1 crystal of the present application.

[0032] Figure 4 X-ray diffraction pattern of the original sample, the slightly crushed sample and the completely ground sample of the D1 crystal of the present application.

[0033] Figure 5 Differential scanning calorimeter curve of the original sample, the slightly crushed sample and the completely ground sample of the D1 crystal of the present application.

[0034] Figure 6Schematic diagram of pressure sensing device in some embodiments of the present application. Figure 5 In the figure, 1 is a D1 coating pressure sensor, 2 is a force to be measured, 3 is a sensor sensing part, 4 is an ultraviolet lamp, 5 is a sensor output signal, 6 is an integrated signal amplifier, 7 is a spectrometer, and 8 is a signal processing part. DETAILED DESCRIPTION

[0035] To enable persons skilled in the art to understand the features and effects of the present application, the following is a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific words used herein have their usual meanings to those skilled in the art of the present application, and in the event of conflict, the definitions in the specification shall prevail.

[0036] Theories or mechanisms described and disclosed herein, whether correct or not, should not be considered limiting on the scope of the present application, that is, the present application can be practiced without regard to any particular theory or mechanism.

[0037] In this document, "comprise", "include", "contain", and similar words are intended to cover "consist essentially of" and "consist of", for example, when this document discloses that "A comprises B and C", "A consists essentially of B and C" and "A consists of B and C" should be considered to have been disclosed herein.

[0038] In this document, all features defined by numerical ranges or percentage ranges, such as values, amounts, contents and concentrations, are intended to be for the sake of brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered to have encompassed and specifically disclosed all possible sub-ranges and individual values within the range (including integers and fractions).

[0039] In this document, unless otherwise specified, percentages refer to mass percentages, and ratios refer to mass ratios.

[0040] In this document, when describing embodiments or examples, it should be understood that they are not intended to limit the present application to these embodiments or examples. On the contrary, all alternatives, modifications and equivalents of the methods and materials described herein that are within the scope of the claims are intended to be encompassed by the present application.

[0041] In this document, for the sake of brevity, not all possible combinations of the technical features in each embodiment or example are described. Therefore, as long as the combinations of the technical features do not conflict, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered to be within the scope of the present specification.

[0042] The multi-phase state force stimulation responsive luminescent material (hereinafter referred to as luminescent material) provided by the present application has a molecular structure with a phenyl-ethynyl-anthracene planar conjugated molecule as a skeleton. The chemical structural formula of the luminescent material of the present application is shown as formula I:

[0043]

[0044] The chemical name of the compound of formula I is anthracene-9,10-diylbis(ethynyl-2,1-diyl)bis(2-cyano-4,1-phenylene)bis(4-methoxybutyrate), also known as compound DCPM.

[0045] The compound of formula I can be prepared by a method comprising the following steps:

[0046] (1) acylating nucleophilic substitution reaction of 4-bromo-2-nitrophenol with 4-methoxybutyryl chloride to generate a compound of formula II;

[0047]

[0048] (2) reduction and diazotization reaction of the compound of formula II to obtain a compound of formula III;

[0049]

[0050] (3) Sonogashira cross-coupling reaction of the compound of formula III with trimethylsilyl acetylene to obtain a compound of formula IV;

[0051]

[0052] (4) trimethylsilyl deprotection reaction of the compound of formula IV to obtain a compound of formula V;

[0053]

[0054] (5) Sonogashira cross-coupling reaction of the compound of formula V with 9,10-dibromoanthracene to obtain the compound of formula I.

[0055] In step (1), acylating nucleophilic substitution reaction of 4-bromo-2-nitrophenol with 4-methoxybutyryl chloride in dichloromethane (DCM) under the action of sodium hydride generates an intermediate product 4-bromo-2-nitrophenyl-4-methoxybutyrate (compound of formula II).

[0056] Preferably, in step (1), the acylation nucleophilic substitution reaction is as follows: 4-bromo-2-nitrophenol and 4-methoxybutyryl chloride are dissolved in dichloromethane, sodium hydride is slowly added after nitrogen replacement under the condition of ice water bath, stirred at room temperature for 12±2 hours, and the reaction is monitored by thin layer chromatography until the starting material point disappears; the reaction is quenched by adding water, the organic phase is extracted with dichloromethane, dried with anhydrous magnesium sulfate, and filtered; after the solvent is evaporated under reduced pressure, the crude product is purified by a chromatographic column with petroleum ether: ethyl acetate as the eluent to obtain a white solid.

[0057] In step (2), the reaction is carried out in two steps: the first step is a reduction reaction, and the second step is a diazotization reaction. In the reduction reaction, first, the compound of formula II is reacted with stannous chloride with ethanol as the reaction solvent, and then the solvent ethanol is evaporated, and the reaction product is reacted with sodium hydroxide in water to cause the compound of formula II to undergo a reduction reaction. In the diazotization reaction, the reduction reaction product is reacted with sodium nitrite and tosyl cyanide as reaction reagents in acetonitrile and hydrochloric acid as reaction solvents under low temperature conditions to obtain the compound of formula III.

[0058] Preferably, in step (2), the reduction reaction is as follows: the compound of formula II is dissolved in ethanol under nitrogen protection, and stannous chloride is added and reacted at 80±5°C for 2±1 hours, after which the solvent ethanol is evaporated, and a 20±5wt% NaOH aqueous solution is added and reacted at room temperature for 2±1 hours. After the reaction is completed, the organic phase is extracted with ethyl acetate, dried with anhydrous magnesium sulfate, and evaporated under reduced pressure. The diazotization reaction is as follows: the product obtained in the previous step is dissolved in acetonitrile, hydrochloric acid is added, the temperature is lowered to -10±1°C, sodium nitrite is added and reacted for 3±1 hours, and then p-toluenesulfonyl cyanide is added and reacted at room temperature for 2±1 hours. After the reaction is completed, the organic phase is extracted with ethyl acetate, dried with anhydrous magnesium sulfate, and purified by column chromatography (petroleum ether: ethyl acetate) to obtain a white solid.

[0059] In step (3), the compound of formula III is subjected to a Sonogashira cross-coupling reaction with trimethylsilyl acetylene under anhydrous and anaerobic conditions with triethylamine as the reaction solvent and triphenylphosphine, tetrakis(triphenylphosphine)palladium, and cuprous iodide as catalysts to obtain the compound of formula IV. In the present application, the Sonogashira cross-coupling reaction (Sonogashira coupling) is known, also called the Sonogashira-Taguchi coupling reaction, and is a Pd / Cu-catalyzed cross-coupling reaction of organic halides with terminal acetylenes.

[0060] Preferably, in step (3), the Sonogashira cross-coupling reaction is as follows: dry triethylamine is taken, oxygen is removed by bubbling nitrogen under the liquid surface, then the compound of formula III, catalyst triphenylphosphine, cuprous iodide, and tetrakis(triphenylphosphine)palladium are sequentially added to the system under bubbling, nitrogen is replaced, and finally trimethylsilyl acetylene is added, and the system is stirred at 65-70°C under nitrogen protection and in anhydrous and oxygen-free conditions for 12±2 hours; after the reaction system is cooled to room temperature, the obtained reaction mixture is concentrated to remove the solvent by using a rotary evaporator, the residue is dissolved with ethyl acetate, the organic layer is sequentially washed with dilute hydrochloric acid, saturated sodium bicarbonate solution, and saturated sodium chloride solution, and dried with anhydrous magnesium sulfate, and filtered; after the solvent is evaporated under reduced pressure, the crude product is purified by a chromatographic column, and petroleum ether: ethyl acetate is used as the eluent to obtain a light yellow solid.

[0061] In step (4), the compound of formula IV is subjected to trimethylsilyl deprotection reaction by adding tetrabutylammonium fluoride in tetrahydrofuran (THF) as the reaction solvent to generate the compound of formula V.

[0062] Preferably, in step (4), the trimethylsilyl deprotection reaction is as follows: the compound of formula IV is added to dry and redistilled tetrahydrofuran, nitrogen is replaced, a tetrahydrofuran solution of tetrabutylammonium fluoride is added to the reaction bottle by using a syringe, the system is sealed with nitrogen and subjected to light shielding treatment, and the system is stirred at room temperature; after the reaction is completed as monitored by thin layer chromatography, the reaction is quenched by adding water, the solution is washed with saturated sodium chloride solution, dried with anhydrous magnesium sulfate, filtered, and the solvent is evaporated under reduced pressure; after the crude product is purified by a chromatographic column, petroleum ether: ethyl acetate is used as the eluent to obtain a light yellow solid.

[0063] In step (5), the compound of formula V is used as the raw material, toluene and triethylamine are used as the mixed reaction solvent, triphenylphosphine, tetrakis(triphenylphosphine)palladium, and cuprous iodide are used as the catalyst, and the compound of formula I is obtained by subjecting the compound of formula V to Sonogashira cross-coupling reaction with 9,10-dibromoanthracene under anhydrous and oxygen-free conditions.

[0064] Preferably, in step (5), the Sonogashira cross-coupling reaction is as follows: dry and redistilled triethylamine and toluene are taken, oxygen is removed by bubbling nitrogen under the surface of the mixed solution, then 9,10-dibromoanthracene, the compound of formula V, triphenylphosphine, cuprous iodide, and tetrakis(triphenylphosphine)palladium are added to the system under the condition of bubbling, vacuum is applied three times and nitrogen is bubbled, the system is heated to 65-70°C under nitrogen protection, and stirred for 12±2 hours; the reaction is monitored by thin layer chromatography, and after the reaction is completed, the reaction system is cooled to room temperature; the solvent is evaporated under reduced pressure, the residue is dissolved in ethyl acetate, the organic layer is washed with dilute hydrochloric acid, saturated sodium bicarbonate solution, and saturated sodium chloride solution in turn, and dried with anhydrous magnesium sulfate, and filtered; after the solvent is evaporated under reduced pressure, the crude product is purified by a chromatographic column with petroleum ether: ethyl acetate as the eluent to obtain a bright yellow solid.

[0065] The compound of formula I of the present application can be dissolved in a mixed solvent of dichloromethane and ethyl acetate to obtain a crystalline material (hereinafter also referred to as D1 crystal) by recrystallization. The material can achieve a fluorescence turn-on response to pressure and further achieve a fluorescence color change response when a friction force is applied, and can be used as a multi-phase state force-stimulated luminescent material. Preferably, the recrystallization is carried out in a mixed solvent of dichloromethane and ethyl acetate in a volume ratio of 1:7-1:9, for example 1:8. In some preferred embodiments, the recrystallization comprises: preparing a saturated solution by adding the compound of formula I to the mixed solvent of dichloromethane and ethyl acetate in batches at 40±5°C; slowly cooling the solution to room temperature, and standing for 3±1 days to obtain the D1 crystal.

[0066] The present application also provides the use of the luminescent material of the present application in the preparation of a mechanical force sensing device, for example a pressure sensor. The pressure sensor can comprise a pressure sensing element and a luminescent signal processing element.

[0067] The method for pressure detection using a pressure sensor comprising the luminescent material of the present application can comprise the following steps:

[0068] (1) dissolving the compound of formula I of the present application in a mixed solution of dichloromethane and ethyl acetate to obtain a crystalline material by recrystallization, or providing the crystalline material of the present application;

[0069] (2) stimulating the crystalline material with different mechanical forces, fitting the quantitative relationship between the luminescent intensity and the applied stress size as the basic parameter of the luminescent signal processing element;

[0070] (3) input and output of the sensor:

[0071] The luminescent material of the present application is arranged on a bearing plate to form a smear, forming a force-induced luminescent material layer. Under the irradiation of an ultraviolet lamp, the original luminescent wavelength of the force-induced luminescent material layer is λ=560nm, and the light signal is received by the designated signal acquisition device to display state S0; when the sample is subjected to force stimulation, the luminescent emission peak changes instantaneously, and at this time the signal is received by the designated signal acquisition device to display state S1; the above-mentioned display states only have one valid signal output at the same time.

[0072] In a preferred embodiment, the display state S0 is only the integrated display of the light signal with a luminescent wavelength of 560nm.

[0073] In a preferred embodiment, the display state S1 is only the integrated display of the light signal that determines the emission peak.

[0074] In a preferred embodiment, the ultraviolet lamp has a luminescent wavelength of 358nm.

[0075] The multi-phase force stimulation responsive luminescent material provided by the present application has the property of homomorphism, and can form multiple initial states with different crystal phase structures by recrystallization in different solvents. The D1 crystal realizes the bright-on-dark signal change after force stimulation, and can be reversibly converted from orange to green through mechanical grinding and solvent fumigation. The luminescent material of the present application can undergo multiple changes in fluorescence intensity or color during the action of force stimulation of different intensities, and the contrast of fluorescence intensity and color is obvious. Unlike general force-responsive organic luminescent materials which only undergo single wavelength change process, the luminescent material of the present application has three states with very different luminescent properties, and can realize luminescent reversible conversion through solvent fumigation and other means. This characteristic is very suitable for non-destructive pressure sensor devices, and has important application prospects in the sensing field which requires high sensitivity and timely information transmission.

[0076] The luminescent material of the present application can be applied to the surface of a part to be tested or a test piece. During the test, different parts of the part or test piece are subjected to different forces, so the material presents different luminescent colors. Through high-speed photography or other recording means, the stress distribution cloud diagram of the part at different test stages can be obtained. Through the stress distribution cloud diagram, the strength test model of the part or test piece can be calibrated, and after iteration, more accurate strength calculation results can be obtained. After the test is completed, the parts or test pieces subjected to the most severe force will have a significant color difference from other parts, and these parts are also the most dangerous parts that cause the failure of the part. By calibrating the key parts, the strength calculation model can be verified, and the failure probability of the part or test piece can be evaluated.

[0077] The luminescent material of the present application can realize fluorescent light-on type response to pressure, and the response threshold is lower than 1 MPa; further, the luminescent material can realize fluorescent color change response when friction force is applied. Therefore, the luminescent material of the present application can realize three-order fluorescent force stimulation response of light-on and color change.

[0078] The present application will be described below in the manner of specific examples. It should be understood that these examples are merely illustrative, and are not intended to limit the scope of the present application. The methods, reagents and materials used in the examples are conventional in the art, unless otherwise specified. The raw material compounds in the examples can be purchased through commercial channels.

[0079] Example 1

[0080] The compound of formula I is prepared by the following steps:

[0081] (1) Synthesis of compound of formula II

[0082]

[0083] 4-bromo-2-nitrophenol (9.17 mmol, 2.0 g), 4-methoxybutyryl chloride (10.00 mmol, 1.36 g) were dissolved in dichloromethane (50 mL), after vacuum and nitrogen three times, sodium hydride (13.87 mmol, 0.33 g) was slowly added under the condition of ice water bath. Stirring at room temperature for 12 hours, thin layer chromatography monitoring reaction to raw material point disappeared. The reaction was quenched by adding water, the organic phase was extracted with dichloromethane, dried over anhydrous magnesium sulfate, and filtered. After the solvent was evaporated under reduced pressure, the crude product was purified by chromatography column, using petroleum ether: ethyl acetate (20:1, v:v) as eluent, to obtain 2.71 g of white solid, with a yield of 93%. 1 H NMR (600 MHz, CDCl3) δ 8.45 (d, J = 1.8 Hz, 1H), 7.97 (dd, J = 7.8, 1.8 Hz, 1H), 7.30 (d, J = 7.8 Hz, 1H), 3.35 (t, J = 4.5 Hz, 2H), 3.23 (s, 3H), 2.52 (t, J = 4.5 Hz, 2H), 1.95 (m, 2H). 13 C NMR (125 MHz, CDCl3) δ 172.31, 144.92, 144.30, 138.11, 127.25, 124.77, 119.40, 71.70, 59.33, 29.89, 24.42.

[0084] (2) Synthesis of compound of formula III (4-bromo-2-cyanophenyl-4-methoxybutyrate)

[0085]

[0086] The compound of formula II (1.60 g, 5 mmol) was dissolved in ethanol (25 mL) with SnCl2-2H2O (5.64 g, 25 mmol) under nitrogen protection and reacted at 80 °C for 2.5 hours. The solvent was evaporated under reduced pressure. Excess 20 wt% NaOH aqueous solution was added to the residue under ice bath and stirred at room temperature for 2 hours. The organic phase was extracted with ethyl acetate and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure and the obtained solid product was directly used in the next step.

[0087] The solid product obtained in the previous step was dissolved in acetonitrile (6 mL) and hydrochloric acid (6 mol / L, 5 mL) and NaNO2(0.42 g, 6 mmol) were added at -10 °C. The mixture was reacted for 2 hours. The reaction mixture was added to a solution of p-toluenesulfonyl cyanide (1.81 g, 10 mmol) in acetonitrile in batches and reacted at room temperature for 2 hours. After the reaction was completed, the reaction was quenched with water. The organic phase was extracted with ethyl acetate and dried over anhydrous magnesium sulfate. Column chromatography (petroleum ether: ethyl acetate) was used for purification. White solid 1.02 g was obtained with a yield of 69%. 1 H NMR (600 MHz, CDC13) δ 7.86 (dd, J = 7.8, 1.8 Hz, 1H), 7.76 (d, J = 1.8 Hz, 1H), 7.22 (d, J = 7.8 Hz, 1H), 3.35 (t, J = 4.5 Hz, 2H), 3.23 (s, 3H), 2.52 (t, J = 4.5 Hz, 2H), 1.95 (m, 2H). 13 C NMR (125 Hz, CDC13) δ 172.31, 151.26, 136.39, 133.72, 124.58, 120.62, 115.82, 110.71, 71.7, 59.3, 29.8, 24.4.

[0088] (3) Synthesis of compound of formula IV (2-cyano-4-(trimethylsilyl)ethynylphenyl-4- methoxybutyric acid ester)

[0089]

[0090] To dry and freshly distilled triethylamine (38 mL), nitrogen was bubbled through the solution (about 1-2 bubbles per second) for 0.5 h, then the compound of formula III (6.76 mmol, 2.02 g), triphenylphosphine (0.99 mmol, 0.24 g), cuprous iodide (0.59 mmol, 0.1 g) and tetrakis(triphenylphosphine)palladium (0.46 mmol, 0.54 g) were added successively under bubbling. The system was vacuumed and filled with nitrogen for three times. Finally, trimethylsilylacetylene (15.38 mmol, 1.5 g) was added. The reaction was stirred at 70 °C under nitrogen for 12 h. After the reaction was cooled to room temperature, the reaction mixture was concentrated by rotary evaporation to remove the solvent. The residue was dissolved in ethyl acetate, and the organic layer was washed successively with 5 wt% hydrochloric acid, saturated sodium bicarbonate solution and saturated sodium chloride solution, dried over anhydrous magnesium sulfate and filtered. The solvent was evaporated under reduced pressure. The crude product was purified by column chromatography using petroleum ether: ethyl acetate (20: 1, v:v) as eluent to give a yellow solid 0.89 g in 41% yield. 1 H NMR (600 MHz, CDC13) δ 7.72 (dd, J = 7.8, 1.8 Hz, 1H), 7.42 (d, J = 1.8 Hz, 1H), 7.30 (d, J = 7.8 Hz, 1H), 3.35 (t, J = 4.5 Hz, 2H), 3.23 (s, 3H), 2.52 (t, J = 4.5 Hz, 2H), 1.97-1.93 (m, 2H), 0.08 (s, 9H). 13 C NMR (125 MHz, CDC13) δ 172.33, 152.02, 137.11, 136.46, 121.91, 120.22, 115.81, 108.11, 98.94, 71.77, 59.32, 53.53, 29.80, 24.41, 3.40.

[0091] (4) Synthesis of compound of formula V

[0092]

[0093] The compound of formula IV (4.87 mmol, 1.54 g) was added to dry and freshly distilled tetrahydrofuran (20 mL). After vacuuming and filling with nitrogen for three times, a solution of tetrabutylammonium fluoride in tetrahydrofuran (1 mol / L, 10 mL) was added to the reaction flask by a syringe. The system was sealed with nitrogen and protected from light, and the reaction was stirred at room temperature. After TLC control showed that the reaction was complete, the reaction was quenched by water. The solution was washed with saturated sodium chloride solution, dried over anhydrous magnesium sulfate, filtered, and the solvent was evaporated under reduced pressure. The crude product was purified by column chromatography using petroleum ether: ethyl acetate (20: 1, v:v) as eluent to give a yellow solid 1.14 g in 96% yield. 1H NMR (600 MHz, CDC13) δ 7.74 (dd, J = 7.8, 1.8 Hz, 1H), 7.44 (d, J = 1.8 Hz, 1H), 7.31 (d, J = 7.8 Hz, 1H), 4.08 (s, 1H), 3.35 (t, J = 4.5 Hz, 2H), 3.23 (s, 3H), 2.52 (t, J = 4.5 Hz, 2H), 1.96-1.93 (m, 2H). 13 C NMR (125 MHz, CDC13) δ 172.34, 152.04, 137.03, 136.51, 121.91, 120.32, 115.81, 108.11, 82.33, 81.49, 71.76, 59.32, 29.80, 24.41.

[0094] (5) Synthesis of compound DCPM (a compound of Formula I)

[0095]

[0096] Take dry and re-distilled triethylamine (20 mL) and toluene (40 mL), bubble nitrogen gas under the surface of the mixed solution (about 1-2 / sec) for 0.5 h, then add 9,10-dibromoanthracene (1.49 mmol, 0.5 g), compound of Formula V (3.73 mmol, 0.92 g), triphenylphosphine (0.36 mmol, 0.09 g), cuprous iodide (0.18 mmol, 0.03 g), tetrakis(triphenylphosphine)palladium (0.09 mmol, 0.10 g) into the system under the condition of bubbling, vacuumize and bubble nitrogen gas for three times, and stir the reaction under the protection of nitrogen gas at 65-70 °C for 12 h. Monitor the reaction by thin layer chromatography, and cool the reaction system to room temperature after the reaction is completed. Evaporate the solvent under reduced pressure, dissolve the residue with ethyl acetate, wash the organic layer with 5 wt% hydrochloric acid, saturated sodium bicarbonate solution and saturated sodium chloride solution in sequence, dry with anhydrous magnesium sulfate, and filter. Purify the crude product by column chromatography after evaporating the solvent under reduced pressure, with petroleum ether: ethyl acetate (8:1, v:v) as the eluent, to obtain 0.69 g of bright yellow solid, with a yield of 80%. 1 H NMR (600 MHz, CDC13) δ 8.47 (dd, J = 7.8, 1.7 Hz, 4H), 7.77 (dd, J = 8.0, 1.8 Hz, 2H), 7.63-7.59 (m, 4H), 7.46 (d, J = 1.7 Hz, 2H), 7.29 (d, J = 8.0 Hz, 2H), 3.35 (t, J = 4.5 Hz, 4H), 3.23 (s, 6H), 2.52 (t, J = 4.6 Hz, 4H), 1.95 (m, 4H). 13C NMR (101 MHz, CDCI3) δ 172.33, 152.09, 139.33, 137.01, 136.44, 135.33, 135.14, 128.89, 128.13, 121.91, 120.20, 119.71, 115.84, 108.11, 71.74, 59.35, 29.84, 24.41.

[0097] Example 2

[0098] Compound DCPM was recrystallized by mixed solvent of dichloromethane and ethyl acetate to obtain D1 crystal sample. The specific operation is as follows: DCPM was added into the mixed solvent of dichloromethane and ethyl acetate (the ratio is 1:8, v:v) at 40°C to prepare a saturated solution. The solution was slowly reduced to room temperature, and D1 crystal was obtained after standing for about 3 days.

[0099] Compound DCPM of the present application has the property of polymorphism, and D1 is selected as the sample to test its color change under force stimulation.

[0100] Test Example 1

[0101] The D1 sample was crushed and ground, and the photoluminescence (PL) spectra of the original sample, the slightly crushed sample and the completely ground sample were tested, and the results are shown in Figure 1 .

[0102] The test method of PL spectrum is as follows: the excitation wavelength is selected as 358 nm, the fluorescence spectrum wavelength range is selected as 400-700 nm, and the appropriate light path slit and scanning speed are selected according to the instrument signal to test the photoluminescence spectrum of the sample.

[0103] Herein, the slightly crushed refers to applying a positive pressure to the crystal to crush the crystal into small crystal grains with irregular shape and size, and the particle size is about 1-3 mm. The completely ground refers to applying a grinding force to the crushed crystal grains to further grind the small crystal grains into powder.

[0104] It can be seen from Figure 1 that D1 exhibits a mechanical stimulation response light-emitting process of multiphase reversible transition: the maximum emission wavelength of the original crystal sample is at 560 nm, and the fluorescence emission intensity is extremely low; after being slightly crushed, the maximum emission wavelength is blue-shifted to 539 nm, and the fluorescence emission intensity is also significantly improved; after being completely ground, the maximum emission wavelength is red-shifted to 578 nm, and the fluorescence emission intensity is basically unchanged.

[0105] The photos of the D1 original sample, the slightly crushed sample and the completely ground sample under 365 nm ultraviolet lamp are as follows: Figure 2As shown, from the original state to slight crushing and then to complete grinding, the fluorescence color changed from dark yellow to bright green, and then to orange. After being fumigated with dichloromethane solvent, the color of the completely ground sample changed from orange to green. The solvent fumigation procedure was as follows: dichloromethane solvent was placed on a 35°C heating stage, and the ground sample was placed above the solvent, allowing the sample to be fumigated by solvent evaporation.

[0106] Test Example 2

[0107] The test results show the normal force required for crystal breakage. Figure 3 As shown, the force required to activate the emission of sample D1 is in the kilopascal range, less than 1 MPa.

[0108] The test method for the normal stress of crystal breakage is as follows: a quantifiable pressure is applied under a microscope using weights to cause the crystal to break slightly. This is repeated 8 times to obtain a scatter plot of the breakage stress.

[0109] Depend on Figure 3 As can be seen, when pressure was applied under a microscope using a weight (20±10g), a slight crack was observed in the crystal (1.5±0.5*1.5±0.5mm). Simultaneously, the new surface of the crystal after cracking was clearly observed to emit a yellow-green light under the microscope. Calculations suggest that the pressure required for the D1 sample to emit light is in the range of 250-500 kPa, less than 1 MPa.

[0110] Test Example 3

[0111] Sample D1 was crushed and ground. X-ray diffraction patterns of the original sample, the slightly crushed sample, and the fully ground sample were measured. The results are as follows: Figure 4 As shown.

[0112] The X-ray diffraction pattern testing method is as follows: the scanning range is set to 5-40°, the scanning mode is continuous scanning, the scanning speed is 2.0000 deg / min, the sample tilt angle is 0.0500 deg, and the adjustment time is 1.50 sec to test the X-ray diffraction pattern of the sample.

[0113] Depend on Figure 4 It can be seen that the changes in the X-ray diffraction spectrum of D1 under mechanical crushing and grinding stimulation correspond one-to-one with the changes in the fluorescence emission spectrum. The diffraction peaks in the original state exhibit a fine structure with high crystallinity, and the diffraction peaks are mainly located at 2θ=12.78°. 2θ = 23.75° 2θ = 25.83° and 2θ = 26.77° This phenomenon can be verified from the single crystal data and the crystal photograph. After slightly breaking the crystal by mechanical force, the intensity of the sharp diffraction peak at the same position of the original crystal state changes, and weak diffraction peaks appear at other angles 2θ = 8.87° 2θ = 12.86° 2θ = 22.96° 2θ = 25.88° and 2θ = 29.16° It is shown that another crystal state appears as an intermediate state before the mechanical force grinding. This intermediate state breaks the unfavorable interaction force of the molecules in the original crystal, so that the order degree of the arrangement and accumulation of the molecules is reduced, thereby achieving the purpose of enabling the fluorescence to be turned on. Then, the broken sample is ground, and the diffraction peaks of the sample basically disappear, and the diffraction peak with the highest intensity moves to a small angle 2θ = 24.94° position, which indicates that the intermolecular face-face distance is increased, which may be the reason for the red shift of the fluorescence; at the same time, the weak diffraction peak also indicates that the crystallinity is significantly reduced, and this phenomenon is also verified by the fluorescence emission spectrum. By analyzing the changes of the X-ray diffraction curve, it can be seen that, through the breaking and grinding stimulation by mechanical force, the D1 crystal sample undergoes a change from high order to gradually reduced crystallinity, and this change may be the main reason for the multi-phase state stimulation response luminescence phenomenon.

[0114] Test Example 4

[0115] The D1 sample is broken and ground, and the differential scanning calorimeter (DSC) curves of the original sample, the slightly broken sample and the completely ground sample are tested, and the results are shown in Figure 5 .

[0116] The test method of the DSC curve is as follows: the protective gas is nitrogen, the gas flow rate is selected to be 50 mL / min, the temperature rising rate is set to be 10 ℃ / min, and the first cycle of temperature rising process is used to draw the DSC curve.

[0117] Figure 5 It is proved that, in the process of slightly breaking the crystal of D1, the sample reaches a transition intermediate state, and the performance in the DSC curve is that there is an endothermic peak 148.23 ℃ (ΔH = 32.89 J / g) different from the original state before melting, and the endothermic peak after melting disappears.

[0118] Application Example

[0119] This application example gives a pressure sensing device, the structure of which is as Figure 6The pressure sensing device is shown in the figure. The pressure sensing device comprises a sensor sensing part 3, an integrated signal amplifier 6 and a signal processing part 8, wherein the sensor sensing part 3 comprises a D1 coating pressure sensor 1 and an ultraviolet lamp 4, and the signal processing part 8 comprises a spectrometer 7. The D1 coating pressure sensor 1 generates a sensor output signal 5 after receiving a force to be measured 2, and the sensor output signal 5 is transmitted to the spectrometer 7 through the integrated signal amplifier 6.

[0120] In the pressure sensing device, the numerical relationship between the size of the force stimulus and the luminescence intensity is made by using the characteristics of the D1 luminescence conversion. Under the irradiation of the ultraviolet lamp 4, the D1 as a sensor converts the force to be measured 2 stimulus into light with different emission peaks, and the light signal processor records the signal emission peak instantaneously and completely, and judges the size of the force received according to its red shift or blue shift relative to the ground state.

[0121] The initial state is that the D1 is not stimulated by force under the irradiation of the ultraviolet lamp 4, and the emission peak is 560 nm. At this time, the fluorescence quantum yield is extremely low, and the signal integration display state is S0. When the recognition signal acquisition device does not collect signals, the control signal acquisition device is closed. When the D1 is stimulated by force, the D1 responds to the force stimulus, and the signal acquisition device is in working condition to recognize it, so as to judge the size of the force received by the D1 coating pressure sensor 1.

Claims

1. Compound of Formula I:

2. A method for preparing the compound of formula I according to claim 1, characterized in that, The method includes the following steps: (1) A nucleophilic substitution reaction of 4-bromo-2-nitrophenol with 4-methoxybutyryl chloride is carried out to generate compound II; (2) The compound of formula II is reduced and diazotized to obtain the compound of formula III; (3) Compound III is subjected to a Sonogashira cross-coupling reaction with trimethylsilylacetylene to obtain compound IV; (4) The compound of formula IV undergoes a trimethylsilyl deprotection reaction to obtain the compound of formula V; (5) Compound V is subjected to a Sonogashira cross-coupling reaction with 9,10-dibromoanthracene to obtain compound I.

3. The method as described in claim 2, characterized in that, In step (1), the reaction solvent is dichloromethane, and the reaction is carried out in the presence of sodium hydride.

4. The method as described in claim 2, characterized in that, Step (2) consists of two reactions. The first reaction is carried out in the presence of stannous chloride with ethanol as the reaction solvent, and then in the presence of sodium hydroxide with water as the reaction solvent. The second reaction is carried out in the presence of sodium nitrite and p-toluenesulfonyl nitrile with acetonitrile and hydrochloric acid as the reaction solvent.

5. The method as described in claim 2, characterized in that, In step (3), the reaction solvent is triethylamine, and the reaction is carried out in the presence of triphenylphosphine, tetra(triphenylphosphine)palladium and cuprous iodide.

6. The method as described in claim 2, characterized in that, In step (4), the reaction solvent is tetrahydrofuran, and the reaction is carried out in the presence of tetrabutylammonium fluoride.

7. The method as described in claim 2, characterized in that, In step (5), the reaction solvent is a mixture of toluene and triethylamine, and the reaction is carried out in the presence of triphenylphosphine, tetra(triphenylphosphine)palladium and cuprous iodide.

8. A luminescent material, characterized in that, The luminescent material is a crystalline material obtained by recrystallization of the compound of Formula I as described in claim 1 dissolved in a mixed solvent of dichloromethane and ethyl acetate.

9. A mechanical force sensor, characterized in that, The mechanical force sensor includes a test sample and a mechanoluminescent coating disposed on the surface of the test sample, wherein the mechanoluminescent coating comprises the compound of formula I as described in claim 1 or the luminescent material as described in claim 8.

10. The application of the compound of formula I according to claim 1 or the luminescent material according to claim 8 in mechanical force sensor devices or in the detection of deformation or stress of parts.

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