Reversible light / magnetic / pressure responsive cyclic trimer dynamic organic framework materials and their preparation and application

Abstract

The present invention belongs to the field of optoelectronic materials, and specifically discloses a reversible light / magnetic / pressure responsive cyclic trimer dynamic organic framework material and its preparation and application. The present invention also discloses a preparation method and application method of the reversible light / magnetic / pressure responsive cyclic trimer dynamic organic framework material. The compound of the new structure described in the present invention has excellent properties and has highly sensitive and highly responsive optical, magnetic and fluorescent response effects under stimulation.

Description

Technical Field

[0001] The invention relates to the field of functional molecules, and in particular to a class of dynamic organic framework materials with reversible light / magnetic / pressure responses. Background Art

[0002] Reversibly transformable solid-state molecular framework materials can significantly change the optical, electrical, and magnetic properties or molecular and framework structures of molecular materials under external stimuli, and have attracted much attention and research due to their potential uses in intelligent sensing, controllable display, soft machinery, information storage, etc. Generally speaking, the reversible response strategy of molecular materials relies on the chemical transformation of compound elements or the physical phase change of molecular aggregation patterns under external stimuli. However, when it comes to specific scenarios, especially solid-state compounds, the reversible conversion efficiency and reversibility of solid-state molecular materials need to be improved due to the low sensitivity of the chemical transformation of compound elements, the slow response speed, or the molecular aggregation state inhibiting the phase change process of the compound. An effective way to overcome this obstacle is to introduce spatial gaps in molecular materials to ensure that active solid-state molecular motion or chemical-physical transformation proceeds rapidly in sufficient space. The solid-state molecular materials thus obtained can show high reversibility, sensitivity, and rapid responsiveness of intelligent modulation material functions in the crystalline solid state. However, the currently reported systems are highly limited to crystalline rigid molecular frameworks, which limit the specific application scenarios and response sensitivity of stimulus-responsive solid-state molecules. Summary of the invention

[0003] In order to solve the specific application limitations and low response sensitivity problems of reversible light / magnetic / pressure responsive solid-state molecules, the first purpose of the present invention is to provide a cyclic trimer dynamic organic framework material, aiming to construct a multifunctional molecular material with new reversible light / magnetic / pressure response.

[0004] The second purpose of the present invention is to provide a method for preparing a cyclic trimer dynamic organic framework material, and the functional molecule can be successfully prepared through a molecular construction method.

[0005] The third purpose of the present invention is to provide the reversible stimulus response properties of the cyclic trimer dynamic organic framework material and its potential application in intelligent sensing.

[0006] The cyclic trimer dynamic organic framework material has a structural formula 1:

[0007]

[0008] In Formula 1, R1 and R2 are independently H, -Cl, -Br, -I, -CN, C1-C24 alkyl, C3-C24 cycloalkyl, C1-C24 alkoxy, halogenated C1-C24 alkyl, halogenated C3-C24 cycloalkyl or halogenated C1-C24 alkoxy or aryl;

[0009] Ar is a five-membered heterocyclic aromatic group, a phenyl group, a substituted phenyl group, a six-membered heterocyclic aromatic group or a condensed-ring aromatic group.

[0010] The present invention provides a novel compound having a special three-dimensional porous skeleton structure, rich pores and channel structures, and a C(sp3)-C(sp3) single bond dissociation enthalpy (BDE, ΔH diss ) as low as 55kJmol -1 , has excellent reactivity and air stability. In terms of performance, the compound has integrated AIE properties, and also has reversible color, fluorescence and magnetism response capabilities to mechanical force / pressure and other stimuli. Not only that, it also has excellent reversible response sensitivity and amplitude. The compound of the present invention provides a broader development space for applications such as smart sensing, information storage and anti-counterfeiting display.

[0011] Preferably, in Formula 1, Ar can be a five-membered heterocyclic aromatic group, a phenyl group, a substituted phenyl group, a six-membered heterocyclic aromatic group, a substituted six-membered heterocyclic aromatic group; or an aromatic hydrocarbon group in which any two or more aromatic rings of a five-membered or six-membered aromatic group are fused.

[0012] More preferably, Ar is selected from the same group; more preferably, it is phenyl, substituted phenyl or a five-membered heterocyclic aromatic group.

[0013] Most preferably, the Ar are all phenyl.

[0014] Preferably, the cyclic trimer dynamic organic framework material has a structural formula 1-A:

[0015]

[0016] Preferably, R1 and R2 are independently selected from H, C1-C24 alkyl, C1-C24 alkoxy or aryl;

[0017] More preferably, in Formula 1, R1 and R2 are independently C1-C4 alkyl groups.

[0018] More preferably, said R1 and R2 are selected from the same group.

[0019] Most preferably, both R1 and R2 are methyl.

[0020] More preferably, the cyclic trimer dynamic organic framework material has a structural formula of Formula 1-A-1:

[0021]

[0022] The absorption spectrum of the cyclic trimer dynamic organic framework material covers the ultraviolet spectrum region and the visible spectrum region of 250-450nm. It has aggregation-induced emission (AIE) properties; its color, fluorescence and magnetism have reversible response properties to temperature and mechanical force / pressure. In addition, it also has excellent reversible response sensitivity and amplitude.

[0023] The present invention discloses a method for preparing the cyclic trimer dynamic organic framework material, wherein the compound of formula 2 and an oxidant are subjected to oxidative cyclization to obtain:

[0024]

[0025] In Formula 2, the selection ranges of R1, R2, and Ar are the same as those in Formula 1.

[0026] In the present invention, based on the compound of formula 2, in combination with oxidative cyclization treatment, the special three-dimensional trimer porous framework material can be unexpectedly obtained, and the material has excellent reversible response sensitivity, amplitude and optical properties.

[0027] In the present invention, there is no particular requirement for the type of the oxidant, for example, it can be at least one of lead dioxide, DDQ or tetrachlorobenzoquinone;

[0028] In the present invention, the amount of the oxidant can be adjusted according to the preparation requirements. Preferably, the molar ratio of Formula 2 to the oxidant is 1:100 to 250; preferably 1:150 to 200;

[0029] Preferably, there is no particular requirement for the temperature of the oxidative cyclization reaction, and it can be, for example, 15 to 45°C; preferably 25 to 35°C.

[0030] In the preparation method of the present invention, the compound of formula 2 is obtained by coupling the compound of formula 3 and the compound of formula 4;

[0031]

[0032] In Formula 3, the selection ranges of R1, R2, and Ar are the same as those in Formula 2, and X is a halogen.

[0033] Preferably, Formula 3 and Formula 4 are subjected to Takahashi coupling reaction under the catalysis of a palladium catalyst, and then reduced with a reducing agent to obtain the Formula 2;

[0034] Preferably, said X is -Br or -I;

[0035] Preferably, the molar ratio of the compound of formula 3 to the compound of formula 4 is 1:4 to 10, preferably 1:7 to 9;

[0036] The palladium catalyst can be a conventional Takahashi reaction catalyst in the industry, preferably Pd(PPh3)4; its dosage is, for example, 0.1 to 0.5 eqv (based on Formula 3).

[0037] The reducing agent may be a conventional reducing component in the industry, such as NaH, and its usage is, for example, 5 to 15 eqv (based on Formula 3).

[0038] Preferably, the reaction solvent has no particular requirement, and may be THF, for example.

[0039] Preferably, the temperature of the Takahashi reaction is 60 to 90°C.

[0040] In the preparation method of the present invention, the compound of formula 3 is obtained by self-coupling the compound of formula 5 under the action of reduced valence titanium. The reduced valence titanium is obtained by the reaction of TiY4 and zinc powder;

[0041]

[0042] Y is halogen, preferably -Cl.

[0043] Preferably, the coupling is a McMurry coupling reaction.

[0044] As a preferred molar ratio of formula 5 to TiY4 and zinc powder is 1:3-6:5-10;

[0045] Preferably, the reaction solvent is not particularly required, and may be THF, for example.

[0046] Preferably, the temperature of the McMurry coupling reaction is 60-90°C.

[0047] Preferably, the compound of formula 5 is prepared by a Friedel-Crafts acylation reaction of a compound of formula 6 and a compound of formula 7 under the action of AlZ3;

[0048]

[0049] Preferably, Z is halogen, preferably -Cl.

[0050] Preferably, the molar ratio of Formula 6 to Formula 7 is 1:1.2-2;

[0051] The temperature of the Friedel-Crafts acylation reaction is not particularly limited, and may be, for example, 15 to 45°C, more preferably 25 to 35°C.

[0052] The preferred synthesis steps of the cyclic trimer dynamic organic framework material of the present invention are:

[0053] Step (1): subjecting the compound represented by Formula 6 and the compound represented by Formula 7 to a Friedel-Crafts acylation reaction in the presence of a catalyst to obtain a compound represented by Formula 5;

[0054] Step (2): subjecting the compound represented by Formula 5 to a McMurry coupling reaction in the presence of a catalyst to obtain a compound represented by Formula 3;

[0055] Step (3): subjecting the compound represented by Formula 3 and the compound represented by Formula 4 to a Takahashi coupling reaction in the presence of a catalyst to obtain a compound represented by Formula 2;

[0056] Step (4): subjecting the compound of formula 2 to an oxidative cyclization reaction under the action of an oxidant to obtain a cyclic trimer dynamic organic framework material of formula 1;

[0057] The preferred preparation method of the present invention, the synthesis route is shown in Equation 1:

[0058]

[0059] The present invention also provides an application of the cyclic trimer dynamic organic framework material, which is used to prepare solid-state luminescent materials and / or intelligent electronic materials;

[0060] Preferably, it is used to prepare a material having a reversible stimulus response;

[0061] Preferably, the material is prepared to have at least one of color, fluorescence and magnetism that responds reversibly under mechanical and temperature stimulation.

[0062] The present invention also provides a mechanical and / or temperature stimulus responsive device, which comprises a cyclic trimer dynamic organic framework material.

[0063] Beneficial Effects

[0064] The present invention provides a novel compound having a special three-dimensional porous skeleton structure, rich pores and channel structures, and a C(sp3)-C(sp3) single bond dissociation enthalpy (BDE, ΔH diss ) as low as 55kJmol -1 , has excellent reactivity and air stability. In the present invention, the compound has integrated AIE properties, and also has reversible color, fluorescence and magnetism response capabilities to mechanical force / pressure and other stimuli. Not only that, it also has excellent reversible response sensitivity and amplitude. The compound of the present invention provides a broader development space for applications such as smart sensing, information storage and anti-counterfeiting display BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 is the hydrogen nuclear magnetic resonance spectrum of formula 1-A-1 obtained in Example 1;

[0066] Figure 2 This is the carbon NMR spectrum of formula 1-A-1 obtained in Example 1.

[0067] Figure 3 This is the mass spectrum of Formula 1-A-1 obtained in Example 1.

[0068] Figure 4 is the UV-visible spectrum of Formula 1-A-1 obtained in Example 1;

[0069] Figure 5 The aggregation-induced emission curve of formula 1-A-1 obtained in Example 1 is

[0070] Figure 6 This is the single crystal diffraction structure diagram of Formula 1-A-1 obtained in Example 1.

[0071] Figure 7 is the electron spin resonance curve of formula 1-A-1 obtained in Example 1;

[0072] Figure 8 is the stimulus response property of Formula 1-A-1 prepared in Example 1;

[0073] Fig. 9 is the pressure sensing property of Formula 1-A-1 obtained in Example 1; DETAILED DESCRIPTION

[0074] In the following examples, the room temperature is, for example, 25 to 30°C.

[0075] Example 1: Synthesis of Formula 1-A-1

[0076]

[0077] After adding aluminum chloride (15g, 110mmol) to a 200ml eggplant-shaped bottle, add 100ml dry dichloromethane, drop compound 7 (3.22mL, 27.46mmol) in an ice-water bath, stir for 10 minutes, add compound 6 (5g, 18.30mmol), and react overnight at room temperature. After the reaction is completed, add 30ml 1M dilute hydrochloric acid to quench the reaction, add 50ml water to separate, collect the organic phase and spin dry, and the residual solid is purified by silica gel flash chromatography column (eluent is petroleum ether: dichloromethane = 3:1) to obtain white compound 5 (5.90g, 86%).

[0078] Add zinc powder (4.16g, 63.61mmol) to a 250ml two-necked bottle, add 100ml of dry tetrahydrofuran and place in an ice-water bath. After stirring for 10 minutes, slowly add titanium tetrachloride (3.49mL, 31.81mmol) and heat to reflux for 1 hour. After the reaction system cools to room temperature, take another 50ml two-necked bottle, add raw material 5 (3.00g, 7.95mmol), add 30ml of anhydrous tetrahydrofuran to dissolve, and slowly add it to the previous two-necked bottle with a syringe, and reflux overnight for reaction. After the reaction is completed, add 50ml of 1M dilute hydrochloric acid in an ice-water bath to quench the reaction, stir for 1 hour, add 50ml of water and separate the liquids, collect the organic phase and spin dry, and purify the residual solid with a silica gel flash chromatography column (eluent is petroleum ether: dichloromethane = 8:1) to obtain yellow-green compound 3 (4.20g, 73%).

[0079] In a 100 ml two-necked flask, malononitrile (914 mg, 13.84 mmol) was added, dissolved in 50 ml of anhydrous tetrahydrofuran, placed in an ice-water bath, sodium hydride (498 mg, 20.76 mmol) was added in batches, stirred in an ice-water bath for 30 minutes, and then stirred at room temperature for 30 minutes, and then raw material 3 (1.25 g, 1.73 mmol) and catalyst Pd (PPh3) 4 (243 mg, 0.35 mmol) were added, and heated under reflux for three days. After the reaction was completed, 20 ml of 1M dilute hydrochloric acid was added to quench the reaction, 50 ml of water was added to separate the liquids, the organic phase was collected and dried, and the residual solid was purified by silica gel flash chromatography column (eluent: petroleum ether: ethyl acetate = 1:1) to obtain a yellow reaction product 2 (0.792 g, 66%).

[0080] Compound 2 (200 mg, 0.3 mmol) and lead dioxide (13.81 g, 57.73 mmol) were added to a 100 ml eggplant-shaped bottle, and 40 ml of dry dichloromethane were added, and the mixture was stirred at room temperature for half an hour. After the reaction was completed, the mixture was filtered and dried, and the residual solid was purified by silica gel flash chromatography (eluent: petroleum ether: dichloromethane = 1:2) to obtain yellow compound 1-A-1 (510 mg, 86%).

[0081] The structure of the compound of formula 1-A-1 is confirmed by hydrogen nuclear magnetic resonance spectrum, carbon nuclear magnetic resonance spectrum, mass spectrum, ultraviolet visible spectrum, single crystal diffraction and the like.

[0082] The H NMR spectrum of Formula 1-A-1 measured at 223K using deuterated chloroform as solvent is shown in Figure 1 ;

[0083] 1H NMR (400MHz, THF-d8, 223K): δ8.05(d,J=8.0Hz,3H),7.90(s,3H),7.86(d,J=10.0Hz,3H),7.70(d,J=8.0Hz,3H),7.63(d,J=7.9Hz,3H),7.42(d, J=8.1Hz,3H),7.25–6.79(m,39H),6.80(t,J=7.3Hz,3H),6.30–6.26(m, 6H),1.46(s,6H),1.27(s,12H),1.04(s,6H),0.96(s,6H),0.23(s,6H).

[0084] The carbon NMR spectrum of formula 1-A-1 measured at 298K using deuterated chloroform as solvent is shown in Figure 2 ;

[0085] 13 C NMR (100MHz, CDCl3):155.30,153.49,144.58,143.48,141.73,135.19,131.50,127 .91,127.29,136.93,126.62,122.52,121.70,120.64,110.75,53.87,46.84,26.35.

[0086] Matrix-assisted laser desorption / ionization time-of-flight mass spectrometry of formula 1-A-1 ( Figure 3 ), since the carbon-carbon bond in Formula 1-A-1 is weak, the laser beam bombardment causes the bond of Formula 1-A-1 to break and form a monomer, so only the molecular ion peak of the monomer is shown in the mass spectrum. The fragile carbon-carbon single bond suggests that Formula 1-A-1 has a stimuli-responsive property.

[0087] HRMS(MALDI-TOF,m / z)calcd for C 50 H 34 N4[M] + ,690.2783; found:690.2780 (error=-0.4ppm).

[0088] The UV-visible absorption spectrum of tetrahydrofuran solution of formula 1-A-1 ( Figure 4 ). Formula 1-A-1 has strong absorption in the range of 300-450nm, and the maximum absorption wavelength is 360nm.

[0089] AIE performance test( Figure 5 ): AIE curve of formula 1-A-1. With tetrahydrofuran as a good solvent and n-hexane as a poor solvent, f Wis the volume ratio of n-hexane in the mixed solvent. The AIE curve shows that formula 1-A-1 has significant AIE properties and W When the concentration is greater than 80%, the AIE effect is significantly enhanced.

[0090] The single crystal structure of formula 1-A-1 is shown in Figure 6 Formula 1-A-1 is the depth The molecule is a bowl-shaped equilateral triangle with a side length of 2 nm, and the monomers are bonded in a "gauche" form, where three M-type monomers form an M-type trimer and three P-type monomers form a P-type trimer.

[0091] VT-ESR spectrum curve is shown in Figure 7 ; VT-ESR spectrum curves of the powder of formula 1-A-1 from 298K to 403K (a) and back to 343 (b), and VT-ESR curves of the toluene solution from 298K to 378K (c) and back to 298K (d). When the powder is heated, the carbon-carbon single bond breaks, the ESR signal is enhanced, and the color gradually darkens. After heating to 403K, the ESR signal is the strongest and the color turns reddish brown. At this time, the carbon-carbon bond in the molecule breaks and the molecular tension is released, so cooling is irreversible. In the solution state, the molecules are in irregular thermal motion, and cooling can quickly form bonds, showing excellent stimuli reversible properties.

[0092] The changes in optics and ESR of the powder of formula 1-A-1 before and after grinding and fumigation with THF are shown in Figure 8 . The color and fluorescence changes of Formula 1-A-1 under sunlight and ultraviolet light (365nm) (a), ESR (b), PL (c) and ESR (d) before and after grinding and fumigation with THF. Before and after mechanical force (grinding) stimulation and after solvent fumigation, the relevant properties of Formula 1-A-1 change: color: yellow-brown-yellow; fluorescence change: yellow fluorescence-no fluorescence-yellow fluorescence; UV absorption: short wavelength-long wavelength-short wavelength; fluorescence: "on-off-on"; ESR signal: weak-strong-weak; It proves that the optical and magnetic properties of Formula 1-A-1 show excellent reversible change properties in response to mechanical force stimulation.

[0093] Fig. 9 The color (top) and fluorescence changes (bottom) of the pressure sensing filter paper coated with Formula 1-A-1 under sunlight and ultraviolet light (365nm): filter paper before pressing (a); filter paper pressed by a tablet press at different pressures (b); pressed filter paper after fumigation with tetrahydrofuran at room temperature (18°C) for 21 hours (c) and 53 hours (d). Under different pressure stimulations, the color and fluorescence of the filter paper change to different degrees, and the contrast with the unstimulated area is obvious, showing the reversible response properties of Formula 1-A-1 to pressure and its application potential in smart sensing.

[0094] In summary, the compound of formula 1 described in the present invention has excellent AIE and reversible light / magnetic / pressure response sensitivity and amplitude, and has special stimulated fluorescence behavior. However, formula 2 before polymerization does not have this performance.

Claims

1. A cyclic trimer dynamic organic framework material, characterized in that: It has the structural formula 1: Formula 1 In Formula 1, R1 and R2 are independently H, -Cl, -Br, -I, -CN, C1-C24 alkyl, C3-C24 cycloalkyl, C1-C24 alkoxy, halogenated C1-C24 alkyl, halogenated C3-C24 cycloalkyl or halogenated C1-C24 alkoxy; Ar is a five-membered heterocyclic aromatic group, a phenyl group or a six-membered heterocyclic aromatic group.

2. The cyclic trimer dynamic organic framework material according to claim 1, characterized in that: The reversible light / magnetic / pressure responsive cyclic trimer dynamic organic framework material and its preparation and application have the structural formula 1-A: Formula 1-A Wherein, R1 and R2 are independently H, C1-C24 alkyl or C1-C24 alkoxy.

3. The cyclic trimer dynamic organic framework material according to claim 2, characterized in that: R1 and R2 are the same group.

4. The cyclic trimer dynamic organic framework material according to claim 3, characterized in that: R1 and R2 are C1-C4 alkyl groups.

5. A method for preparing the cyclic trimer dynamic organic framework material according to any one of claims 1 to 4, characterized in that: The compound described in Formula 2 is subjected to an oxidative cyclization reaction with an oxidant to obtain: Formula 2 In Formula 2, the selection ranges of R1, R2, and Ar are the same as those in Formula 1.

6. The preparation method according to claim 5, characterized in that: The solvent for the oxidative cyclization reaction is a hydrophobic organic solvent.

7. The preparation method according to claim 6, characterized in that: The solvent for the oxidative cyclization reaction is dichloromethane.

8. The preparation method according to claim 5, characterized in that: The oxidant is at least one of PbO2, DDQ or chloranil.

9. The preparation method according to claim 5, characterized in that: The molar ratio of Formula 2 to the oxidant is 1:100-250.

10. The preparation method according to claim 5, characterized in that: The temperature range of the oxidative cyclization reaction is 15~45℃.

11. The preparation method according to claim 5, characterized in that: The temperature range of the oxidative cyclization reaction is 25~35℃.

12. The preparation method according to claim 5, characterized in that: The compound of formula 2 is obtained by coupling the compound of formula 3 and the compound of formula 4; Formula 3 Formula 4 In Formula 3, the selection ranges of R1, R2, and Ar are the same as those in Formula 2, and X is a halogen.

13. The preparation method according to claim 12, characterized in that: Formula 3 and Formula 4 are subjected to Takahashi coupling reaction under the catalysis of a palladium catalyst, and then reduced with a reducing agent to obtain the formula 2.

14. The preparation method according to claim 13, characterized in that: The X is -Br or -I.

15. The preparation method according to claim 13, characterized in that: The molar ratio of the compound of formula 3 to the compound of formula 4 is 1:4-10.

16. The preparation method according to claim 13, characterized in that: The palladium catalyst is Pd(PPh3)4.

17. The preparation method according to claim 13, characterized in that: The reducing agent is NaH.

18. The preparation method according to claim 13, characterized in that: The temperature of the Takahashi coupling reaction is 60-90°C.

19. The preparation method according to claim 12, characterized in that: The compound of formula 3 The compound described in Formula 5 is obtained by McMurry coupling reaction under the action of reduced valence titanium, and the reduced valence titanium is obtained by the reaction of TiY4 and zinc powder; Formula 5 Y is halogen.

20. The preparation method according to claim 19, characterized in that: The molar ratio of formula 5 to TiY4 and zinc powder is 1:3~6:5~10; The temperature of the McMurry coupling reaction is 60~90℃.

21. The preparation method according to claim 19, characterized in that: The compound of formula 5 is prepared by subjecting the compound of formula 6 and the compound of formula 7 to Friedel-Crafts acylation under the action of AlZ3; Formula 6 Formula 7 Z is halogen.

22. The preparation method according to claim 21, characterized in that: The molar ratio of Formula 6 to Formula 7 is 1:1.2-2; The temperature of the Friedel-Crafts acylation reaction is 15~45°C.

23. An application of the cyclic trimer dynamic organic framework material according to any one of claims 1 to 4, characterized in that: The polyol is used to prepare solid-state light-emitting materials and / or smart electronic materials.

24. The use of the cyclic trimer dynamic organic framework material according to claim 23, characterized in that: It is used to prepare materials with reversible stimulus response.

25. The use of the cyclic trimer dynamic organic framework material according to claim 24, characterized in that: The material is prepared to have at least one of color, fluorescence and magnetism that responds reversibly under mechanical and temperature stimulation.

26. A mechanical and / or temperature stimulus responsive device, characterized in that: A cyclic trimer dynamic organic framework material comprising any one of claims 1 to 4.

Images