A pyrene-benzonitrile derivative based on trifluoromethyl substitution, and a preparation method and application thereof

Abstract

This invention relates to a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative, its preparation method, and its application. A trifluoromethyl-substituted pyrene-phenylacetonitrile derivative has the structural formula: [formula omitted]. The preparation method involves dissolving 1-pyrene formaldehyde, the corresponding trifluoromethylphenylacetonitrile, and an alkaline catalyst in an organic solvent, and carrying out a Knoevenagel condensation reaction under heating conditions. The reaction product is then post-treated to obtain the pyrene-phenylacetonitrile derivative. The application of a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative in electrical storage devices is also discussed. This invention achieves precise control of storage performance by introducing trifluoromethyl groups at different positions on the benzene ring of the pyrene-phenylacetonitrile backbone, providing a novel design approach for developing new multi-level electrical storage materials. The synthesis route is concise and has broad application prospects in the field of high-density non-volatile memory.

Description

Technical Field

[0001] This invention relates to the field of organic functional materials and microelectronic devices, and in particular to a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative, its preparation method, and its application. Background Technology

[0002] With the rapid development of information technology, higher requirements have been placed on the capacity, speed, power consumption and integration of memory. Resistive random access memory (RAM) is regarded as a strong competitor to the next generation of non-volatile memory technology due to its advantages such as simple structure, fast read and write speed, low power consumption and easy high-density integration. Its core lies in finding high-performance resistive switching materials.

[0003] Organic small molecule materials have attracted much attention in the field of electrical storage due to their advantages such as strong structural designability, easy energy level control, and the ability to form high-quality thin films through vacuum evaporation. However, most existing organic storage materials typically exhibit only binary (high-resistivity / low-resistivity) storage behavior, limiting further improvements in storage density. Developing organic materials with multi-valued (e.g., ternary and higher) storage properties through molecular structure design is one of the effective ways to overcome the bottleneck of storage density.

[0004] Therefore, designing and synthesizing novel organic small molecule materials with simple structures, stable performance, and the ability to achieve multi-value storage has important scientific significance and application value. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative, its preparation method, and its applications. By introducing trifluoromethyl groups at different positions on the benzene ring of the pyrene-phenylacetonitrile skeleton, precise control over storage performance is achieved, providing a novel design approach for developing new multi-level electronic storage materials. The synthesis route is concise, and the device fabrication process is compatible with current semiconductor processes, showing broad application prospects in the field of high-density non-volatile memory.

[0006] The first aspect of this invention provides a pyrene-phenylacetonitrile derivative based on trifluoromethyl substitution, the structural formula of which is: ,or .

[0007] Preferably, the pyrene-phenylacetonitrile derivative is synthesized from 1-pyrene formaldehyde and trifluoromethylphenylacetonitrile; wherein the trifluoromethylphenylacetonitrile is 2-(trifluoromethyl)phenylacetonitrile or 3-(trifluoromethyl)phenylacetonitrile.

[0008] The second aspect of the present invention provides a method for preparing a pyrene-phenylacetonitrile derivative based on trifluoromethyl substitution, comprising the following steps: dissolving 1-pyrene formaldehyde, the corresponding trifluoromethylphenylacetonitrile, and an alkaline catalyst in an organic solvent, carrying out a Knoevenagel condensation reaction under heating conditions, and after the reaction is completed, obtaining the pyrene-phenylacetonitrile derivative by post-treatment of the reaction product.

[0009] Preferably, the alkaline catalyst is one of potassium hydroxide, sodium hydroxide, and potassium tert-butoxide; the organic solvent is one or more of ethanol, methanol, and tetrahydrofuran in any proportion.

[0010] Preferably, in the Knoevenagel condensation reaction, the reaction temperature is 50-80℃ and the reaction time is 6-24 hours.

[0011] A third aspect of the present invention provides the application of a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative in an electrical storage device.

[0012] Preferably, the storage device has a sandwich structure of bottom electrode / active layer / top electrode; and the active layer material is based on a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative.

[0013] Preferably, the structural formula of the trifluoromethyl-substituted pyrene-phenylacetonitrile derivative is as follows: At that time, the electrical storage device exhibits ternary non-volatile resistive switching characteristics; the structural formula of the trifluoromethyl-substituted pyrene-phenylacetonitrile derivative is as follows: At that time, the electrical storage device exhibits binary non-volatile resistive switching characteristics.

[0014] Advantages of this invention: This invention provides a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative, its preparation method, and its application. When a meta-trifluoromethyl group is introduced onto the benzene ring of the pyrene-phenylacetonitrile skeleton, the resulting derivative, used as the active layer material, produces a sandwich structure exhibiting clear ternary non-volatile resistive switching characteristics, possessing three stable resistance states and a high switching current ratio (>10). 3 When a trifluoromethyl group is introduced at an ortho position onto the benzene ring of the pyrene-phenylacetonitrile backbone, the resulting derivative, when used as the active layer material, produces a sandwich structure that exhibits typical binary switching characteristics. By introducing trifluoromethyl groups at different positions onto the benzene ring of the pyrene-phenylacetonitrile backbone, precise control of storage performance can be achieved, providing a novel design approach for developing new multi-level electronic storage materials. The synthesis route is concise, and the device fabrication process is compatible with current semiconductor processes, showing broad application prospects in the field of high-density non-volatile memory. Attached Figure Description

[0015] Figure 1The 1H NMR spectrum of the pyrene-phenylacetonitrile derivative (compound 1) prepared in Example 1;

[0016] Figure 2 The image shows the carbon NMR spectrum of the pyrene-phenylacetonitrile derivative (compound 1) prepared in Example 1.

[0017] Figure 3 The 1H NMR spectrum of the pyrene-phenylacetonitrile derivative (compound 2) prepared in Example 2 is shown below.

[0018] Figure 4 The image shows the carbon NMR spectrum of the pyrene-phenylacetonitrile derivative (compound 2) prepared in Example 2.

[0019] Figure 5 The PXRD patterns are of the pyrene-phenylacetonitrile derivative (compound 1) prepared in Example 1 and the pyrene-phenylacetonitrile derivative (compound 2) prepared in Example 2.

[0020] Figure 6 The images show the FT-IR spectra of the pyrene-phenylacetonitrile derivative (compound 1) prepared in Example 1 and the pyrene-phenylacetonitrile derivative (compound 2) prepared in Example 2.

[0021] Figure 7 The UV-Vis absorption spectra of the pyrene-phenylacetonitrile derivative (compound 1) prepared in Example 1 and the pyrene-phenylacetonitrile derivative (compound 2) prepared in Example 2 are shown.

[0022] Figure 8 The cyclic voltammetry curves are for the pyrene-phenylacetonitrile derivative (compound 1) prepared in Example 1.

[0023] Figure 9 The cyclic voltammetry curves are for the pyrene-phenylacetonitrile derivative (compound 2) prepared in Example 2.

[0024] Figure 10 IV curves of the ITO / Compound 1 / Al sandwich device prepared using the pyrene-phenylacetonitrile derivative (Compound 1) of Example 1;

[0025] Figure 11 The image shows the IV curve of the ITO / Compound 2 / Al sandwich device prepared using the pyrene-phenylacetonitrile derivative (Compound 2) of Example 2. Detailed Implementation

[0026] To enhance understanding of the present invention, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. These embodiments are only used to explain the invention and do not limit the scope of protection of the invention.

[0027] Example 1

[0028] This embodiment provides a pyrene-phenylacetonitrile derivative based on trifluoromethyl substitution, with the following structural formula: .

[0029] This embodiment also provides a method for preparing a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative, specifically: 1-pyrenecarboxaldehyde (2.3 g, 10 mmol), 3-(trifluoromethyl)phenylacetonitrile (2.12 g, 12 mmol), potassium hydroxide (0.67 g, 12 mmol), and ethanol (100 mL) are added to a 250 mL single-necked flask; the mixture is stirred at 60 °C for 12 hours; after the reaction, the mixture is cooled to room temperature, filtered, and the resulting solid is washed three times with ethanol, then dried under vacuum at 60 °C for 12 hours to obtain a yellow solid product, which is the trifluoromethyl-substituted pyrene-phenylacetonitrile derivative (denoted as: Compound 1); the yield is approximately 87%.

[0030] The reaction formula for synthesizing compound 1 is:

[0031] .

[0032] The proton NMR spectrum of compound 1 is as follows: Figure 1 As shown, 1 H NMR (400 MHz, CDCl3) δ 8.69 - 8.60(m, 2H), 8.28-8.15 (m, 6H), 8.13-8.01 (m, 4H), 7.73 (d, J = 7.8 Hz, 1H), 7.68(d, J = 7.8 Hz, 1H).

[0033] The carbon NMR spectrum of compound 1 is as follows: Figure 2 As shown, 13 C NMR (101 MHz, CDCl3) δ 142.08 (s,3H), 135.46 (s, 1H), 133.23 (s, 3H), 131.26 (s, 2H), 130.65 (s, 2H), 129.94(d, J = 16.8 Hz), 129.57 (s), 129.10 (d, J = 2.4 Hz), 127.38 (d, J = 13.3Hz), 126.50 (s), 126.21 (d, J = 13.3 Hz), 125.04 (s), 124.72 (s), 124.49 (s),122.93 (s), 122.39 (s), 117.81 (s), 113.31 (s).

[0034] Example 2

[0035] This embodiment provides a pyrene-phenylacetonitrile derivative based on trifluoromethyl substitution, with the following structural formula: .

[0036] This embodiment also provides a method for preparing a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative, which differs from Example 1 in that: 1-pyrenecarboxaldehyde (2.3 g, 10 mmol), 2-(trifluoromethyl)phenylacetonitrile (2.12 g, 12 mmol), potassium hydroxide (0.67 g, 12 mmol), and ethanol (100 mL) are added to a 250 mL single-necked flask; the mixture is stirred at 60 °C for 12 hours; after the reaction, the mixture is cooled to room temperature, filtered, and the resulting solid is washed three times with ethanol, and then dried under vacuum at 60 °C for 12 hours to obtain a yellow solid product, which is the trifluoromethyl-substituted pyrene-phenylacetonitrile derivative (denoted as: compound 2); the yield is approximately 76%.

[0037] The reaction formula for synthesizing compound 2 is:

[0038] .

[0039] The proton NMR spectrum of compound 2 is as follows: Figure 3 As shown, 1 H NMR (400 MHz, CDCl3) δ 8.68 (dd, J= 8.0, 2.3 Hz, 1H), 8.26-8.00 (m, 9H), 7.86 (d, J = 7.9 Hz, 1H), 7.70 (d, J =3.6 Hz, 2H), 7.61 (s, 1H).

[0040] The carbon NMR spectrum of compound 2 is as follows: Figure 4 As shown, 13C NMR (101 MHz, CDCl3) δ 146.87 (s),134.33 (s), 133.07 (s), 132.38 (s), 131.60 (s), 131.18 (s), 130.58 (s),129.70 (s), 129.59 (d, J = 22.9 Hz), 128.96 (d, J = 6.4 Hz), 127.38 (s), 127.39-126.79 (m), 126.35 (d, J = 6.9 Hz), 126.00 (d, J = 18.7 Hz), 125.31(s), 125.02 (s), 124.50 (d, J = 20.3 Hz), 122.59 (s), 122.44 (d, J = 31.2Hz), 117.86 (s), 111.05 (s).

[0041] like Figures 1 to 4 As shown, through analysis, both Compound 1 and Compound 2 prepared have high chemical purity and can be used in subsequent organic materials for the active layer of electrical storage.

[0042] Powder X-ray diffraction (PXRD) analysis was performed on the trifluoromethyl-substituted pyrene-phenylacetonitrile derivative (compound 1) prepared in Example 1 and the trifluoromethyl-substituted pyrene-phenylacetonitrile derivative (compound 2) prepared in Example 2. The results are as follows: Figure 5 As shown; from Figure 5 It can be observed that both compound 1 and compound 2 have multiple strong Bragg diffraction peaks; the different substitution positions of trifluoromethyl induce a significant difference in the molecular stacking modes of compound 1 and compound 2; the meta-substituted trifluoromethyl has less steric hindrance, which is more conducive to its participation in molecular self-assembly, while the ortho-substituted trifluoromethyl has greater steric hindrance, which makes it difficult for trifluoromethyl to play a role in the molecular stacking process.

[0043] Fourier transform infrared (FT-IR) spectroscopy analysis was performed on the trifluoromethyl-substituted pyrene-phenylacetonitrile derivative (compound 1) prepared in Example 1 and the trifluoromethyl-substituted pyrene-phenylacetonitrile derivative (compound 2) prepared in Example 2. The results are as follows: Figure 6 As shown; from Figure 6 It can be observed that 2213 cm -1 The infrared characteristic absorption peak observed at 1118 cm⁻¹ corresponds to the cyano group in the molecular structures of compounds 1 and 2. -1 and 1170 cm -1The infrared characteristic absorption peak observed corresponds to trifluoromethyl, further indicating that compounds 1 and 2 were successfully prepared.

[0044] The trifluoromethyl-substituted pyrene-phenylacetonitrile derivatives (compound 1) prepared in Example 1 and (compound 2) prepared in Example 2 were analyzed by ultraviolet-visible absorption spectroscopy (UV-Vis). The results are as follows: Figure 7 As shown; from Figure 7 It can be observed that the dichloromethane solution of compound 1 has two ultraviolet absorption peaks at 303 nm and 383 nm. The first absorption peak can be attributed to the π-π* electronic transition in the molecular skeleton, and the second absorption peak is attributed to the intramolecular charge transfer (CT) absorption peak. Compared with compound 1, the ultraviolet absorption peaks of compound 2 have undergone a blue shift, with two absorption peaks at 295 nm and 374 nm, respectively, which are also attributed to the π-π* electronic transition and the intramolecular charge transfer, respectively.

[0045] Cyclic voltammetry was performed on the trifluoromethyl-substituted pyrene-phenylacetonitrile derivative (compound 1) prepared in Example 1 and the trifluoromethyl-substituted pyrene-phenylacetonitrile derivative (compound 2) prepared in Example 2. A standard three-electrode electrochemical cell was used. The glassy carbon electrode, serving as the working electrode, was immersed in a dichloromethane solution containing 0.1 M tetrabutylammonium hexafluorophosphate and compound (1 or 2). A platinum electrode was used as the auxiliary electrode, and an Ag / AgCl electrode was used as the reference electrode. The results are as follows: Figure 8 and Figure 9 As shown. From Figure 8 It can be observed that compound 1 has two oxidation peaks at 1.25 V and 1.76 V, which correspond to the charge transfer between the electron-donating pyrene and the cyano and trifluoromethyl groups, respectively. Figure 9 It can be observed that, compared with compound 1, compound 2 also has two oxidation peaks at 1.23 V and 1.73 V. However, the first oxidation peak of compound 2 is weaker than that of compound 1. This may be due to the closer distance between the trifluoromethyl group and the cyano group at the ortho position.

[0046] Application Example 1

[0047] This application example uses the trifluoromethyl-substituted pyrene-phenylacetonitrile derivative (compound 1) prepared in Example 1 as the active layer material in an ITO / active layer material / Al sandwich structure device; the specific preparation method is as follows:

[0048] 1. Substrate cleaning: The glass substrate with the indium tin oxide (ITO) pattern is placed in deionized water, acetone and ethanol in sequence for ultrasonic cleaning for 15 minutes each, and then dried with nitrogen.

[0049] II. Active Layer Deposition: Compound 1 from Example 1 was used as the evaporation source, and the deposition was carried out using a high-vacuum thermal evaporation system (vacuum degree better than 5 × 10⁻⁶). -4 Pa) deposits an organic thin film with a thickness of approximately 100 nm on an ITO substrate;

[0050] III. Top Electrode Fabrication: A mask plate with an array of circular holes with a diameter of 2 mm is covered on the evaporated organic thin film. An aluminum (Al) electrode with a thickness of about 100 nm is evaporated in the same vacuum chamber to form a sandwich structure device of ITO / compound 1 / Al.

[0051] Application Example 2

[0052] The difference between this application example and application example one is that: in this application example, the trifluoromethyl-substituted pyrene-phenylacetonitrile derivative (compound 1) obtained in example two is used as the active layer material in the ITO / active layer material / Al sandwich structure device; in the specific preparation method, compound 2 obtained in example two is used to replace compound 1 obtained in example one in the preparation method of the application example; and an ITO / compound 2 / Al sandwich structure device is obtained.

[0053] The current-voltage (IV) characteristics of the ITO / compound 1 / Al device in Application Example 1 and the ITO / compound 2 / Al device in Application Example 2 were tested using a semiconductor parameter analyzer (Hachioji B1500A (Agilent Technologies)). The voltage scan sequence for the ITO / compound 1 / Al device was: 0 V → -4 V → 0 V; the voltage scan sequence for the ITO / compound 2 / Al device was: 0 V → -6 V → 0 V. The results are as follows: Figure 10 and Figure 11 As shown.

[0054] from Figure 10 It can be observed that during the negative voltage scan of the ITO / Compound 1 / Al device from 0 to -4 V, when the voltage reaches -1.62 V, the device current spikes for the first time, and the ON / OFF current ratio reaches 10. 3 This indicates that the device transitions from the OFF state to the ON1 state, and this transition process can be seen as the first writing process of device information; when the voltage reaches -2.81 V, the device current increases instantaneously again, and the ON / OFF current ratio reaches 10. 5 This can be seen as the second writing process of device information; the device current increases significantly twice at about -1.62 V and -2.81 V, and the device switches from the initial high-resistivity state (OFF) to the first low-resistivity state (ON1) and the second low-resistivity state (ON2) in sequence, showing clear ternary non-volatile storage characteristics.

[0055] from Figure 11 It can be observed that during the negative voltage scan of the ITO / Compound 2 / Al device from 0 to -6 V, when the voltage reaches -4.26 V, the device current instantaneously rises to the high conduction state, and the ON / OFF current ratio reaches 10. 5 This indicates that the ITO / compound 2 / Al device exhibits binary electrical storage performance.

[0056] This invention can effectively control the resistive switching behavior of electrical storage devices based on this series of derivatives by precisely controlling the substitution position (meta or ortho) of trifluoromethyl on the benzene ring, thereby realizing the transformation from binary to ternary storage performance; it has great potential in high-density, multi-value storage applications.

[0057] The above embodiments should not limit the present invention in any way. All technical solutions obtained by equivalent substitution or equivalent conversion fall within the protection scope of the present invention.

Claims

1. A pyrene-phenylacetonitrile derivative based on trifluoromethyl substitution, characterized in that, Its structural formula is: ,or .

2. The pyrene-phenylacetonitrile derivative based on trifluoromethyl substitution according to claim 1, characterized in that, The pyrene-phenylacetonitrile derivative is synthesized from 1-pyrene formaldehyde and trifluoromethylphenylacetonitrile; wherein, the trifluoromethylphenylacetonitrile is 2-(trifluoromethyl)phenylacetonitrile or 3-(trifluoromethyl)phenylacetonitrile.

3. A method for preparing a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative as described in claim 1 or 2, characterized in that, The process includes the following steps: dissolving 1-pyrene formaldehyde, the corresponding trifluoromethylphenylacetonitrile, and an alkaline catalyst in an organic solvent, carrying out a Knoevenagel condensation reaction under heating conditions, and obtaining the pyrene-phenylacetonitrile derivative by post-treatment of the reaction product after the reaction is completed.

4. The method for preparing a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative according to claim 3, characterized in that, The alkaline catalyst is one of potassium hydroxide, sodium hydroxide, and potassium tert-butoxide; the organic solvent is one or more of ethanol, methanol, and tetrahydrofuran in any proportion.

5. The method for preparing a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative according to claim 3, characterized in that, In the Knoevenagel condensation reaction, the reaction temperature is 50-80℃ and the reaction time is 6-24 hours.

6. An application of a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative in electrical storage devices.

7. The application of a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative according to claim 6, characterized in that, The storage device has a sandwich structure of bottom electrode / active layer / top electrode; the active layer material is based on a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative.

8. The application of a trifluoromethyl-substituted pyrene-phenylacetonitrile derivative according to claim 7, characterized in that, The structural formula of the trifluoromethyl-substituted pyrene-phenylacetonitrile derivative is as follows: At that time, the electrical storage device exhibits ternary non-volatile resistive switching characteristics; the structural formula of the trifluoromethyl-substituted pyrene-phenylacetonitrile derivative is as follows: At that time, the electrical storage device exhibits binary non-volatile resistive switching characteristics.

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