Halogen bond interaction auxiliary molecule self-assembly method, preparation method of eutectic film and application of eutectic film

Abstract

The invention discloses a halogen bond action auxiliary molecule self-assembly method. The method comprises the following steps: selecting an organic multi-system small molecule material containing a pyridine group at the tail end as a halogen bond receptor; selecting a derivative of 1, 4-diiodobenzene as a halogen bond donor; the halogen bond acceptor and the halogen bond donor are dissolved in a solvent, heating, stirring and ultrasonic treatment are performed, after the solution is clarified and transparent, an assembly solution is obtained, and the solvent is slowly evaporated by controlling the environment temperature to obtain the eutecticum. The invention discloses a preparation method of a eutectic film, which is characterized in that a eutectic system is prepared into the eutectic film matched with a device structure by regulating and controlling a decompression sublimation film forming process. According to the halogen bond action auxiliary molecule self-assembly method, the synthesis process of molecules can be greatly reduced, the controllable accumulation among the molecules can be greatly improved, and the halogen bond action auxiliary molecule self-assembly method can be applied to ultrahigh-density information storage.

Description

Technical Field

[0001] The present invention belongs to the fields of functional semiconductor materials and electronic information, and relates to a method for assisting molecular self-assembly by halogen bonding, a method for preparing a co-crystal film, and their applications. Background Art

[0002] The packing state of molecules will largely affect the effective transport of charge carriers in the film and the electrical properties of the device. Small molecule materials have the advantages of single component, clear structure, high synthesis repeatability, good film crystallinity, and the same optical / electrical properties for different batches of small molecules. Therefore, the current main focus is to regulate the structure of small molecules to try to understand the interactions and packing states of molecules in the film. However, the currently designed small molecule materials are becoming more and more complex in structure, and a large number of covalent single bonds in the molecular skeleton will also cause the rotation of each functional fragment to a great extent, which greatly hinders the accurate judgment of the molecular spatial conformation by researchers. At the same time, the unpredictable spatial conformation also hinders the formation of the overall consistency of the molecule to a great extent, thus affecting the intermolecular interaction and resulting in poor overall packing consistency among molecules. In addition, there are also problems with the matching between the packing direction of molecules and the "sandwich" device structure. At the same time, its cumbersome and demanding molecular preparation process also limits the practical application of small molecule materials in the field of multi-valued storage to a great extent.

[0003] In summary, the key reasons for the problems of existing ternary storage devices include the following three points: First, the molecular structure designed through time-consuming and laborious efforts is still difficult to accurately judge the intermolecular interactions and packing states in the film; second, the packing consistency among all molecules in the film and the overall consistency of the film external morphology are poor; third, there is a problem with the matching between the molecular packing direction in the film and the "sandwich" device structure, thus unable to ensure the effective transport of charge carriers in the device. Summary of the Invention

[0004] Object of the Invention: The object of the present invention is to provide a method for assisting molecular self-assembly by halogen bonding to overcome the problems of unclear molecular packing, inconsistent morphology, poor device stability and reproducibility in existing multi-valued storage devices.

[0005] The present invention provides a method for preparing a co-crystal film.

[0006] The present invention provides an application of the above co-crystal film as an ultra-high density information storage.

[0007] Technical Solution: A method for assisting molecular self-assembly by halogen bonding according to the present invention includes the following steps: (1) Select an organic multi-valued small molecule material with a pyridine group at the end as a halogen bond acceptor; Molecular structural formula (I) of the organic multi - valued small - molecule material. When the terminal group R1 is a C atom, R2 is an N atom; when R1 is an N atom, R2 is a C atom. Pyridine not only belongs to Lewis acid, but its derivatives are also a typical weak electron - withdrawing functional group, which can act as a "charge trap" to satisfy the charge transfer process under the action of an electric field, thereby changing the electrical response of the device and achieving the purpose of information storage performance.

[0008]

[0009] (2) Select a derivative of 1,4 - diiodobenzene as the halogen - bond donor; (3) Dissolve the halogen - bond acceptor and the halogen - bond donor in steps (1) and (2) in a solvent, heat, stir, and ultrasonicate. After the solution becomes clear and transparent, an assembly solution is obtained, and the solvent is evaporated to obtain a co - crystal.

[0010] Further, in step (1), the terminal group of the organic multi - valued small - molecule material is one of 4 - pyridyl and 2 - pyridyl.

[0011] Further, the second functional group of the organic multi - valued small - molecule material is one of 1,2,4,5 - tetrazine, thiazole, and naphthalimide, and the molecular structural formulas are as follows (II), (III), (IV).

[0012]

[0013] Further, in step (2), the halogen - bond donor is one of 1,4 - diiodo - 2 - fluorobenzene, 1,3 - difluoro - 2,5 - diiodobenzene, 1,4 - difluoro - 2,5 - diiodobenzene, and 1,4 - diiodotetrafluorobenzene.

[0014] Further, in step (3), the molar ratio of the halogen - bond acceptor to the halogen - bond donor is 1:(1 - 4).

[0015] Further, in step (3), the concentration of the halogen - bond acceptor in the assembly solution is 10 -3 - 10 -2 mol / L.

[0016] Further, in step (3), the solvent is one of anhydrous ethanol, tetrahydrofuran, dichloromethane, and chloroform.

[0017] Further, in step (3), the environmental temperature for evaporating the solvent is 25 - 35 °C.

[0018] A method for preparing a co - crystal thin film, which uses the co - crystal prepared above to prepare a co - crystal thin film, including the following steps: (1) Place the co - crystal in the heating zone; (2)Place the substrate in the cooling zone; (3)After evacuation, slowly heat the heating zone to 130 - 200 °C, and introduce nitrogen. The flow rate of the nitrogen is 30 - 50 mL / min. Continue heating for 10 - 30 minutes under a stable nitrogen flow rate, and then cool to room temperature to obtain a eutectic thin film.

[0019] An application of the above eutectic thin film in ultra-high density information storage.

[0020] Beneficial effects: Compared with the prior art, the present invention has the following remarkable advantages: (1) In the organic multi-valued halogen bond acceptor of the present invention, not only two electron-withdrawing groups are introduced into the molecular backbone, but the pyridine group at the molecular end can also act as a Lewis acid to form an intermolecular C-N…I halogen bond with the halogen bond donor.

[0021] (2)The fluorine atom additionally introduced into the halogen bond donor of the present invention can not only enhance the polarizability of the iodine atom, but its smallest atomic radius and the largest electronegativity can also simultaneously induce an intermolecular C-H…F hydrogen bond. In addition, the strong electron-withdrawing ability of fluorobenzene can also generate an intermolecular charge transfer (CT) with the halogen bond acceptor, which is more conducive to the interaction and close packing mode of molecules.

[0022] (3)The halogen bond-assisted molecular self-assembly method of the present invention can not only greatly reduce the synthesis process of molecules, but also greatly improve the controllable packing between molecules. Moreover, the raw materials are simple and easy to obtain, and the operation is simple, which is conducive to large-scale application.

[0023] (4)Compared with the solution spin-coating film-forming technology, the vacuum co-sublimation film-forming technology of the present invention is less restricted by factors such as the type of solvent and the assembly ratio, and can also achieve a close and controllable face-to-face or one-dimensional π-π stacking mode between the components in the thin film, which is conducive to the effective and rapid transmission of charge carriers in the eutectic thin film. Description of the Drawings

[0024] Figure 1 is the molecular structural formula of the halogen bond acceptor; Figure 2 is the molecular structural formula of the halogen bond donor; Figure 3 is the theoretical simulation diagram of the halogen bond acceptor; Figure 4 (a) is the schematic diagram of the halogen bond in Example 1, Figure 4 (b) is the crystal packing structure of the eutectic obtained in Example 1, Figure 4 (c) is the length of the halogen bond C-N…I in the eutectic obtained in Example 1; Figure 5 (a) is the theoretical calculation diagram of the charge transfer of the eutectic obtained in Example 1,Figure 5 (b) shows the intermolecular interaction pattern diagram contained in the cocrystal obtained in Example 1.

[0025] Figure 6 is the crystal structure of the cocrystal obtained in Example 11; Figure 7 is the crystal structure of the cocrystal obtained in Example 13; Figure 8 is the schematic diagram of the reduced-pressure co-sublimation film-forming device used in Examples 14 - 22; Figure 9 (a) is the atomic force microscope image of the organic cocrystal film prepared in Example 14, Figure 9 (b) is the X-ray diffraction pattern of the organic cocrystal film prepared in Example 14; Figure 10 (a) is the structural diagram of the "sandwich" structure electrical storage device prepared based on the organic cocrystal film, Figure 10 (b) is the electrical property diagram of the separate organic multi-valued halogen bond acceptor, Figure 10 (c) is the electrical property diagram of the cocrystal film, Figure 10 (d) is the device efficiency statistical chart of the separate organic multi-valued halogen bond acceptor and the cocrystal system. Specific Embodiments

[0026] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments cited are not intended to limit the present invention.

[0027] As Figure 1 , 2 shown, the molecular structural formulas of the organic multi-valued halogen bond acceptor and the halogen bond donor used in the assembly process; as Figure 3 shown in the theoretical simulation diagram of the organic multi-valued halogen bond acceptor, it can be seen that there are still two electron-withdrawing groups with different strengths in the molecular skeleton, which satisfy the multiple transfers of charge carriers under the action of an electric field and thus realize multi-valued storage. Example 1

[0028] Self-assembly of the organic multi-valued halogen bond acceptor and the halogen bond donor, the specific steps are as follows: Disperse 2,5-bis(pyridin-4-yl)thiazolothiazole (29.6 mg, 0.1 mmol) and 1,4-diiodotetrafluorobenzene (40.1 mg, 0.1 mmol) in 10 ml of chloroform solvent at a molar ratio of 1:1, and control the concentration of 2,5-bis(pyridin-4-yl)thiazolothiazole to be 10 -2Dissolve it completely by ultrasonic treatment at a concentration of

[0029] As Figure 4 shown, the length of the halogen bond C-N…I in the prepared co-crystal is 2.84 Å. As Figure 5 (a) shows, it can be seen from the theoretical calculation diagram that there is a charge transfer effect between the terminal pyridine of the prepared co-crystal and 1,4-diiodotetrafluorobenzene, which is beneficial to the intermolecular interaction and close packing mode; as Figure 5 (b) shows, in addition to the halogen bond non-covalent interaction between the organic multi-valent halogen bond acceptor and the halogen bond donor, there are also cooperative charge transfer (CT) effects, π-π stacking and C-H…F hydrogen bond effects to form a close and ordered intermolecular packing mode. Example 2

[0030] Self-assembly of the organic multi-valent halogen bond acceptor and the halogen bond donor is carried out as follows: Disperse 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole (29.6 mg, 0.1 mmol) and 1,4-diiodotetrafluorobenzene (80.2 mg, 0.2 mmol) in 10 ml of chloroform solvent at a molar ratio of 1:2, and control the concentration of 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole to be 10 -2 mol / L, and dissolve it completely by ultrasonic treatment to form a clear and transparent solution system. Control the room temperature at 25 °C, and wait for the chloroform solvent to evaporate slowly to form several prismatic yellow crystals. Example 3

[0031] Self-assembly of the organic multi-valent halogen bond acceptor and the halogen bond donor is carried out as follows: Disperse 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole (29.6 mg, 0.1 mmol) and 1,4-diiodotetrafluorobenzene (160.4 mg, 0.4 mmol) in 10 ml of chloroform solvent at a molar ratio of 1:4, and control the concentration of 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole to be 10 -2 mol / L, and dissolve it completely by ultrasonic treatment to form a clear and transparent solution system. Control the room temperature at 25 °C, and wait for the chloroform solvent to evaporate slowly to form several prismatic yellow crystals. Example 4

[0032] Self-assembly of the organic multi-valent halogen bond acceptor and the halogen bond donor is carried out as follows: Disperse 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole (29.6 mg, 0.1 mmol) and 1,4-diiodotetrafluorobenzene (40.1 mg, 0.1 mmol) in 100 ml of chloroform solvent at a molar ratio of 1:1, and control the concentration of 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole to be 10 -3 mol / L. Sonicate to completely dissolve it to form a clear and transparent solution system. Control the room temperature at 25 °C, and wait for the chloroform solvent to slowly evaporate to form several prismatic yellow crystals. Example 5

[0033] Self-assembly of organic multi-valent halogen bond acceptors and halogen bond donors, the specific steps are as follows: Disperse 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole (29.6 mg, 0.1 mmol) and 1,4-diiodotetrafluorobenzene (40.1 mg, 0.1 mmol) in 50 ml of chloroform solvent at a molar ratio of 1:1, and control the concentration of 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole to be 2*10 -3 mol / L. Sonicate to completely dissolve it to form a clear and transparent solution system. Control the room temperature at 25 °C, and wait for the chloroform solvent to slowly evaporate to form several prismatic yellow crystals. Example 6

[0034] Self-assembly of organic multi-valent halogen bond acceptors and halogen bond donors, the specific steps are as follows: Disperse 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole (29.6 mg, 0.1 mmol) and 1,4-diiodotetrafluorobenzene (40.1 mg, 0.1 mmol) in 10 ml of dichloromethane solvent at a molar ratio of 1:1, and control the concentration of 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole to be 10 -2 mol / L. Sonicate to completely dissolve it to form a clear and transparent solution system. Control the room temperature at 25 °C, and wait for the chloroform solvent to slowly evaporate to form several prismatic yellow crystals. Example 7

[0035] Self-assembly of organic multi-valent halogen bond acceptors and halogen bond donors, the specific steps are as follows: Disperse 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole (29.6 mg, 0.1 mmol) and 1,4-diiodotetrafluorobenzene (40.1 mg, 0.1 mmol) in 10 ml of absolute ethanol solvent at a molar ratio of 1:1, and control the concentration of 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole to be 10 -2 mol / L. Sonicate to completely dissolve it to form a clear and transparent solution system. Control the room temperature at 25 °C, and wait for the chloroform solvent to slowly evaporate to form several prismatic yellow crystals. Example 8

[0036] Self-assembly of organic multi-valent halogen bond acceptors and halogen bond donors is carried out as follows: Disperse 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole (29.6 mg, 0.1 mmol) and 1,4-diiodotetrafluorobenzene (40.1 mg, 0.1 mmol) in a molar ratio of 1:1 in 10 ml of tetrahydrofuran solvent, and control the concentration of 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole to be 10 -2 mol / L, and ultrasonically dissolve it to form a clear and transparent solution system. Control the room temperature at 25 °C, and wait for the chloroform solvent to slowly evaporate to form several prismatic yellow crystals. Example 9

[0037] Self-assembly of organic multi-valent halogen bond acceptors and halogen bond donors is carried out as follows: Disperse 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole (29.6 mg, 0.1 mmol) and 1,4-diiodotetrafluorobenzene (40.1 mg, 0.1 mmol) in a molar ratio of 1:1 in 10 ml of chloroform solvent, and control the concentration of 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole to be 10 -2 mol / L, and ultrasonically dissolve it to form a clear and transparent solution system. Control the room temperature at 35 °C, and wait for the chloroform solvent to slowly evaporate to form several prismatic yellow crystals.

[0038] Example 10: Self-assembly of organic multi-valent halogen bond acceptors and halogen bond donors is carried out as follows: Disperse 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole (29.6 mg, 0.1 mmol) and 1,4-diiodotetrafluorobenzene (40.1 mg, 0.1 mmol) in a molar ratio of 1:1 in 10 ml of chloroform solvent, and control the concentration of 2,5-bis(pyridin-4-yl)thiazolo[5,4-d]thiazole to be 10 -2 mol / L, and ultrasonically dissolve it to form a clear and transparent solution system. Control the room temperature at 30 °C, and wait for the chloroform solvent to slowly evaporate to form several prismatic yellow crystals.

[0039] Example 11: Self-assembly of organic multi-valent halogen bond acceptors and halogen bond donors is carried out as follows: Disperse 3,6-bis(pyridin-4-yl)tetrazine (23.6 mg, 0.1 mmol) and 1,4-diiodotetrafluorobenzene (40.1 mg, 0.1 mmol) in a molar ratio of 1:1 in 10 ml of chloroform solvent, and control the concentration of 3,6-bis(pyridin-4-yl)tetrazine to be 10-2 Dissolve it completely by ultrasonic wave at a concentration of 10 mol / L to form a clear and transparent solution system. Control the room temperature at 25 °C, and wait for the chloroform solvent to slowly evaporate to form several prismatic purple-red crystals.

[0040] As Figure 6 shown, from the internal packing structure diagram of the obtained co-crystal, it can be seen that in the co-crystal prepared from 3,6-bis(pyridin-4-yl)tetrazine and 1,4-diiodotetrafluorobenzene, the length of the halogen bond C-N…I is 2.976 Å, and a face-to-face layer-by-layer packing mode is also formed between molecules.

[0041] Example 12: Self-assembly of organic multi-valent halogen bond acceptors and halogen bond donors, the specific steps are as follows: Disperse 2,7-bis(pyridin-4-yl)naphthalimide (42.0 mg, 0.1 mmol) and 1,4-diiodotetrafluorobenzene (40.1 mg, 0.1 mmol) in 10 ml of chloroform solvent in a molar ratio of 1:1, and control the concentration of 2,7-bis(pyridin-4-yl)naphthalimide to be 10 -2 mol / L, and dissolve it completely by ultrasonic wave to form a clear and transparent solution system. Control the room temperature at 25 °C, and wait for the chloroform solvent to slowly evaporate to form several blocky yellow crystals.

[0042] Example 13: Self-assembly of organic multi-valent halogen bond acceptors and halogen bond donors, the specific steps are as follows: Disperse 3,6-bis(pyridin-2-yl)tetrazine (23.6 mg, 0.1 mmol) and 1,4-diiodotetrafluorobenzene (40.1 mg, 0.1 mmol) in 10 ml of chloroform solvent in a molar ratio of 1:1, and control the concentration of 3,6-bis(pyridin-2-yl)tetrazine to be 10 -2 mol / L, and dissolve it completely by ultrasonic wave to form a clear and transparent solution system. Control the room temperature at 25 °C, and wait for the chloroform solvent to slowly evaporate to form several blocky purple-red crystals.

[0043] As Figure 7 shown, from the internal packing structure diagram of the obtained co-crystal, it can be seen that in the co-crystal prepared from 3,6-bis(pyridin-2-yl)tetrazine and 1,4-diiodotetrafluorobenzene, the length of the halogen bond C-N…I is 3.05 Å, and a herringbone-type slip packing mode is also formed between molecules.

[0044] The following examples are carried out by using as Figure 8The eutectic thin film is prepared by a vacuum reduced-pressure co-sublimation film-forming device based on a tube furnace. The prepared eutectic is placed at the heating zone 2 of the tube furnace, and an indium tin oxide (ITO) glass sheet is placed at the cooling zone 3 of the tube furnace. A vacuum pumping device 1 is used to perform a vacuum pumping operation, and the arrow indicates the direction of nitrogen gas introduction.

[0045] Example 14: The co-assembled eutectic system is used to prepare an organic eutectic semiconductor thin film by a reduced-pressure thermal sublimation technique. The specific steps are as follows: Weigh 50 mg of the eutectics in Examples 1 to 13 and place them in the heating zone of the tube furnace. Then, place several washed ITO glass sheets in the cooling zone of the tube furnace. Finally, tighten each valve to ensure its airtightness. After the operation is completed, first use a mechanical pump to perform a vacuum pumping operation on the tube furnace for 30 minutes, then perform a slow heating operation on the tube furnace until the temperature rises and stabilizes at 130 °C. Secondly, open the nitrogen gas device and control its flow rate to be 30 milliliters per minute. When the nitrogen gas flow rate is stable, continuously heat the eutectic for 10 minutes, then turn off the heating source. After it cools down to room temperature, an organic eutectic thin film can be obtained.

[0046] As Figure 9 shown, it can be seen from the AFM image and XRD pattern of the eutectic thin film: Through the AFM image, it can be seen that the eutectic thin film prepared by the reduced-pressure co-sublimation method shows an obvious granular morphology, indicating that the thin film obtained by this method still has a high degree of crystallinity; through the XRD pattern, it can be seen that the stacking mode of the formed eutectic thin film is different from that of a single halogen bond acceptor or halogen bond donor, and the XRD diffraction peaks shown by the eutectic thin film can basically match the simulated XRD pattern of the crystal.

[0047] Example 15: The co-assembled eutectic system is used to prepare an organic eutectic semiconductor thin film by a reduced-pressure thermal sublimation technique. The specific steps are as follows: Weigh 80 mg of the eutectics in Examples 1 to 13 and place them in the heating zone of the tube furnace. Then, place several washed ITO glass sheets in the cooling zone of the tube furnace. Finally, tighten each valve to ensure its airtightness. After the operation is completed, first use a mechanical pump to perform a vacuum pumping operation on the tube furnace for 30 minutes, then perform a slow heating operation on the tube furnace until the temperature rises and stabilizes at 130 °C. Secondly, open the nitrogen gas device and control its flow rate to be 30 milliliters per minute. When the nitrogen gas flow rate is stable, continuously heat the eutectic for 10 minutes, then turn off the heating source. After it cools down to room temperature, an organic eutectic thin film can be obtained.

[0048] Example 16: The co-assembled eutectic system is used to prepare an organic eutectic semiconductor thin film by a reduced-pressure thermal sublimation technique. The specific steps are as follows: Weigh 120 mg of the co-crystals in Examples 1 to 13 and place them in the heating zone of a tube furnace. Then, place several washed ITO glass slides in the cooling zone of the tube furnace. Finally, tighten each valve to ensure its airtightness. After the operation is completed, first use a mechanical pump to evacuate the tube furnace for 30 minutes, and then slowly heat the tube furnace until the temperature rises and stabilizes at 130 °C. Secondly, turn on the nitrogen gas device and control its flow rate to be 30 milliliters per minute. When the nitrogen gas flow rate is stable, continuously heat the co-crystals for 10 minutes, then turn off the heating source. After it cools down to room temperature, an organic co-crystal thin film can be obtained.

[0049] Example 17: Use the vacuum thermal sublimation technique to prepare an organic co-crystal semiconductor thin film from the co-assembled co-crystal system. The specific steps are as follows: Weigh 50 mg of the co-crystals in Examples 1 to 13 and place them in the heating zone of a tube furnace. Then, place several washed ITO glass slides in the cooling zone of the tube furnace. Finally, tighten each valve to ensure its airtightness. After the operation is completed, first use a mechanical pump to evacuate the tube furnace for 30 minutes, and then slowly heat the tube furnace until the temperature rises and stabilizes at 150 °C. Secondly, turn on the nitrogen gas device and control its flow rate to be 30 milliliters per minute. When the nitrogen gas flow rate is stable, continuously heat the co-crystals for 10 minutes, then turn off the heating source. After it cools down to room temperature, an organic co-crystal thin film can be obtained.

[0050] Example 18: Use the vacuum thermal sublimation technique to prepare an organic co-crystal semiconductor thin film from the co-assembled co-crystal system. The specific steps are as follows: Weigh 50 mg of the co-crystals in Examples 1 to 13 and place them in the heating zone of a tube furnace. Then, place several washed ITO glass slides in the cooling zone of the tube furnace. Finally, tighten each valve to ensure its airtightness. After the operation is completed, first use a mechanical pump to evacuate the tube furnace for 30 minutes, and then slowly heat the tube furnace until the temperature rises and stabilizes at 220 °C. Secondly, turn on the nitrogen gas device and control its flow rate to be 30 milliliters per minute. When the nitrogen gas flow rate is stable, continuously heat the co-crystals for 10 minutes, then turn off the heating source. After it cools down to room temperature, an organic co-crystal thin film can be obtained.

[0051] Example 19: Use the vacuum thermal sublimation technique to prepare an organic co-crystal semiconductor thin film from the co-assembled co-crystal system. The specific steps are as follows: Weigh 50 mg of the co-crystals in Examples 1 to 13 and place them in the heating zone of a tube furnace. Then, place several washed ITO glass slides in the cooling zone of the tube furnace. Finally, tighten each valve to ensure its airtightness. After the operation is completed, first use a mechanical pump to evacuate the tube furnace for 30 minutes, then slowly heat the tube furnace until the temperature rises and stabilizes at 130 °C. Secondly, turn on the nitrogen gas device and control its flow rate at 40 milliliters per minute. Under the condition of stable nitrogen gas flow rate, continuously heat the co-crystals for 10 minutes, then turn off the heating source. After it cools down to room temperature, an organic co-crystal thin film can be obtained.

[0052] Example 20: Use the vacuum thermal sublimation technique to prepare an organic co-crystal semiconductor thin film from the co-assembled co-crystal system. The specific steps are as follows: Weigh 50 mg of the co-crystals in Examples 1 to 13 and place them in the heating zone of a tube furnace. Then, place several washed ITO glass slides in the cooling zone of the tube furnace. Finally, tighten each valve to ensure its airtightness. After the operation is completed, first use a mechanical pump to evacuate the tube furnace for 30 minutes, then slowly heat the tube furnace until the temperature rises and stabilizes at 130 °C. Secondly, turn on the nitrogen gas device and control its flow rate at 50 milliliters per minute. Under the condition of stable nitrogen gas flow rate, continuously heat the co-crystals for 10 minutes, then turn off the heating source. After it cools down to room temperature, an organic co-crystal thin film can be obtained.

[0053] Example 21: Use the vacuum thermal sublimation technique to prepare an organic co-crystal semiconductor thin film from the co-assembled co-crystal system. The specific steps are as follows: Weigh 50 mg of the co-crystals in Examples 1 to 13 and place them in the heating zone of a tube furnace. Then, place several washed ITO glass slides in the cooling zone of the tube furnace. Finally, tighten each valve to ensure its airtightness. After the operation is completed, first use a mechanical pump to evacuate the tube furnace for 30 minutes, then slowly heat the tube furnace until the temperature rises and stabilizes at 130 °C. Secondly, turn on the nitrogen gas device and control its flow rate at 30 milliliters per minute. Under the condition of stable nitrogen gas flow rate, continuously heat the co-crystals for 20 minutes, then turn off the heating source. After it cools down to room temperature, an organic co-crystal thin film can be obtained.

[0054] Example 22: Use the vacuum thermal sublimation technique to prepare an organic co-crystal semiconductor thin film from the co-assembled co-crystal system. The specific steps are as follows: Weigh 50 mg of the cocrystals in Examples 1 to 13 and place them in the heating zone of a tube furnace. Then, place several washed ITO glass slides in the cooling zone of the tube furnace. Finally, tighten each valve to ensure its airtightness. After the operation is completed, first use a mechanical pump to evacuate the tube furnace for 30 minutes, and then slowly heat the tube furnace until the temperature rises and stabilizes at 130 °C. Secondly, turn on the nitrogen device and control its flow rate to be 30 milliliters per minute. When the nitrogen flow rate is stable, continuously heat the cocrystal for 30 minutes, then turn off the heating source. After it cools to room temperature, an organic cocrystal thin film can be obtained.

[0055] Test Example: Preparation of organic cocrystal devices and testing of their electrical properties are as follows: As Figure 10 (a) shows, place the prepared organic cocrystal thin film in a vacuum evaporation device, and evaporate a layer of aluminum electrode with a thickness of 100 nanometers on its surface to obtain a storage device with a "sandwich" structure. Then place this device on a semiconductor parameter analyzer, apply a scanning voltage from 0 to -5 V and 0 to 5 V to it, and record its electrical properties.

[0056] As Figure 10 (b), 10(c), 10(d) show: Figure 10 (b) is the electrical property diagram of a single halogen bond acceptor without halogen bond interaction, Figure 10 (c) is the electrical property diagram of the cocrystal thin film assembled through halogen bond interaction. It can be seen from this that, Figure 10 Although the single halogen bond acceptor in (b) can also exhibit a certain number of ternary storage properties, but from Figure 10 (d), it can be seen that its reproducibility is only about 5%; while Figure 10 (c) The cocrystal thin film can not only exhibit typical ternary storage properties, but the reproducibility of its device unit can be as high as over 80%, which has great practical application value.

[0057] Obviously, the above-mentioned embodiments are only examples clearly described and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of this invention.

Claims

1. A method for halogen-assisted molecular self-assembly, characterized in that: The following steps are involved: (1) Selecting organic polyfunctional small molecule materials containing a pyridine group at the end as halogen bond acceptors; (2) Selecting a derivative of 1,4-diiodobenzene as a halogen bond donor; (3) Dissolving the halogen bond acceptor and the halogen bond donor in steps (1) and (2) in a solvent, heating, stirring, and ultrasonicating, and after the solution becomes clear and transparent, obtaining an assembly solution, and evaporating the solvent to obtain a eutectic.

2. The halogen bond-assisted molecular self-assembly method according to claim 1, characterized in that: In step (1), the terminal group of the organic polyvalent small molecule material is one of 4-pyridyl and 2-pyridyl.

3. The halogen bond-assisted molecular self-assembly method according to claim 1, characterized in that: The second functional group of the organic multi-functional small molecule material is one of 1,2,4,5-tetrazine, thiazole and naphthaleneimide.

4. The halogen bond-assisted molecular self-assembly method according to claim 1, characterized in that: In step (2), the halogen bond donor is one of 1,4-diiodo-2-fluorobenzene, 1,3-difluoro-2,5-diiodobenzene, 1,4-difluoro-2,5-diiodobenzene, and 1,4-diiodotetrafluorobenzene.

5. The halogen bond-assisted molecular self-assembly method according to claim 1, characterized in that: In step (3), the molar ratio of the halogen bond acceptor to the halogen bond donor is 1:(1-4).

6. The halogen bond-assisted molecular self-assembly method according to claim 1, characterized in that: In step (3), the concentration of the halogen bond acceptor in the assembly solution is 10 -3 -10 -2 mol / L.

7. The halogen bond-assisted molecular self-assembly method according to claim 1, characterized in that: In step (3), the solvent is one of anhydrous ethanol, tetrahydrofuran, dichloromethane and chloroform.

8. The halogen bond-assisted molecular self-assembly method according to claim 1, characterized in that: In step (3), the ambient temperature for volatilizing the solvent is 25-35°C.

9. A method for preparing a eutectic thin film, characterized in that: The method of preparing a eutectic film using the eutectic prepared by the halogen bond-assisted molecular self-assembly method according to any one of claims 1 to 8 comprises the following steps: (1) placing the eutectic in a heating zone; (2) Place the substrate in a cooling zone; (3) After evacuation, the heating zone is slowly heated to 130-200° C. and nitrogen is introduced at a flow rate of 30-50 ml / min. Heating is continued for 10-30 minutes at a stable nitrogen flow rate. After cooling to room temperature, a eutectic film is obtained.

10. Use of the eutectic film as claimed in claim 9 as ultra-high density information storage.

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