CN114292201A

CN114292201A - Compound with quantum interference effect and monomolecular field effect transistor comprising same

Info

Publication number: CN114292201A
Application number: CN202111615533.7A
Authority: CN
Inventors: 郭雪峰; 李佩慧; 贾传成; 汪博宇; 常新月
Original assignee: Beijing Weimingyuanshang Molecular Technology Co ltd; Nankai University
Current assignee: Beijing Weimingyuanshang Molecular Technology Co ltd; Nankai University
Priority date: 2021-12-27
Filing date: 2021-12-27
Publication date: 2022-04-08
Anticipated expiration: 2041-12-27

Abstract

The application provides a compound with quantum interference effect and a monomolecular field effect transistor comprising the compound, and due to the quantum interference effect, the switch of the monomolecular field effect transistor is improved by orders of magnitude compared with the field effect transistor constructed by common molecules. In the monomolecular field effect transistor, the compound with the quantum interference effect can be stably connected with the gap of the two-dimensional single-layer graphene with the nano-gap array through an amide covalent bond to form a molecular heterojunction, the novel two-dimensional material with the atomic-level flatness and controllable atomic layer thickness is adopted, van der Waals stacking assembly is carried out through different two-dimensional materials, a van der Waals heterostructure is formed, accurate control preparation of a monomolecular field effect transistor device can be achieved, the monomolecular field effect transistor has strong grid electric field regulation and control capacity, and the monomolecular field effect transistor has good stability and integration.

Description

Compound with quantum interference effect and monomolecular field effect transistor comprising same

Technical Field

The application relates to the technical field of field effect transistors, in particular to a compound with quantum interference effect and a monomolecular field effect transistor comprising the compound.

Background

The rapid growth of nanotechnology research has brought great insights into the development of computing devices, solar collection, chemical sensing, photonics and optoelectronics, biomedical electronics (e.g., cell-chip connections, electronic cells, electronic therapy and prosthetics), and biofuel cells. The development of electronic devices based on controlled molecular conduction meets the urgent need for further device miniaturization on the one hand and the need for organic and inorganic materials for biomedical and nanoelectronic applications on the other hand. The organic molecular field effect transistor has a molecular level size, and the energy level position of molecules can be regulated by applying gate voltage in a molecular heterojunction, so that the relative position of the molecular energy level and the Fermi level of an electrode is changed, and the conduction characteristic of the molecules is regulated.

At present, the most mature system in the control strategy of the unimolecular field effect transistor device is based on the electrostatic field generated by the traditional solid-state gate, but the control efficiency of the control method is low, the stability and the integration of the unimolecular field effect transistor device are poor, the device is sensitive to the thickness of a dielectric layer, particularly, the current dielectric layer is mostly made of silicon dioxide, hafnium dioxide and other materials, the preparation of the solid-state dielectric layer with the thickness matched with the molecular size is extremely difficult in process implementation, and the application of the solid-state dielectric layer in the prior manufacturing process is limited due to the low dielectric constant of the silicon dioxide. Therefore, it is necessary to develop a single-molecule field effect transistor with strong gate field control capability, good stability and good integration.

Disclosure of Invention

The application aims to provide a compound with a quantum interference effect and a monomolecular field effect transistor comprising the compound, so as to obtain the monomolecular field effect transistor with stronger gate electric field regulation and control capability, better stability and integration.

The specific technical scheme is as follows:

in a first aspect, the present application provides a compound having a quantum interference effect, the structural formula of which is shown in formula a:

H₂N-R₂-R₁-R₂-NH₂

formula A;

wherein R is₁Any one selected from formula I-formula VI;

R₂is selected from- (CH) — (CH)₂)_m-or

m is an integer of 1 to 6;

r, Rx, Ry are each independently selected from CH₃(CH₂)_nAnd n is an integer of 0 to 5.

A second aspect of the present application provides a single molecule field effect transistor comprising any one of the compounds having quantum interference effects provided by the first aspect of the present application.

A third aspect of the present application provides a method for manufacturing a single-molecule field effect transistor, which includes the steps of:

1) preparing a graphene gate electrode layer on a substrate;

2) preparing Bi on the upper surface of a graphene gate electrode layer₂SeO₅A dielectric layer;

3) in Bi₂SeO₅Preparing a graphene electrode layer on the upper surface of the dielectric layer;

4) constructing a nano gap on a graphene electrode layer to obtain a graphene point electrode, wherein the graphene point electrode comprises a graphene source end electrode and a graphene drain end electrode;

5) connecting the graphene point electrode with a molecular heterojunction through an amide bond; the molecular heterojunction is composed of any one of the compounds having quantum interference effect provided in the first aspect of the present application;

6) and covering an h-BN protective layer on the upper surfaces of the graphene point electrode and the molecular heterojunction to obtain the monomolecular field effect transistor.

The application provides a compound with quantum interference effect and a monomolecular field effect transistor comprising the compound, and the monomolecular field effect transistor has the advantage that due to the quantum interference effect, the switch of the monomolecular field effect transistor is improved by orders of magnitude compared with the field effect transistor constructed by common molecules. In the monomolecular field effect transistor, the compound with the quantum interference effect can be stably connected with the gap of the two-dimensional single-layer graphene with the nano-gap array through an amide covalent bond to form a molecular heterojunction, the novel two-dimensional material with the atomic-level flatness and controllable atomic layer thickness is adopted, van der Waals stacking assembly is carried out through different two-dimensional materials, a van der Waals heterostructure is formed, accurate control preparation of a monomolecular field effect transistor device can be achieved, the monomolecular field effect transistor has strong grid electric field regulation and control capacity, and the monomolecular field effect transistor has good stability and integration.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and it is also obvious for a person skilled in the art to obtain other embodiments according to the drawings.

Fig. 1 is a perspective view of a monomolecular field effect transistor of example 1; the reference signs are: 1. graphene gate electrode layer, 2.Bi₂SeO₅The graphene-based photovoltaic module comprises a dielectric layer, 3 graphene source-end electrodes, 4 graphene drain-end electrodes, 5 molecular heterojunction formed by a compound A1 and 6.h-BN protective layer.

Fig. 2 is a graph showing a current-bias characteristic of the single molecule field effect transistor of example 1 at a gate voltage of 0V.

Fig. 3 is a characteristic graph of a current according to a gate voltage at a bias voltage of 0.1V in the single molecule field effect transistor of example 1.

Fig. 4 is a graph showing a current-bias characteristic of the single molecule field effect transistor of example 2 at a gate voltage of 0V.

FIG. 5 is a graph showing the characteristics of the current with respect to the gate voltage in the case of the single molecule field effect transistor of example 2 at a bias voltage of 0.1V.

Fig. 6 is a graph showing current-bias characteristics of the single molecule field effect transistor of example 3 at a gate voltage of 0V.

FIG. 7 is a graph showing the characteristics of the current with respect to the gate voltage in the case of the single molecule field effect transistor of example 3 at a bias voltage of 0.1V.

Fig. 8 is a graph showing current-bias characteristics of the single molecule field effect transistor of example 4 at a gate voltage of 0V.

FIG. 9 is a graph showing the characteristics of the current with respect to the gate voltage in the case of the single molecule field effect transistor of example 4 at a bias voltage of 0.1V.

Fig. 10 is a graph showing current-bias characteristics of the single molecule field effect transistor of example 5 at a gate voltage of 0V.

FIG. 11 is a graph showing the characteristics of the current with respect to the gate voltage in the case of the single molecule field effect transistor of example 5 at a bias voltage of 0.1V.

Fig. 12 is a graph showing current-bias characteristics of the single molecule field effect transistor of example 6 at a gate voltage of 0V.

FIG. 13 is a characteristic graph of a current according to a gate voltage in the case of the single molecule field effect transistor of example 6 at a bias voltage of 0.1V.

Fig. 14 is a graph showing current-bias characteristics of the single molecule field effect transistor of example 7 at a gate voltage of 0V.

FIG. 15 is a characteristic curve of a current according to a gate voltage in the case of the single molecule field effect transistor of example 7 at a bias voltage of 0.1V.

Fig. 16 is a graph showing current-bias characteristics of the single molecule field effect transistor of example 8 at a gate voltage of 0V.

FIG. 17 is a characteristic graph of a current according to a gate voltage in the case of the single molecule field effect transistor of example 8 at a bias voltage of 0.1V.

Fig. 18 is a graph showing current-bias characteristics of the single molecule field effect transistor of example 9 at a gate voltage of 0V.

FIG. 19 is a graph showing the characteristics of the current with respect to the gate voltage in the case of the single molecule field effect transistor of example 9 at a bias voltage of 0.1V.

Fig. 20 is a graph showing current-bias characteristics of the single molecule field effect transistor of example 10 at a gate voltage of 0V.

FIG. 21 is a graph showing the characteristics of the current with respect to the gate voltage in the case of the single molecule field effect transistor of example 10 at a bias voltage of 0.1V.

Fig. 22 is a graph showing current-bias characteristics of the single molecule field effect transistor of example 11 at a gate voltage of 0V.

FIG. 23 is a characteristic curve of a current according to a gate voltage in the case of the single molecule field effect transistor of example 11 at a bias voltage of 0.1V.

Fig. 24 is a graph showing current-bias characteristics of the single molecule field effect transistor of example 12 at a gate voltage of 0V.

FIG. 25 is a characteristic curve of a current with a gate voltage in the case of the single molecule field effect transistor of example 12 at a bias voltage of 0.1V.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments that can be derived by one of ordinary skill in the art from the description herein are intended to be within the scope of the present disclosure.

H₂N-R₂-R₁-R₂-NH₂

formula A;

wherein R is₁Any one selected from formula I-formula VI;

R₂is selected from- (CH) — (CH)₂)_m-or

m is an integer of 1 to 6;

In some embodiments of the first aspect of the present application, the compound having quantum interference effects is selected from any one of formula a 1-formula a 12:

The application comprises the monomolecular field effect transistor with the quantum interference effect compound, due to quantum interference effect, in the monomolecular field effect transistor device, when transmission electrons pass through a specific molecular track of a molecular functional unit in the device, quantum interference destructive effect can occur, so that the electron transport capacity is reduced by orders of magnitude compared with that of common molecules in an off state, and the on-off ratio of the monomolecular field effect transistor is improved by orders of magnitude compared with that of a field effect transistor constructed by common molecules. In the monomolecular field effect transistor containing the compound with the quantum interference effect, the compound with the quantum interference effect can be stably connected with a gap of two-dimensional single-layer graphene with a nano gap array through an amide covalent bond to form a molecular heterojunction, and two-dimensional materials with atomic level flatness and controllable atomic layer thickness are adopted, and van der waals heterostructure is formed through van der waals stacking assembly of different two-dimensional materials, so that the monomolecular field effect transistor has stronger grid electric field regulation and control capability, better stability and integration.

In some embodiments of the second aspect of the present application, the single-molecule field effect transistor further comprises a graphene gate electrode layer, Bi₂SeO₅The graphene source-end electrode, the graphene drain-end electrode, the molecular heterojunction and the h-BN protective layer are arranged on the dielectric layer; the molecular heterojunction is composed of the compound having the quantum interference effect.

The application adopts two-dimensional material bismuth oxyselenite (Bi)₂SeO₅) As a dielectric layer, the dielectric layer has a high dielectric constant (k ═ 21) and good insulating performance, and can provide stronger gate electric field regulation and control capability; the hexagonal boron nitride (h-BN) is used as a protective layer for packaging, so that the interference of the external environment can be greatly reduced, and the stability of the monomolecular field effect transistor is further improved.

The two-dimensional material adopted by the application has a layered crystal structure with strong in-plane covalent bonds, and has no dangling bonds on the surface, so that the two-dimensional material can also show excellent electronic and optical properties even under the limit of the thickness of a single atom; meanwhile, the two-dimensional material layers are coupled together through weak van der Waals force (vdW) to form a van der Waals heterostructure, so that close contact between the layers can be kept, and the stability of the monomolecular field effect transistor is improved; the planar machinability of the two-dimensional material is beneficial to improving the integration of the monomolecular field effect transistor.

The application provides a monomolecular field effect transistor who contains compound that has quantum interference effect that formula A shows, compound that has quantum interference effect can form the molecular heterojunction through amide covalent bond stable connection in the clearance that has the two-dimensional monolayer graphite alkene of nanometer clearance array to adopt novel two-dimensional material to replace grid and dielectric layer material among the traditional field effect transistor, van der Waals heterostructure is formed through the assembling of piling up of van der Waals of different two-dimensional materials, monomolecular field effect transistor's dielectric layer and grid reach atomic level and just atomic layer thickness is controllable, realize the accurate control preparation of monomolecular field effect transistor device, make monomolecular field effect transistor have stronger grid electric field regulatory ability, better stability and integration.

The thickness of each two-dimensional material layer is required to be matched with the molecular size of the compound with quantum interference effect, and the specific thickness of each two-dimensional material layer is not particularly limited as long as the purpose of the present application can be achieved, and in some embodiments of the second aspect of the present application, the thickness of the graphene gate electrode layer may be 0.7-20 nm; the Bi₂SeO₅The thickness of the dielectric layer can be 1-20 nm; the thickness of the h-BN protective layer can be 0.7-20 nm; the thickness of the graphene source electrode can be 0.7-3 nm; the thickness of the graphene drain terminal electrode can be 0.7-3 nm; the thickness of the molecular heterojunction can be 0.7-3 nm; the thickness of the graphene source end electrode and the graphene drain end electrode and the thickness of the molecular heterojunction can be the same or different. Wherein, said Bi₂SeO₅The thickness of the dielectric layer is 1-20nm, and the corresponding applicable grid voltage is 0.1-10V.

In some embodiments of the second aspect of the present application, the single molecule field effect transistor further comprises a substrate; the substrate is not particularly limited in kind as long as the object of the present application can be achieved, and for example, the substrate may be an atomically flat silicon wafer, mica, or sapphire.

In some embodiments of the second aspect of the present application, the graphene gate electrode layer is a strip with a width of 5-100nm and is located vertically below the molecular heterojunction.

This application graphene gate electrode layer can realize accurate graphics, promptly the graphene gate electrode layer can prepare with the controllable strip of molecular dimension assorted width that has quantum interference effect compound, the graphene gate electrode layer is the strip form, and the width is 5-100nm, is located under the perpendicular of molecule heterojunction, and is located Bi₂SeO₅And the dielectric layer and the substrate are arranged between the substrate, so that the precise regulation and control of the grid electrode on molecules are realized, the contact area of the grid electrode and the graphene source/drain terminal electrode is reduced, and the generation of leakage current is reduced.

In this application, the term "atomically flat" means that the roughness of the surface of the material is at the atomic level.

1) preparing a graphene gate electrode layer on a substrate;

The unimolecular field effect transistor described herein is a two-dimensional stacked assembly. Contact between two-dimensional materials by van der Waals forces, e.g. Bi₂SeO₅Van der Waals contact is formed between the dielectric layer and the graphene gate electrode layer, and the Bi₂SeO₅And van der waals contact is also formed between the dielectric layer and the graphene source/drain terminal electrode. The h-BN protective layer covers the graphene source/drain terminal electrode and the top of the molecular heterojunction, so that on one hand, the molecular stability is improved through Van der Waals contact, on the other hand, the interference of the external environment is isolated, the air effect is isolated, and the monomolecular field effect transistor device is protected.

By adopting the preparation method, the monomolecular field effect transistor device with good reproducibility can be prepared; based on the monomolecular field effect transistor, a molecular switch device with a high on-off ratio can be prepared.

In some embodiments of the third aspect of the present application, the substrate may be an atomically flat silicon wafer, mica or sapphire.

In the step 4), the obtaining manner of the graphene dot electrode is not particularly limited, as long as the purpose of the present application can be achieved, for example, a graphene electrode layer is subjected to electron beam Exposure (EBL) and Reactive Ion Etching (RIE) to form a gap of 1-4nm, so as to obtain the graphene dot electrode, where the graphene dot electrode includes a graphene source terminal electrode and a graphene drain terminal electrode.

In the step 5), the compound with the quantum interference effect is contacted with the semi-finished device obtained in the step 4) for self-assembly, and the compound with the quantum interference effect and the graphene dot electrode (graphene source-end electrode and graphene drain-end electrode) are connected through an amide bond (see, specifically, angelw.chem.int.ed.2013, 52,8666).

In some embodiments of the third aspect of the present application, the step 5) self-assembly comprises: dissolving the compound with the quantum interference effect and a dehydration activating agent in a solvent to obtain a mixed solution; and then immersing the semi-finished device obtained in the step 4) into the mixed solution, reacting for 24-48h in inert gas under the dark condition, taking out, washing and drying.

In some embodiments of the third aspect of the present application, the dehydration activator is selected from at least one of 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, dicyclohexylcarbodiimide, or N, N' -diisopropylcarbodiimide; the solvent is selected from at least one of pyridine, dimethyl sulfoxide or trichlorobenzene; the inert gas is argon or nitrogen;

the molar ratio of the compound with the quantum interference effect to the dehydration activator is 1 (20-40);

the concentration of the dehydration activator is 2 x 10^-3-4×10^-3mol/L。

In some embodiments of the third aspect of the present application, the graphene gate electrode layer and Bi₂SeO₅The dielectric layer and the graphene electrode layer are obtained through dry transfer or wet transfer.

The present application is not particularly limited in specific manner of dry transfer or wet transfer, as long as the object of the present application can be achieved, and examples of the gate electrode layer of graphene and the Bi described in the present application₂SeO₅The dielectric layer and the graphene electrode layer can be prepared by mechanical stripping-dry transfer or Chemical Vapor Deposition (CVD) synthesis-wet transfer and other methods.

The dry transfer method can be used for obtaining the two-dimensional material by adopting a mechanical stripping mode. Illustratively, firstly tearing off a small piece from the two-dimensional material crystal a by using an adhesive tape, and then continuously tearing the small piece by using a new adhesive tape to obtain a single-layer or few-layer two-dimensional material a; adhering the adhesive tape adhered with the two-dimensional material a on the substrate, and then tearing the adhesive tape to obtain a thin layer of the two-dimensional material a on the substrate; obtaining a single-layer or few-layer two-dimensional material b by using an adhesive tape by using the same mechanical stripping method, then contacting the two-dimensional material b on the adhesive tape with Polydimethylsiloxane (PDMS) on the top of the glass slide, and when the two-dimensional material b is separated again, leaving a thin layer of the two-dimensional material b on the PDMS; and then finding an ultrathin two-dimensional material b on the PDMS under a microscope, distinguishing the spatial positions of the two-dimensional materials through the microscope, adjusting a and b to be completely consistent on the spatial positions through a three-dimensional translation stage so as to overlap and contact, slightly applying force to a glass slide where the b is positioned, adhering the a and the b together, slowly separating the PDMS from the a-b heterojunction, separating the PDMS from the b, and only leaving the a-b heterojunction on the substrate, thereby realizing the further assembly of the two-dimensional material layer.

The application describes wet transfer with graphene gate electrode layer and Bi₂SeO₅The dielectric layer is taken as an example: (1) firstly, growing a large-area graphene film on a copper foil by using a Chemical Vapor Deposition (CVD) method; (2) the method comprises the steps of spin-coating polymethyl methacrylate (PMMA) glue on graphene to form a PMMA-graphene-copper foil sandwich structure, placing the structure into an ammonium persulfate solution with the concentration of 3% for etching, and transferring the structure into clean deionized water after the copper foil is dissolved so as to remove ammonium persulfate remaining in the graphene; (3) then transferring the graphene-PMMA structure onto a silicon substrate, and removing PMMA glue by soaking in an acetone solution to obtain a graphene gate electrode layer; (4) growing layered two-dimensional semiconductor bismuth selenide (Bi) on mica by CVD method₂O₂Se); (5) to two-dimensional semiconductor Bi layered on mica₂O₂Se is subjected to thermal oxidation operation at high temperature (see Nat Electron 2020,3,473-478) so that more oxygen atoms are embedded into the two-dimensional structure, Bi₂O₂Se layer by layer controllable conversion to Bi₂SeO₅(ii) a (6) Then adopting Polystyrene (PS) to assist the non-corrosive transfer method to transfer Bi₂SeO₅Transferring to the graphene gate electrode layer obtained in the step (3), and specifically: in Bi₂SeO₅Spin-coating PS on the substrate to form PS-Bi₂SeO₅-mica sandwich structure, then baked at 80 ℃ for 15 min; then, the PS film and Bi are mixed with the help of deionized water (DI)₂SeO₅Peeling from mica together, and then separating PS-Bi₂SeO₅Placing the graphene gate electrode layer obtained in the step (3), baking the graphene gate electrode layer at 70 ℃ for 1 hour, finally washing away PS with toluene to leave Bi on the graphene gate electrode layer₂SeO₅To obtain Bi₂SeO₅A dielectric layer; (6) then 200-500 ℃ annealing treatment is carried out to lead the two-dimensional materials to be mutually separatedThe stack is more compact.

In some embodiments of the third aspect of the present application, the graphene gate electrode layer has a thickness of 0.7-20 nm; the Bi₂SeO₅The thickness of the dielectric layer is 1-20 nm; the thickness of the h-BN protective layer is 0.7-20 nm; the thickness of the graphene source electrode is 0.7-3 nm; the thickness of the graphene drain terminal electrode is 0.7-3 nm; the thickness of the molecular heterojunction is 0.7-3 nm.

In some embodiments of the third aspect of the present application, the graphene gate electrode layer has a stripe shape with a width of 5-100nm and is located vertically below the molecular heterojunction.

The quantum interference effect refers to quantum interference cancellation effect, and due to the difference of specific sites of molecules externally connected with groups, the electron transmission of different orbits of the molecules generates interference cancellation under specific conditions, so that lower conductance is generated.

The "on-off ratio" in the present application is calculated from a ratio of a maximum value of a current to a minimum value of the current in a result of a characteristic curve of the current with respect to a gate voltage when the bias voltage of the monomolecular field effect transistor is 0.1V.

It should be noted that the documents cited herein are incorporated by reference in their entirety and will not be described in detail herein.

The present application will be specifically described below with reference to examples, but the present application is not limited to these examples. The experimental materials and methods used in the following examples are, unless otherwise specified, conventional materials and methods.

The present application records compounds on a Varian Mercury plus 300MHz and Bruker ARX 500NMR spectrometer¹H and¹³a CNMR spectrum;¹all chemical shifts for H are referenced to tetramethylsilane (TMS, δ ═ 0.00ppm) or deuterated Chloroform (Chloroform-d, CDCl)₃，δ＝7.26ppm)，¹³C NMR chemical Shift reference CDCl₃(δ 77.00 ppm). Mass spectra were recorded on a Bruker APEX IV mass spectrometer.

The electrical test involved in the present application is under vacuum condition (<1×10^-4Pa) inAnd (4) row by row. Testing an instrument: agilent 4155C semiconductor tester, ST-500-Probe station (Janis Research Company), comprehensive physical Property testing System (PPMS). The test temperature is accurately regulated and controlled by combining liquid nitrogen, liquid helium and a heating platform.

Electrical testing: at any temperature in the temperature interval of 2K-300K, the voltage applied to the fixed graphene gate electrode strip array is 0V, and the source-drain voltage is applied within the range: measuring a current-bias voltage characteristic curve of the monomolecular field effect transistor along with the change of the bias voltage at an interval of 5mV between 1V and 1V; the fixed bias voltage is 0.1V, and the voltage applied to the graphene gate electrode strip array is changed in the range: and (4) measuring a current-gate voltage characteristic curve of the monomolecular field effect transistor regulated by the gate voltage at an interval of 10mV between 2V and 2V.

All reactions herein were carried out using standard schicker techniques (Schlenk techniques) in an inert atmosphere of dry solvent and argon or nitrogen.

Example 1 preparation of a monomolecular field effect transistor based on Compound A1

(1) Synthesis of compound a 1:

weighing 1g of m-bromobenzoic acid (compound 1-1, 5.11mmol), slowly dropping in 20ml of 20% sulfuric acid aqueous solution under nitrogen atmosphere, and stirring and refluxing in 100-200 ℃ oil bath for 24 hours; extracting with dichloromethane to obtain an organic phase, and washing the organic phase with saturated sodium bicarbonate solution for three times; the organic phase was distilled under reduced pressure, and the resulting mixture was stirred with silica gel and then subjected to column chromatography to obtain 0.85g of compound 1-2 (yield 93%).¹H NMR(500MHz,Chloroform-d)δ8.02(s,1H),7.91(s,1H),7.65(s,1H)。¹³C NMR(125MHz,CDCl₃) δ 179.52(s),137.65(s),135.18(s),134.03(s),127.16(s),126.78(s), 125.70(s). High resolution mass spectrometry (electrospray time-of-flight mass spectrometry) in positive ion mode (proton number/charge number) (HRMS (TOF-ESI)⁺) (m/z)) of the formula C₁₄H₆Br₂O₂，m/z＝365.87。

Weighing 1g of compound 1-2(2.73mmol), slowly dropwise adding into 20ml of Tetrahydrofuran (THF) containing 0.15g of activated magnesium chips (Mg, 6.52mmol) under nitrogen atmosphere, adding 0.1g of iodine as an initiator, initiating reaction by locally heating the reaction system with an electric hair drier, and stirring and refluxing at room temperature for 2 hours to obtain compound 1-3; after the reaction is finished, cooling and stirring the system containing the compounds 1-3 in ice-water bath, slowly dropwise adding a mixed solution of 2.9ml of 3-amino-1-acetone (6.52mmol) and 10ml of anhydrous ether from a dropping funnel, and keeping the micro-boiling reaction for 1 hour; then, the mixture was cooled in ice water, 50ml of 20% sulfuric acid was added thereto from a dropping funnel in portions to separate layers, and the separated aqueous layer was extracted with ether, washed with saturated sodium carbonate, and finally dried with anhydrous potassium carbonate, and subjected to column chromatography to obtain 0.87g of compounds 1 to 4 (yield 91%).¹H NMR(500MHz,Chloroform-d)δ7.79(d,J＝5.0Hz,4H),7.39(s,2H),4.41(s,1H),2.70(s,2H),2.15(s,4H),1.60(s,2H),1.15(s,4H)。¹³C NMR(125MHz,CDCl₃)δ181.39(s),149.71(s),133.94(s),133.10(s),131.37(s),125.99(s),124.35(s),73.69(s),40.52(s),39.12(s)。HRMS(TOF-ESI⁺) (m/z) formula C₂₀H₂₂N₂O₄，m/z＝354.16。

1g of the compound 1-4(2.81mmol), 7ml of trifluoroacetic acid (TFA) and 5ml of MeNO were weighed out₂(Co-solubilisation) in 20ml of tetrahydrofuran, 1ml of triethylsilane (Et) are added₃SiH, 6.31mmol), added over 5 minutes; stirring and reacting for 48 hours at room temperature to generate precipitate, and filtering; the precipitate was dissolved by addition of 20ml of acetone, followed by addition of 30ml of water; filtering, and adjusting pH of the filtrate to 8 with ammonia water at 15 deg.C to obtain precipitate; the precipitate was collected by filtration, washed with water, dried, and recrystallized from anhydrous ether to obtain 0.75g of Compound A1 (yield 82%).¹H NMR(500MHz,Chloroform-d)δ7.76(s,1H),7.70(s,1H),7.11(s,1H),2.69(s,2H),2.64(s,1H),1.59(s,2H),1.51(s,1H),1.12(s,2H)。¹³C NMR(125MHz,CDCl₃)δ182.36(s),150.03(s),133.81(s),132.32(s),131.29(s),126.69(d,J＝10.3Hz),41.32(s),36.45(s),31.33(s),28.01(s)。HRMS(TOF-ESI⁺) (m/z) formula C₂₀H₂₂N₂O₂，m/z＝322.17。

(2) Preparation of a monomolecular field effect transistor comprising compound a 1:

firstly, obtaining 5nm graphene by a mechanical stripping mode, namely repeatedly tearing the graphene by using an adhesive tape; then, transferring graphene onto a silicon substrate by using Polydimethylsiloxane (PDMS) as a transfer medium to serve as a bottom gate electrode; specifically, the method comprises the following steps: contacting the graphene on the adhesive tape with PDMS on the top of the glass slide, and leaving a graphene thin layer on the PDMS during separation; adjusting the alignment of the graphene and the silicon substrate through a three-dimensional translation table in a microscope system, slightly applying force to a glass slide at the moment to enable the graphene to be adhered to the silicon substrate, then slowly separating PDMS (polydimethylsiloxane), and successfully transferring the graphene to the silicon substrate to obtain a graphene gate electrode layer with the thickness of 5 nm;

then, taking Polycarbonate (PC) glue as a transfer medium, and adopting a dry transfer method to transfer Bi₂SeO₅Transferring the thin layer onto a graphene gate electrode layer; specifically, the method comprises the following steps: the appropriate Bi is first prepared on the PC surface on top of the glass slide 1 by mechanical lift-off₂SeO₅(ii) a Taking a glass slide 2 with PDMS on the top, and taking off the PC-Bi from the glass slide 1 by using a transparent adhesive tape₂SeO₅On PDMS, Bi₂SeO₅In the upward direction, PDMS-PC-Bi is formed₂SeO₅The structure of (1); bi is controlled by an optical microscope₂SeO₅Almost contacting with graphene on a silicon substrate, heating to 60-90 ℃, wherein the PC glue can be heated and stretched, the contact area between the PC and the silicon can be enlarged, and in the process of gradually moving, Bi is added₂SeO₅Completely contacting with graphene, stopping heating, cooling the PC glue gradually, shrinking and separating from silicon at the moment, and Bi₂SeO₅Then binding to graphene; finally, slowly separating the PC glue and the Bi₂SeO₅Then Bi can be obtained₂SeO₅Graphene Van der Waals heterostructure yielding Bi of thickness 10nm₂SeO₅A dielectric layer;

then growing the crystal on Bi by using a plasma enhanced chemical vapor deposition (PE-CVD) method₂SeO₅And growing a layer of graphene on the surface of the dielectric layer to obtain a thickness of 0.A 7nm graphene electrode layer;

forming a 2nm gap in the graphene electrode layer through electron beam exposure and reactive ion etching to obtain a graphene nano gap point electrode, wherein the graphene nano gap point electrode comprises a graphene source end electrode and a graphene drain end electrode;

connecting a graphene source end electrode, a graphene drain end electrode and a molecular heterojunction through an amide bond, specifically:

dissolving compound A1 and dehydration activator 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride (EDCI) in pyridine to obtain a mixed solution, wherein the concentration of A1 is 1 × 10^-4mol/L, EDCI concentration of 3X 10^-3mol/L; then a graphene gate electrode layer and Bi are included₂SeO₅Immersing the semi-finished devices of the dielectric layer, the graphene source end electrode and the graphene drain end electrode into the mixed solution, reacting for 48 hours in an argon atmosphere under a dark condition, then taking out the devices from the solution, washing the devices with acetone and ultrapure water for three times respectively, and drying the devices with nitrogen flow;

finally, covering an h-BN protective layer with the thickness of 10nm on the top of the device to obtain the monomolecular field effect transistor containing the compound A1; the graphene gate electrode layer is in a strip shape, has a width of 50nm, and is located right below a molecular heterojunction formed by the compound A1.

The monomolecular field effect transistor comprises a graphene gate electrode layer and Bi₂SeO₅The graphene-based photovoltaic module comprises a dielectric layer, a graphene source end electrode, a graphene drain end electrode, a molecular heterojunction formed by a compound A1 and an h-BN protective layer, and the three-dimensional structure diagram is shown in figure 1. The current-bias characteristic curve of the monomolecular field effect transistor, which changes with the bias voltage when the gate voltage is 0V, was tested using an Agilent 4155C semiconductor tester and an ST-500-probe station, and the result is shown in fig. 2; an Agilent 4155C semiconductor tester and an ST-500-probe station are adopted to test the current-gate voltage characteristic curve of the monomolecular field effect transistor regulated by the gate voltage when the bias voltage is 0.1V, and the result is shown in figure 3; the temperature dependence was tested by using the comprehensive physical property test system, and the results were found to be consistent in the range of 2-300K, and it can be seen from FIGS. 2 and 3 that the single molecular field effect transistor was biased at 1VThe current of 40nA can be obtained, the on-off ratio can reach 400, and the obtained monomolecular field effect transistor has strong regulation and control capability on molecular conductivity and can stably exist in an air environment for a long time.

Example 2 preparation of a monomolecular field effect transistor based on Compound A2

(1) Synthesis of compound a 2:

1g of m-iodobenzoic acid (compound 2-1, 4.033mmol) was weighed and refluxed in 30ml of 20% aqueous sulfuric acid at 200 ℃ for 24 hours under a nitrogen atmosphere; extraction with dichloromethane gave dichloromethane extract, which was washed three times with saturated sodium bicarbonate solution, and the extract was distilled under reduced pressure and then subjected to column chromatography to give 0.76g of compound 2-2 (yield 82%).¹H NMR(500MHz,Chloroform-d)δ8.78(s,1H),8.25(s,1H),7.53(s,1H)。¹³C NMR(125MHz,CDCl₃)δ179.70(s),140.87(s),135.48(s),133.65(s),132.07(s),128.03(s),110.76(s)。HRMS(TOF-ESI⁺) (m/z) formula C₁₄H₆I₂O₂，m/z＝459.85。

1g of Compound 2-2(2.17mmol), 0.11g of triethylamine (Et)₃N, 1.08mmol), 0.251g of tetrakis (triphenylphosphine) palladium (Pd (PPh)₃)₄0.217mmol), 0.1g of cuprous iodide (CuI, 0.52mmol) are dissolved in 30ml of diethyl ether, 500ml of acetylene (C) are used₂H₂22.3mmol) of air bag is connected in a sealed reaction system at room temperature overnight; adding water to quench the reaction, shaking and extracting an organic phase, and washing the organic phase for three times by using a saturated sodium chloride solution; then, the column chromatography was performed to obtain 0.32g of Compound 2-3 (yield 57%).¹H NMR(500MHz,Chloroform-d)δ8.24(s,1H),7.75(d,J＝15.0Hz,2H),3.07(s,1H)。¹³C NMR(125MHz,CDCl₃)δ180.60(s),137.42(s),135.19(s),134.87(s),133.88(s),129.45(s),127.61(s),83.97(s),75.07(s)。HRMS(TOF-ESI⁺) (m/z) formula C₁₈H₈O₂，m/z＝256.05。

1g of Compound 2-3(3.91mmol), 0.14g of diethylamine (Et)₂NH, 1.96mmol), 0.088g Palladium acetate (Pd (OAc)₂0.391mmol), 0.1g of CuI (0.52mmol) are dissolved in 30ml of diethyl ether, and 0.51g of triphenylphosphine (PPh) are added₃1.96 mmol); a solution of 1.71g of p-iodoaniline (7.82mmol) in 10ml of diethyl ether was slowly added under a nitrogen atmosphere; refluxing and reacting for 8 hours; adding water to quench the reaction, shaking and extracting an organic phase, and washing the organic phase for three times by using a saturated sodium chloride solution; then, the mixture was subjected to column chromatography to obtain 1.17g of Compound A2 (yield: 69%).¹H NMR(500MHz,Chloroform-d)δ8.28(s,1H),7.80(s,1H),7.72(s,1H),7.31(s,2H),6.29(s,2H),3.91(s,2H)。¹³C NMR(125MHz,CDCl₃)δ180.60(s),148.61(s),137.80(s),135.71(s),134.97(s),132.34(d,J＝12.7Hz),129.62(s),128.38(s),114.79(s),113.64(s),91.51(s),87.34(s)。HRMS(TOF-ESI⁺) (m/z) formula C₃₀H₁₈N₂O₂,m/z＝438.14。

(2) Preparation of a monomolecular field effect transistor comprising compound a 2:

the procedure was as in example 1, except that Compound A2 was used in place of Compound A1.

The current-bias characteristic curve of the monomolecular field effect transistor, which changes with the bias voltage when the gate voltage is 0V, was tested using an Agilent 4155C semiconductor tester and an ST-500-probe station, and the result is shown in fig. 4; an Agilent 4155C semiconductor tester and an ST-500-probe station are adopted to test the current-gate voltage characteristic curve of the monomolecular field effect transistor regulated by the gate voltage when the bias voltage is 0.1V, and the result is shown in FIG. 5; the comprehensive physical property test system is used for testing the temperature dependence, the results are consistent within the range of 2-300K, according to the graphs in fig. 4 and 5, the monomolecular field effect transistor can obtain 80nA current under the bias voltage of 1V, the on-off ratio can reach 1000, and the monomolecular field effect transistor has strong regulation and control capacity on molecular conductivity and can stably exist in the air environment for a long time.

Example 3 preparation of a monomolecular field effect transistor based on Compound A3

(1) Synthesis of compound a 3:

weighing 1g of 2, 6-lutidine (compound 3-1, 9.34mmol), dissolving 0.02g of dibenzoyl peroxide (BPO, 0.0934mmol) in 30ml of carbon tetrachloride, slowly adding 3.3g N-bromosuccinimide (NBS, 18.68mmol) in three portions, and refluxing under nitrogen atmosphere for 8 hours; after the completion of the reaction, the reaction mixture was frozen in a refrigerator at-20 ℃ and filtered to remove the residue, and the remaining liquid was evaporated by rotary chromatography to obtain 1.04g of Compound 3-2 (yield 42%).¹H NMR(500MHz,Chloroform-d)δ7.56(s,1H),6.85(s,2H),5.01(s,4H)。¹³C NMR(125MHz,CDCl₃)δ157.93(s),138.82(s),116.75(s),30.67(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₇H₇Br₂N，m/z＝264.89。

Weighing 1g of compound 3-2(3.80mmol), dissolving the compound and 0.2g of magnesium chips (8mmol) in 20ml of tetrahydrofuran, adding one iodine particle, and locally heating and reacting by using a drying gun under the nitrogen atmosphere until the iodine particle disappears, wherein the reaction releases heat automatically; keeping the micro-boiling state for reflux reaction for 1 hour to generate a compound 3-3; dropwise adding a mixed solution of 5ml of ethylene oxide and 10ml of tetrahydrofuran into a reaction system containing the compound 3-3 under a nitrogen atmosphere; refluxing and reacting for 2 hours; after completion of the reaction, the reaction mixture was subjected to rotary evaporation and purified by column chromatography to obtain 0.68g of compound 3-4 (yield 93%).¹H NMR(500MHz,Chloroform-d)δ7.40(s,2H),7.05(s,7H),3.52(s,10H),3.25(s,7H),2.76(s,8H),1.82(s,13H)。¹³C NMR(125MHz,CDCl₃)δ161.22(s),142.14(s),119.82(s),62.80(s),36.11(s),32.75(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₁₁H₁₇NO₂，m/z＝195.13。

Weighing 1g of the compound 3-4(5.2mmol), adding to 20ml of tetrahydrofuran solution, dropwise adding a mixture of 1.12g of phthalimide (7.6mmol), 0.66g of diethyl azodicarboxylate (DEAD, 3.8mmol) and 1.0g of triphenylphosphine (3.8mmol) dissolved in 10ml of tetrahydrofuran under a nitrogen atmosphere, and reacting under reflux for 2 hours; then 0.25ml hydrazine (7.6mmol) and 5ml tetrahydrofuran were addedThe mixed solution is refluxed and reacted for 16 hours at the temperature of 0 to 25 ℃; after washing the reaction solution three times with a saturated sodium chloride solution, the organic phase was rotary evaporated and subjected to column chromatography to obtain 0.77g of compound a3 (yield 76%).¹H NMR(500MHz,Chloroform-d)δ7.39(s,4H),7.04(s,16H),2.76(s,18H),2.67(s,16H),2.08(s,32H),1.08(s,31H)。¹³C NMR(125MHz,CDCl₃)δ161.22(s),142.14(s),119.82(s),40.82(s),36.31(s),32.57(s)。HRMS(TOF-ESI⁺) (m/z) formula C₁₁H₁₉N₃，m/z＝193.16。

(2) Preparation of a monomolecular field effect transistor comprising compound a 3:

the procedure was as in example 1, except that Compound A3 was used in place of Compound A1.

The current-bias characteristic curve of the monomolecular field effect transistor, which changes with the bias voltage when the gate voltage is 0V, was tested using an Agilent 4155C semiconductor tester and an ST-500-probe station, and the result is shown in fig. 6; an Agilent 4155C semiconductor tester and an ST-500-probe station are adopted to test the current-gate voltage characteristic curve of the monomolecular field effect transistor regulated by the gate voltage when the bias voltage is 0.1V, and the result is shown in FIG. 7; the comprehensive physical property test system is used for testing the temperature dependence, the results are consistent within the range of 2-300K, according to the graphs in fig. 6 and 7, the monomolecular field effect transistor can obtain 20nA current under the bias voltage of 1V, the on-off ratio can reach 4000, and the monomolecular field effect transistor has strong regulation and control capability on molecular conductivity and can stably exist in the air environment for a long time.

Example 4 preparation of a monomolecular field effect transistor based on Compound A4

(1) Synthesis of compound a 4:

weighing 1g of p-iodoaniline (compound 4-1, 4.57mmol), adding 8ml of sodium acetylene (18 wt% with mass fraction of 18%) under the liquid nitrogen cooling environment, sealing the tube and reacting in liquid nitrogen for 2 hours; opening the tube after the reaction10ml of water was slowly dropped in an ice bath to extract and separate liquid, thereby obtaining an organic phase, which was washed three times with 10ml of 10% HCl, and the washed organic phase was purified by column chromatography after vacuum distillation, thereby obtaining 0.41g of compound 4-2 (yield 76.6%).¹H NMR(500MHz,Chloroform-d)δ7.27(s,2H),6.30(s,2H),3.79(s,2H),2.82(s,1H)。¹³C NMR(125MHz,CDCl₃)δ148.55(s),132.20(s),114.49(s),109.14(s),84.01(s),77.45(s)。HRMS(TOF-ESI⁺) (m/z) formula C₈H₇N,m/z＝117.06。

1g of 2, 6-diiodopyridine (compound 4-3, 3.02mmol) and 0.067g of palladium acetate (0.302mmol), 0.079g of triphenylphosphine (0.302mmol), 0.29g of cuprous iodide (1.5mmol), 0.11g of diethylamine (1.5mmol) were weighed out and dissolved in 30ml of tetrahydrofuran under nitrogen atmosphere, and 10ml of tetrahydrofuran solution in which 0.72g of compound 4-2(6.1mmol) was dissolved was slowly added dropwise thereto; refluxing and reacting for 8 hours; after completion of the reaction, the reaction was quenched with 50ml of distilled water, followed by extraction and liquid separation, and the organic phase was rotary evaporated and then subjected to column chromatography to obtain 0.79g of compound a4 (yield 85%).¹H NMR(500MHz,Chloroform-d)δ7.50(s,3H),7.27(s,24H),6.92(s,12H),6.30(s,24H),4.06(s,23H)。¹³C NMR(125MHz,CDCl₃)δ148.61(s),142.73(s),140.35(s),132.39(s),128.71(s),114.79(s),113.64(s),90.71(s),86.17(s)。HRMS(TOF-ESI⁺) (m/z) formula C₂₁H₁₅N₃，m/z＝309.13。

(2) Preparation of a monomolecular field effect transistor comprising compound a 4:

the procedure was as in example 1, except that Compound A4 was used in place of Compound A1.

The current-bias characteristic curve of the monomolecular field effect transistor, which changes with the bias voltage when the gate voltage is 0V, was tested using an Agilent 4155C semiconductor tester and an ST-500-probe station, and the result is shown in fig. 8; an Agilent 4155C semiconductor tester and an ST-500-probe station are adopted to test the current-gate voltage characteristic curve of the monomolecular field effect transistor regulated by the gate voltage when the bias voltage is 0.1V, and the result is shown in figure 9; the comprehensive physical property test system is used for testing the temperature dependence, the results are consistent within the range of 2-300K, according to the graphs in fig. 8 and fig. 9, the monomolecular field effect transistor can obtain 20nA current under the bias voltage of 1V, and the on-off ratio can reach 1700, which shows that the monomolecular field effect transistor has strong regulation and control capability on molecular conductivity characteristics and can stably exist in the air environment for a long time.

Example 5 preparation of a monomolecular field effect transistor based on Compound A5

(1) Synthesis of compound a 5:

1g of 1, 3-xylene (compound 5-1, 9.4mmol) and 0.02g of dibenzoyl peroxide (0.094mmol) were weighed out and dissolved in 30ml of carbon tetrachloride, 3.34g N-bromosuccinimide (18.8mmol) was added slowly in three portions, and the mixture was refluxed for 8 hours under a nitrogen atmosphere; after the completion of the reaction, the reaction mixture was frozen in a refrigerator at-20 ℃ and filtered to remove the residue, and the remaining liquid was evaporated by rotary chromatography to obtain 1.12g of compound 5-2 (yield 44%).¹H NMR(500MHz,Chloroform-d)δ7.59(s,1H),7.31(s,2H),7.06(s,1H),4.99(s,4H)。¹³C NMR(125MHz,CDCl₃)δ140.67(s),128.18(s),126.56(s),124.24(s),31.45(s)。HRMS(TOF-ESI⁺) (m/z) formula C₈H₈Br₂，m/z＝263.90。

Weighing 1.4g of compound 5-2(5.15mmol), dissolving the compound 5-2 and 0.25g of magnesium chips (10.5mmol) in 20ml of tetrahydrofuran, adding one iodine particle, and locally heating and reacting by using a drying gun under the nitrogen atmosphere until the iodine particle disappears, wherein the reaction releases heat automatically; keeping the micro-boiling state for reflux reaction for 1 hour to generate a compound 5-3; dropwise adding a mixed solution of 5ml of ethylene oxide and 10ml of tetrahydrofuran into a reaction system containing the compound 5-3 under a nitrogen atmosphere; refluxing and reacting for 2 hours; after completion of the reaction, the reaction mixture was subjected to rotary evaporation and then purified by column chromatography to obtain 0.88g of compound 5-4 (yield: 88%).¹H NMR(500MHz,Chloroform-d)δ7.53(s,4H),7.13(s,17H),6.90(s,8H),3.53(s,21H),2.77(s,18H),1.82(s,28H),1.20(s,16H)。¹³C NMR(125MHz,CDCl₃)δ142.35(s),130.55(s),129.16(s),125.80(s),62.80(s),34.38(s),33.19(s)。HRMS(TOF-ESI⁺) (m/z) formula C₁₂H₁₈O₂,m/z＝194.13。

Weighing 1g of compound 5-4(5.2mmol), adding to 20ml of tetrahydrofuran solution, dropwise adding a mixed solution of 1.15g of phthalimide (7.8mmol), 0.68g of diethyl azodicarboxylate (3.9mmol) and 1.1g of triphenylphosphine (3.9mmol) dissolved in 10ml of tetrahydrofuran under nitrogen atmosphere, and refluxing for 2 hours; then adding a mixed solution of 8ml of hydrazine and 5ml of tetrahydrofuran, and carrying out reflux reaction for 16 hours at the temperature of 0-25 ℃; after washing the reaction solution three times with a saturated sodium chloride solution, the organic phase was rotary evaporated and subjected to column chromatography to obtain 0.79g of compound a5 (yield 79%).¹H NMR(500MHz,Chloroform-d)δ7.53(s,3H),7.13(s,12H),6.90(s,6H),2.68(s,16H),2.63(s,13H),2.09(s,21H),1.16(s,23H)。¹³C NMR(125MHz,CDCl₃)δ142.35(s),130.55(s),129.16(s),125.80(s),40.82(s),34.04(s),32.42(s)。HRMS(TOF-ESI⁺) (m/z) formula C₁₂H₂₀N₂，m/z＝192.16。

(2) Preparation of a monomolecular field effect transistor comprising compound a 5:

the procedure was as in example 1, except that Compound A5 was used in place of Compound A1.

The current-bias characteristic curve of the unimolecular field effect transistor changing with the bias voltage when the gate voltage is 0V was tested using an Agilent 4155C semiconductor tester and an ST-500-probe station, and the result is shown in fig. 10; an Agilent 4155C semiconductor tester and an ST-500-probe station are adopted to test the current-gate voltage characteristic curve of the monomolecular field effect transistor regulated by the gate voltage when the bias voltage is 0.1V, and the result is shown in FIG. 11; the temperature dependence is tested by using a comprehensive physical property testing system, the results are consistent within the range of 2-300K, according to the graph shown in the figure 10 and the graph shown in the figure 11, the monomolecular field effect transistor can obtain 30nA current under the bias voltage of 1V, and the on-off ratio can reach 2900, so that the monomolecular field effect transistor has strong regulation and control capability on the molecular conductivity and can stably exist in the air environment for a long time.

Example 6 preparation of a monomolecular field effect transistor based on Compound A6

(1) Synthesis of compound a 6:

weighing 1g of p-iodoaniline (compound 6-1, 4.57mmol), adding 10ml of mixed solution of sodium acetylene (18 wt% and xylene as a dispersant) and 10ml of diethyl ether in a liquid nitrogen cooling environment, sealing a tube and reacting in liquid nitrogen for 2 hours; after the reaction, the tube was opened, 10ml of water was slowly dropped in the tube in ice bath to extract and separate the liquid, thereby obtaining an organic phase, 10ml of 10% HCl was used for extraction three times, and the organic phase was subjected to pressure distillation and then column chromatography purification, thereby obtaining 0.38g of compound 6-2 (yield 71%).¹H NMR(500MHz,Chloroform-d)δ7.27(s,2H),6.30(s,2H),3.79(s,2H),2.82(s,1H)。¹³C NMR(125MHz,CDCl₃)δ148.55(s),132.20(s),114.49(s),109.14(s),84.01(s),77.45(s)。HRMS(TOF-ESI⁺) (m/z) formula C₈H₇N,m/z＝117.06。

1g of o-diiodobenzene (compound 6-3, 3.03mmol) and 0.067g of palladium acetate (0.302mmol), 0.079g of triphenylphosphine (0.302mmol), 0.29g of cuprous iodide (1.5mmol), 0.11g of diethylamine (1.5mmol) were weighed out and dissolved in 30ml of tetrahydrofuran under nitrogen atmosphere, and 10ml of tetrahydrofuran solution in which 0.72g of compound 6-2(6.1mmol) was dissolved was slowly added dropwise thereto; refluxing and reacting for 8 hours; after completion of the reaction, the reaction was quenched with 50ml of distilled water, followed by extraction and liquid separation, and the organic phase was rotary evaporated and then subjected to column chromatography to obtain 0.72g of compound a6 (yield 80%).¹H NMR(500MHz,Chloroform-d)δ7.46(s,15H),7.41(s,9H),7.31(s,28H),7.23(s,4H),6.29(s,31H),3.86(s,30H)。¹³C NMR(125MHz,CDCl₃)δ148.61(s),133.50(s),132.39(s),131.69(s),130.09(s),125.41(s),114.79(s),113.64(s),88.76(s),87.89(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₂₂H₁₆N₂，m/z＝308.13。

(2) Preparation of a monomolecular field effect transistor comprising compound a 6:

the procedure was as in example 1, except that Compound A6 was used in place of Compound A1.

The current-bias characteristic curve of the unimolecular field effect transistor changing with the bias voltage when the gate voltage is 0V was tested using an Agilent 4155C semiconductor tester and an ST-500-probe station, and the result is shown in fig. 12; an Agilent 4155C semiconductor tester and an ST-500-probe station are adopted to test the current-gate voltage characteristic curve of the monomolecular field effect transistor regulated by the gate voltage when the bias voltage is 0.1V, and the result is shown in FIG. 13; the temperature dependence is tested by utilizing a comprehensive physical property testing system, the results are consistent within the range of 2-300K, according to the graph shown in the figure 12 and the graph shown in the figure 13, the monomolecular field effect transistor can obtain 15nA current under the bias voltage of 1V, the on-off ratio can reach 2000, and the monomolecular field effect transistor has strong regulation and control capability on molecular conductivity and can stably exist in the air environment for a long time.

Example 7 preparation of a monomolecular field effect transistor based on Compound A7

(1) Synthesis of compound a 7:

1g of Compound 7-1(0.011mol) was weighed, and 3.5g of liquid bromine (Br) was added₂0.022mol) and 3.2g of iron bromide (FeBr)₃0.011mol) is heated to 300 ℃ in oil bath under the nitrogen atmosphere, and the reflux reaction is carried out for 16 hours; after the reaction is finished, adding water for quenching, and washing an organic phase by using 10ml of 10% HCl solution for three times; the organic phase thus obtained was subjected to vacuum distillation and then subjected to column chromatography to obtain 0.63g of Compound 7-2 (yield 22%). In this example, the nmr data used R ═ CH₃The determination is carried out by the following steps,¹H NMR(500MHz,Chloroform-d)δ8.68(s,2H),2.45(s,3H)。¹³C NMR(125MHz,CDCl₃)δ152.19(s),150.07(s),120.77(s),23.13(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₆H₅Br₂N，m/z＝250.88。

Weighing 1g of compound 7-2(3.99mmol), dissolving in 10ml of tetrahydrofuran solution, and successively and slowly dropping 1.7g of tetrahydrofuran solution dissolved with 3-amino-propyl zinc chloride (II) in nitrogen atmosphere; 0.8g of 3-chloropropylamine (8mmol) and 0.047g of tetrakis (triphenylphosphine) palladium (Pd) were dissolved(PPh₃)₄0.04mmol) in 15ml of Dimethylformamide (DMF); reacting for 16 hours at the reflux temperature of 153 ℃; after the reaction is finished, 20ml of water is used for extraction, and the organic phase is washed by 10% HCl solution for three times; the organic phase thus obtained was subjected to rotary evaporation and then to column chromatography to obtain 0.79g of Compound 7-3 (yield 94%).¹H NMR(500MHz,Chloroform-d)δ8.43(s,1H),2.68(s,1H),2.63(s,1H),2.29(s,1H),2.09(s,1H),1.11(s,2H)。¹³C NMR(125MHz,CDCl₃)δ147.09(s),140.61(s),136.38(s),40.82(s),31.66(s),30.53(s),16.88(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₁₂H₂₁N₃，m/z＝207.17。

Weighing 1g of the compound 7-3(4.82mmol) dissolved in 20ml of tetrahydrofuran solution, and further adding dropwise a solution of 0.68g of n-bromobutane (4.82mmol) dissolved in 10ml of tetrahydrofuran solution under a nitrogen atmosphere; refluxing and reacting for 8 hours; after extraction with 10ml of water, the aqueous phase was retained and distillation was carried out under reduced pressure to obtain a solid product, i.e., 0.66g of Compound 7-4 (yield 39%).¹H NMR(500MHz,Chloroform-d)δ8.31(s,10H),3.17(s,7H),2.68(s,15H),2.63(s,13H),2.27(s,15H),2.09(s,13H),2.04(s,11H),1.25(s,6H),1.10(s,20H),0.89(s,8H)。¹³C NMR(125MHz,CDCl₃)δ146.14(s),145.57(s),139.22(s),62.52(s),40.82(s),31.66(s),30.36(d,J＝6.4Hz),19.62(s),16.88(s),14.00(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₁₆H₃₀BrN₃，m/z＝343.16。

Weighing 1g of the compound 7-4(2.91mmol) and 0.07g of sodium hydride (2.91mmol) in 15ml of a dimethylformamide solution, and slowly adding dropwise a further 5ml of a dimethylformamide solution containing 0.2g of cyclopentadiene (2.91mmol) in nitrogen; after 16 hours at room temperature, the reaction was quenched by addition of water, the organic phase was washed three times with 10ml 10% HCl solution, and the organic phase was subjected to column chromatography after rotary evaporation to give 0.72g of Compound A7 (yield 95%).¹H NMR(500MHz,Chloroform-d)δ8.31(s,15H),7.90(s,4H),7.38(s,15H),2.68(s,18H),2.63(s,17H),2.27(s,22H),2.09(s,23H),1.21(s,29H)。¹³C NMR(125MHz,CDCl₃)δ138.84(s),138.31(s),137.40(s),133.79(s),132.86(s),131.30(s),117.31(d,J＝15.0Hz),41.19(s),31.65(s),30.06(s),16.49(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₁₇H₂₄N₂，m/z＝256.19。

(2) Preparation of a monomolecular field effect transistor comprising compound a 7:

the procedure was as in example 1, except that Compound A7 was used in place of Compound A1.

The current-bias characteristic curve of the unimolecular field effect transistor changing with the bias voltage when the gate voltage is 0V was tested using an Agilent 4155C semiconductor tester and an ST-500-probe station, and the result is shown in fig. 14; an Agilent 4155C semiconductor tester and an ST-500-probe station are adopted to test the current-gate voltage characteristic curve of the monomolecular field effect transistor regulated by the gate voltage when the bias voltage is 0.1V, and the result is shown in FIG. 15; the temperature dependence is tested by using a comprehensive physical property testing system, the results are consistent within the range of 2-300K, according to the graph shown in the figure 14 and the graph shown in the figure 15, the monomolecular field effect transistor can obtain 100nA current under the bias voltage of 1V, and the on-off ratio can reach 2700, so that the monomolecular field effect transistor has strong regulation and control capability on molecular conductivity characteristics and can stably exist in the air environment for a long time.

Example 8 preparation of a monomolecular field effect transistor based on Compound A8

(1) Synthesis of compound A8:

1g of compound 8-1(2.90mmol) was weighed, dissolved in 20ml of tetrahydrofuran together with 0.53g of iodobutane (2.90mmol), and heated under reflux under nitrogen atmosphere for 16 hours; after the reaction, 20ml of water was added to quench the reaction, followed by extraction and liquid separation, and the aqueous phase was retained and subjected to rotary evaporation to obtain 0.88g of compound 8-2 (yield: 75%) as a solid product. In this example, the nmr data used R ═ CH₃The determination is carried out by the following steps,¹H NMR(500MHz,Chloroform-d)δ9.35(s,10H),3.02(s,5H),2.43(s,15H),2.03(s,4H),1.25(s,6H),0.89(s,8H)。¹³C NMR(125MHz,CDCl₃)δ157.81(s),156.23(s),66.30(s),62.52(s),30.33(s),20.76(s),19.62(s),14.00(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₁₀H₁₄I₂N⁺，m/z＝401.92。

1g of compound 8-2(2.48mmol) and 0.03g of sodium hydride (1.24mmol) were weighed out and dissolved in 15ml of dimethylformamide, a solution of 0.17g of cyclopentadiene (2.48mmol) in 5ml of dimethylformamide was slowly added dropwise under a nitrogen atmosphere, after reaction at room temperature for 16 hours, the reaction was quenched by addition of water, and extraction separation was carried out, and the organic phase was washed three times with 10% HCl solution, and subjected to distillation under reduced pressure and column chromatography to give 0.76g of compound 8-3 (yield 77%).¹H NMR(500MHz,Chloroform-d)δ8.31(s,4H),7.90(s,1H),7.38(s,4H),2.43(s,6H)。¹³C NMR(125MHz,CDCl₃)δ144.24(s),139.77(s),132.86(s),128.07(s),126.60(s),118.50(d,J＝15.0Hz),21.50(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₁₁H₈I₂，m/z＝393.99。

1g of the compound 8-3(2.52mmol) was weighed, and 0.057g of palladium acetate (0.252mmol), 0.066g of triphenylphosphine (0.252mmol), 0.24g of cuprous iodide (1.25mmol), 0.09g of diethylamine (1.25mmol) were dissolved in 30ml of tetrahydrofuran under a nitrogen atmosphere, and a solution of p-ethynylaniline 0.6g (5.04mmol) dissolved in 10ml of tetrahydrofuran was slowly dropped thereinto; refluxing and reacting for 8 hours; after completion of the reaction, the reaction was quenched with 50ml of distilled water, followed by extraction and separation, and the organic phase was subjected to rotary evaporation and then column chromatography to obtain 0.90g of compound A8 (yield 90%).¹H NMR(500MHz,Chloroform-d)δ8.31(s,4H),7.90(s,1H),7.33(d,J＝55.0Hz,12H),6.30(s,8H),3.66(s,8H),2.43(s,6H)。¹³C NMR(125MHz,CDCl₃)δ154.61(s),148.61(s),142.86(s),135.86(s),132.86(s),132.39(s),127.95(s),123.13(s),119.85(d,J＝15.0Hz),114.79(s),113.64(s),103.78(s),86.18(s),17.64(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₂₇H₂₀N₂，m/z＝372.16。

(2) Preparation of a monomolecular field effect transistor comprising compound A8:

the procedure was as in example 1, except that Compound A8 was used in place of Compound A1.

The current-bias characteristic curve of the unimolecular field effect transistor changing with the bias voltage when the gate voltage is 0V was tested using an Agilent 4155C semiconductor tester and an ST-500-probe station, and the result is shown in fig. 16; an Agilent 4155C semiconductor tester and an ST-500-probe station are adopted to test the current-gate voltage characteristic curve of the monomolecular field effect transistor regulated by the gate voltage when the bias voltage is 0.1V, and the result is shown in FIG. 17; the comprehensive physical property test system is utilized to test the temperature dependence, the results are consistent within the range of 2-300K, according to the graphs in fig. 16 and 17, the monomolecular field effect transistor can obtain 200nA current under the bias voltage of 1V, and the on-off ratio can reach 3000, which shows that the monomolecular field effect transistor has strong regulation and control capability on molecular conductivity characteristics and can stably exist in the air environment for a long time.

Example 9 preparation of a monomolecular field effect transistor based on Compound A9

(1) Synthesis of compound a 9:

1g of Compound 9-1(3.01mmol) was weighed out and dissolved in 20ml of tetrahydrofuran solvent together with 1.07g N-bromosuccinimide (6.02mmol) and 0.007g benzoyl peroxide (0.0301 mmol); reacting for 8 hours in a nitrogen atmosphere; after the reaction was completed, the reaction was quenched with 20ml of water, the organic phase was washed three times with 10ml of 10% HCl solution, and the organic phase was distilled under reduced pressure and separated by column chromatography to obtain 0.77g of compound 9-2 (yield 52%). In this example, the nmr data used R ═ CH₃The determination is carried out by the following steps,¹H NMR(500MHz,Chloroform-d)δ8.22(d,J＝69.8Hz,2H),7.55(s,1H),7.47(s,1H),5.45(s,2H),2.73(s,3H)。¹³C NMR(125MHz,CDCl₃)δ140.64(s),130.27(s),130.04(s),129.44(s),128.07(s),126.18(d,J＝19.6Hz),121.22(s),117.85(d,J＝17.3Hz),116.88(s),30.67(s),18.61(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₂₆H₁₈Br₂，m/z＝489.98。

1g of Compound 9-2(2.05mmol) was weighed,dissolving the magnesium chips (4.1mmol) and 0.1g of magnesium chips in 20ml of tetrahydrofuran together, adding one iodine particle, and locally heating and reacting by using a drying gun under the nitrogen atmosphere until the iodine particle disappears, wherein the reaction releases heat automatically; keeping the micro-boiling state for reflux reaction for 1 hour to obtain a compound 9-3; dropwise adding a mixed solution of 5ml of ethylene oxide and 10ml of tetrahydrofuran into a reaction system containing the compound 9-3 under a nitrogen atmosphere; refluxing and reacting for 2 hours; after completion of the reaction, the reaction mixture was subjected to rotary evaporation and then purified by column chromatography to obtain 0.76g of compound 9-4 (yield 88%).¹H NMR(500MHz,Chloroform-d)δ8.15(s,5H),7.92(s,5H),7.55(s,5H),7.47(s,5H),3.53(s,9H),3.07(s,5H),2.73(s,15H),1.84(s,7H),1.49(s,5H)。¹³C NMR(125MHz,CDCl₃)δ140.92(s),132.20(s),131.91(s),129.70(s),128.07(s),126.24(d,J＝5.0Hz),120.54(s),119.92(s),118.40(s),116.50(s),62.80(s),33.06(s),32.70(s),18.61(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₃₀H₂₈O₂，m/z＝420.21。

1g of compound 9-4(2.38mmol) was weighed, added to 20ml of a tetrahydrofuran solution, and a mixed solution of 0.56g of phthalimide (3.8mmol), 0.33g of diethyl azodicarboxylate (1.9mmol) and 0.50g of triphenylphosphine (1.9mmol) dissolved in 10ml of tetrahydrofuran was added dropwise thereto under a nitrogen atmosphere, followed by reflux reaction for 2 hours; then adding a mixed solution of 8ml of hydrazine and 5ml of tetrahydrofuran, and reacting for 16 hours at the temperature of 0-20 ℃; the reaction solution was washed three times with a saturated sodium chloride solution, and the obtained organic phase was rotary evaporated and subjected to column chromatography to obtain 0.79g of compound a9 (yield 79%).¹H NMR(500MHz,Chloroform-d)δ8.10(s,1H),7.87(s,1H),7.50(s,1H),7.42(s,1H),3.05(s,1H),2.71(s,3H),2.66(s,1H),2.10(s,1H),1.49(s,2H)。¹³C NMR(125MHz,CDCl₃)δ140.92(s),132.20(s),131.91(s),129.70(s),128.07(s),126.24(d,J＝5.0Hz),120.54(s),119.92(s),118.40(s),116.50(s),40.82(s),32.21(d,J＝16.4Hz),18.61(s)。HRMS(TOF-ESI⁺) (m/z) formula C₃₀H₃₀N₂，m/z＝418.24。

(2) Preparation of a monomolecular field effect transistor comprising compound a 9:

the procedure was as in example 1, except that Compound A9 was used in place of Compound A1.

The current-bias characteristic curve of the unimolecular field effect transistor changing with the bias voltage when the gate voltage is 0V was tested using an Agilent 4155C semiconductor tester and an ST-500-probe station, and the result is shown in fig. 18; an Agilent 4155C semiconductor tester and an ST-500-probe station are adopted to test the current-gate voltage characteristic curve of the monomolecular field effect transistor regulated by the gate voltage when the bias voltage is 0.1V, and the result is shown in figure 19; the comprehensive physical property test system is used for testing the temperature dependence, the results are consistent within the range of 2-300K, according to the graph in fig. 18 and the graph in fig. 19, the unimolecular field effect transistor can obtain 50nA current under the bias voltage of 1V, the on-off ratio can reach 600, and the obtained unimolecular field effect transistor has strong regulation and control capacity on the molecular conductance characteristics and can stably exist in the air environment for a long time.

Example 10 preparation of a monomolecular field effect transistor based on Compound A10

(1) Synthesis of compound a 10:

weighing 1g of compound 10-1(1.80mmol), 0.05g of palladium acetate (0.18mmol), 0.05g of triphenylphosphine (0.18mmol), 0.17g of cuprous iodide (0.9mmol) and 0.06g of diethylamine (0.9mmol) in 30ml of tetrahydrofuran under nitrogen, and slowly adding dropwise a solution of p-ethynylaniline in 0.46g (3.85mmol) of 10ml of tetrahydrofuran; refluxing and reacting for 8 hours; after completion of the reaction, the reaction was quenched with 50ml of distilled water, followed by extraction and separation, and the obtained organic phase was subjected to rotary evaporation and then column chromatography to obtain 0.90g of compound a10 (yield 94%).¹H NMR(500MHz,Chloroform-d)δ8.54(s,4H),8.21(s,4H),7.71(s,4H),7.47(s,2H),7.31(s,9H),6.29(s,8H),4.14(s,8H),2.73(s,12H)。¹³C NMR(125MHz,CDCl₃)δ148.61(s),135.27(s),134.71(s),132.98(s),132.39(s),128.39(s),127.21(s),126.43(s),125.70(s),124.31(s),123.96(s),122.88(s),121.81(s),114.79(s),113.64(s),92.89(s),85.17(s),18.61(s)。HRMS(TOF-ESI⁺) (m/z) formula C₄₀H₂₆N₂，m/z＝534.21。

(2) Preparation of a monomolecular field effect transistor comprising compound a 10:

the procedure was as in example 1, except that Compound A10 was used in place of Compound A1.

The current-bias characteristic curve of the unimolecular field effect transistor changing with the bias voltage when the gate voltage is 0V was tested using an Agilent 4155C semiconductor tester and an ST-500-probe station, and the result is shown in fig. 20; an Agilent 4155C semiconductor tester and an ST-500-probe station are adopted to test the current-gate voltage characteristic curve of the monomolecular field effect transistor regulated by the gate voltage when the bias voltage is 0.1V, and the result is shown in figure 21; the temperature dependence is tested by using a comprehensive physical property testing system, the results are consistent within the range of 2-300K, according to the graph 20 and the graph 21, the monomolecular field effect transistor can obtain 10nA current under the bias voltage of 1V, the on-off ratio can reach 250, and the monomolecular field effect transistor has strong regulation and control capability on molecular conductivity and can stably exist in the air environment for a long time.

EXAMPLE 11 preparation of a monomolecular field-effect transistor based on Compound A11

(1) Synthesis of compound a 11:

weighing 1g of m-toluic acid (compound 11-1, 7.46mmol), dissolving in 10ml of tetrahydrofuran solution under nitrogen atmosphere together with 0.1g of zinc powder (1.5mmol) and 0.29g of titanium tetrachloride (1.5mmol), sealing the tube at low temperature, and reacting at 0-85 ℃ for 8 hours; after the reaction, the reaction tube was opened, and the mixture was slowly added to 10ml of water and subjected to extraction and liquid separation to obtain an organic phase, and the organic phase was washed with 10ml of a saturated sodium chloride solution, distilled under reduced pressure, and then subjected to column chromatography to obtain 0.75g of compound 11-2 (yield 92%).¹H NMR(500MHz,Chloroform-d)δ7.43(s,2H),7.28(s,2H),7.19(s,1H),6.93(d,J＝20.0Hz,4H),2.42(s,6H)。¹³C NMR(125MHz,CDCl₃)δ139.04(s),137.08(s),130.15(s),129.89(s),128.84(s),128.52(s),125.83(s),21.23(s)。HRMS(TOF-ESI⁺) (m/z) formula C₁₆H₁₆，m/z＝208.13。

1g of Compound 11-2(4.80mmol) was weighed out and dissolved in 20ml of tetrahydrofuran solvent together with 1.71g N-bromosuccinimide (9.60mmol) and 0.01g benzoyl peroxide (0.0480 mmol); reacting for 8 hours in a nitrogen atmosphere; after the reaction was completed, the reaction was quenched with 20ml of water and the separated liquid was extracted to obtain an organic phase, the organic phase was washed three times with 10ml of 10% HCl solution, the organic phase was distilled under reduced pressure and then subjected to column chromatography to obtain 0.71g of compound 11-3 (yield 40%).¹H NMR(500MHz,Chloroform-d)δ7.45(d,J＝50.0Hz,6H),7.27(s,2H),7.19(s,3H),6.95(s,3H),4.78(s,6H)。¹³C NMR(125MHz,CDCl₃)δ143.44(s),135.79(s),128.84(s),128.37(s),128.10(d,J＝18.7Hz),124.39(s),31.45(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₁₆H₁₄Br₂，m/z＝365.94。

Weighing 1g of compound 11-3(2.73mmol), dissolving the compound and 0.14g of magnesium chips (5.5mmol) in 20ml of tetrahydrofuran, adding one iodine particle, and locally heating and reacting by using a drying gun under the nitrogen atmosphere until the iodine particle disappears, wherein the reaction releases heat automatically; keeping the micro-boiling state for reflux reaction for 1 hour to generate a compound 11-4; dropwise adding a mixed solution of 5ml of ethylene oxide and 10ml of tetrahydrofuran into a reaction system containing the compound 11-4 under a nitrogen atmosphere; refluxing and reacting for 2 hours; after completion of the reaction, rotary evaporation was carried out, and the reaction mixture was purified by column chromatography to obtain 0.73g of compound 11-5 (yield 90%).¹H NMR(500MHz,Chloroform-d)δ7.43(s,4H),7.32(s,4H),7.24(s,2H),7.08(s,5H),6.95(s,4H),3.53(s,5H),2.77(s,4H),1.82(s,7H),1.24(s,4H)。¹³C NMR(125MHz,CDCl₃)δ144.38(s),138.74(s),131.95(s),130.57(s),128.84(s),128.57(s),125.13(s),62.80(s),34.38(s),33.19(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₂₀H₂₄O₂,m/z＝296.41。

1g of Compound 11-5(3.37mmol) was weighed, and added to 20ml of a tetrahydrofuran solution, and 0.78g of phthalimide (5.1mmol), 0.89g of diethyl azodicarboxylate (5.1mmol) and 0.66g of triphenyl were added dropwise to the system under a nitrogen atmosphereDissolving phenylphosphine (2.5mmol) in 10ml of tetrahydrofuran mixture, and carrying out reflux reaction for 2 hours; then adding a mixed solution of 8ml of hydrazine and 5ml of tetrahydrofuran, and reacting for 12 hours at the temperature of 0-20 ℃; after the reaction solution was washed three times with a saturated sodium chloride solution, the obtained organic phase was subjected to rotary evaporation and then column chromatography to obtain 0.79g of compound a11 (yield 79%).¹H NMR(500MHz,Chloroform-d)δ7.38(d,J＝55.0Hz,61H),7.27(s,7H),7.24(s,15H),7.08(s,42H),6.95(s,26H),2.68(s,31H),2.63(s,40H),2.09(s,60H),1.10(s,58H)。¹³C NMR(125MHz,CDCl₃)δ144.38(s),138.74(s),131.95(s),130.57(s),128.84(s),128.57(s),125.13(s),40.82(s),34.04(s),32.42(s)。HRMS(TOF-ESI⁺) (m/z): molecular formula C₂₀H₂₆N₂，m/z＝294.21。

(2) Preparation of a monomolecular field effect transistor comprising compound a 11:

the procedure was as in example 1, except that Compound A11 was used in place of Compound A1.

The current-bias characteristic curve of the unimolecular field effect transistor changing with the bias voltage when the gate voltage is 0V was tested using an Agilent 4155C semiconductor tester and an ST-500-probe station, and the result is shown in fig. 22; an Agilent 4155C semiconductor tester and an ST-500-probe station are adopted to test the current-gate voltage characteristic curve of the monomolecular field effect transistor regulated by the gate voltage when the bias voltage is 0.1V, and the result is shown in figure 23; the temperature dependence is tested by using a comprehensive physical property testing system, the results are consistent within the range of 2-300K, according to the graph 22 and the graph 23, the monomolecular field effect transistor can obtain 40nA current under the bias voltage of 1V, the on-off ratio can reach 170, and the monomolecular field effect transistor has strong regulation and control capability on molecular conductivity and can stably exist in the air environment for a long time.

Example 12 preparation of a monomolecular field effect transistor based on Compound A12

(1) Synthesis of compound a 12:

weighing 1g of m-iodobenzoic acid (compound 12-1, 4.06mmol), dissolving in 10ml of tetrahydrofuran solution under nitrogen atmosphere together with 0.05g of zinc powder (0.81mmol) and 0.15g of titanium tetrachloride (0.81mmol), sealing the tube at low temperature, and reacting at 0-85 ℃ for 8 hours; after the reaction, the reaction tube was opened, and the mixture was slowly added to 10ml of water and subjected to extraction and liquid separation to obtain an organic phase, and the organic phase was washed with 10ml of a saturated sodium chloride solution, distilled under reduced pressure, and then subjected to column chromatography to obtain 0.75g of compound 12-2 (yield 84%).¹H NMR(500MHz,Chloroform-d)δ7.88(s,2H),7.61(s,2H),7.52(s,2H),7.09(s,1H),6.95(s,2H)。¹³C NMR(125MHz,CDCl₃)δ140.44(s),139.09(s),137.77(s),130.98(s),129.85(s),128.84(s),95.66(s)。HRMS(TOF-ESI⁺) (m/z) formula C₁₄H₁₀I₂，m/z＝431.89。

Weighing 1g of the compound 12-2(2.32mmol), 0.05g of palladium acetate (0.23mmol), 0.06g of triphenylphosphine (0.23mmol), 0.23g of cuprous iodide (1.2mmol), 0.08g of diethylamine (1.2mmol) in 30ml of tetrahydrofuran under a nitrogen atmosphere, and slowly dropwise adding thereto a solution of p-ethynylaniline 0.55g (4.7mmol) in 10ml of tetrahydrofuran; refluxing and reacting for 8 hours; after completion of the reaction, the reaction was quenched with 50ml of distilled water and subjected to extraction and liquid separation to obtain an organic phase, which was subjected to rotary evaporation and then to column chromatography to obtain 0.89g of compound a12 (yield 91%).¹H NMR(500MHz,Chloroform)δ7.90(s,2H),7.45(d,J＝10.0Hz,5H),7.38(s,1H),7.31(s,4H),6.95(s,2H),6.29(s,4H),3.87(s,4H)。¹³C NMR(125MHz,CDCl₃)δ148.61(s),136.27(s),132.39(s),131.10(s),130.02(s),128.91(d,J＝16.6Hz),128.51(s),127.76(s),114.79(s),113.64(s),88.76(s),87.89(s)。HRMS(TOF-ESI⁺) (m/z) formula C₃₀H₂₂N₂，m/z＝410.22。

(2) Preparation of a monomolecular field effect transistor comprising compound a 12:

the procedure was as in example 1, except that Compound A12 was used in place of Compound A1.

The current-bias characteristic curve of the unimolecular field effect transistor changing with the bias voltage when the gate voltage is 0V was tested using an Agilent 4155C semiconductor tester and an ST-500-probe station, and the result is shown in fig. 24; an Agilent 4155C semiconductor tester and an ST-500-probe station are adopted to test the current-gate voltage characteristic curve of the monomolecular field effect transistor regulated by the gate voltage when the bias voltage is 0.1V, and the result is shown in FIG. 25; the comprehensive physical property test system is utilized to test the temperature dependence, the results are consistent within the range of 2-300K, according to the graph 24 and the graph 25, the unimolecular field effect transistor can obtain 35nA current under the bias voltage of 1V, the on-off ratio can reach 400, and the obtained unimolecular field effect transistor has strong regulation and control capability on the molecular conductance characteristic and can stably exist in the air environment for a long time.

And (3) calculating yield:

the yield is the mass of the actual synthesis product/the mass of the theoretical synthesis product x 100%.

The above description is only for the preferred embodiment of the present application and is not intended to limit the scope of the present application. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. A compound with quantum interference effect has a structural formula shown as formula A:

H₂N-R₂-R₁-R₂-NH₂

formula A;

wherein R is₁Any one selected from formula I-formula VI;

R₂is selected from- (CH) — (CH)₂)_m-or

m is an integer of 1 to 6;

2. The compound having a quantum interference effect according to claim 1, wherein the compound having a quantum interference effect is selected from any one of formula a 1-formula a 12:

3. a monomolecular field effect transistor comprising any one of the compounds having a quantum interference effect according to claim 1.

4. The single molecule field effect transistor according to claim 3, wherein the single molecule field effect transistor further comprises a graphene gate electrode layer, Bi₂SeO₅The graphene source-end electrode, the graphene drain-end electrode, the molecular heterojunction and the h-BN protective layer are arranged on the dielectric layer; the molecular heterojunction is composed of the compound having the quantum interference effect.

5. The single molecule field effect transistor according to claim 4, wherein the graphene gate electrode layer has a thickness of 0.7-20 nm; the Bi₂SeO₅The thickness of the dielectric layer is 1-20 nm; the thickness of the h-BN protective layer is 0.7-20 nm; the thickness of the graphene source electrode is 0.7-3 nm; the thickness of the graphene drain terminal electrode is 0.7-3 nm; the thickness of the molecular heterojunction is 0.7-3 nm.

6. The single molecule field effect transistor of claim 4, wherein the single molecule field effect transistor further comprises a substrate; the substrate is an atomically flat silicon wafer, mica or sapphire.

7. The single-molecule field effect transistor according to claim 4, wherein the graphene gate electrode layer is in a strip shape with a width of 5-100nm and is located vertically below the molecular heterojunction.

8. A preparation method of a monomolecular field effect transistor comprises the following steps:

1) preparing a graphene gate electrode layer on a substrate;

5) connecting the graphene point electrode with a molecular heterojunction through an amide bond; the molecular heterojunction is composed of any one of the compounds having quantum interference effect according to claim 1;

9. The production method according to claim 8, wherein step 4) includes: and (3) constructing a 1-4nm gap on the graphene electrode layer through electron beam exposure and reactive ion etching to obtain the graphene point electrode, wherein the graphene point electrode comprises a graphene source end electrode and a graphene drain end electrode.

10. The production method according to claim 8, wherein step 5) includes: dissolving the compound with the quantum interference effect and a dehydration activating agent in a solvent to obtain a mixed solution; and then immersing the semi-finished device obtained in the step 4) into the mixed solution, reacting for 24-48h in inert gas under the dark condition, taking out, washing and drying.

11. The production method according to claim 10, wherein the dehydration activating agent is selected from at least one of 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, dicyclohexylcarbodiimide, or N, N' -diisopropylcarbodiimide; the solvent is selected from at least one of pyridine, dimethyl sulfoxide or trichlorobenzene; the inert gas is argon or nitrogen;

the concentration of the dehydration activator is 2 x 10^-3-4×10^-3mol/L。

12. The preparation method according to claim 8, wherein the graphene gate electrode layer and Bi are formed₂SeO₅The dielectric layer and the graphene electrode layer are obtained through dry transfer or wet transfer.

13. The preparation method according to claim 8, wherein the thickness of the graphene gate electrode layer is 0.7-20 nm; the Bi₂SeO₅The thickness of the dielectric layer is 1-20 nm; the thickness of the h-BN protective layer is 0.7-20 nm; the thickness of the graphene source electrode is 0.7-3 nm; the thickness of the graphene drain terminal electrode is 0.7-3 nm; the thickness of the molecular heterojunction is 0.7-3 nm.

14. The preparation method according to claim 8, wherein the graphene gate electrode layer is in a strip shape, has a width of 5-100nm, and is positioned vertically below the molecular heterojunction.