Dihydrophenazine molecule-based destructive quantum interference effect regulation and control method

Abstract

The invention relates to a destructive quantum interference effect regulation and control method based on dihydrophenazine molecules, and belongs to the technical field of molecular electronics. Two nitrogen atoms are introduced into a central benzene ring of a traditional diphenylanthracene molecule to prepare a dihydrophenazine molecule, and a new electron transmission path is introduced while the good electron transmission characteristic of diphenylanthracene is reserved, so that the quantum interference effect is accurately controlled. On the basis of a scanning tunneling microscope split junction technology, conductivity testing is carried out on the molecule under different testing solvents, concentrations and voltages, and it is found that the conductivity value of the nitrogen atom introduced dihydrophenazine molecule is remarkably reduced. The core of the invention lies in that the interference on the electron wave function is realized through the elaborate design of the molecular structure, and the destructive quantum interference effect is effectively adjusted. The method not only provides a new possibility for regulation and control of the quantum interference effect, but also shows a wide application prospect in the fields of molecular electronic devices, such as molecular field effect transistors and molecular circuits.

Description

Technical Field

[0001] The present invention belongs to the field of molecular electronics. Based on the scanning tunneling microscope-junction technique (STM-BJ), single-molecule device conductivity testing is performed on molecules with a dihydrophenazine structure that introduce nitrogen atoms, the electron transmission on the single-molecule skeleton is regulated, and the quantum interference effect is further controlled. The method realizes the control of the quantum interference effect by molecular structure design at the single-molecule scale. Background Art

[0002] Molecular electronics is the study and utilization of the electronic properties of individual molecules or molecular assemblies to realize the functionality of electronic devices. With the advancement of nanotechnology and the deepening of quantum physics theory, the construction of electronic devices using single molecules has moved from theoretical to practical application. Single-molecule devices, due to their extremely small size, low energy consumption, and diverse functionality, hold enormous potential for future applications in high-performance computing, information storage, sensing, and quantum computing. However, the key to realizing these applications lies in precisely controlling and regulating the electron transport properties within molecules, with the regulation of quantum interference effects being particularly important. The role of quantum interference effects in single-molecule electronic devices cannot be underestimated. At the quantum scale, the wave nature of electrons means that electron transport within molecules is not simply linear motion, but rather involves the superposition and interference of multiple pathways. This interference can be constructive, enhancing electron transport, or destructive, inhibiting electron transport. Therefore, quantum interference effects directly influence key performance indicators of single-molecule devices, such as conductivity, on / off ratio, and response speed.

[0003] In recent years, scientists have observed in multiple studies that quantum interference effects significantly influence the performance of single-molecule devices. For example, by changing the conformation, topology, or charge distribution of the molecule, the quantum interference effect can be controlled, thereby optimizing the electronic transport performance of the device. These findings not only provide a new perspective for understanding the behavior of electrons at the molecular scale, but also provide practical operational means for designing and manufacturing high-performance single-molecule electronic devices. However, to effectively control the quantum interference effect, we need to have a deep understanding of the quantum interference mechanism within the molecule, including how factors such as the electronic structure of the molecule, charge distribution, and interface effects between the molecule and the electrode work together to affect the transport path and interference pattern of electrons. In addition, to achieve precise control of the quantum interference effect in single-molecule devices at room temperature, it is necessary to develop new molecular design strategies, synthesis methods, and measurement techniques.

[0004] 9,10-Diphenyldihydrophenazine is a phenazine-like organic compound. Its basic structure consists of a six-membered ring containing two nitrogen atoms. In the parent all-carbon 9,10-diphenylanthracene molecule, this six-membered ring is present as a single benzene ring. In dihydrophenazine, the introduction of two nitrogen atoms transforms this benzene ring into a six-membered ring with single bonds, altering the electronic structure and reactivity of the entire molecule. This structural modification imparts chemical and physical properties distinct from those of the parent all-carbon diphenylanthracene molecule and may also alter its optical and electronic properties. Dihydrophenazines and their derivatives have a wide range of applications in medicinal chemistry, biochemistry, and organic electronics. Their electronic properties make them promising for use in organic electronics, such as as active layer materials in organic light-emitting diodes (OLEDs) or organic solar cells. Summary of the Invention

[0005] The main technical problem solved by the present invention is to find a new method to prepare a new dihydrophenazine molecule by introducing a nitrogen atom into the central benzene ring of the diphenylanthracene molecular structure, thereby regulating the electron transport mode of the molecule and thus precisely controlling the quantum interference effect.

[0006] To solve the above technical problems, the present invention is accomplished by the following methods:

[0007] (1) The method for preparing molecular solutions is relatively simple. The specific steps are as follows: Taking the preparation of dihydrophenazine molecule (TCB) solution as an example, a certain amount of dihydrophenazine molecules is weighed into a sample bottle using a weighing balance. An appropriate amount of 1,2,4-trichlorobenzene solvent is pipetted into the sample bottle containing the weighed molecular sample at a certain ratio (1mM) using a pipette. The sample bottle is capped and placed in an ultrasonic instrument for 1 minute to ultrasonicate until a clear and transparent uniform solvent appears in the bottle. The preparation methods of other solutions are similar to the preparation method of dihydrophenazine molecules mentioned above and will not be described in detail here.

[0008] (2) Use the mechanical shearing method to prepare the Au tip electrode. The specific steps are as follows: Use clean and dry tweezers to insert the prepared gold wire into the probe holder and fix it. After reserving a certain length of gold wire, use clean and dry pliers to quickly cut the gold wire at a certain tilt angle to ensure that the cross-section of the tip of the gold wire presents a certain slope. Place the cut gold wire at the probe holder end under an optical microscope for observation to ensure that the Au tip is sharp and clean. Repeat the above steps until the Au tip electrode is prepared.

[0009] (3) The Au substrate electrode was prepared using the thermal evaporation method. The specific steps are as follows: After fixing the stainless steel substrate, the surface of the stainless steel substrate was polished to be even and smooth using an electric grinder. The polished substrate was immersed in a small beaker containing acetone solvent and placed in an ultrasonic cleaner for cleaning. This was repeated 3-5 times. The cleaned stainless steel substrate was placed in a clean and dry glass dish with the polished and smooth side facing upwards. The prepared glass dish with the evenly smooth stainless steel bottom was placed in a high vacuum resistance evaporation coating machine for evaporation gold plating.

[0010] (4) The specific operating steps for the scanning tunneling microscope-bend junction (STM-BJ) test of molecules are as follows: the cut Au tip and the Au substrate with a uniform and smooth surface after evaporation are fixed on the test instrument as two metal electrodes, and an appropriate amount of prepared 1mM molecular solution is placed on the Au substrate. The lifting plate is operated to make the Au tip contact the Au substrate. Under the application of a bias voltage of 100mV, the Au tip and the Au substrate with the solution are continuously in contact and then disconnected, repeatedly forming and breaking the molecular junction.

[0011] (5) Test target molecules, molecular solvents (1,2,4-trichlorobenzene, propylene carbonate, chloronaphthalene), molecular solution concentrations (0.01 mM, 0.1 mM, 1 mM), and screening voltages (100 mV, 500 mV, 800 mV, 1000 mV).

[0012] (6) After the reaction in step (5) is completed, the current is recorded and collected using a data acquisition device, and the conductance is calculated using the formula G = I / V. Without filtering any experimental data, a one-dimensional conductance histogram and a two-dimensional conductance-displacement histogram are constructed.

[0013] The advantages of the present invention are:

[0014] The present invention introduces nitrogen atoms into the all-carbon diphenylanthracene molecule and innovatively proposes a new molecular structure. Through this molecular structure design, two nitrogen atoms are introduced into the central benzene ring of the traditional diphenylanthracene molecule to innovatively prepare dihydrophenazine molecules. This not only retains the good electron transport properties of diphenylanthracene, but also introduces a new electron transport pathway, thereby precisely controlling the quantum interference effect and affecting the conductivity of the molecule, providing application prospects for the quantum interference effect of related structures and providing new ideas and methods for research in the field of molecular electronics and the development of molecular devices. DETAILED DESCRIPTION

[0015] The present invention will be further described below by way of examples, but the embodiments of the present invention are not limited thereto and should not be construed as limiting the scope of protection of the present invention.

[0016] Example 1: Take an appropriate amount of dihydrophenazine molecules in a sample bottle, use a pipette to add a certain proportion of 1,2,4-trichlorobenzene (TCB) solvent, and use an ultrasonic instrument to sonicate for 1 minute to prepare a 0.01mM molecular solution. Use a pipette to take 30μL of the prepared molecular solution and place it on the Au substrate. After operating the instrument to make the Au tip electrode and the Au substrate end electrode contact, apply a 100mV bias voltage and use the scanning tunneling microscope-break junction (STM-BJ) technique to repeatedly form and break the molecular junction to test the molecular conductance. The current is recorded and collected by using a data acquisition device, and the conductance is calculated using the formula G=I / V. Without screening any experimental data, a one-dimensional conductance histogram and a two-dimensional conductance-displacement histogram are constructed.

[0017] Example 2: Take an appropriate amount of dihydrophenazine molecules in a sample bottle, use a pipette to add a certain proportion of propylene carbonate (PC) solvent, and use an ultrasonic instrument to sonicate for 1 minute to prepare a 0.01mM molecular solution. Use a pipette to take 30μL of the prepared molecular solution and place it on the Au substrate. After operating the instrument to make the Au tip electrode and the Au substrate end electrode contact, apply a 100mV bias voltage and use the scanning tunneling microscope-break junction (STM-BJ) technique to repeatedly form and break the molecular junction to test the molecular conductivity. The current is recorded and collected by using a data acquisition device, and the conductance is calculated using the formula G=I / V. Without screening any experimental data, a one-dimensional conductance histogram and a two-dimensional conductance-displacement histogram are constructed.

[0018] Example 3: Take an appropriate amount of dihydrophenazine molecules in a sample bottle, use a pipette to add a certain proportion of chloronaphthalene solvent, and use an ultrasonic instrument to sonicate for 1 minute to prepare a 0.01mM molecular solution. Use a pipette to take 30μL of the prepared molecular solution and place it on the Au substrate. After operating the instrument to make the Au tip electrode and the Au substrate end electrode contact, apply a 100mV bias voltage and use the scanning tunneling microscope-break junction (STM-BJ) technique to repeatedly form and break the molecular junction to test the molecular conductivity. The current is recorded and collected by using a data acquisition device, and the conductance is calculated using the formula G=I / V. Without screening any experimental data, a one-dimensional conductance histogram and a two-dimensional conductance-displacement histogram are constructed.

[0019] Example 4: Take an appropriate amount of dihydrophenazine molecules in a sample bottle, use a pipette to add a certain proportion of 1,2,4-trichlorobenzene (TCB) solvent, and use an ultrasonic instrument to sonicate for 1 minute to prepare a 0.1mM molecular solution. Use a pipette to take 30μL of the prepared molecular solution and place it on the Au substrate. After operating the instrument to make the Au tip electrode and the Au substrate end electrode contact, apply a 100mV bias voltage and use the scanning tunneling microscope-break junction (STM-BJ) technique to repeatedly form and break the molecular junction to test the molecular conductivity. The current is recorded and collected by using a data acquisition device, and the conductance is calculated using the formula G=I / V. Without screening any experimental data, a one-dimensional conductance histogram and a two-dimensional conductance-displacement histogram are constructed.

[0020] Example 5: Take an appropriate amount of dihydrophenazine molecules in a sample bottle, use a pipette to add a certain proportion of propylene carbonate (PC) solvent, and use an ultrasonic instrument to sonicate for 1 minute to prepare a 0.1mM molecular solution. Use a pipette to take 30μL of the prepared molecular solution and place it on the Au substrate. After operating the instrument to make the Au tip electrode and the Au substrate end electrode contact, apply a 100mV bias voltage and use the scanning tunneling microscope-break junction (STM-BJ) technique to repeatedly form and break the molecular junction to test the molecular conductivity. The current is recorded and collected by using a data acquisition device, and the conductance is calculated using the formula G=I / V. Without screening any experimental data, a one-dimensional conductance histogram and a two-dimensional conductance-displacement histogram are constructed.

[0021] Example 6: Take an appropriate amount of dihydrophenazine molecules in a sample bottle, use a pipette to add a certain proportion of chloronaphthalene solvent, and use an ultrasonic instrument to sonicate for 1 minute to prepare a 0.1mM molecular solution. Use a pipette to take 30μL of the prepared molecular solution and place it on the Au substrate. After operating the instrument to make the Au tip electrode and the Au substrate end electrode contact, apply a 100mV bias voltage and use the scanning tunneling microscope-break junction (STM-BJ) technique to repeatedly form and break the molecular junction to test the molecular conductivity. The current is recorded and collected by using a data acquisition device, and the conductance is calculated using the formula G=I / V. Without screening any experimental data, a one-dimensional conductance histogram and a two-dimensional conductance-displacement histogram are constructed.

[0022] Example 7: Take an appropriate amount of dihydrophenazine molecules in a sample bottle, use a pipette to add a certain proportion of 1,2,4-trichlorobenzene (TCB) solvent, and use an ultrasonic instrument to sonicate for 1 minute to prepare a 1mM molecular solution. Use a pipette to take 30μL of the prepared molecular solution and place it on the Au substrate. After operating the instrument to make the Au tip electrode and the Au substrate end electrode contact, apply a 100mV bias voltage and use the scanning tunneling microscope-break junction (STM-BJ) technique to repeatedly form and break the molecular junction to test the molecular conductivity. The current is recorded and collected by using a data acquisition device, and the conductance is calculated using the formula G=I / V. Without screening any experimental data, a one-dimensional conductance histogram and a two-dimensional conductance-displacement histogram are constructed.

[0023] Example 8: Take an appropriate amount of dihydrophenazine molecules in a sample bottle, use a pipette to add a certain proportion of propylene carbonate (PC) solvent, and use an ultrasonic instrument to sonicate for 1 minute to prepare a 1mM molecular solution. Use a pipette to take 30μL of the prepared molecular solution and place it on the Au substrate. After operating the instrument to make the Au tip electrode and the Au substrate end electrode contact, apply a 100mV bias voltage and use the scanning tunneling microscope-break junction (STM-BJ) technique to repeatedly form and break the molecular junction to test the molecular conductivity. The current is recorded and collected by using a data acquisition device, and the conductance is calculated using the formula G=I / V. Without screening any experimental data, a one-dimensional conductance histogram and a two-dimensional conductance-displacement histogram are constructed.

[0024] Example 9: Take an appropriate amount of dihydrophenazine molecules in a sample bottle, use a pipette to add a certain proportion of chloronaphthalene solvent, and use an ultrasonic instrument to sonicate for 1 minute to prepare a 1mM molecular solution. Use a pipette to take 30μL of the prepared molecular solution and place it on the Au substrate. After operating the instrument to make the Au tip electrode and the Au substrate end electrode contact, apply a 100mV bias voltage and use the scanning tunneling microscope-break junction (STM-BJ) technique to repeatedly form and break the molecular junction to test the molecular conductivity. The current is recorded and collected by using a data acquisition device, and the conductance is calculated using the formula G=I / V. Without screening any experimental data, a one-dimensional conductance histogram and a two-dimensional conductance-displacement histogram are constructed.

[0025] Example 10: Take an appropriate amount of dihydrophenazine molecules in a sample bottle, use a pipette to add a certain proportion of 1,2,4-trichlorobenzene (TCB) solvent, and use an ultrasonic instrument to sonicate for 1 minute to prepare a 1mM molecular solution. Use a pipette to take 30μL of the prepared molecular solution and place it on the Au substrate. After operating the instrument to make the Au tip electrode and the Au substrate end electrode contact, apply a 500mV bias voltage and use the scanning tunneling microscope-break junction (STM-BJ) technique to repeatedly form and break the molecular junction to test the molecular conductivity. The current is recorded and collected by using a data acquisition device, and the conductance is calculated using the formula G=I / V. Without screening any experimental data, a one-dimensional conductance histogram and a two-dimensional conductance-displacement histogram are constructed.

[0026] Example 11: Take an appropriate amount of dihydrophenazine molecules in a sample bottle, use a pipette to add a certain proportion of 1,2,4-trichlorobenzene (TCB) solvent, and use an ultrasonic instrument to sonicate for 1 minute to prepare a 1mM molecular solution. Use a pipette to take 30μL of the prepared molecular solution and place it on the Au substrate. After operating the instrument to make the Au tip electrode and the Au substrate end electrode contact, apply an 800mV bias voltage and use the scanning tunneling microscope-break junction (STM-BJ) technique to repeatedly form and break the molecular junction to test the molecular conductivity. The current is recorded and collected by using a data acquisition device, and the conductance is calculated using the formula G=I / V. Without screening any experimental data, a one-dimensional conductance histogram and a two-dimensional conductance-displacement histogram are constructed.

[0027] Example 12: Take an appropriate amount of dihydrophenazine molecules in a sample bottle, use a pipette to add a certain proportion of 1,2,4-trichlorobenzene (TCB) solvent, and use an ultrasonic instrument to sonicate for 1 minute to prepare a 1mM molecular solution. Use a pipette to take 30μL of the prepared molecular solution and place it on the Au substrate. After operating the instrument to make the Au tip electrode and the Au substrate end electrode contact, apply a 1000mV bias voltage and use the scanning tunneling microscope-break junction (STM-BJ) technique to repeatedly form and break the molecular junction to test the molecular conductivity. The current is recorded and collected by using a data acquisition device, and the conductance is calculated using the formula G=I / V. Without screening any experimental data, a one-dimensional conductance histogram and a two-dimensional conductance-displacement histogram are constructed.

Claims

1. A method for controlling the destructive quantum interference effect based on dihydrophenazine molecules. Through this molecular structure design, two nitrogen atoms are introduced into the central benzene ring of the traditional diphenylanthracene molecule to innovatively prepare a dihydrophenazine molecule. This not only retains the good electron transport properties of diphenylanthracene, but also introduces a new electron transport pathway, thereby precisely controlling the quantum interference effect and affecting the conductivity of the molecule. This provides application prospects for the quantum interference effect of related structures and offers new ideas and methods for research in the field of molecular electronics and the development of molecular devices.

2. The method for controlling the destructive quantum interference effect based on dihydrophenazine molecules according to claim 1, further characterized by: Molecular conductivity testing is performed based on the scanning tunneling microscope splitting technique. The specific operating steps are as follows: a cut Au tip and an Au substrate with a uniform and smooth surface after evaporation are fixed on the testing instrument as two metal electrodes, an appropriate amount of prepared 1 mm molecular solution is placed on the Au substrate, and the lifting plate is operated to make the Au tip contact the Au substrate. Under the application of a bias voltage of 100 mV, the Au tip and the Au substrate with the solution are continuously in contact and then disconnected, repeatedly forming and breaking the molecular junction.

3. The method for controlling the destructive quantum interference effect based on dihydrophenazine molecules according to claim 1, further characterized by: Dihydrophenazine molecules are used as target molecules, and 1,2,4-trichlorobenzene, propylene carbonate and chloronaphthalene are used as solvents.

4. The method for controlling the destructive quantum interference effect based on dihydrophenazine molecules according to claim 1, further characterized by: The concentrations of the prepared molecular solutions were 0.01 mM, 0.1 mM, and 1 mM.

5. The method for controlling the destructive quantum interference effect based on dihydrophenazine molecules according to claim 1, further characterized by: The purity of the gold is ≥99.999%.

6. The method for controlling the destructive quantum interference effect based on dihydrophenazine molecules according to claim 1, further characterized by: Based on the scanning tunneling microscope crack junction test, the applied bias voltages were 100mV, 500mV, 800mV, and 1000mV.

7. The method for controlling the destructive quantum interference effect based on dihydrophenazine molecules according to claim 1, further characterized by: The test current was recorded and collected using a data logger, and the conductance was calculated using the formula G = I / V. Without filtering any experimental data, one-dimensional conductance histograms and two-dimensional conductance-displacement histograms were constructed to analyze the conductance.