CN108264496A - The organic luminescent device of phenanthrene derivative and its preparation with aggregation inducing Ultraluminescence enhancing - Google Patents

Abstract

The invention discloses a phenanthrene derivative with aggregation-induced ultraviolet fluorescence enhancement and an organic light-emitting device prepared therefrom. The luminescence band of the phenanthrene derivative is located in the ultraviolet region, and has an aggregation-state ultraviolet fluorescence enhancement characteristic, which can avoid a light-emitting layer during film formation. The fluorescence of the aggregation state is quenched, and the luminescent material is used as a light-emitting layer to make an electroluminescent device (OLED device), which can effectively improve the luminous efficiency of the device.

Description

Phenanthrene Derivatives with Aggregation-Induced Ultraviolet Fluorescence Enhancement and Their Prepared Organic Luminescence device

technical field

The invention relates to a class of 9,(10)-heterocyclic substituted phenanthrene derivatives and their preparation method and application. The luminescence band is located in the ultraviolet light region, and has the characteristics of enhanced fluorescence of aggregated ultraviolet light, and can be used to prepare ultraviolet light organic electroluminescence The active layer material of the device.

Background technique

The fluorescence intensity of organic light-emitting molecules is high in dilute solution, and the fluorescence intensity is weakened in the aggregated state (solid state). This fluorescence quenching phenomenon is caused by molecular aggregation. In the manufacture of organic light-emitting devices, the light-emitting materials need to be coated, so this kind of fluorescence quenching is inevitable. How to overcome the concentration effect of fluorescence, reduce the fluorescence quenching of the aggregated state, and improve the luminous intensity of solid-state materials has been a difficult problem in the field of optoelectronic materials. In 2001, Tang Benzhong's team discovered for the first time that silacyclopentadiene hardly emits light in a solvent, but its luminescence effect suddenly increases when it forms an aggregated state, and named this phenomenon aggregation-induced emission enhancement (AIEE) ), and since then, the team has successively discovered a series of AIEE materials and discussed their applications in the fields of organic electroluminescent devices, chemical detection and biosensors. In 2017, the scientific research achievement of "aggregation-induced luminescence" led by Tang Benzhong won the first prize of the National Natural Science Award (No. Z-103-1-01). In 2010, Tao Xutang's team first discovered that the "Λ-type" TB (Tröger's base) skeleton molecule has AIEE characteristics, and thus developed a series of AIEE red light materials. In 2009, Tian Wenjing's team discovered that distyryl anthracene has AIEE properties. In 2003, our research group found that the solid-state fluorescence enhancement of tetraphenylethylene derivatives is due to the fact that four substituents are connected on both sides of the double bond of olefin, which leads to the increase of the steric hindrance of the adjacent group, which effectively restrains the free rotation of the double bond. Sincerely. So far, the luminescence bands of the reported AIEE materials cover the entire visible light band from blue light to red light, and no AIEE materials in the ultraviolet luminescent region have been reported. The AIEE material of ultraviolet light is expected to have potential application prospects in medical sterilization and water quality cleaning, and the research on AIEE material of ultraviolet light is of great significance. However, organic molecules with high fluorescence quantum yields usually have delocalized large p-bonds, which often lead to a red-shift of the emission band to the visible region.

Contents of the invention

The object of the present invention is to provide a class of 9, (10)-heterocyclic substituted phenanthrene derivatives. The fluorescence emission of this type of 9, (10)-heterocyclic substituted phenanthrene derivatives is in the ultraviolet range and has aggregation state luminescence characteristics, which can be prepared in The application of ultraviolet aggregated fluorescent enhanced materials and their light-emitting devices has important application value in the fields of organic light-emitting diodes, optical switches, and bioluminescent sensors.

In order to achieve the purpose of the invention, the technical solution adopted in the present invention is: a phenanthrene derivative with enhanced fluorescence in an ultraviolet aggregation state, the general structural formula of the phenanthrene derivative is one of the following chemical structural formulas:

,

Wherein, R is _one of the following groups:

, , ,

R is one of the following groups:

, , .

The 9,(10)-heterocyclic substituted phenanthrene derivatives of the present invention not only avoid the fluorescence quenching of the aggregation state, but also solve the contradiction of the red shift of the emission band of the aggregation state (increased concentration).

The present invention also discloses a preparation method of the above-mentioned phenanthrene derivatives with polyultraviolet condensed state fluorescence enhancement, including the following steps: in a nitrogen atmosphere, in the presence of a palladium catalyst, in an organic solvent, bromophenanthrene and a boric acid compound are refluxed for 24- 36h, to obtain phenanthrene derivatives; the boronic acid compound is thiophene-3-boronic acid, furan-3-boronic acid, benzofuran-2-boronic acid, dibenzofuran-4-boronic acid; the conjugation degree of the substituent is increased, The greater the red shift of the fluorescence peak, the higher the fluorescence quantum yield of the 9,(10)-heterocyclic substituted phenanthrene derivative.

In the above technical solution, the catalyst is tetrakistriphenylphosphopalladium; the boiling point of the organic solvent is 100° C. to 110° C., such as toluene and dioxane.

The preparation method of the 9,(10)-heterocyclic substituted phenanthrene derivatives disclosed by the present invention with enhanced ultraviolet fluorescence in an aggregated state comprises adding bromophenanthrene and boroester compounds in sequence to an organic solvent, and then adding lye after mixing , and then in a nitrogen atmosphere, add a palladium catalyst, and then reflux for 24 to 36 hours to obtain a 9, (10)-heterocyclic substituted phenanthrene derivative; further, after the reaction is completed, the solvent is distilled off under reduced pressure, and then ethyl acetate is used to Extraction was carried out, and the organic phase was separated by column chromatography to obtain product 9, (10)-heterocyclic substituted phenanthrene derivative.

The phenanthrene derivatives disclosed in the present invention can be used to prepare luminescent agents in the ultraviolet region, and have the fluorescence enhancement characteristics of the ultraviolet aggregation state. The aggregation state fluorescence quenching of the light-emitting layer in the film is helpful to improve the light-emitting performance of the device. Therefore, the present invention also discloses the application of the above-mentioned phenanthrene derivatives with enhanced fluorescent aggregation in the preparation of the light-emitting layer of the organic light-emitting diode, and the light-emitting device can be widely used in lighting, medical and health, scientific research and other fields; The light-emitting diodes are organic electro-ultraviolet light diodes (OLEDs).

The invention also discloses a light-emitting layer of an organic light-emitting diode. The light-emitting layer of an organic light-emitting diode is prepared from the above-mentioned phenanthrene derivative. The specific preparation method includes the following steps: preparing a solution of the above-mentioned phenanthrene derivative, and then preparing a thin film by spin coating , that is, the light-emitting layer of the organic light-emitting diode is obtained; in the solution of the phenanthrene derivative, the solvent is DMF or a DMF/water mixed solution.

The invention also discloses an organic light-emitting device, which includes a light-emitting layer; the light-emitting layer is prepared from the above-mentioned phenanthrene derivatives, and the rest of the components are conventional technologies; the organic light-emitting device is an organic electroluminescent ultraviolet light diode . For example, an organic light-emitting device made of the above-mentioned phenanthrene derivatives as a light-emitting layer includes an ITO glass substrate, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and an electrode, wherein the hole transport layer is 4,4'-di (9-carbazole)biphenyl, the light-emitting layer is the above-mentioned phenanthrene derivative, the electron transport layer is 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline, the electrode is aluminum, The electron injection layer is 8-hydroxyquinoline lithium, and the steps for preparing an organic light-emitting device are as follows: clean the ITO glass substrate: wipe with acetone cotton, detergent cotton and rinse with pure water; then use glass cleaner, ethanol, etc. , Acetone ultrasonic for 15min; then place it in a plasma processor (model ICP-5000) for treatment (100W, 3min); finally put the treated ITO substrate into the cavity of the vacuum coating machine, at a vacuum degree of 4×10 Vacuum thermal evaporation of organic materials under the condition of ^-4 Pa: vapor deposition of 4,4'-bis(9-carbazole)biphenyl (CBP, as a hole transport layer), and the above-mentioned phenanthrene derivatives (as a light emitting layer) , 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP, as the electron transport layer), 8-hydroxyquinolate lithium (Liq, as the electron injection layer), and finally Evaporated metallic aluminum was used as the cathode.

The invention also discloses the application of the above-mentioned phenanthrene derivatives in the preparation of ultraviolet aggregation-induced fluorescence enhancement materials.

Due to the use of the above-mentioned technical solutions, the present invention has the following advantages compared with the prior art:

The emission band of the 9,(10)-heterocyclic substituted phenanthrene derivative disclosed in the present invention for the first time is located in the ultraviolet light region, and has the characteristics of enhanced ultraviolet fluorescence in the aggregated state, which can avoid the quenching of the aggregated state fluorescence of the luminescent layer during film formation. The luminescent material is used as a luminescent layer to make an electroluminescent device (OLED device), which can effectively improve the luminous efficiency of the device. The present invention discloses for the first time the application of the above-mentioned 9,(10)-heterocyclic substituted phenanthrene derivatives in ultraviolet organic light-emitting diode devices. More importantly, since the luminescence peak of this derivative is located in the ultraviolet region, its energy level can match that of TiO ₂ (bandgap 3.2 eV, 380nm), the most common semiconductor material at present, and has potential in photocatalytic applications. Value.

Description of drawings

Fig. 1 is the ultraviolet absorption spectrogram of 9-(3-furan) phenanthrene in the mixed solvent of water and DMF different proportions among the embodiment 1;

Fig. 2 is the fluorescence emission figure of 9-(3-furan) phenanthrene in the mixed solvent of water and DMF different proportions in embodiment 1;

Fig. 3 is the ultraviolet absorption spectrogram of 9-(2-benzofuran) phenanthrene in mixed solvents of different proportions of water and DMF in embodiment 2;

Fig. 4 is the fluorescence emission figure of 9-(2-benzofuran) phenanthrene in mixed solvents with different ratios of water and DMF in embodiment 2;

Fig. 5 is the ultraviolet absorption spectrogram of 9-(4-dibenzofuran) phenanthrene in mixed solvents of different proportions of water and DMF in embodiment 3;

Fig. 6 is the fluorescence emission figure of 9-(4-dibenzofuran) phenanthrene in mixed solvents with different proportions of water and DMF in embodiment 3;

Fig. 7 is the ultraviolet absorption spectrogram of 9-(3-thiophene) phenanthrene in mixed solvents with different proportions of water and DMF in Example 4;

Fig. 8 is the fluorescence emission diagram of 9-(3-thiophene) phenanthrene in mixed solvents with different proportions of water and DMF in Example 4;

Fig. 9 is the ultraviolet absorption spectrogram of 9,10-benzofuran phenanthrene in mixed solvents with different proportions of water and DMF in Example 5;

Fig. 10 is the fluorescence emission diagram of 9,10-benzofuran phenanthrene in mixed solvents with different proportions of water and DMF in Example 5;

FIG. 11 is a diagram of an OLED device in which 9-(4-dibenzofuran)phenanthrene is a light-emitting layer in Example 3;

Figure 12 is the voltage-current density of the OLED device in which 9-(4-dibenzofuran)phenanthrene is the light-emitting layer in Example 3;

Fig. 13 is the electroluminescence (EL) spectrum of the OLED device with 9-(4-dibenzofuran)phenanthrene as the light-emitting layer in Example 3, where the inset is the photoluminescence spectrum (PL) of the thin film.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the present invention will be further described:

In this embodiment, the measurement of infrared spectrum: measured on ATR-FTAK Nicolet Fourier Transform Infrared Spectrometer. Fluorescence emission and aggregation state emission spectra were measured with Edinburgh FLS 920 fluorescence spectrometer, and the excitation wavelength corresponds to the long-wavelength absorption band (ICT absorption band) of each compound. The 9,(10)-heterocyclic substituted phenanthrene derivative of the present invention is used as an ultraviolet light aggregated fluorescent enhancement material for the first time, and the prepared light-emitting layer can effectively avoid the quenching effect of aggregated fluorescence, thereby improving the luminous efficiency of the device.

Example 1

Weigh 1g (3.89mmol) of 9-bromophenanthrene and 0.43g (3.85mmol) of furan-3-boronic acid into a 50ml three-necked flask, add 20ml of 1,4-dioxane, stir to dissolve, and then add 1.0M Potassium carbonate aqueous solution 10ml. Vacuum and nitrogen gas were repeatedly evacuated for 3 times, and finally 0.2 g of tetrakistriphenylphosphine palladium catalyst was added, and heated to reflux for 24 hours under the protection of nitrogen gas. The system changed from light yellow to black. Spot plate tracking found that the boroester had reacted completely. The solvent was distilled off as much as possible under reduced pressure, followed by extraction with ethyl acetate. Separation by column chromatography, the mobile phase is petroleum ether. After purification, 0.47 g of a light yellow solid powder was obtained, with a yield of about 58.1%. Analyze the resulting compound:

Melting point: 47.5~48.2℃;

Mass spectrum: calculated value: 244.09; measured value: 244.1;

¹ H NMR (DMSO-d ₆ , 400MHz, TMS) d, ppm 6.920~6.914 (t, 1H), 7.771~7.654 (m,4H), 7.875 (s, 1H), 7.918~7.909 (d, 1H), 8.021~7.998 (d, 1H), 8.083 (s, 1H), 8.166~8.143 (d, 1H), 8.869~8.849 (d, 1H), 8.941~8.921 (d, 1H); ¹³ C NMR (DMSO-d ₆ , 400MHz, TMS): d, PPM 144.07, 141.52, 131.57, 130.65, 129.85, 129.22,128.94, 127.56, 127.42, 126.36, 123.85, 123.24,112.86; 3000 cm ^-1 (Ar-H), 1450~1488 cm ^-1 (phenanthrene ring C=C benzene ring skeleton vibration), 1020~1160 cm ^-1 (COC), 750~690 cm ^-1 (CH);

The molecular structural formula of the compound (9-(3-furan)phenanthrene) obtained in this embodiment is:

Fig. 1 is the ultraviolet absorption spectrogram of the above-mentioned 9-(3-furan)phenanthrene in mixed solvents with different proportions of water and DMF. It can be seen that the compound exhibits two absorption bands in pure DMF solvent—located at ~267 nm and ~299 nm respectively, the former corresponds to the absorption of the parent phenanthrene, and the latter corresponds to the intramolecular charge transfer absorption band. As the water content in the mixed solvent increases from 10% to 40%, 9-(3-furan)phenanthrene begins to form aggregates due to the decrease in solubility, and at this time, the short-wavelength absorption peak is blue-shifted (the long-wavelength absorption peak is close to unchanged), indicating that the molecules are H-aggregates arranged face-to-face; continue to increase the water content of the mixed solvent from 50% to 60%, and the short-wavelength absorption peak will continue to blue-shift and the absorbance will drop sharply.

Fig. 2 is the fluorescence emission diagram of the above-mentioned 9-(3-furan)phenanthrene in mixed solvents with different ratios of water and DMF. It can be seen that the compound presents dual fluorescence peaks of equal height in pure DMF solvent—located at ~355 nm and ~375 nm respectively. As the water content in the mixed solvent increases from 10% to 50%, 9-(3-furan)phenanthrene Aggregates began to form due to the decrease in solubility. At this time, the double fluorescence peak positions did not shift and the fluorescence intensity increased significantly, showing the property of aggregation-induced fluorescence enhancement, which was caused by the aggregation of molecules with H-. Continuing to increase the water content of the mixed solvent to 60%, the fluorescence intensity decreased. It can be seen that the fluorescence intensity of the derivative is about 3 times that of its molecular state (pure DMF solvent) when the water content is 50%. Making the molecule into a luminescent film (that is, aggregated state) can avoid the aggregation fluorescence quenching effect, and using the luminescent material as a luminescent layer to make an electroluminescent device (OLED device) can effectively improve the luminous efficiency of the device. More importantly, since the luminescence peak of this derivative is in the ultraviolet region, its energy level can match that of TiO ₂ (bandgap 3.2 eV, 380nm), the most common semiconductor material at present, and has potential in photocatalytic applications. Value.

Example 2

Weigh 1g (3.89mmol) of 9-bromophenanthrene and 0.623g (3.85mmol) of benzofuran-2-boronic acid into a 50ml three-necked flask, add 25ml of 1,4-dioxane, stir to dissolve, and then add 1.0 M potassium carbonate aqueous solution 10ml. Vacuum and nitrogen gas were repeatedly evacuated for 3 times, and finally 0.2 g of tetrakistriphenylphosphine palladium catalyst was added, and heated to reflux for 24 hours under the protection of nitrogen gas. The system changed from light yellow to black. Spot plate tracking found that the boroester had reacted completely. The solvent was distilled off as much as possible under reduced pressure, followed by extraction with ethyl acetate. Separation by column chromatography, the mobile phase is petroleum ether. After purification, 0.56 g of a light yellow solid powder was obtained, with a yield of about 51.3%. Analyze the resulting compound:

Melting point: 102.5~103.2°C;

Mass spectrum: calculated value: 294.10; measured value: 294.1;

¹ H NMR (DMSO-d ₆ , 400 MHz): d, ppm 8.98-9.00 (m, 1H, Ar-H), 8.90-8.92 (m,1H, Ar-H), 8.45-8.47 (m, 1H, Ar-H), 8.33 (s, 1H, Ar-H), 8.13-8.15 (m, 1H, Ar-H), 7.73-7.78 (m, 6H, Ar-H), 7.36-7.46 (m, 3H, Ar-H); ¹³ C NMR (DMSO-d ₆ , 400MHz, TMS): d, ppm 155.18, 154.85, 131.07, 130.75, 130.49, 129.69, 129.16, 129.07, 129.05, 128.51, 126.97, 127.81 126.28, 125.23,124.06, 123.72, 123.39, 121.80, 111.70, 107.11; IR (KBr) n: 3100~3000 cm ^-1 (Ar-H), 1560~1488 cm ^-1 (phenanthrene ring C=C benzene ring skeleton vibration ), 1260 cm ^-1 (COC), 710~750 cm ^-1 (CH);

The molecular structural formula of the compound (9-(2-benzofuran)phenanthrene) obtained in this example is:

Fig. 3 is the ultraviolet absorption spectrum of the above-mentioned 9-(2-benzofuran)phenanthrene in a mixed solvent of water and DMF in different proportions. It can be seen that the compound exhibits two absorption bands in pure DMF solvent—located at ~267 nm and ~320 nm, respectively, the former corresponds to the absorption of the parent phenanthrene, and the latter corresponds to the intramolecular charge transfer absorption band. As the water content in the mixed solvent increases from 10% to 40%, 9-(2-benzofuran)phenanthrene begins to form aggregates due to the decrease in solubility. The peak is almost unchanged), indicating that the molecules are H-aggregates arranged face-to-face; continue to increase the water content of the mixed solvent from 50% to 60%, and the short-wavelength absorption peak will continue to blue-shift and the absorbance will drop sharply.

Fig. 4 is a fluorescence emission diagram of the above-mentioned 9-(2-benzofuran)phenanthrene in mixed solvents with different ratios of water and DMF. It can be seen that the compound presents dual fluorescence peaks of equal height in pure DMF solvent—located at ~388 nm and ~402 nm respectively. As the water content in the mixed solvent increases from 10% to 50%, 9-(2-benzofuran ) phenanthrene began to form aggregates due to the decrease in solubility. At this time, the double fluorescence peak position did not shift and the fluorescence intensity increased significantly, showing the property of aggregation-induced fluorescence enhancement, which was caused by the aggregation of molecules with H-. Continuing to increase the water content of the mixed solvent to 60%, the fluorescence intensity decreased. It can be seen that the fluorescence intensity of the derivative is about 5 times that of its molecular state (pure DMF solvent) when the water content is 50%. Making the molecule into a luminescent film (that is, aggregated state) can avoid the aggregation fluorescence quenching effect, and using the luminescent material as a luminescent layer to make an electroluminescent device (OLED device) can effectively improve the luminous efficiency of the device. More importantly, since the luminescence peak of this derivative is located in the ultraviolet region, its energy level can match that of TiO ₂ (bandgap 3.2 eV, 380nm), the most common semiconductor material at present, and has potential in photocatalytic applications. Value.

Example 3

Weigh 1g (3.89mmol) of 9-bromophenanthrene and 0.816g (3.85mmol) of dibenzofuran-4-boronic acid into a 50ml three-necked flask, add 25ml of 1,4-dioxane, stir to dissolve, and then add 10ml of 1.0M potassium carbonate aqueous solution. Vacuum and nitrogen gas were repeatedly evacuated for 3 times, and finally 0.2 g of tetrakistriphenylphosphine palladium catalyst was added, and heated to reflux for 24 hours under the protection of nitrogen gas. The system changed from light yellow to black. Spot plate tracking found that the boroester had reacted completely. The solvent was distilled off as much as possible under reduced pressure, followed by extraction with ethyl acetate. Separation by column chromatography, the mobile phase is petroleum ether. After purification, 0.59 g of white solid powder was obtained, and the yield was about 60.9%. Analyze the resulting compound:

Melting point: 108.7~109.1℃;

Mass spectrum: calculated value: 344.1; measured value: 344.1;

¹ H NMR (400 MHz, CD ₃ Cl) d, 8.83 (d, J = 8.4 Hz, 1H), 8.79 (d, J = 8.3 Hz, 1H), 8.08 (d, J = 7.7, 1.4 Hz, 1H) , 8.04 (d, J = 7.4, 1.2 Hz, 1H), 7.96 –7.92 (m, 1H), 7.90 (s, 1H), 7.76 – 7.62 (m, 4H), 7.59 (d, J = 7.5, 1.4 Hz ,1H), 7.55 – 7.43 (m, 2H), 7.44 – 7.34 (m, 3H); ¹³ C NMR (101 MHz, CD ₃ Cl) d,156.23, 133.33, 131.54, 130.97, 130.44, 129.20, 128.87, 128.7 , 127.24,127.00, 126.92, 126.86, 126.62, 124.98, 124.31, 122.93, 122.77, 122.66,120.72, 120.15, 112.00, 77.24, 1.06; IR(KBr) n: 3100~3000 cm ^-1 (Ar-H), 1500 ~1450 cm ^-1 (phenanthrene ring C=C benzene ring skeleton vibration), 1200~1150 cm ^-1 (COC), 770~700 cm ^-1 (CH);

The molecular structural formula of the compound (9-(4-dibenzofuran)phenanthrene) obtained in this example is:

Fig. 5 is the ultraviolet absorption spectrum of the above-mentioned 9-(4-dibenzofuran)phenanthrene in a mixed solvent of water and DMF in different proportions. It can be seen that the compound exhibits two absorption bands in pure DMF solvent—located at ~268 nm and ~300 nm, respectively, the former corresponds to the absorption of the parent phenanthrene, and the latter corresponds to the intramolecular charge transfer absorption band. As the water content in the mixed solvent increased from 10% to 40%, 9-(4-dibenzofuran)phenanthrene began to form aggregates due to the decrease in solubility, and at this time, the short-wavelength absorption peak was blue-shifted (long-wavelength The absorption peak is almost unchanged), indicating that the molecules are H-aggregates arranged face-to-face; continue to increase the water content of the mixed solvent from 50% to 60%, and the short-wavelength absorption peak will continue to blue-shift and the absorbance will drop sharply.

Fig. 6 is a graph of fluorescence emission of the above-mentioned 9-(4-dibenzofuran)phenanthrene in mixed solvents with different ratios of water and DMF. It can be seen that the compound presents dual fluorescence peaks of equal height in pure DMF solvent—located at ~363 nm and ~380 nm respectively. As the water content in the mixed solvent increases from 10% to 50%, 9-(4-dibenzo Furan) phenanthrene began to form aggregates due to the decrease in solubility. At this time, the double fluorescence peak position did not shift and the fluorescence intensity increased significantly, showing the property of aggregation-induced fluorescence enhancement, which was caused by the aggregation of molecules with H-. Continuing to increase the water content of the mixed solvent to 60%, the fluorescence intensity decreased. It can be seen that the fluorescence intensity of the derivative is about 4.5 times that of its molecular state (pure DMF solvent) when the water content is 50%. Making the molecule into a luminescent film (that is, aggregated state) can avoid the aggregation fluorescence quenching effect, and using the luminescent material as a luminescent layer to make an electroluminescent device (OLED device) can effectively improve the luminous efficiency of the device. More importantly, since the luminescence peak of this derivative is in the ultraviolet region, its energy level can match that of TiO ₂ (bandgap 3.2 eV, 380nm), the most common semiconductor material at present, and has potential in photocatalytic applications. Value.

Example 4

Weigh 1g (3.89mmol) of 9-bromophenanthrene and 0.493g (3.85mmol) of thiophene-3-boronic acid into a 50ml three-necked flask, add 25ml of 1,4-dioxane, stir to dissolve, and then add 1.0M Potassium carbonate aqueous solution 10ml. Vacuum and nitrogen gas were repeatedly evacuated for 3 times, and finally 0.2 g of tetrakistriphenylphosphine palladium catalyst was added, and heated to reflux for 24 hours under the protection of nitrogen gas. The system changed from light yellow to black. Spot plate tracking found that the boroester had reacted completely. The solvent was distilled off as much as possible under reduced pressure, followed by extraction with ethyl acetate. Separation by column chromatography, the mobile phase is petroleum ether. After purification, 0.41 g of white solid powder was obtained, with a yield of about 45.9%. Analyze the resulting compound:

Melting point: 119.3~120.6°C;

Mass spectrum: calculated value: 260.07; measured value: 260.1;

¹ H NMR (DMSO-d ₆ , 400MHz, TMS): d, ppm 7.414~7.398 (m, 1H), 7.788~7.636(m, 6H), 7.860 (s, 1H), 8.034~8.014(d, 1H) , 8.876~8.856(d, 1H), 8.943~8.923(d, 1H); ¹³ C NMR (DMSO-d ₆ , 400MHz, TMS): d, ppm 140.76, 133.40, 131.54, 130.85,130.61, 129.93, 129.85, 129.05, 127.81, 127.57, 127.45, 127.30, 126.85,126.54, 124.81, 123.81, 123.24; IR (KBr) n: 3100~3000 cm ^-1 (Ar-H), 1450~1488cm ^-1 (phenanthrene ring C=C benzene ring skeleton vibration), 1080 cm ^-1 (CSC), 750~690 cm ^-1 (CH);

The molecular structural formula of the compound (9-(3-thiophene)phenanthrene) obtained in this embodiment is:

Fig. 7 is the ultraviolet absorption spectrum of the above-mentioned 9-(3-thiophene)phenanthrene in mixed solvents with different ratios of water and DMF. It can be seen that the compound exhibits two absorption bands in pure DMF solvent—located at ~267 nm and ~299 nm respectively, the former corresponds to the absorption of the parent phenanthrene, and the latter corresponds to the intramolecular charge transfer absorption band. As the water content in the mixed solvent increases from 10% to 40%, 9-(3-thiophene)phenanthrene begins to form aggregates due to the decrease in solubility, and at this time, the short-wavelength absorption peak is blue-shifted (the long-wavelength absorption peak is close to unchanged), indicating that the molecules are H-aggregates arranged face-to-face; continue to increase the water content of the mixed solvent from 50% to 60%, and the short-wavelength absorption peak will continue to blue-shift and the absorbance will drop sharply.

Fig. 8 is a graph showing the fluorescence emission of the above-mentioned 9-(3-thiophene)phenanthrene in mixed solvents with different proportions of water and DMF. It can be seen that the compound presents dual fluorescence peaks of equal height in pure DMF solvent—located at ~360 nm and ~379 nm respectively. As the water content in the mixed solvent increases from 10% to 50%, 9-(3-thiophene)phenanthrene Aggregates began to form due to the decrease in solubility. At this time, the double fluorescence peak positions did not shift and the fluorescence intensity increased significantly, showing the property of aggregation-induced fluorescence enhancement, which was caused by the aggregation of molecules with H-. Continuing to increase the water content of the mixed solvent to 60%, the fluorescence intensity decreased. It can be seen that the fluorescence intensity of the derivative is about 2 times that of its molecular state (pure DMF solvent) when the water content is 50%. Making the molecule into a luminescent film (that is, aggregated state) can avoid the aggregation fluorescence quenching effect, and using the luminescent material as a luminescent layer to make an electroluminescent device (OLED device) can effectively improve the luminous efficiency of the device. More importantly, since the luminescence peak of this derivative is in the ultraviolet region, its energy level can match that of TiO ₂ (bandgap 3.2 eV, 380nm), the most common semiconductor material at present, and has potential in photocatalytic applications. Value.

Example 5

Weigh 1g (3.89mmol) of 9,10-bromophenanthrene and 1.246g (7.70mmol) of benzofuran-2-boronic acid into a 50ml three-necked flask, add 25ml of 1,4-dioxane, stir to dissolve, and then 10 ml of 1.0 M potassium carbonate aqueous solution was added. Vacuum and nitrogen gas were repeatedly evacuated for 3 times, and finally 0.2 g of tetrakistriphenylphosphine palladium catalyst was added, and heated to reflux for 24 hours under the protection of nitrogen gas. The system changed from light yellow to black. Spot plate tracking found that the boroester had reacted completely. The solvent was distilled off as much as possible under reduced pressure, followed by extraction with ethyl acetate. Column chromatography separation, the mobile phase is petroleum ether. After purification, 0.37 g of a light yellow solid powder was obtained, with a yield of about 23.8%. Analyze the resulting compound:

Melting point: 128.1~129.8°C;

Mass spectrum: calculated value: 410.1; measured value: 410.12;

¹ H NMR (400 MHz, CD ₃ Cl) d, 8.83 – 8.69 (m, 3H), 8.50 (s, 1H), 8.17 (s,1H), 7.97 (d, J = 7.9 Hz, 1H), 7.76 – 7.62 (m, 8H), 7.42 – 7.29 (m, 3H), 7.15(s, 1H); ¹³ C NMR (101 MHz, CD ₃ Cl) d, 127.93, 127.58, 123.07, 122.78, 121.31, 111.62, 108.38, 77.24, 1.06; IR (KBr) n: 3100~3000 cm ^-1 (Ar-H), 1510~1460 cm ^-1 (phenanthrene ring C=C benzene ring skeleton vibration), 1250 cm ^-1 (COC), 710~ 750 cm ^-1 (CH);

The molecular structural formula of the compound (9,10-benzofuranphenanthrene) obtained in this example is:

Fig. 9 is the ultraviolet absorption spectrum of the above-mentioned 9,10-benzofuranphenanthrene in a mixed solvent of water and DMF in different proportions. It can be seen that the compound exhibits two absorption bands in pure DMF solvent—located at ~267 nm and ~312 nm respectively, the former corresponds to the absorption of the parent phenanthrene, and the latter corresponds to the intramolecular charge transfer absorption band. As the water content in the mixed solvent increased from 10% to 40%, 9,10-benzofuranphenanthrene began to form aggregates due to the decrease in solubility, and at this time the short-wavelength absorption peak shifted blue (the long-wavelength absorption peak was close to unchanged), indicating that the molecules are H-aggregates arranged face-to-face; continue to increase the water content of the mixed solvent from 50% to 60%, and the short-wavelength absorption peak will continue to blue-shift and the absorbance will drop sharply.

Fig. 10 is a graph showing the fluorescence emission of the above-mentioned 9,10-benzofuranphenanthrene in mixed solvents with different proportions of water and DMF. It can be seen that the compound presents dual fluorescence peaks of equal height in pure DMF solvent—located at ~388 nm and ~409 nm respectively. Aggregates began to form due to the decrease in solubility. At this time, the double fluorescence peak positions did not shift and the fluorescence intensity increased significantly, showing the property of aggregation-induced fluorescence enhancement, which was caused by the aggregation of molecules with H-. Continuing to increase the water content of the mixed solvent to 60%, the fluorescence intensity decreased. It can be seen that the fluorescence intensity of the derivative is about 3 times that of its molecular state (pure DMF solvent) when the water content is 50%. Making the molecule into a luminescent film (that is, aggregated state) can avoid the aggregation fluorescence quenching effect, and using the luminescent material as a luminescent layer to make an electroluminescent device (OLED device) can effectively improve the luminous efficiency of the device. More importantly, since the luminescence peak of this derivative is located in the ultraviolet region, its energy level can match that of TiO ₂ (bandgap 3.2 eV, 380nm), the most common semiconductor material at present, and has potential in photocatalytic applications. Value.

Table 1 shows the absorption peak position (λ _abs ), luminescence peak position (λ _aem ) and fluorescence quantum yield of Examples 1-5 in solution state (Sol.) and aggregated state (Agg.).

Table 1 Absorption peak position (λ _abs ) of Examples 1-5 in solution state (Sol.) and aggregated state (Agg.),

Luminescence peak position (λ _aem ) and fluorescence quantum yield

Example 6

The OLED light-emitting device made by using the light-emitting material in Example 3 as the light-emitting layer, the ITO glass substrate is cleaned before the device is prepared: wipe with acetone cotton, detergent cotton and rinse with pure water; then use glass cleaning agent respectively , ethanol, and acetone for 15 minutes; then place it in a plasma processor (model ICP-5000) for processing (100W, 3 minutes); finally put the processed ITO substrate into the chamber of the vacuum coating machine, and place it in a vacuum of 4 Vacuum thermal evaporation of organic materials under the condition of ×10 ^-4 Pa: evaporation of 4,4'-bis(9-carbazole)biphenyl (CBP, as a hole transport layer), 9-dibenzofuranphenanthrene (i.e. the product of Example 3, which is used as the light-emitting layer), 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP, used as the electron transport layer), 8-hydroxyquinoline Lithium morphine (Liq, as the electron injection layer), and finally evaporated metal aluminum as the cathode. Fig. 11 is a schematic structural view of an OLED light-emitting device fabricated by using Example 3 as a light-emitting layer. Figure 12 is the voltage-current density curve of the OLED light-emitting device, indicating that the OLED light-emitting device has a turn-on voltage of 8V, which has certain application value; as the applied voltage of the device increases from 8V to 10V, the brightness of the device increases to the maximum (see Figure 13). Figure 13 is the electroluminescence spectrum (EL) of the above-mentioned luminescent material. The luminescence peaks are located at 380nm~400nm, and three of the luminescence peaks are at 384, 392 and 400 nm respectively; The luminescence spectrum (PL) shows three luminescence peaks at 335, 384 and 401 nm respectively. It can be seen that the PL spectrum is similar to the EL spectrum, indicating that the electroluminescence in Figure 13 comes from the light-emitting layer (Example 3). It can be seen that the emission band of the OLED light-emitting device can match the energy level of TiO ₂ (bandgap 3.2eV, absorption peak 380nm), which has practical value.

The invention discloses a class of 9,(10)-heterocyclic substituted phenanthrene derivatives. The non-linear conjugation structure of the phenanthrene ring reduces the conjugation effect of the delocalized bond, making its luminescence band in the ultraviolet region, which overcomes the existing There is a contradiction between high luminous efficiency and the red shift of the luminescent band; and the molecule presents H-aggregated form and exhibits the characteristic of enhanced ultraviolet fluorescence in the aggregated state. Using the luminescent material as a luminescent layer to make an electroluminescent device (OLED device) can effectively improve the luminous efficiency of the device. More importantly, since the luminescence peak of this derivative is located in the ultraviolet region, its energy level can match that of TiO ₂ (bandgap 3.2eV, 380nm), the most common semiconductor material at present, and it has potential applications in photocatalysis. Value.

Claims (10)

1. A phenanthrene derivative with aggregation-induced ultraviolet fluorescence enhancement, characterized in that: the general structural formula of the phenanthrene derivative is one of the following chemical structural formulas: , Wherein, R is _one of the following groups: , , , R is one of the following groups: , , . 2. The preparation method of the phenanthrene derivatives with aggregation-induced ultraviolet fluorescence enhancement as claimed in claim 1, characterized in that, comprising the following steps: in a nitrogen atmosphere, in the presence of a palladium catalyst, in an organic solvent, bromophenanthrene and boric acid Compounds were refluxed for 24-36 hours to obtain phenanthrene derivatives; the boronic acid compounds include thiophene-3-boronic acid, furan-3-boronic acid, benzofuran-2-boronic acid, and dibenzofuran-4-boronic acid. 3. The preparation method of the phenanthrene derivatives with aggregation-induced ultraviolet light fluorescence enhancement according to claim 2, is characterized in that: after the reaction ends, the solvent is removed by distillation under reduced pressure, and then ethyl acetate is used to extract, and the organic phase passes through the column layer The product phenanthrene derivative is obtained by analysis and separation; the palladium catalyst is tetrakistriphenylphosphorous palladium; the organic solvent is toluene or dioxane. 4. The use of the phenanthrene derivative according to claim 1 in the preparation of a light-emitting layer of an organic light-emitting device or an organic light-emitting device. 5. The application according to claim 4, characterized in that: the organic light emitting device is an organic electroluminescent ultraviolet light diode. 6. A light-emitting layer of an organic light-emitting diode, characterized in that: the light-emitting layer of an organic light-emitting diode is prepared from the phenanthrene derivative of claim 1. 7. A method for preparing the light-emitting layer of an organic light-emitting diode, characterized in that it comprises the following steps: configuring the solid of the phenanthrene derivative according to claim 1, and then preparing a thin film by evaporation to obtain the light-emitting layer of an organic light-emitting diode. 8. An organic light-emitting device, characterized in that: the organic light-emitting device comprises a light-emitting layer; the light-emitting layer is prepared from the phenanthrene derivative of claim 1. 9 . The organic light-emitting device according to claim 8 , wherein the organic light-emitting device is an organic electro-ultraviolet light diode. 10. The use of the phenanthrene derivatives as claimed in claim 1 in the preparation of ultraviolet aggregation-induced fluorescence enhancement materials.