Phosphorus-coordinated manganese halide complexes, methods of making and using the same

Abstract

The application provides a phosphorus-coordinated manganese halide complex and a preparation method and application thereof, and belongs to the technical field of luminescent materials. The complex is an ionic luminescent complex formed by coordination of triphenylmethyl (trityl) phosphonium salt as an organic ligand and a manganese halide ion. The complex is synthesized by using a "solution method", has a simple flow, low preparation cost, excellent photophysical properties, green light emission in a solid state, weak self-absorption and high light quantum yield, can be applied to the fields of photoelectric detection, lighting display and the like as a fluorescent powder, a thin film prepared based on the complex can be applied to OLED devices as a luminescent layer, and the complex has excellent X-ray response performance, so that the complex can be made into a scintillator thin film and applied to the fields of X-ray detection and imaging, and has wide application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of luminescent materials, and in particular relates to a type of phosphorus-coordinated manganese halide complex and a preparation method and application thereof. Background Art

[0002] Scintillators, which convert high-energy X-ray photons into visible light signals, are core components of X-ray detectors and play an irreplaceable role in medical imaging, security inspections, and space exploration. Currently, commercial inorganic scintillators typically appear in the form of large crystals, which suffer from complex manufacturing processes, high costs, and difficulty in tunable luminescence. As an emerging class of semiconductor materials, metal halides are ideal candidates for the development of high-performance scintillators due to their diverse crystal structures, tunable band gaps, and excellent photophysical properties.

[0003] Furthermore, organic-inorganic hybrid metal halides have sparked a wave of research in the field of scintillators due to their facile low-temperature solution preparation, excellent scintillation properties, and rich crystal structure flexibility. Among them, manganese(II) halides have become emerging candidates for X-ray scintillators due to their high photoluminescence quantum yield (PLQY), weak self-absorption, and lack of toxic elements. They typically exhibit efficient green emission originating from dd transitions in a tetrahedral coordination environment, which coincides with the peak response of complementary metal oxide semiconductor (CMOS) sensors used in flat-panel X-ray imaging cameras.

[0004] Compared to most metal complexes, Mn(II) complexes offer advantages such as low cost, superior luminescence properties, high stability, low toxicity, and high abundance. Emission from manganese complexes primarily originates from spin-orbit-forbidden dd orbital transitions (4T1(G)-6A1). Phosphorescence is extremely sensitive to the ligand field and coordination crystal field near the manganese center. The coordination crystal field is primarily related to the coordination number, and there are two main coordination modes: four-coordination and six-coordination. Four-coordination exhibits a tetrahedral spatial structure and emits green light, while six-coordination exhibits an octahedral spatial structure and emits red light. Chinese patent CN 108191915 B previously disclosed an ionic tetracoordinate manganese compound, P-Mn, obtained by reacting an organic phosphorus ligand, P (ethyltriphenylphosphine bromide), with manganese bromide tetrahydrate. P-Mn emits green light in n-hexane solution. Combining it with PEG-PPG-PEG can create a new type of rewritable paper. Its fluorescence can be quenched by water, enabling pure water printing. This patent primarily reveals the water-quenching properties of P-Mn, but the complex does not exhibit X-ray responsiveness, likely due to the choice of organic ligand. Therefore, selecting the appropriate organic ligand is crucial for the successful application of Mn(II) complexes in X-ray detection and imaging. SUMMARY

[0005] The present application aims at solving the problems in the prior art, and provides a phosphorus-coordinated manganese halide complex and a preparation method thereof.

[0006] The specific technical scheme of the present application is as follows: a phosphorus-coordinated manganese halide complex is an ionic luminescent complex formed by coordination of triphenylmethyl (trityl) phosphonium salt as an organic ligand and manganese halide ions, and has the following general structure:

[0007]

[0008] A is selected from any one of the following groups:

[0009]

[0010] B is selected from any one of the following groups:

[0011]

[0012] Further, the phosphorus-coordinated manganese halide complex has a double emission characteristic, emits green light in a solid state, and has weak self-absorption and high irradiation luminescence intensity.

[0013] The preparation method of the phosphorus-coordinated manganese halide complex is as follows: MnX2 and triphenylmethyl (trityl) phosphonium salt are weighed, mixed, dissolved with an organic solvent, heated and evaporated, and crystals are precipitated to obtain a manganese halide complex with a triphenylmethyl (trityl) phosphonium salt structure, and the preparation route is as follows:

[0014]

[0015] X is Cl or Br.

[0016] Further, the molar ratio of MnX2 and triphenylmethyl (trityl) phosphonium salt is 1-3:2-6.

[0017] Further, the organic solvent is ethanol, and the evaporation temperature is 40-80 DEG C.

[0018] The scintillator thin film prepared from the phosphorus-coordinated manganese halide complex does not emit light under sunlight, emits green light under ultraviolet and X-ray irradiation, and can be successfully applied to the field of X-ray detection and imaging based on its responsiveness to X-rays.

[0019] The phosphorus-coordinated manganese halide complex can be used in OLED devices. Specifically, the phosphorus-coordinated manganese halide complex can be prepared into a thin film by vacuum evaporation, and then the thin film can be used as a light-emitting layer in the OLED device.

[0020] Based on the solid-state luminescence properties of the above-mentioned phosphorus-coordinated manganese halide complexes, such materials can also be ground into powder and used as phosphors in the fields of solid-state lighting or optoelectronic displays.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. The phosphorus-coordinated manganese halide complex disclosed in this application has excellent photophysical properties, with green light emission in the solid state, weak self-absorption and high quantum yield;

[0023] 2. The phosphorus-coordinated manganese halide complex disclosed in this application has excellent response performance to X-rays and can be prepared into scintillator films for application in the field of X-ray detection and imaging;

[0024] 3. The phosphorus-coordinated manganese halide complex disclosed in this application is prepared into a thin film by vacuum evaporation, and the thin film can be used as a light-emitting layer in an OLED device;

[0025] 4. Based on the solid-state luminescence properties of the phosphorus-coordinated manganese halide complex disclosed in this application, it can be ground into a powder and used as a phosphor in solid-state lighting or optoelectronic display applications. It can also be prepared into a powder and mixed with an organic solvent as an ink for printing or printing applications.

[0026] 5. The phosphorus-coordinated manganese halide complex disclosed in this application can achieve light regulation by changing the type of halogen;

[0027] 6. The phosphorus-coordinated manganese halide complex disclosed in this application is synthesized using a "solution method", which has a simple process, low preparation cost, low toxicity and environmental protection, and is easy to promote and apply on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is the single crystal structure diagram of complex Ⅰ;

[0029] Figure 2 is the single crystal XRD powder diffraction pattern of complex Ⅰ;

[0030] Figure 3 is the single crystal structure diagram of complex II;

[0031] Figure 4 is the single crystal XRD powder diffraction pattern of complex II;

[0032] Figure 5 is the absorption coefficient and photon energy spectrum of complex I and complex II to high energy X-ray;

[0033] Figure 6 is the normalized solid-state emission spectrum of complex Ⅰ;

[0034] Figure 7 is the normalized solid-state emission spectrum of complex II;

[0035] Figure 8 Emission spectra of complex I (a) and complex II (b) under different doses of X-rays;

[0036] Figure 9 X-ray linear response spectra of complex I (a) and complex II (b);

[0037] Figure 10 is the normalized excitation-emission spectrum of complex Ⅰ;

[0038] Figure 11 is the normalized excitation-emission spectrum of complex II;

[0039] Figure 12 is the CIE 1931 chromaticity diagram of complex I;

[0040] Figure 13 is the CIE 1931 chromaticity diagram of complex II;

[0041] Figure 14 This is the relationship between the attenuation coefficient of complex I and complex II after X-ray absorption and thickness;

[0042] Figure 15 is the irradiation luminescence intensity diagram of complex II and inorganic scintillator LuAG:Ce;

[0043] Figure 16 This is the image of shrimp under X-ray irradiation using the scintillator film prepared based on complex II;

[0044] Figure 17 The small figures (a) and (b) are images of the springs made of scintillator films based on complex I and complex II under X-ray irradiation, respectively;

[0045] Figure 18 This is a simple schematic diagram of an X-ray imaging device, where 1 is the X-ray tube, 2 is the sample, 3 is the scintillator, 4 is the reflector, 5 is the camera, and 6 is the computer.

[0046] Figure 19 This is the luminescence image of the thin film OLED device prepared based on complex II. DETAILED DESCRIPTION

[0047] The technical solutions of the present application are further described below with reference to the drawings, but are not limited thereto, and any modification or equivalent replacement within the spirit and scope of the technical solutions of the present application shall be covered in the protection scope of the present application.

[0048] Example 1

[0049] The synthesis route of the phosphorus-coordinated manganese halide complex I is as follows:

[0050]

[0051] The specific preparation process of the complex I is as follows:

[0052] Preparation of the phosphorus-coordinated manganese halide complex: MnCl2(1 mmol) and C 37 H 30 ClP (ligand A, 1 mmol) were charged into a 20 mL vial, 5 mL of ethanol was added for complete dissolution, and then slowly evaporated at 40°C. Crystals were precipitated after about a week, which was the complex with the structure shown in formula I. The single crystal structure diagram of the complex I is shown in Figure 1 , and the single crystal XRD powder diffraction diagram of the complex I is shown in Figure 2 .

[0053] Example 2

[0054] The synthesis route of the phosphorus-coordinated manganese halide complex II is as follows:

[0055]

[0056] The specific preparation process of the complex II is as follows:

[0057] Preparation of the phosphorus-coordinated manganese halide complex: MnCl2(1 mmol) and C 37 H 30 BrP (ligand B, 1 mmol) were charged into a 20 mL vial, 5 mL of ethanol was added for complete dissolution, and then slowly evaporated at 40°C. Crystals were precipitated after about a week, which was the complex with the structure shown in formula II. The single crystal structure diagram of the complex II is shown in Figure 3 , and the single crystal XRD powder diffraction diagram of the complex II is shown in Figure 4 .

[0058] Related performance tests

[0059] 1) The absorption coefficient of the complex to high-energy X-rays and the photon energy spectrum can be obtained by measuring the irradiation emission spectrum, Figure 5That is the absorption coefficient and photon energy spectrum of complex I and complex II. It can be seen from the figure that the X-ray energy range is from 0.001MeV to 1MeV, which is at the same order of magnitude as the absorption coefficient of inorganic scintillators LuAG:Ce and CsI:TI.

[0060] 2) Figure 6 、 Figure 7 They are the normalized solid-state emission spectra of complex I and complex II, respectively. As can be seen from the figure, the emission characteristic peaks of complex I are located at 514nm and 561nm, and the emission characteristic peaks of complex II are located at 511nm and 604nm.

[0061] 3) Figure 8 Panels (a) and (b) are the emission spectra of complex I and complex II under different doses of X-rays, respectively. As can be seen from the figures, both complexes show a monotonically increasing response under X-ray irradiation (60kV, 0.15μGy / s→3.35μGy / s), and exhibit a good linear response in the range of 0.15μGy / s→3.35μGy / s.

[0062] Figure 9 Panels (a) and (b) show the relationship between irradiation intensity and X-ray dose rate for Complex I and Complex II, respectively. The detection limit was set when the signal-to-noise ratio was 3. The detection limits for Complex I and Complex II were 96.4 nGyaiX / s and 112.7 nGyaiX / s, respectively, far below the standard limit for medical X-ray diagnosis (5.5 μGyaiX / s).

[0063] 4) The excitation and emission spectra were measured on an Edinburgh FLS-980 spectrophotometer. The emission spectra were obtained using a 460W xenon lamp in the range of 300nm-800nm. The normalized solid-state excitation-emission spectra of complex I and complex II are shown in Figure 2. Figure 10 、 Figure 11 As shown, the emission characteristic peaks of complex I are located at 514nm and 561nm, and the emission characteristic peaks of complex II are located at 511nm and 604nm, respectively. The emission bands are consistent with [MnX4] 2- Tetraligand Mn in the unit 2+ Ions 4 T1(G) to 6 A1 radiative transition, the crystal has only one luminescent center, emitting green light. Both have large Stokes shifts, with the Stokes shifts of complex I being 65nm and 112nm, and those of complex II being 42nm and 135nm, showing weak self-absorption.

[0064] 5) The emission spectra of complexes I and II were calculated using CIE 1931 software. The results are shown in Figure 12 and Figure 13 The chromaticity values ​​of complex I and complex II were (0.349, 0.561) and (0.249, 0.557), respectively, both of which are green light.

[0065] 6) The material density data of complex I and complex II were obtained by calculating the X-ray absorption coefficient and XRD characterization experiment, and the curve of the attenuation coefficient of the two complexes after absorbing X-rays with an energy of 60keV as a function of thickness was drawn. The results are shown in Figure 14 ,As can be seen from the figure, the crystal thickness of Complex Ⅰ and Complex Ⅱ is at the same level as the inorganic scintillator LuAG:Ce after 2 mm.

[0066] 7) A comparison of the light yield of complex II and the inorganic scintillator LuAG:Ce was obtained under X-ray irradiation at the same dose rate. The results are shown in Figure 15 As can be seen from the figure, the light yield of complex II is more than twice that of the inorganic scintillator LuAG:Ce, which can meet the application needs of many fields such as space exploration and medical imaging.

[0067] Application Example 1

[0068] Based on the unique green light emission and high luminescence quantum efficiency characteristics of complex I and complex II, attempts were made to make these two complexes into scintillator films for use in the field of X-ray imaging.

[0069] The film preparation process is as follows: 1g of polymethyl methacrylate (PMMA) is dissolved in 10g of toluene to form a pre-clear solution, which is then mixed with the powder of complex II (0.4g) ground three times, stirred evenly, and then titrated on a glass slide and evaporated at room temperature to obtain a 1.7mm thick scintillator film.

[0070] The scintillator film prepared based on complex II does not emit light under sunlight, but emits green light under ultraviolet and X-ray irradiation. Since different metals have different absorption degrees of X-rays, different spatial saturations are formed on the scintillator, so it can be used for optical imaging, such as Figure 16 As shown, when the shrimp is imaged using the film under X-ray irradiation, a clear shrimp structure can be observed.

[0071] Based on the same method, a scintillator film prepared using complex I can be obtained. Figure 17 The small figures (a) and (b) are the images of the springs made of scintillator films based on complex I and complex II under X-ray irradiation, respectively. Very clear spring images can be observed.

[0072] Application Example 2

[0073] Complex II was ground into powder and placed in an evaporation boat. The ITO substrate (ITO side facing down) was then placed in a vacuum evaporation chamber. The corresponding mask was rotated under the substrate and the ITO surface was shielded with a baffle. The chamber was evacuated. The evaporation power was turned on to vacuum coat the evaporation boat. The resulting film was applied as a light-emitting layer to an OLED device for luminescence experiments. Figure 19 The luminescence image shows green light emission. This phenomenon is also observed when a thin film made from complex I is applied to an OLED device.

[0074] It can be seen from this that the thin film materials made by vacuum evaporation based on complex I and complex II can be used as light-emitting layers in OLED devices.

[0075] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A phosphorus-coordinated manganese halide complex characterized by: It is an ionic luminescent complex formed by triphenylmethyl (trityl) phosphine salt as an organic ligand coordinated with manganese halide ions. Its general structural formula is as follows: Wherein, A is selected from any one of the following groups: B is selected from any one of the following groups:

2. The phosphorus-coordinated manganese halide complex according to claim 1, wherein The phosphorus-coordinated manganese halide complex has dual emission characteristics, emits green light in the solid state, and has weak self-absorption and high irradiation luminescence intensity.

3. The method for preparing the phosphorus-coordinated manganese halide complex according to any one of claims 1 to 2, characterized in that: Weigh MnX2 and triphenylmethyl (trityl) phosphine salt, mix them, fully dissolve them in an organic solvent, heat and evaporate them, and precipitate crystals to obtain a manganese halide complex with a triphenylmethyl (trityl) phosphine salt structure. The preparation route is as follows: Wherein, X is Cl or Br.

4. The method for preparing the phosphorus-coordinated manganese halide complex according to claim 3, wherein: The molar ratio of MnX2 to triphenylmethyl (trityl) phosphine salt is 1-3:2-6.

5. The method for preparing the phosphorus-coordinated manganese halide complex according to claim 4, wherein: The organic solvent is ethanol, and the evaporation temperature is 40-80°C.

6. Use of the phosphorus-coordinated manganese halide complex according to any one of claims 1 to 2 in X-ray detection and imaging.

7. Use of the phosphorus-coordinated manganese halide complex according to any one of claims 1 to 2 in an OLED device, characterized in that: The phosphorus-coordinated manganese halide complex is prepared into a thin film by vacuum evaporation and then the thin film is used as a light-emitting layer in an OLED device.

8. Use of the phosphorus-coordinated manganese halide complex according to any one of claims 1 to 2 in solid-state lighting or optoelectronic display.

9. A scintillator thin film, characterized in that: It is prepared based on the phosphorus-coordinated manganese halide complex described in any one of claims 1 to 2. The scintillator film does not emit light under sunlight, but emits green light under ultraviolet and X-ray irradiation.

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