Phosphorus coordination manganese halide complex as well as preparation method and application thereof

Abstract

The invention provides a phosphorus coordination manganese halide complex as well as a preparation method and application thereof, and belongs to the technical field of luminescent materials. The complex is an ionic luminous complex which is formed by taking triphenylmethyl (triphenylmethyl) phosphine salt as an organic ligand and coordinating and combining with manganese halide ions. A solution method is adopted for synthesis, the process is simple, the preparation cost is low, and the complex has excellent photophysical performance, emits green light in a solid state, and is weak in self-absorption and high in light quantum yield; the fluorescent powder can be applied to the fields of photoelectric detection, illumination display and the like; a thin film prepared on the basis of the complex can also be used as a light-emitting layer to be applied to an OLED (Organic Light Emitting Diode) device; and the complex has excellent X-ray response performance, so that the complex can be prepared into a scintillator film to be applied to the fields of X-ray detection and imaging, and has a wide application prospect.

Description

Technical Field

[0001] The 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 can convert high-energy X-ray photons into visible light signals. They are the core components of X-ray detectors and play an irreplaceable role in medical imaging, security inspections, space exploration and other fields. Currently, commercial inorganic scintillators usually appear in the form of large-sized crystals, which have defects such as complex manufacturing processes, high costs and difficult to tune luminescence. As an emerging class of semiconductor materials, metal halides have become one of the ideal candidate materials for the development of high-performance scintillators due to their rich crystal structures, adjustable band gaps and excellent photophysical properties.

[0003] In addition, organic-inorganic hybrid metal halides have triggered a research boom in the field of scintillators due to their simple low-temperature solution preparation process, excellent scintillation performance and rich crystal structure flexibility. Among them, manganese (II) halide has become an emerging candidate material for X-ray scintillators due to its high photoluminescence quantum yield (PLQY), weak self-absorption and lack of toxic elements. It usually exhibits efficient green emission, originating from dd transitions in a tetrahedral coordination environment, which is consistent with the peak response of complementary metal oxide semiconductor (CMOS) sensors used in flat panels or cameras for X-ray imaging.

[0004] Compared with most metal complexes, Mn(II) complexes have the advantages of low cost, superior luminescence performance, high stability, low toxicity, and high abundance. The emission of manganese complexes mainly originates from the spin-orbit forbidden dd orbital transition (4T1(G)-6A1). The phosphorescence emission is extremely sensitive to the ligand field and coordination crystal field near the manganese center. The coordination crystal field is mainly related to the coordination number. There are two main coordination modes: one is four-coordination and the other is six-coordination. Among them, the four-coordination mainly presents a tetrahedral spatial structure and emits green light; while the six-coordination presents an octahedral spatial structure and shows red light emission. Chinese patent CN 108191915 B has disclosed an ionic tetracoordinate manganese compound P-Mn, which is obtained by mixing an organic phosphorus ligand P (ethyl triphenylphosphine ligand bromide) and tetrahydrated manganese bromide and reacting them. P-Mn emits green light in n-hexane solution. Combining it with PEG-PPG-PEG can construct a new type of rewritable paper, and the fluorescence can be quenched by water stimulation to achieve the goal of pure water printing. This patent mainly reveals that P-Mn has the characteristic of water quenching fluorescence, but the complex does not show response performance to X-rays, which may be related to the choice of organic ligands. Therefore, if you want to successfully apply Mn(II) complexes to the field of X-ray detection and imaging, choosing a suitable organic ligand is the key. Summary of the invention

[0005] The purpose of the present invention is to solve the deficiencies in the prior art and provide a type of phosphorus-coordinated manganese halide complex and a preparation method thereof. The present application specifically selects organic ligands such as triphenylmethyl (trityl) phosphine salts containing multiple benzene rings and large molecular weight to construct manganese-based metal halides. After in-depth research on its photophysical properties, it is found that such manganese halide complexes have bimodal emission characteristics and high irradiation luminescence intensity, can be used in the fields of photoelectric detection, lighting display, etc., and have excellent X-ray imaging performance.

[0006] The specific technical scheme of the present invention is: a type of phosphorus-coordinated manganese halide complex, which is an ionic luminescent complex formed by triphenylmethyl (trityl) phosphine salt as an organic ligand coordinated with a manganese halide ion, and its general structural formula is as follows:

[0007]

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

[0009]

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

[0011]

[0012] Furthermore, 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.

[0013] The preparation method of the above-mentioned phosphorus-coordinated manganese halide complex is: 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:

[0014]

[0015] Wherein, X is Cl or Br.

[0016] Furthermore, the molar ratio of MnX2 to triphenylmethyl (trityl) phosphine salt is 1-3:2-6.

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

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

[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 an 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 field of solid-state lighting or optoelectronic display.

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

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

[0023] 2. The phosphorus-coordinated manganese halide complex disclosed in the present 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 the present 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 characteristics of the phosphorus-coordinated manganese halide complex disclosed in this application, it can be ground into powder and used as phosphor in the field of solid lighting or optoelectronic display, or it can be prepared into powder and mixed with an organic solvent as ink for use in the field of printing or printing;

[0026] 5. The phosphorus-coordinated manganese halogen 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 the present 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 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 The emission spectra of complex Ⅰ(a) and complex Ⅱ(b) under different doses of X-rays;

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

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

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

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

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

[0041] Fig.14 The spectrum of the relationship between the attenuation coefficient of complex Ⅰ and complex Ⅱ after X-ray absorption and thickness;

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

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

[0044] Fig.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] Fig.18 It is a simple schematic diagram of an X-ray imaging device, wherein 1-X-ray tube, 2-sample, 3-scintillator, 4-reflector, 5-camera, 6-computer;

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

[0047] The technical solution of the present invention is further described below in conjunction with the accompanying drawings, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be included in the protection scope of the present invention.

[0048] Example 1

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

[0050]

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

[0052] Preparation of phosphorus-coordinated manganese halide complex: weigh MnCl2 (1 mmol) and C 37 H 30 ClP (ligand A, 1 mmol) was placed in a 20 mL vial, 5 mL of ethanol was added to fully dissolve, and then slowly evaporated at 40 ° C. After about a week, crystals were precipitated, which was the complex shown in formula I. The single crystal structure of complex I is shown in the figure Figure 1 The single crystal XRD powder diffraction pattern of complex Ⅰ is shown in Figure 2 shown.

[0053] Example 2

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

[0055]

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

[0057] Preparation of phosphorus-coordinated manganese halide complex: weigh MnCl2 (1 mmol) and C 37 H 30 BrP (ligand B, 1 mmol) was placed in a 20 mL vial, 5 mL of ethanol was added to fully dissolve it, and then slowly evaporated at 40 ° C. After about a week, crystals were precipitated, which was the complex with the structure shown in formula II. The single crystal structure of complex II is shown in the figure Figure 3 The single crystal XRD powder diffraction pattern of complex II is shown in Figure 4 shown.

[0058] Related performance tests

[0059] 1) The absorption coefficient and photon energy spectrum of the complex to high-energy X-rays 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. It can be seen from the figure that 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. It can be seen from the figures that both complexes show a monotonically increasing trend under X-ray irradiation (60 kV, 0.15 μGy / s→3.35 μGy / s), and exhibit a good linear response in the range of 0.15 μGy / s→3.35 μGy / s.

[0062] Fig. 9 The small figures (a) and (b) reflect the relationship between the irradiation intensity and X-ray dose rate of complex I and complex II, respectively. The detection limit is set when the signal-to-noise ratio is equal to 3. The detection limits of complex I and complex II are 96.4nGyaiX / s and 112.7nGyaiX / s, respectively, which are far lower than the standard limit of X-ray medical diagnosis (5.5μGyaiX / s).

[0063] 4) The excitation spectrum and emission spectrum were measured on an Edinburgh FLS-980 spectrophotometer. The emission spectrum was measured 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 Fig.10 , Fig.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- The tetraligand Mn in the unit 2+ Ions 4 T1(G) to 6 A1 radiation transition, the crystal has only one luminescent center, emitting green light. Both have large Stokes shifts, the Stokes shifts of complex I are 65nm and 112nm, and the Stokes shifts of complex II are 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 Fig.12 and Fig.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 attenuation coefficient of the two complexes after absorbing X-rays with an energy of 60 keV was plotted as a function of thickness. The results are shown in Fig.14 ,From the figure, it can be seen that the crystal thickness of complex Ⅰ and complex Ⅱ is at the same level as the inorganic scintillator LuAG:Ce after 2mm.

[0066] 7) Under the same dose rate of X-ray irradiation, the light yield of complex II and inorganic scintillator LuAG:Ce was compared. The results are shown in Fig.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 requirements in many fields such as space detection and medical imaging.

[0067] Application Example 1

[0068] Based on the unique green light emission and high luminescence quantum efficiency characteristics of complexes I and 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 dripped onto 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 of X-rays, different spatial saturation is formed on the scintillator, so it can be used for optical imaging, such as Fig.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. Fig.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. Very clear images of the springs can be observed.

[0072] Application Example 2

[0073] The complex II was ground into powder, and the powder was placed in an evaporation boat. The ITO substrate (ITO side facing down) was placed in a vacuum evaporation chamber, and the corresponding mask was rotated to the bottom of the substrate. The ITO surface was covered with a baffle, and the chamber was evacuated. The evaporation power was turned on to vacuum coat the evaporation boat. The obtained film was applied as a light-emitting layer to an OLED device for a light-emitting experiment. Fig.19 This is the luminescence image, and green light emission is observed. The same phenomenon occurs when the film made based on complex I is applied to OLED devices.

[0074] It can be seen from this that the thin film material made by vacuum evaporation based on complex I and complex II can be used as a light-emitting layer 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 specification 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 and 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, characterized in that: The phosphorus coordinated manganese halogen 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, characterized in that: 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, characterized in that: 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 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 lighting or optoelectronic display.

9. A scintillator 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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