Guest-regulated near-infrared light-emitting material and preparation method thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHENJIANG PUYUE OPTOELECTRONIC MATERIALS CO LTD
- Filing Date
- 2026-02-13
- Publication Date
- 2026-06-26
Smart Images
Figure CN122277611A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of luminescent materials, and in particular to a near-infrared luminescent material with object-modulated emission and its preparation method. Background Technology
[0002] Platinum(II) polypyridine complexes typically have a square-plane d 8 Electronic configurations of these complexes have attracted widespread attention due to their excellent photophysical properties, self-assembly behavior, and potential applications. During molecular aggregation, these complexes readily generate intermolecular Pt(II)···Pt(II) metal affinity interactions, thus exhibiting unique spectral and luminescent properties, and have been applied in fields such as luminescent materials, sensing, gels, and biomedicine. However, the Pt(II)···Pt(II) interaction itself is relatively weak, and can usually only be effectively observed under solid-state, high-concentration, or induced aggregation conditions. The interaction distance and strength are difficult to precisely control in dilute solutions, limiting the rational design and application expansion of related functional materials.
[0003] To modulate the Pt(II)···Pt(II) interaction, researchers have attempted to induce self-assembly through external stimuli such as temperature, solvent, and pH. However, these methods often lack precision and controllability. In contrast, host-guest supramolecular assembly, due to its high designability and reversibility, offers a new approach to regulating weak interactions. Especially in mechanically interlocked structures such as rotaxanes, the spatial distance between adjacent macrocycles can be effectively controlled by designing the structure, length, and binding site distribution of the axon molecules, thereby achieving fine-tuning of intermolecular interactions.
[0004] Hydrogen-bonded aromatic amides or acylhydrazone macrocycles are a new class of supramolecular host molecules. Their skeletons are pre-organized through intramolecular hydrogen bonds, exhibiting structural stability, well-defined cavities, ease of functionalization, and good host-guest recognition capabilities. They have been used to construct supramolecular systems such as vesicles, gels, and rotaxanes. However, in current technology, supramolecular systems based on these macrocycles and combined with platinum(II) complexes, which allow for precise control of Pt(II) interactions and their luminescence properties in solution through the addition of guest molecules, are still relatively lacking. Therefore, there is an urgent need to develop a new supramolecular strategy to achieve controllable regulation of Pt(II) metal affinity interactions and related optical properties. Summary of the Invention
[0005] To achieve the above objectives, the embodiments in this specification adopt the following technical solutions: In a first aspect, this application provides a near-infrared luminescent material, comprising: a trinuclear alkynylplatinum(II) terpyridine complex MC2 based on an acylhydrazone macrocycle and pyridine salt guest cations BP2, BP3, and BP4 with electron-deficient characteristics, with the following structural formulas respectively. ; .
[0006] Secondly, this application provides a method for preparing an infrared luminescent material, comprising the following steps: Step S1. Dissolve the trinuclear alkynylplatinum(II) terpyridine complex MC2 based on the acylhydrazone macrocycle in the organic solvent acetone or methanol to obtain a macrocyclic MC2 solution; Step S2. Dissolve the pyridinium salt guest cations BP2, BP3 and BP4 in organic solvents acetone or methanol respectively to obtain pyridinium salt solutions; Step S3: Slowly add the pyridine salt solution from step S2 to the macrocyclic MC2 solution from step S1 to obtain the near-infrared luminescent material.
[0007] A preferred technical solution for the preparation of an infrared luminescent material is that the trinuclear alkynylplatinum(II) terpyridine complex MC2 based on an acylhydrazone macrocycle is prepared by a dynamic covalent chemistry method, including the following steps: S11. Compound 1 Sodium hydroxide is dissolved in organic solvent I, and compound 2 is added. The reaction system was heated until complete, then the mixture was concentrated and ammonia water was added and heated until complete. After impurity removal and purification, compound 3 was obtained; wherein, the structural formula of compound 3 is: ; S12. Compound 3 and potassium hypochloroplatinate were dissolved in organic solvent II and reacted with stirring at room temperature. After purification and removal of impurities, compound 4 was obtained. The structural formula of compound 4 is as follows: ; S13. Compound 5 EDCI and Compound 6 The compound was added to organic solvent III, stirred at room temperature, and purified to obtain compound 7. ; S14. Compound 7 and trifluoroacetic acid were added to organic solvent IV, and the mixture was heated to react. After removing impurities and purifying, compound 8 was obtained. ; S15. Compound 4, compound 8, cuprous iodide and triethylamine were added to organic solvent V and reacted at room temperature until complete. After removing impurities and purifying, the trinuclear alkynylplatinum(II) terpyridine complex MC2 based on the acylhydrazone macrocycle was obtained.
[0008] As a preferred technical solution for the preparation of an infrared luminescent material, the pyridine salt guest BP2 is prepared by the following method: 1,2-bis(4-pyridine)ethylene, 1-bromooctane and N,N-dimethylformamide are added sequentially, the mixture is heated to 120°C and stirred for 24 hours, cooled, filtered, and the filter residue is collected. The residue is then washed alternately with a small amount of N,N-dimethylformamide and diethyl ether to obtain a yellow solid powder. Anion exchange is then performed to obtain a bright yellow solid powder BP2.
[0009] A preferred technical solution for preparing an infrared luminescent material is as follows: the pyridinium salt guest BP3 is prepared by the following method under inert gas protection: p-dibromobenzene, pinacol 4-pyridinium borate, tetrakis(triphenylphosphine)palladium, and cesium carbonate are added to a mixed solvent composed of N,N-dimethylformamide and toluene, and the mixture is heated to obtain a reaction solution containing the target intermediate; after cooling, the mixture is filtered through diatomaceous earth to remove the solvent and then subjected to extraction, washing with water, and drying. Subsequently, an acidic reagent is added to the obtained organic phase to precipitate the product. After alkalization, the product is filtered to obtain a white solid intermediate EXBIPY. The obtained intermediate EXBIPY is dissolved in N,N-dimethylformamide with 1-bromooctane and heated to react. After cooling, an ether solvent is added to precipitate the product. After filtration and washing, a crude pyridinium salt product is obtained. Subsequently, the crude product is dissolved in water, and ammonium hexafluorophosphate is added to carry out anion exchange reaction. The mixture is filtered and dried to obtain a pale yellow solid.
[0010] A preferred technical solution for the preparation of an infrared luminescent material is as follows: the pyridine salt guest BP4 is prepared by the following method: under inert gas protection, 4,4′-dibromobiphenyl, 4-pyridineboronic acid, palladium catalyst and inorganic base are added to a mixed solvent composed of water, toluene and 1,4-dioxane, and heated to obtain a reaction solution containing a bispyridine intermediate; after cooling, the solution is filtered through diatomaceous earth to remove the solvent and then subjected to extraction, water washing and drying. Subsequently, it is purified by column chromatography to obtain a white solid intermediate EX2BIPY. The intermediate EX2BIPY is dissolved in N,N-dimethylformamide with 1-bromooctane and heated to react. After cooling, an ether solvent is added to precipitate the product. After filtration and washing, a crude pyridine salt product is obtained; then the crude product is dissolved in water, and ammonium hexafluorophosphate is added to carry out anion exchange reaction. After filtration and drying, a pale yellow solid is obtained.
[0011] Compared with the prior art, the quasi-rotaxane near-infrared luminescent material provided by the present invention, which is based on the trinuclear alkynyl platinum(II) terpyridine complex MC2 of acylhydrazone macrocycle and electron-deficient pyridine salt guests BP2, BP3, and BP4, has significant beneficial effects: through a simple host-guest supramolecular self-assembly, in dilute solutions (concentration as low as 4.5 × 10⁻⁶), it can achieve near-infrared luminescence. -5 mol·L-1 This method enables precise and reversible control of the distance and intensity of the Pt(II)···Pt(II) metal affinity interaction. By simply changing the conjugation length of the guest axis molecules, a gradient of near-infrared luminescence enhancement from weak to strong can be obtained, overcoming the shortcomings of existing technologies where this interaction can only be effectively activated in solid state or at high concentrations and lacks precision in regulation. At the same time, the material preparation method is simple, the conditions are mild, and the yield is high. Moreover, the assemblies form ordered nanostructures at the microscale, providing a new strategy and practical approach for developing high-performance solution-processable near-infrared luminescent materials, supramolecular sensors, and bioimaging probes. Attached Figure Description
[0012] Figure 1 The NMR spectrum of compound 4; Figure 2 The NMR spectrum of compound 7; Figure 3 The NMR spectrum of compound 8; Figure 4 The NMR spectrum of MC2; Figure 5 The NMR spectrum of BP2; Figure 6 The NMR spectrum of BP3; Figure 7 The NMR spectrum of BP4; Figure 8 The fluorescence titration spectrum of the quasi-[4]rotaxane prepared in Example 1 of this invention is shown.
[0013] Figure 9 The fluorescence titration spectrum of quasi-[4]rotaxane prepared in Example 2 of this invention is shown.
[0014] Figure 10 The fluorescence titration spectrum of quasi-[4]rotaxane prepared in Example 3 of this invention is shown.
[0015] Figure 11 A statistical graph showing the changes in fluorescence intensity of each quasi[4] rotaxane.
[0016] Figure 12 Transmission electron microscopy (TEM) image of the MC2 macroring prepared for Example 1.
[0017] Figure 13 This is a transmission electron microscope image of the quasi-[4]rotaxane obtained in Example 1 of the present invention. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0019] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. Preparation Example Preparation Example 1
[0020] The trinuclear alkynylplatinum(II) terpyridine complex MC2 based on the acylhydrazone macrocycle was prepared by a dynamic covalent chemistry method, including the following steps: S11. Compound 1 Sodium hydroxide is dissolved in organic solvent I, and compound 2 is added. The reaction system was heated until complete, then the mixture was concentrated and ammonia water was added and heated until complete. After impurity removal and purification, compound 3 was obtained; wherein, the structural formula of compound 3 is: .
[0021] Reaction formula: .
[0022] S12. Compound 3 and potassium hypochloroplatinate were dissolved in organic solvent II and reacted with stirring at room temperature. After purification and removal of impurities, compound 4 was obtained. The structural formula of compound 4 is as follows: Its NMR spectrum is as follows Figure 1 As shown; Reaction formula: .
[0023] S13. Compound 5 EDCI and Compound 6 The compound was added to organic solvent III, stirred at room temperature, and purified to obtain compound 7. Its NMR spectrum is as follows: Figure 2 As shown; Reaction formula: .
[0024] In step S14, compound 7 and trifluoroacetic acid were added to organic solvent IV, and the mixture was heated to react. After removing impurities and purifying, compound 8 was obtained. Its NMR spectrum is as follows: Figure 3 As shown; Reaction formula: .
[0025] S15. Compounds 4 and 8, cuprous iodide, and triethylamine were added to organic solvent V and reacted at room temperature until complete. After purification and removal of impurities, the trinuclear alkynylplatinum(II) terpyridine complex MC2 based on an acylhydrazone macrocycle was obtained, and its NMR spectrum is shown below. Figure 4 As shown.
[0026] Reaction formula: . Preparation Example 2
[0027] The pyridine salt guest BP2 was prepared as follows: 1,2-bis(4-pyridine)ethylene, 1-bromooctane, and N,N-dimethylformamide were added sequentially, the mixture was heated to 120°C and stirred for 24 hours, cooled, filtered, and the residue was collected. The residue was then washed alternately with a small amount of N,N-dimethylformamide and diethyl ether to obtain a yellow solid powder. Anion exchange was then performed to obtain a bright yellow solid powder, BP2. The NMR spectrum of BP2 is shown below. Figure 5 As shown.
[0028] The reaction formula is: . Preparation Example 3
[0029] The pyridinium salt guest BP3 was prepared as follows: Under inert gas protection, p-dibromobenzene, pinacol 4-pyridinium borate, tetrakis(triphenylphosphine)palladium, and cesium carbonate were added to a mixed solvent composed of N,N-dimethylformamide and toluene, and the reaction was heated to obtain a reaction solution containing the target intermediate. After cooling, the solution was filtered through diatomaceous earth to remove the solvent, and then extracted, washed with water, and dried. Subsequently, an acidic reagent was added to the obtained organic phase to precipitate the product. After alkalization, the product was filtered to obtain a white solid intermediate EXBIPY. The obtained intermediate EXBIPY was dissolved in N,N-dimethylformamide with 1-bromooctane and the reaction was heated. After cooling, an ether solvent was added to precipitate the product. After filtration and washing, a crude pyridinium salt product was obtained. Subsequently, the crude product was dissolved in water, and an anion exchange reaction was carried out with ammonium hexafluorophosphate. After filtration and drying, a pale yellow solid was obtained. The NMR spectrum of BP3 is shown below. Figure 6 As shown.
[0030] Reaction formula: . Preparation Example 4
[0031] The pyridine salt guest BP4 was prepared as follows: Under inert gas protection, 4,4′-dibromobiphenyl, 4-pyridineboronic acid, palladium catalyst, and an inorganic base were added to a mixed solvent composed of water, toluene, and 1,4-dioxane. The mixture was heated to obtain a reaction solution containing a bispyridine intermediate. After cooling, the solution was filtered through diatomaceous earth to remove the solvent, and then extracted, washed, and dried. Subsequently, the solution was purified by column chromatography to obtain a white solid intermediate EX2BIPY. The intermediate EX2BIPY was dissolved in N,N-dimethylformamide with 1-bromooctane and heated. After cooling, an ether solvent was added to precipitate the product. After filtration and washing, a crude pyridine salt product was obtained. The crude product was then dissolved in water, and an anion exchange reaction was carried out with ammonium hexafluorophosphate. After filtration and drying, a pale yellow solid, BP4, was obtained. Figure 7 As shown.
[0032] Reaction formula: . Example Example 1
[0033] Quasi-[4]rotaxane MC23BP2 with strong near-infrared fluorescence emission was prepared.
[0034] Weigh 1.78 mg (0.45 μmol, molecular weight 3945) of the trinuclear alkynylplatinum(II) terpyridine complex MC2 at room temperature (20-25 ℃), place it in a 20 mL dry and clean glass reaction flask, add 10.0 mL of analytical grade acetone to the reaction flask, and dissolve it completely to prepare a solution with a concentration of 4.5 × 10⁻⁶. -5 mol·L -1 A clear solution was obtained. The reaction flask was placed in an ultrasonic cleaner and sonicated for 5 min to promote complete dissolution of the solid, resulting in a homogeneous and transparent solution. Separately, 0.104 mg (0.148 μmol, 0.33 eq, molecular weight 698) of the guest molecule BP2 was dissolved in 0.50 mL of analytical grade acetone to prepare a BP2 stock solution. A magnetic stirrer was turned on (500 rpm) to maintain the system temperature at room temperature (20-25 °C). Using a microsyringe, the BP2 stock solution was slowly added dropwise to the MC2 solution over 1-3 min, with continuous stirring during the addition to ensure thorough mixing. After the addition was complete, the reaction was continued at room temperature for 30 min to allow self-assembly complexation between the host and guest molecules through coordination and π-π interactions. During the reaction, the solution color gradually deepened from light yellow, and its fluorescence titration spectrum is shown in the figure. Figure 8As shown, under the excitation condition of 460 nm light, a significantly enhanced near-infrared fluorescence emission can be observed. After the reaction is completed, stop stirring, and the resulting reaction solution can be directly used for ultraviolet-visible absorption spectroscopy and fluorescence spectroscopy testing. If it is necessary to separate the solid product, transfer the reaction solution into a rotary evaporator flask, remove the acetone solvent at 35-40 °C under reduced pressure, and obtain the yellow solid product quasi-[4]rotaxane supramolecular assembly MC23BP2 1.88 mg. Example 2
[0035] According to the method in Example 1, quasi-[4] rotaxane MC23BP3 with moderate near-infrared fluorescence emission intensity was prepared.
[0036] Weigh 1.78 mg (0.45 μmol, molecular weight 3945) of the trinuclear alkynylplatinum(II) terpyridine complex MC2 at room temperature (20-25 ℃), place it in a 20 mL dry and clean glass reaction flask, add 10.0 mL of analytical grade acetone to the reaction flask, and dissolve it completely to prepare a solution with a concentration of 4.5 × 10⁻⁶. -5 mol·L -1 A clear solution was obtained. The reaction flask was placed in an ultrasonic cleaner and sonicated for 5 min to promote complete dissolution of the solid, resulting in a homogeneous and transparent solution. Separately, 0.111 mg (0.148 μmol, 0.33 eq, molecular weight 748) of the guest molecule BP3 was dissolved in 0.50 mL of analytical grade acetone to prepare a BP3 stock solution. A magnetic stirrer was turned on (500 rpm) to maintain the system temperature at room temperature (20-25 °C). Using a microsyringe, the BP3 stock solution was slowly added dropwise to the MC2 solution over 1-3 min, with continuous stirring during the addition to ensure thorough mixing. After the addition was complete, the reaction was continued at room temperature for 30 min to allow self-assembly complexation between the host and guest molecules through coordination and π-π interactions. During the reaction, the solution color gradually deepened from light yellow, as shown in the fluorescence titration spectrum. Figure 9 As shown, under the excitation condition of 460 nm light, a significantly enhanced near-infrared fluorescence emission can be observed. After the reaction is completed, stop stirring, and the resulting reaction solution can be directly used for ultraviolet-visible absorption spectroscopy and fluorescence spectroscopy testing. If it is necessary to separate the solid product, transfer the reaction solution into a rotary evaporator flask, remove the acetone solvent at 35-40 °C under reduced pressure, and obtain the yellow solid product quasi-[4]rotaxane supramolecular assembly MC23BP3 1.89 mg. Example 3
[0037] According to the method in Example 1, quasi-[4]rotaxane MC23BP4 with weak near-infrared fluorescence emission intensity was prepared.
[0038] Weigh 1.78 mg (0.45 μmol, molecular weight 3945) of the trinuclear alkynylplatinum(II) terpyridine complex MC2 at room temperature (20-25 ℃), place it in a 20 mL dry and clean glass reaction flask, add 10.0 mL of analytical grade acetone to the reaction flask, and dissolve it completely to prepare a solution with a concentration of 4.5 × 10⁻⁶. -5 mol·L -1 A clear solution was obtained. The reaction flask was placed in an ultrasonic cleaner and sonicated for 5 min to promote complete dissolution of the solid, resulting in a homogeneous and transparent solution. Separately, 0.122 mg of the guest molecule BP4 (0.148 μmol, 0.33 eq, molecular weight 824) was dissolved in 0.50 mL of analytical grade acetone to prepare a BP4 stock solution. A magnetic stirrer was turned on (500 rpm) to maintain the system temperature at room temperature (20-25 °C). Using a microsyringe, the BP4 stock solution was slowly added dropwise to the MC2 solution over 1-3 min, with continuous stirring during the addition to ensure thorough mixing. After the addition was complete, the reaction was continued at room temperature for 30 min to allow self-assembly complexation between the host and guest molecules through coordination and π-π interactions. During the reaction, the solution color gradually deepened from light yellow, as shown in the fluorescence titration spectrum. Figure 10 As shown, under the excitation condition of 460 nm light, a significantly enhanced near-infrared fluorescence emission can be observed. After the reaction is completed, stop stirring, and the resulting reaction solution can be directly used for ultraviolet-visible absorption spectroscopy and fluorescence spectroscopy testing. If it is necessary to separate the solid product, transfer the reaction solution into a rotary evaporator flask, remove the acetone solvent at 35-40 °C under reduced pressure, and obtain the yellow solid product quasi-[4]rotaxane supramolecular assembly MC23BP4 1.90 mg. Example 4
[0039] Comparison of near-infrared luminescence enhancement effects induced by different guests in fluorescence titration experiments.
[0040] Under room temperature (20–25 °C) conditions, the concentrations prepared in Examples 1, 2, and 3 were respectively taken as 4.5 × 10⁻⁶. -5 mol·L -110.0 mL of each of the MC2 acetone solutions were placed in a 20 mL dry, clean glass reaction flask as the main solution for the fluorescence titration. The reaction flask was ultrasonically cleaned for 5 min to ensure the solution was homogeneous and transparent. Separately, 0.104 mg (0.148 μmol, molecular weight 698) of guest molecules BP2, 0.111 mg (0.148 μmol, molecular weight 748) of BP3, and 0.122 mg (0.148 μmol, molecular weight 824) of BP4 were dissolved in 0.50 mL of analytical grade acetone to prepare the corresponding guest molecule stock solutions. The magnetic stirrer was turned on (500 rpm) and the system temperature was maintained at room temperature (20–25 °C). Using a microsyringe, the mother solutions of BP2, BP3, and BP4 were slowly added dropwise to the corresponding MC2 solutions in multiple portions. After each addition, the mixture was stirred for 2 minutes to ensure thorough mixing. Samples were then transferred to a 1 cm quartz fluorescence cuvette, and emission spectra were recorded under 460 nm excitation until the total guest concentration reached 1.6 × 10⁻⁶. -4 mol·L -1 After the addition was complete, stirring continued at room temperature for 30 min to allow the host and guest components to fully self-assemble and complex. During the experiment, using the emission intensity at 730 nm of the pure MC2 solution as a benchmark, the increase in intensity ΔI at that wavelength after each addition was calculated, and plotted with ΔEmission Intensity at 730 nm as the ordinate and [Guest] × 10 -5 Plotting a curve with M as the x-axis, the result is as follows: Figure 11 As shown.
[0041] Combining Examples 1 to 3 and Figures 8 to 10 The fluorescence titration spectrum shows that: when the MC2 concentration is fixed at 4.5 × 10⁻⁶, -5 mol·L -1 In an acetone solution, 0.33 eq of guest BP2, BP3, or BP4 was slowly added dropwise. All three systems exhibited significant near-infrared emission enhancement under 460 nm excitation. Figure 8 (BP2) shows a broadband NIR spectrum (720–730 nm) that increases from near zero to 350–380 au, with a clean spectrum and no visible region residue, indicating that the vinyl-bridged short-axis BP2 brings the Pt(II)···Pt(II) between the three MC2 macrorings to the closest distance and the strongest interaction. Figure 9 (BP3) NIR band enhancement to 550–580 a.u., with a small amount of visible region remaining at low concentrations, indicating a moderate modulation effect; Figure 10(BP4) initially showed strong monomer emission at 550 nm, which was gradually suppressed with drop addition. At the same time, the NIR band slowly increased, but the overall amplitude was the smallest, reflecting that the long axis of the biphenyl caused a large macrocyclic spacing and the Pt(II)···Pt(II) effect was weak.
[0042] Combined with Example 4 and Figure 11 It can be seen that: with a fixed MC2 concentration of 4.5 × 10⁻⁶ -5 mol·L -1 In an acetone solution, BP2, BP3, and BP4 were added dropwise in portions (to achieve a final concentration of 1.6 × 10⁻⁶). -4 mol·L -1 Fluorescence titration experiments were conducted at 0.33 eq. The increase in near-infrared emission intensity (ΔI) at 730 nm under 460 nm excitation of the three groups of quasi-[4]rotaxanes showed significant differences with the change of guest concentration: MC23BP2 had the steepest curve and the earliest saturation, with a final ΔI as high as 410 au; MC23BP3 was second, with a final ΔI of about 330 au; MC23BP4 had the gentlest curve and the smallest enhancement amplitude, with a final ΔI of about 300 au. This quantitative result clearly shows that the shorter the conjugation length of the guest axis molecule, the closer the three MC2 macrocycles are in the quasi-[4]rotaxane structure, the stronger the Pt(II)···Pt(II) metal affinity interaction, which leads to a more significant near-infrared luminescence enhancement effect. This fully verifies that the present invention precisely controls the Pt(II)···Pt(II) interaction and luminescence performance in solution through guest molecules.
[0043] In conjunction with Example 1 and Figure 12 , Figure 13 The transmission electron microscopy (TEM) images show that in a pure MC2 macrocyclic acetone solution, Figure 12 It shows that it mainly consists of dispersed amorphous nanoparticles or small aggregates with a diameter of about tens of nanometers, without obvious ordered supramolecular structure; while in Example 1, the quasi-[4] rotaxane MC23BP2 formed after adding 0.33 eq guest BP2 to the same concentration of MC2 solution, Figure 13 Clearly showing significant nanoscale ordered assemblies (such as fibrous structures), with sizes increasing to hundreds of nanometers, regular morphology, and high contrast. This striking contrast indicates that the electron-deficient pyridinium salt guest BP2 effectively induces supramolecular self-assembly in solution through host-guest recognition and mechanical interlocking with the three MC2 macrocycles, promoting the ordered stacking of Pt(II) complex units and the enhancement of Pt(II)···Pt(II) metal affinity interactions, thereby verifying the successful construction of quasi-rotaxane structures and morphological evidence of guest regulation at the microscale.[4]
Claims
1. A near-infrared luminescent material, characterized in that, include: It comprises a trinuclear alkynylplatinum(II) terpyridine complex MC2 based on an acylhydrazone macrocycle and pyridine salt guest cations BP2, BP3, or BP4 with electron-deficient characteristics, with the following structural formulas respectively. ； 。 2. A method for preparing the infrared luminescent material as described in claim 1, characterized in that, Includes the following steps: Step S1. Dissolve the trinuclear alkynylplatinum(II) terpyridine complex MC2 based on the acylhydrazone macrocycle in the organic solvent acetone or methanol to obtain a macrocyclic MC2 solution; Step S2. Dissolve the pyridinium salt guest cations BP2, BP3 or BP4 in an organic solvent, such as acetone or methanol, to obtain a pyridinium salt solution; Step S3: Slowly add the pyridine salt solution from step S2 to the macrocyclic MC2 solution from step S1 to obtain the near-infrared luminescent material.
3. The preparation method according to claim 2, characterized in that, The trinuclear alkynylplatinum(II) terpyridine complex MC2 based on the acylhydrazone macrocycle was prepared by a dynamic covalent chemistry method, including the following steps: S11. Compound 1 Sodium hydroxide is dissolved in organic solvent I, and compound 2 is added. The reaction system was heated until complete, then the mixture was concentrated and ammonia water was added and heated until complete. After impurity removal and purification, compound 3 was obtained; wherein, the structural formula of compound 3 is: ; S12. Compound 3 and potassium hypochloroplatinate were dissolved in organic solvent II and reacted with stirring at room temperature. After purification and removal of impurities, compound 4 was obtained. The structural formula of compound 4 is as follows: ; S13. Compound 5 EDCI and Compound 6 The compound was added to organic solvent III, stirred at room temperature, and purified to obtain compound 7. ; S14. Compound 7 and trifluoroacetic acid were added to organic solvent IV, and the mixture was heated to react. After removing impurities and purifying, compound 8 was obtained. ; S15. Compound 4, compound 8, cuprous iodide and triethylamine were added to organic solvent V and reacted at room temperature until complete. After removing impurities and purifying, the trinuclear alkynylplatinum(II) terpyridine complex MC2 based on the acylhydrazone macrocycle was obtained.
4. The preparation method according to claim 2, characterized in that, The pyridine salt guest BP2 was prepared by the following method: 1,2-bis(4-pyridine)ethylene, 1-bromooctane and N,N-dimethylformamide were added sequentially, the mixture was heated to 120°C and stirred for 24 hours, cooled, filtered, and the filter residue was collected. The residue was washed alternately with a small amount of N,N-dimethylformamide and diethyl ether to obtain a yellow solid powder. Then, anion exchange was performed to obtain a bright yellow solid powder.
5. The preparation method according to claim 2, characterized in that, The pyridinium salt guest BP3 was prepared by the following method: Under inert gas protection, p-dibromobenzene, pinacol 4-pyridinium borate, tetrakis(triphenylphosphine)palladium, and cesium carbonate were added to a mixed solvent composed of N,N-dimethylformamide and toluene, and the mixture was heated to obtain a reaction solution containing the target intermediate. After cooling, the solution was filtered through diatomaceous earth to remove the solvent and then subjected to extraction, washing with water, and drying. Subsequently, an acidic reagent was added to the obtained organic phase to precipitate the product. After alkalization, the product was filtered to obtain a white solid intermediate EXBIPY. The obtained intermediate EXBIPY was dissolved in N,N-dimethylformamide with 1-bromooctane and the mixture was heated to react. After cooling, an ether solvent was added to precipitate the product. After filtration and washing, a crude pyridinium salt product was obtained. Subsequently, the crude product was dissolved in water, and ammonium hexafluorophosphate was added to carry out anion exchange reaction. The mixture was then filtered and dried to obtain a pale yellow solid.
6. The preparation method according to claim 2, characterized in that, The pyridine salt guest BP4 was prepared by the following method: Under inert gas protection, 4,4′-dibromobiphenyl, 4-pyridineboronic acid, palladium catalyst, and inorganic base were added to a mixed solvent composed of water, toluene, and 1,4-dioxane, and the mixture was heated to obtain a reaction solution containing a bispyridine intermediate. After cooling, the solution was filtered through diatomaceous earth to remove the solvent and then extracted, washed with water, and dried. Subsequently, the solution was purified by column chromatography to obtain a white solid intermediate EX2BIPY. The intermediate EX2BIPY was dissolved in N,N-dimethylformamide with 1-bromooctane and the mixture was heated to react. After cooling, an ether solvent was added to precipitate the product. After filtration and washing, a crude pyridine salt product was obtained. The crude product was then dissolved in water, and ammonium hexafluorophosphate was added to carry out anion exchange reaction. The mixture was then filtered and dried to obtain a pale yellow solid.