A method, device, equipment and medium for detecting endohedral metallofullerenes

Abstract

A kind of detection method, device, equipment and medium of metal-embedded fullerene, the detection method includes: obtaining the mass spectrum of metal-embedded fullerene sample, and the molecular weight and molecular formula of metal-embedded fullerene sample are obtained by analysis;Judgment is carried out based on the molecular weight and molecular formula of metal-embedded fullerene sample, if the metal-embedded fullerene corresponding to the molecular weight and molecular formula is non-target metal-embedded fullerene after judgment, stop subsequent detection work;If the metal-embedded fullerene corresponding to the molecular weight and molecular formula is target metal-embedded fullerene after judgment, based on the purification of metal-embedded fullerene sample, obtain its ultraviolet-visible-near infrared absorption spectrum and X-ray diffraction image.This kind of detection method of the present application can reduce sample consumption and save cost.

Description

Technical Field

[0001] This invention belongs to the field of fullerene analysis and detection technology, and in particular relates to a method, apparatus, equipment and medium for detecting endogenous metallofullerenes. Background Technology

[0002] Fullerenes are a class of cage-like molecules composed of carbon atoms, with C being a representative substance. 60 It possesses a perfectly symmetrical structure, similar to that of a soccer ball. Since its discovery, the family of endohedral metallofullerenes has expanded to include C... 70 Higher-order endohedral metallofullerenes, endohedral metallofullerenes (such as metallofullerene La@C) 82 Metal-embedded fullerenes form a vast system, including various functionalized derivatives such as fullerols. Due to their unique physicochemical properties, such as excellent electron affinity, free radical scavenging ability, high mechanical strength, and biocompatibility, endohedral metal-fullerenes have shown enormous application potential in many cutting-edge fields, such as energy and electronics, biomedicine, and new materials. The decreasing cost of fullerene preparation and the deepening of application research have accelerated their industrialization process. However, the broadening of application areas places higher demands on the accurate detection of the structure, purity, and optical properties of fullerene products, which directly relates to the performance, safety, and compliance of end products. The high cost of endohedral metal-fullerenes makes achieving accurate detection with lower sample consumption a major challenge in the field of fullerene detection.

[0003] While current detection techniques for endohedral metallofullerenes include Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible-near-infrared absorption spectroscopy (UV-Vis), Raman spectroscopy, nuclear magnetic resonance (NMR), mass spectrometry (MS), high-performance liquid chromatography (HPLC), gas chromatography (GC), scanning tunneling microscopy, atomic force microscopy, and single-crystal X-ray diffraction, relying on only one technique is insufficient for accurately characterizing the structure of endohedral metallofullerenes. Furthermore, combining multiple techniques presents challenges such as high sample consumption (e.g., conventional NMR requires several milligrams of sample), high instrument costs, and long detection times. Therefore, there is an urgent need to develop a reproducible, standardized, and multi-dimensional detection method for endohedral metallofullerenes to achieve accurate characterization of their structures. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a method, apparatus, equipment and medium for detecting embedded metal fullerenes, in order to solve the problems of lack of standardized procedures for detecting embedded metal fullerene structures, incomplete detection methods, high costs and large sample consumption in the prior art.

[0005] To achieve the above and other related objectives, the present invention provides a method, apparatus, device, and medium for detecting endogenous metallofullerenes, wherein the detection method includes:

[0006] Mass spectra of endogenous metal-fullerene samples were obtained, and their molecular weight and molecular formula were determined by analysis.

[0007] The determination is based on the molecular weight and molecular formula of the endohedral metallofullerene sample.

[0008] If it is determined that the endogenous metal-fullerene corresponding to the molecular weight and molecular formula is a non-target endogenous metal-fullerene, the subsequent detection work shall be stopped.

[0009] If it is determined that the endohedral metallofullerene corresponding to the molecular weight and molecular formula is the target endohedral metallofullerene...

[0010] Based on the purified product of the metallofullerene sample, its ultraviolet-visible-near-infrared absorption spectrum and X-ray diffraction image were obtained.

[0011] Based on the obtained ultraviolet-visible-near-infrared absorption spectra, the carbon cage structure and / or optical properties of the metal-embedded fullerene samples were analyzed.

[0012] Based on the acquired X-ray diffraction images, the three-dimensional crystal structure of the metal-embedded fullerene sample was obtained.

[0013] Since the synthesized sample may contain other empty fullerene impurities in addition to the endogenous metal-encapsulated metal-fullerene, after determining the molecular weight and molecular formula by mass spectrometry, the above detection method needs to use high performance liquid chromatography to determine the purity of the target endogenous metal-encapsulated metal-fullerene and separate and purify the target endogenous metal-encapsulated metal-fullerene for subsequent accurate characterization.

[0014] Preferably, the target endohedral metallofullerene comprises: the type of endohedral metal, the number of endohedral metals, and the total number of carbon atoms in the carbon cage. For example, the desired target endohedral metallofullerene has the structural formula Gd₂C₅. 72 If the target endohedral metal fullerene is determined to be: the type of endohedral metal is Gd, the number of endohedral metals is 2, and the total number of carbon atoms in the carbon cage is 72, then the endohedral metal fullerene corresponding to the molecular weight and molecular formula obtained from the mass spectrum analysis is determined to be the target endohedral metal fullerene.

[0015] Preferably, the mass spectrum of the endogenous metal-fullerene sample is obtained by high-resolution mass spectrometry, including: dissolving the endogenous metal-fullerene sample in toluene to form a first sample solution, and testing the first sample solution by high-resolution mass spectrometry.

[0016] Preferably, the purified product of the metal-embedded fullerene sample is obtained by separation using high performance liquid chromatography, comprising: dissolving the metal-embedded fullerene sample in toluene to form a second sample solution, and separating the second sample solution using high performance liquid chromatography to obtain the purified product of the metal-embedded fullerene.

[0017] Preferably, the ultraviolet-visible-near-infrared absorption spectrum is obtained by using an ultraviolet-visible-near-infrared spectrometer, including: dissolving a portion of the purified extract of the endohedral metal fullerene sample in CS2 to form a third sample solution, and testing the third sample solution using an ultraviolet-visible-near-infrared spectrometer.

[0018] Preferably, the X-ray diffraction image is obtained by testing with a single-crystal X-ray diffractometer, including: taking a portion of the purified product of the metal-embedded fullerene sample for crystallization treatment, and taking a single crystal and placing it into the single-crystal X-ray diffractometer for testing.

[0019] Preferably, the optical properties include electronic bandgap and light absorption properties.

[0020] Preferably, the three-dimensional crystal structure includes any one or more of the following: carbon-carbon bond length, bond angle, shape and size of the carbon cage, and three-dimensional coordinates of the inlay.

[0021] The spectral characteristics of the aforementioned UV-Vis-NIR absorption spectra include: peak position, peak intensity, peak shape, and fine structure. The absorption edge of the first absorption peak represents the lowest energy allowed transition in the spectrum, and its wavelength (λ_onset) corresponds to the optical band gap. The electronic band gap can be calculated using the formula: Eg = 1240 / λ_onset (eV). Different fullerene cages (such as C...) 60 C 70 C 82 Different metals (e.g., metals with different symmetries and π-electron systems) exhibit variations in the position and shape of characteristic absorption peaks in their ultraviolet (UV) spectra. Different metals also possess varying electron-donating abilities, affecting the degree of charge transfer and thus altering the absorption spectrum. By comparing the spectra with those of known analogues or theoretically calculated spectra, the structure of unknown endohedral metal-encapsulated fullerenes can be inferred. Based on the initial position of the absorption peaks in the UV spectrum, the absorption range of the fullerene can be determined, and its light absorption capacity can be obtained from the absorption intensity (molar absorptivity ε). Higher absorbance indicates stronger light absorption capacity.

[0022] Preferably, the concentration of the metal-embedded fullerene sample in the first sample solution is 0.1~0.5 mg / mL.

[0023] Preferably, the high-resolution mass spectrometry test mode is positive ion mode.

[0024] Preferably, the laser energy for the high-resolution mass spectrometry test is 20% to 45% of the maximum output energy.

[0025] Preferably, the high-resolution mass spectrometry is time-of-flight mass spectrometry.

[0026] More preferably, the high-resolution mass spectrometer has a resolution of 5000-6500 Th / Th.

[0027] Preferably, the concentration of the metal-embedded fullerene sample in the second sample solution is 0.1~0.5 mg / mL.

[0028] Preferably, the detector in the high-performance liquid chromatography is an ultraviolet detector or a diode array detector.

[0029] Preferably, the purity of the endohedral metallofullerene is calculated using the following formula.

[0030]

[0031] Xi represents the purity of the endogenous metallofullerene;

[0032] Ai represents the peak area of ​​the endogenous metallofullerene, expressed in microvolt-seconds (μV·s).

[0033] Am represents the peak area of ​​each chromatographic peak after deducting the solvent peak, expressed in microvolt-seconds (μV·s).

[0034] Preferably, the high-performance liquid chromatograph uses an NPE column.

[0035] More preferably, the high-performance liquid chromatograph uses a 5-NPE column; the 5-NPE column represents that the particle size of the packing material is 5 micrometers, and the packing material is silica gel bonded with nitrophenylethyl functional groups.

[0036] Preferably, the mobile phase in the high-performance liquid chromatograph is toluene.

[0037] Preferably, the flow rate of the mobile phase in the high-performance liquid chromatograph is 1.5~2.5 mL / min.

[0038] Preferably, the injection volume in the high performance liquid chromatograph is 0.5~1.5 mL.

[0039] Preferably, the column temperature in the high-performance liquid chromatograph is 25~30℃.

[0040] Preferably, the detection wavelength in the high-performance liquid chromatograph is 330 nm.

[0041] Fullerene molecules such as C60 and C70 exhibit significant ultraviolet absorption peaks near a wavelength of 330 nm. Selecting a wavelength around 330 nm allows for effective detection of the ultraviolet absorption signal of fullerene molecules, while interference from other impurities or solvents is relatively minimal.

[0042] Preferably, the scanning range of the ultraviolet-visible-near-infrared spectrometer is 300~2000nm.

[0043] Preferably, the scanning speed of the ultraviolet-visible-near-infrared spectrometer is 100~200 nm / min.

[0044] Preferably, the spectral bandwidth of the ultraviolet-visible-near-infrared spectrometer is 1~2nm.

[0045] Preferably, the concentration of the purified metal-embedded fullerene sample in the third sample solution is 0.1~0.5 mg / mL.

[0046] Preferably, the cuvette used in the ultraviolet-visible-near-infrared spectrometer test is a glass cuvette.

[0047] Preferably, the temperature during testing with the single-crystal X-ray diffractometer is 100~200K.

[0048] Preferably, the resolution of the single-crystal X-ray diffractometer is 0.8~0.9 Å.

[0049] Preferably, the crystallization process includes concentrating a toluene solution containing the target endogenous metal-embedded fullerene, transferring it to a conical tube, slowly adding a saturated toluene solution of NiII–OEP, sealing the tube opening with a sealing film (with a hole punched at the top), and allowing the crystals to precipitate after standing.

[0050] Preferably, the single crystal size is 0.2~0.55 mm when tested by the single crystal X-ray diffractometer.

[0051] A second aspect of the present invention provides a detection device for embedded metal fullerenes, the device comprising: a mass spectrum acquisition module, used to acquire the mass spectrum of an embedded metal fullerene sample and analyze it to obtain the molecular weight and molecular formula of the embedded metal fullerene sample;

[0052] The judgment module is used to determine whether the endohedral metal-fullerene corresponding to the molecular weight and molecular formula of the endohedral metal-fullerene sample is the target endohedral metal-fullerene.

[0053] Preferably, the device further includes: an ultraviolet-visible-near-infrared absorption spectrum acquisition module, used to acquire the ultraviolet-visible-near-infrared absorption spectrum of the purified metal-embedded fullerene sample based on the judgment result of the judgment module when the judgment result is the target embedded metal fullerene.

[0054] Preferably, the device further includes an X-ray diffraction image acquisition module, used to acquire an X-ray diffraction image of the purified metal-embedded fullerene sample when the judgment result of the judgment module is the target embedded metal fullerene.

[0055] Preferably, the device further includes: an output module for outputting the carbon cage structure and / or optical properties of the embedded metal fullerene sample based on ultraviolet-visible-near-infrared absorption spectroscopy, and for outputting the three-dimensional crystal structure of the embedded metal fullerene sample based on X-ray diffraction images.

[0056] Preferably, the device further includes a termination module, used to stop subsequent detection work when the judgment result of the judgment module is a non-target endogenous metal fullerene.

[0057] A third aspect of the present invention provides a computer-readable storage medium storing a computer program for causing a processor to execute the above-described detection method.

[0058] A fourth aspect of the present invention provides an electronic device comprising: a processor, a memory, and a computer program; the memory is communicatively connected to the processor, the memory stores the computer program, and the processor executes the computer program to implement the above-described detection method.

[0059] As described above, the detection method, apparatus, device, and medium for endohedral metallofullerenes of the present invention have the following beneficial effects:

[0060] This invention provides a new systematic detection method, device, equipment, and medium for endohedral metallofullerenes, solving the problems of complex and unsystematic detection methods and large sample consumption in existing fullerene detection methods. This invention constructs a detection method consisting of "high-resolution mass spectrometry initial screening, high-performance liquid chromatography separation and purification, ultraviolet-visible-near-infrared absorption spectroscopy for optical performance study, and single-crystal X-ray diffraction for precise determination of three-dimensional crystal structure". First, preliminary screening using mass spectrometry can quickly eliminate non-target endohedral metallofullerenes, reducing the unnecessary investment in subsequent high-cost characterization. This process requires only micrograms of sample. After determining the molecular weight and molecular formula of the target endohedral metallofullerene using mass spectrometry, high-performance liquid chromatography (HPLC) is used to determine the purity of the target endohedral metallofullerene, and the target endohedral metallofullerene is separated and purified for subsequent spectral and structural studies. Vibrational and electronic energy level information of the target endohedral metallofullerene is determined by ultraviolet-visible-near-infrared absorption spectroscopy. Finally, the three-dimensional crystal structure is determined by single-crystal X-ray diffraction, thus completing the structural analysis. The method of this invention can minimize sample loss. The entire process only requires a trace amount of sample to achieve a comprehensive and accurate analysis of the structural information of the target endohedral metallofullerene. Attached Figure Description

[0061] Figure 1 The diagram shown is a flowchart of one embodiment of the detection method for embedded metallofullerenes of the present invention.

[0062] Figure 2 The diagram shown is a schematic diagram of the judgment logic in one embodiment of the detection method for embedded metal fullerenes of the present invention.

[0063] Figure 3 The diagram shown is a structural schematic of one embodiment of the detection device for embedded metal fullerenes of the present invention.

[0064] Figure 4 The diagram shown is a structural schematic of an electronic device according to an embodiment of the present invention.

[0065] Figure 5 The image shown is of the embedded metallofullerene Sc2C2@C in Embodiment 1 of the present invention. s (hept)-C 88 The mass spectrum.

[0066] Figure 6 The image shown is of the embedded metallofullerene Sc2C2@C in Embodiment 1 of the present invention. s (hept)-C 88 UV-Vis-NIR spectrum.

[0067] Figure 7 The image shown is of the embedded metallofullerene Sc2C2@C in Embodiment 1 of the present invention. s (hept)-C 88 Crystal structure diagram. Detailed Implementation

[0068] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0069] Furthermore, it should be understood that the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps, does not preclude the presence of other method steps before or after the combined steps, unless otherwise stated. It should also be understood that the combined connection relationship between one or more devices / apparatus mentioned in this invention does not preclude the existence of other devices / apparatus before or after the combined devices / apparatus, or the insertion of other devices / apparatus between these explicitly mentioned devices / apparatus. Moreover, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and not for limiting the order of the method steps or defining the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0070] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or equivalent to those described, apparatus, and materials in the embodiments of this invention may be used to implement the present invention.

[0071] To facilitate understanding of the embodiments of this application, firstly, in conjunction with... Figure 1 Detailed explanation. Figure 1 A schematic flowchart of a detection method for endogenous metallofullerenes according to an embodiment of the present invention is shown, including the following steps:

[0072] S1, the molecular weight and molecular formula of the target endohedral metallofullerene were determined by high-resolution mass spectrometry.

[0073] Matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MADS) was used to detect target endogenous metallofullerenes. DCTB was used as the matrix solution, and toluene as the solvent, with a concentration of 0.1 mg / mL. During the test, a low-resolution full-spectrum scan was first performed in linear mode to locate the peak clusters of multi-isotopic metallofullerenes. Then, a high-resolution reflectance mode was used to precisely scan the identified peak clusters. Based on the molecular ion peaks and isotopic peak clusters, the molecular weight and molecular formula were determined. Furthermore, high-resolution mass spectrometry can eliminate interference from empty-cage fullerene impurities, obtaining a clean spectrum of the target endogenous metallofullerenes. If no target endogenous metallofullerenes were detected after mass spectrometry, subsequent testing could be stopped, saving subsequent costs and time. The detection results showed that the molecular weight and molecular formula matched the target endogenous metallofullerenes, allowing for further detection.

[0074] S2, the target endogenous metallofullerene was purified and separated by high performance liquid chromatography.

[0075] Purity testing and target substance separation were performed using a high-performance liquid chromatograph equipped with a UV detector, a 5 NPE column, a column temperature of 30℃, toluene as the mobile phase, and a detection wavelength of 330 nm. Toluene was used as the solvent, and the concentration of the test solution was 1 mg / mL. After baseline stabilization, the retention times of the solvent and empty fullerenes were first confirmed, followed by sample testing to determine the peak time of the target endogenous metallofullerene. Purity was calculated according to the following formula:

[0076]

[0077] In the formula:

[0078] X i —Purity of the target endohedral metallofullerene;

[0079] A i —Peak area of ​​the target endogenous metallofullerene, in microvolt-seconds (μV·s).

[0080] A m —The peak area of ​​each chromatographic peak after deducting the solvent peak, in microvolt-seconds (μV·s).

[0081] After determining the elution time of the target endogenous metallofullerene, the liquid at the tail of the column is collected when the elution time is approaching, and collection is stopped after the peak is completely eluted, thus obtaining the pure target endogenous metallofullerene.

[0082] S3, the optical properties of the target endogenous metallofullerene were determined using ultraviolet-visible-near-infrared absorption spectroscopy.

[0083] The tests were conducted using UV-Vis-NIR absorption spectroscopy with optical glass cuvettes, a scanning range of 400-2000 nm, a scanning speed of 100 nm / min, and a bandwidth of 1 nm. CS2 was used as the solvent (since CS2 has no absorption peak in the 400-2000 nm range, it was chosen as the test solvent), and the concentration of the test solution was 0.1 mg / mL. After baseline calibration using a blank solvent, the sample solution was scanned. Molecular vibrational and electronic energy level information was obtained. After the tests, the molar absorptivity and optical band gap of the target endohedral metallofullerene were calculated using the Lambert-Beer law to determine the results and evaluate its optical properties.

[0084] Electronic energy level information includes: the energy distribution of excited states; each absorption peak in the spectrum corresponds to a specific electronic transition; and the peak position (λ_max) gives the relative energy of these excited states. Furthermore, the peak intensity reflects the oscillator strength of the electronic transition.

[0085] Molecular vibrational information can be revealed through the fine structure and bandwidth of the spectrum.

[0086] S4. The three-dimensional crystal structure of the target endogenous metal fullerene was determined by single-crystal X-ray diffraction.

[0087] Single-crystal A-ray diffractometer with a copper target was used for testing, achieving a resolution of 0.837 Å. The detectors and goniometers used were a 135 mm Atlas and a 92 mm EOS CCD detector, and a four-circle Kappa goniometer, respectively. The cryogenic system was 100 K; the chiller was 23 °C; and the slides were 75 mm × 25 mm. The purified toluene solution containing intercalated metallofullerenes was concentrated, and then Ni was added dropwise. II A saturated toluene solution of OEP was left to stand for ten days to allow it to crystallize naturally. Clean and uniform high-quality single crystals with a crystal size between 0.2 mm and 0.55 mm were selected for testing. After processing, the carbon-carbon bond length, bond angle, shape and size of the carbon cage, and three-dimensional coordinates of the embedded structures could be obtained.

[0088] like Figure 2 The diagram shown illustrates the judgment logic of the endogenous metallofullerene detection method of the present invention in one embodiment, including the following steps:

[0089] S21, Obtain the mass spectrum of the metal-embedded fullerene sample, and analyze it to obtain the molecular weight and molecular formula of the metal-embedded fullerene sample;

[0090] S22, determine whether the endogenous metal-fullerene corresponding to the molecular weight and molecular formula is the target endogenous metal-fullerene;

[0091] S23, if not, stop the detection;

[0092] S24, if so, then proceed with subsequent detection, including: S241, obtaining the ultraviolet-visible-near-infrared absorption spectrum of the purified sample based on the metal-embedded fullerene sample; S242, obtaining the X-ray diffraction image of the purified sample based on the metal-embedded fullerene sample.

[0093] like Figure 3 The diagram shown is a schematic diagram of the detection device for embedded metal fullerenes of the present invention in one embodiment. The detection device includes: a mass spectrum acquisition module 31, a judgment module 32, a termination module 33, an ultraviolet-visible-near-infrared absorption spectrum acquisition module 341, an X-ray diffraction image acquisition module 342, and an output module 35.

[0094] like Figure 4The diagram shows the structure of an electronic device for the detection method of embedded metallofullerenes according to the present invention. It includes at least one memory 120, at least one processor 130, and a computer program stored on the memory 120 and executable on the processor 130. A communication interface 110 is used for communication between the memory 120 and the processor 130. The processor 130 can be a dedicated or general-purpose programmable processor. The computer program can be written using any combination of one or more programming languages. The computer program can be executed entirely on the machine, partially on the machine, partially on a remote machine as a standalone software package, or entirely on a remote machine or server.

[0095] Example 1

[0096] This embodiment 1 analyzes a specific endohedral metallofullerene Sc2C2@C s (hept)-C 88 Specifically, it includes the following steps:

[0097] S1. The molecular weight and molecular formula of the target endohedral metallofullerene were determined by matrix-assisted laser desorption / ionization time-of-flight mass spectrometry.

[0098] 1) Sample preparation

[0099] Dissolve 1 mg of sample in 10 mL of toluene to prepare a first sample solution with a concentration of 0.1 mg / mL.

[0100] 2) Spotting

[0101] Using a pipette, take 5 μL of matrix solution (trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malonitrile, DCTB) and place it in the well of the target plate. Then, take 5 μL of the first sample solution and place it on the matrix solution. Use a pipette to quickly aspirate and drop the solution in the well three times to mix thoroughly. Allow it to air dry. Record the position.

[0102] 3) Transferring the sample target

[0103] Place the target holder containing the sample target onto the sample target platform and then introduce the ion source.

[0104] 4) Detection

[0105] First, a low-resolution full-spectrum scan was performed using a linear mode with a wide quality range of m / z 600~2000 and a medium laser energy. Peak clusters of multi-isotope metal-intercalated fullerenes were then searched in the full spectrum.

[0106] The discovered peak cluster region was precisely scanned using a reflective high-resolution mode, and the laser energy was optimized to obtain clear isotope peak shapes.

[0107] 5) Analysis

[0108] The molecular ion peaks and isotope peak clusters in the detected mass spectrum were analyzed, such as... Figure 5 As shown, the molecular weight is determined to be 1169.824, and the molecular formula is Sc2C. 90 .

[0109] S2. The purity of the target endogenous metallofullerene was determined and separated using high performance liquid chromatography.

[0110] 1) Instruments, equipment, and chromatographic conditions

[0111] The high-performance liquid chromatograph is equipped with an ultraviolet detector, a φ10 × 250 mm 5 NPE column, toluene as the mobile phase, a detection wavelength of 330 nm, and a column temperature of 30 °C.

[0112] 2) Sample processing

[0113] Take 1 mg of sample and place it in a sample vial. Add 10 mL of toluene, sonicate to dissolve, filter through a 0.22 μm filter membrane, and retain the filtrate as the sample solution.

[0114] 3) Detection

[0115] Baseline stability verification: If the dynamic short-term baseline noise does not exceed 0.05 mAU and the dynamic baseline drift does not exceed 1 mAU / h within a detection time of not less than 15 minutes, the baseline detection is passed.

[0116] Confirmation of solvent retention time: Perform chromatographic analysis on toluene, record the retention time, repeat the operation twice, and take the arithmetic mean of the two retention times as the solvent retention time result.

[0117] Sample testing: High-performance liquid chromatography (HPLC) was used for analysis. A 5 NPE column was used as the separating column, toluene as the mobile phase, and the flow rate was typically set to 2.0 mL / min. The detection wavelength was set to 330 nm. The sample solution was injected into the HPLC system via an autosampler, with an injection volume of approximately 1 mL per injection. After entering the column, the sample was separated based on the size and polarity differences of the different fullerenes. Each fullerene produced a chromatographic peak at a different retention time.

[0118] Throughout the chromatographic analysis process, chromatographic software is used to record and collect chromatographic data.

[0119] 4) Data processing

[0120] The peak area of ​​the chromatographic peak is calculated using the integration function of the chromatography software.

[0121] Purity uniformity calculation: The purity of the target endogenous metal-encapsulated fullerene is calculated by dividing the chromatographic peak area of ​​the target endogenous metal-encapsulated fullerene by the sum of the chromatographic peak areas of all other endogenous metal-encapsulated fullerenes.

[0122] Purity is calculated using the following formula:

[0123]

[0124] In the formula:

[0125] X i —Purity of the target endohedral metallofullerene;

[0126] A i —Peak area of ​​the target endogenous metallofullerene, in microvolt-seconds (μV·s).

[0127] A m —The peak area of ​​each chromatographic peak after deducting the solvent peak, in microvolt-seconds (μV·s).

[0128] The purity of the target endogenous metallofullerene was determined to be 99.1% by high performance liquid chromatography and calculated using the above formula (sample peak area was 11765 au, total peak area was 11872 au). The main peak was extracted and preserved for subsequent UV-Vis-NIR spectroscopy and single-crystal X-ray diffraction tests.

[0129] S3. The structure and optical properties of the target endogenous metallofullerene were determined using ultraviolet-visible-near-infrared absorption spectroscopy.

[0130] 1) Instrument and equipment settings and parameter settings

[0131] Ultraviolet-Vis-NIR spectrometer (Agilent Cary 5000 UV-Vis-NIR); optical glass cuvette; scanning range: 400-2000 nm; scanning speed: 100 nm / min; bandwidth: 1 nm.

[0132] 2) Sample preparation

[0133] The sample was dissolved in CS2, sonicated, and prepared into a solution with a concentration of 0.1 mg / mL.

[0134] 3) Testing

[0135] Turn on the UV-Vis-NIR spectrometer, preheat for about 15 minutes to ensure the light source is stable, and complete the parameter settings.

[0136] Fill the cuvette with blank CS2 solvent, place it in the sample cell, and calibrate the instrument with zero absorbance or 100% transmittance. Eliminate solvent interference with the spectrum.

[0137] Fill the cuvette with a blank solution, i.e., pure solvent CS2, place it in the sample cell, and measure the baseline.

[0138] Pour the sample solution into the cuvette, gently agitate the cuvette to distribute the solution evenly, avoiding the formation of air bubbles. Place the sample cuvette into the sample chamber of the spectrometer, and then start the measurement.

[0139] 4) Spectral Analysis

[0140] Figure 6 Demonstrated Sc2C 90 The UV-Vis-NIR absorption spectrum of the CS2 solution was obtained. Strong absorption was observed at 1094 nm, with additional absorptions at 491, 603, 696, 808, 962, and 1478 nm. UV-Vis-NIR absorption spectra are typically characteristic markers of specific fullerene cages and their electronic structures, primarily originating from π-π* transitions within the fullerene cages. The initial absorption wavelength λ_onset = 384 nm was determined from the spectrum, and the optical band gap Eg = 3.23 eV was calculated using Eg = 1240 / λ_onset.

[0141] Based on the effective absorption range of the absorption spectrum, the wider the range, the wider the spectrum of captured photons.

[0142] S4. The three-dimensional crystal structure of the target endohedral metallofullerene was determined using single-crystal X-ray diffraction.

[0143] 1) Instruments and equipment

[0144] Single-crystal X-ray diffractometer: A Rigaku micro-focusing rotating target single-crystal diffractometer from Japan, employing a copper target for testing, with a resolution of 0.837 Å. The detectors and goniometers used are a 135 mm Atlas and a 92 mm EOS CCD detector, and a four-circle Kappa goniometer. Cryogenic system: 100 K; chiller: 23℃; slides: 75 mm × 25 mm.

[0145] 2) Single crystal cultivation

[0146] First, the purified toluene solution containing the intercalated metallofullerenes was concentrated, then transferred to a conical tube with a bottom diameter of approximately 1.5 mm, and Ni was slowly added dropwise. II A saturated toluene solution of OEP was prepared, and then the tube opening was sealed with a sealing film (with a hole punched in the top). After about ten days of evaporation, the solution had completely evaporated, and black blocky single crystals could be seen on the tube walls and bottom.

[0147] 3) Single crystal selection

[0148] Take a small sample and place it on a glass slide. Then, drop an appropriate amount of crystal-picking oil onto the slide and use a needle or similar tool to disperse the sample in the oil to prevent multiple crystals from sticking together. Carefully search for high-quality single crystals under a microscope. Generally, a good single crystal should be clean and uniform. Use a high-magnification microscope for observation to avoid cracks or twins that are invisible under low-magnification microscopes. Furthermore, try to avoid other impurities or small fragments adhering to the single crystal. If this is encountered, repeatedly wash the single crystal with a needle in clean oil until it is completely clean. For copper targets, the ideal crystal size should be between 0.2 mm and 0.55 mm (X-ray spot size is 0.8 mm). The minimum crystal size is not strictly limited and mainly depends on its diffraction intensity. For crystals with high X-ray absorption, ensure a minimum X-ray transmittance of 10-20%. If a suitable crystal size is unavailable, large crystals or crystal clusters can be cut with a blade.

[0149] 4) Crystal testing

[0150] Capture a high-quality single crystal using a crystal ring. Mount the crystal ring with the single crystal attached to the base. For irregularly shaped crystals, try to center the crystal's centroid. For long, needle-like crystals, try placing them along the axis of the base. Ensure the crystal still has diffraction points at higher angles, and adjust the resolution step to 0.83 Å. Perform tests and acquire diffraction images.

[0151] 5) Crystal data reconstruction and analysis

[0152] The data measured by the instrument is analyzed by software to obtain the structure of the embedded metallofullerene. Further data processing software measurements can then determine the carbon-carbon bond lengths, bond angles, the shape and size of the carbon cage, and the three-dimensional coordinates of the embedded structure. For example... Figure 7 As shown, the endohedral metallofullerene molecule was ultimately confirmed to be Sc2C2@C s (hept)-C 88 The polygonal Sc2C2 unit is C s (hept)-C 88 Cage capture.

[0153] In summary, the detection method of this invention employs high-resolution mass spectrometry as the first step, requiring only microgram-level samples to determine molecular weight and elemental composition, rapidly eliminating non-target products (such as hollow fullerene impurities), and reducing the unnecessary investment in subsequent high-cost characterization. Then, high-performance liquid chromatography (HPLC) is used to determine the purity of the target analyte, and the purified analyte is separated for subsequent spectral analysis and crystal characterization. Spectroscopic analysis utilizes microgram-level samples to obtain molecular vibrational and electronic energy level information; X-ray single-crystal diffraction serves as the final step, relying on the single-crystal cultivation conditions determined in the preceding steps, and requiring only a small amount of single crystal (≤10 μg) to complete structural analysis, minimizing sample loss. The synergistic development of these characterization techniques enables comprehensive and accurate analysis of fullerene structural information. It clearly reveals the intrinsic relationship between structure and performance—for example, how carbon cage symmetry affects electron transport efficiency and how metal atoms within the cage modulate optical absorption characteristics—providing clear experimental guidance for the performance regulation of fullerenes. Based on these established structure-property relationships, the application of novel fullerenes in fields such as optoelectronic devices (e.g., solar cells, field-effect transistors), biomedicine (e.g., targeted drug carriers, magnetic resonance imaging contrast agents), and catalysis (e.g., highly efficient hydrogenation reaction catalysts) is no longer limited to theoretical speculation, but has the scientific basis for targeted design and optimization, driving fullerenes from laboratory research to practical application scenarios.

[0154] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for detecting endohedral metallofullerenes, characterized in that, The detection method includes: Mass spectra of endogenous metal-fullerene samples were obtained, and their molecular weight and molecular formula were determined by analysis. The determination is based on the molecular weight and molecular formula of the endohedral metallofullerene sample. If it is determined that the endogenous metal-fullerene corresponding to the molecular weight and molecular formula is a non-target endogenous metal-fullerene, the subsequent detection work shall be stopped. If it is determined that the endohedral metallofullerene corresponding to the molecular weight and molecular formula is the target endohedral metallofullerene... Based on the purified product of the metallofullerene sample, its ultraviolet-visible-near-infrared absorption spectrum and X-ray diffraction image were obtained. Based on the obtained ultraviolet-visible-near-infrared absorption spectra, the carbon cage structure and / or optical properties of the metal-embedded fullerene samples were analyzed. Based on the acquired X-ray diffraction images, the three-dimensional crystal structure of the metal-embedded fullerene sample was determined. The mass spectrum of the endogenous metal-fullerene sample was obtained by high-resolution mass spectrometry (HMS), including: dissolving the endogenous metal-fullerene sample in toluene to form a first sample solution, and testing the first sample solution using HMS; the concentration of the endogenous metal-fullerene sample in the first sample solution was 0.1~0.5 mg / mL; the HMS mode was positive ion mode; the laser energy for the HMS was 20%~45% of the maximum output energy; and the HMS was time-of-flight mass spectrometry.

2. The detection method according to claim 1, characterized in that, The target endohedral metallofullerene includes: the type of endohedral metal, the number of endohedral metals, and the total number of carbon atoms in the carbon cage; And / or, the purified product of the metal-embedded fullerene sample is obtained by separation using high performance liquid chromatography, including: dissolving the metal-embedded fullerene sample in toluene to form a second sample solution, separating the second sample solution using high performance liquid chromatography to obtain the purified product of the metal-embedded fullerene. And / or, the ultraviolet-visible-near-infrared absorption spectrum is obtained by using an ultraviolet-visible-near-infrared spectrometer, including: dissolving a portion of the purified extract of the endohedral metal fullerene sample in CS2 to form a third sample solution, and testing the third sample solution using an ultraviolet-visible-near-infrared spectrometer; And / or, the X-ray diffraction image is obtained by testing with a single-crystal X-ray diffractometer, including: taking a portion of the purified product of the metal-embedded fullerene sample for crystallization treatment, and taking a single crystal and placing it into a single-crystal X-ray diffractometer for testing; And / or, the optical properties include electronic bandgap and light absorption properties; And / or, the three-dimensional crystal structure includes any one or more of the following: carbon-carbon bond length, bond angle, shape and size of the carbon cage, and three-dimensional coordinates of the inlay.

3. The detection method according to claim 2, characterized in that, The concentration of the metal-embedded fullerene sample in the second sample solution is 0.1~0.5 mg / mL; And / or, the detector of the high performance liquid chromatograph is an ultraviolet detector or a diode array detector; And / or, the high performance liquid chromatograph uses an NPE column; And / or, the mobile phase in the high-performance liquid chromatograph is toluene; And / or, the flow rate of the mobile phase in the high-performance liquid chromatograph is 1.5~2.5 mL / min; And / or, the injection volume in the high-performance liquid chromatograph is 0.5~1.5 mL; And / or, the column temperature in the high performance liquid chromatograph is 25~30℃; And / or, the detection wavelength in the high-performance liquid chromatograph is 330 nm.

4. The detection method according to claim 2, characterized in that, The scanning range of the ultraviolet-visible-near-infrared spectrometer is 300~2000nm; And / or, the scanning speed of the ultraviolet-visible-near-infrared spectrometer is 100~200 nm / min; And / or, the spectral bandwidth of the ultraviolet-visible-near-infrared spectrometer is 1~2nm; And / or, the concentration of the purified metal-embedded fullerene sample in the third sample solution is 0.1~0.5 mg / mL; And / or, the cuvettes used in the ultraviolet-visible-near-infrared spectrometer tests are glass cuvettes.

5. The detection method according to claim 2, characterized in that, The temperature during testing with the single-crystal X-ray diffractometer is 100~200K; And / or, the resolution of the single-crystal X-ray diffractometer is 0.8~0.9 Å; And / or, the single crystal size is 0.2~0.55 mm when tested with the single crystal X-ray diffractometer; And / or, the crystallization process includes concentrating a toluene solution containing the target endohedral metallofullerene, transferring it to a conical tube, and slowly adding Ni dropwise. II – A saturated toluene solution of OEP is used, the tube is sealed, and crystals precipitate out after standing.

6. A detection device for embedded metallofullerenes, characterized in that, The device includes: a mass spectrum acquisition module, used to acquire the mass spectrum of the metal-embedded fullerene sample and analyze it to obtain the molecular weight and molecular formula of the metal-embedded fullerene sample; The judgment module is used to determine whether the endogenous metal-fullerene corresponding to the molecular weight and molecular formula of the endogenous metal-fullerene sample is the target endogenous metal-fullerene. The UV-Vis-NIR absorption spectroscopy acquisition module is used to acquire the UV-Vis-NIR absorption spectrum of the purified metal-embedded metal fullerene sample when the judgment result of the judgment module is the target metal-embedded fullerene. The X-ray diffraction image acquisition module is used to acquire the X-ray diffraction image of the purified metal-embedded fullerene sample when the judgment result of the judgment module is the target metal-embedded fullerene. The output module is used to output the carbon cage structure and / or optical properties of the embedded metal fullerene sample based on the ultraviolet-visible-near-infrared absorption spectrum, and to output the three-dimensional crystal structure of the embedded metal fullerene sample based on the X-ray diffraction image. The termination module is used to stop subsequent detection work when the judgment result of the judgment module is a non-target endogenous metallofullerene.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that enables a processor to execute the detection method as described in any one of claims 1 to 5.

8. An electronic device, characterized in that, The electronic device includes: a processor, a memory, and a computer program; the memory is communicatively connected to the processor, the memory stores the computer program, and the processor executes the computer program to implement the detection method as described in any one of claims 1 to 5.

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