A cationic rare-earth doped aluminum oxide cluster compound, a method for its large-scale preparation and applications

Abstract

The present invention provides a cationic rare-earth-doped aluminum oxide cluster compound, a method for its macroscale preparation and applications. The molecular formula of the aluminum oxide cluster compound is [Al8M(μ2-OH)8(μ3-OH)8(A)8(B)2]·xC, where μ2-OH represents a di-connected OH, and μ3-OH represents a tri-connected OH; M is selected from one of rare-earth ions; A are the same or different and independently selected from residues of aromatic carboxylic acids containing a five- or six-membered aromatic ring with substituents; B is a water molecule; C are the same or different and independently selected from organic acid root ions or inorganic acid root ions; x is the number of free C and is an integer between 0 and 10. The present invention adopts a solvothermal synthesis method, that is, a heating reaction is carried out in a solvent, and the reaction raw materials are simply mixed. Through a one-step self-assembly reaction, the aluminum oxide cluster compound can be obtained. The synthesis requirements of this method are simple, the purity requirements for raw materials are low, the raw materials are easily obtained and inexpensive, and the yield of aluminum oxide cluster a therein reaches more than 40%, and it can be synthesized on a macroscale, which is conducive to large-scale production.

Description

Technical Field

[0001] The present invention belongs to the technical field of crystal material preparation, and particularly relates to a cationic rare-earth-doped aluminum oxo cluster compound, a macro-preparation method thereof, and an application thereof. Background Art

[0002] With the continuous in-depth research in the field of inorganic chemistry, main group elements have become the focus of research. Aluminum, as the third most abundant element on earth and also the most abundant metal element, the synthesis of aluminum metal-oxygen cluster compounds is still in the exploratory stage. Alumina (Al2O3) is non-toxic, harmless, rich in reserves, and has excellent physical and chemical properties, and has multiple variants. It has a high melting point, is resistant to acids and alkalis, and is often used to make bearings, abrasives, and refractory materials.

[0003] Rare earth is the general term for seventeen metal elements including lanthanide elements in the periodic table, scandium, and yttrium. Rare earth is known as the "gold" of industry. Due to its excellent physical properties such as light, electricity, and magnetism, it can form new materials with different properties and varieties with other materials. Its most significant function is to greatly improve the quality and performance of other products.

[0004] Currently, there are not many reported types of aluminum oxo cluster compounds, and Al 3+ is prone to hydrolysis, which poses certain challenges to researchers in designing and synthesizing aluminum oxo clusters. Summary of the Invention

[0005] In order to achieve the above object, the present invention provides a cationic rare-earth-doped aluminum oxo cluster compound, a macro-preparation method thereof, and an application thereof by using a coordination delayed hydrolysis strategy. The aluminum oxo cluster compound is the first cationic aluminum oxo wheel cluster and has a cubic cage-like packing. The preparation method of the aluminum oxo cluster compound is simple and efficient, and can achieve macro-preparation, meeting the requirements of green environmental protection.

[0006] The first aspect of the present invention is to provide a cationic rare-earth-doped aluminum oxo cluster compound, and the molecular formula of the aluminum oxo cluster compound is as follows:

[0007] [Al8M(μ2-OH)8(μ3-OH)8(A)8(B)2]·xC

[0008] Among them, μ2-OH represents di-connected OH, and μ3-OH represents tri-connected OH;

[0009] M is selected from one of rare earth ions;

[0010] A is the same or different, and independently of each other, is selected from the residues of aromatic carboxylic acids containing a five- or six-membered aromatic ring with substituents;

[0011] B is a water molecule;

[0012] C is the same or different and is independently selected from organic acid root ions or inorganic acid root ions;

[0013] x is the number of free C and is an integer between 0 and 10.

[0014] Exemplarily, x is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0015] According to the present invention, M is selected from one of 17 rare earth ions, selected from La 3+ , Ce 3+ , Pr 3+ , Nd 3+ , Pm 3+ , Sm 3 + , Eu 3+ , Gd 3+ , Tb 3+ , Dy 3+ , Ho 3+ , Er 3+ , Tm 3+ , Yb 3+ , Lu 3+ , Y 3+ and Sc 3+ ; for example, selected from one of light rare earth ions (La 3+ , Ce 3+ , Pr 3+ , Nd 3+ ).

[0016] According to the present invention, M is selected from La 3+ , Ce 3+ , Pr 3+ , Nd 3+ , Pm 3+ , Sm 3+ , or Eu 3+ ; preferably Ce 3+ .

[0017] According to the present invention, A is the same or different and is independently selected from residues of aromatic carboxylic acids containing a five- or six-membered aromatic ring with substituents; preferably, selected from residues of aromatic carboxylic acids containing a six-membered aromatic ring with substituents; more preferably, selected from residues of aromatic carboxylic acids containing a six-membered aromatic ring; further preferably, selected from residues of aromatic monocarboxylic acids containing a six-membered aromatic ring.

[0018] According to the present invention, the "five- or six-membered aromatic ring" refers to an aromatic ring containing a total of 5 to 6 ring atoms and optionally containing 1 to 3 heteroatoms selected from N, O, and S. Specifically, the "five- or six-membered aromatic ring" may be selected from benzene, furan, thiophene, pyrrole, thiazole, imidazole, pyridine, pyrazine, pyrimidine, pyridazine, pyran, etc.

[0019] According to the present invention, the "substituent" is a conventional substituent in the art, such as a hydroxyl group, C 1-6 alkyl group, C 1-6 alkoxy group or amino group, preferably a hydroxyl group, a methyl group, an amino group or a methoxy group.

[0020] According to the present invention, the As are the same or different and are independently selected from the residues of benzoic acid, the residue of 2-pyridinecarboxylic acid, the residue of 3-pyridinecarboxylic acid, the residue of 4-pyridinecarboxylic acid, the residue of 2H-pyran-2-carboxylic acid, the residue of 4H-pyran-4-carboxylic acid, the residue of pyridazinecarboxylic acid, the residue of pyrimidinecarboxylic acid, the residue of pyrazinecarboxylic acid; preferably the residue of benzoic acid.

[0021] According to the present invention, B is a water molecule, which is derived from the water molecule generated by the esterification reaction of an acid and an alcohol in the reaction system, or from the water contained in the solvent.

[0022] According to the present invention, the Cs are the same or different and are independently selected from organic or inorganic acid root ions; preferably, they are selected from inorganic acid root ions; more preferably, they are selected from oxygen-containing inorganic acid root ions.

[0023] According to the present invention, the Cs are the same or different and are independently selected from formate, acetate, hypochlorite, chlorite, perchlorate, sulfate, nitrate, borate, nitrite, metaaluminate, manganate, permanganate, carbonate, phosphate; preferably nitrate.

[0024] According to the present invention, the aluminoxane is a pure-phase transparent colorless cubic crystalline substance.

[0025] According to the present invention, the aluminoxane is an organic-inorganic hybrid compound.

[0026] According to the present invention, the cluster core size of the crystalline substance of the aluminoxane is

[0027] According to the present invention, the crystalline substance of the aluminoxane has a symmetric structure.

[0028] According to an embodiment of the present invention, the molecular formula of the aluminoxane is:

[0029] [Al8M(μ2-OH)8(μ3-OH)8(A)8(B)2]·3C

[0030] wherein M is Ce3+ ; A is the residue of benzoic acid; B is a water molecule; C is a nitrate ion.

[0031] It should be noted that in the present invention, the residue refers to the group remaining after removing all the hydrogens on the carboxyl group of an organic acid or the group remaining after removing the hydrogen on the oxygen of an inorganic acid.

[0032] According to an exemplary embodiment of the present invention, the molecular formula of the aluminoxane is C 56 H 60 O 43 N3Al8Ce, C 56 H 60 O 43 N3Al8La, C 56 H 60 O 43 N3Al8Pr or C 56 H 60 O 43 N3Al8Nd. Denote the C 56 H 60 O 43 N3Al8Ce as aluminoxane a, the C 56 H 60 O 43 N3Al8La as aluminoxane b, the C 56 H 60 O 43 N3Al8Pr as aluminoxane c, and the C 56 H 60 O 43 N3Al8Nd as aluminoxane d.

[0033] According to the present invention, the crystal system of the aluminoxane a is the tetragonal system, the space group is P4 / nnc, and the unit cell parameters a are b is c is α is 90°, β is 90°, γ is 90°, and V is

[0034] According to the present invention, the relative molecular mass Mr of the aluminoxane a is 1819.16.

[0035] According to the present invention, the aluminoxane a has a crystal structure substantially as Figure 1 shown.

[0036] According to the present invention, the aluminoxane a has a cubic cage-like packing structure substantially as Figure 2 shown.

[0037] According to the present invention, the aluminoxane a has substantially as Figure 4 the X-ray powder diffraction pattern shown.

[0038] According to the present invention, the crystal parameters of the aluminoxane a are shown in Table 1:

[0039] Table 1

[0040]

[0041] The second aspect of the present invention is to provide a method for preparing the above aluminoxane, the method comprising the following steps: mixing a rare earth salt, an aluminum salt, an organic acid, an organic nitrile, a nitrogen-containing six-membered heterocyclic compound, and an inorganic acid, and carrying out a solvothermal reaction to obtain the aluminoxane.

[0042] According to the present invention, the method specifically comprises the following steps:

[0043] 1) Mixing the rare earth (IV) salt or quaternary ammonium salt, an aluminum salt, a rare earth (III) salt, an organic acid, an organic nitrile, a nitrogen-containing six-membered heterocyclic compound, and an inorganic acid, and carrying out a solvothermal reaction to obtain a mixture;

[0044] 2) Separating the mixture obtained after the reaction in step 1), and the solid phase obtained is the aluminoxane.

[0045] According to the present invention, the aluminum salt is a compound formed by the aluminum ion and an alcohol after removing the hydrogen on the alcohol hydroxyl group.

[0046] According to the present invention, the aluminum salt is selected from at least one of aluminum ethoxide, aluminum tert-butoxide, aluminum isobutoxide, aluminum n-butoxide, aluminum n-propoxide, and aluminum isopropoxide, and preferably aluminum isopropoxide.

[0047] According to the present invention, the rare earth (III) salt is selected from at least one of acetate, nitrate, acetylacetonate, carbonate, and halide of rare earth (III) ions. For example, taking cerium as an example, it is selected from at least one of cerium (III) acetate, cerium (III) nitrate, cerium (III) acetylacetonate, cerium (III) carbonate, cerium (III) fluoride, and cerium (III) trichloride, and preferably nitrate, such as cerium (III) nitrate.

[0048] According to the present invention, the quaternary ammonium salt is selected from at least one of tetramethylammonium chloride, tetramethylammonium bromide, tetraethylammonium chloride, tetraethylammonium bromide, tetrapropylammonium chloride, tetrapropylammonium bromide, and tetrabutylammonium chloride, and preferably tetraethylammonium chloride.

[0049] According to the present invention, the rare earth (IV) salt is selected from at least one of sulfate, nitrate, and oxide of rare earth (IV) ions. For example, taking cerium as an example, it can be exemplified by at least one of ammonium cerium (IV) sulfate, cerium (IV) sulfate, ammonium cerium (IV) nitrate, and cerium (IV) oxide, and preferably ammonium cerium (IV) nitrate.

[0050] According to the present invention, the organic acid is selected from aromatic carboxylic acids or mixtures thereof containing a five- or six-membered aromatic ring with substituents (preferably a six-membered aromatic ring with substituents, more preferably a six-membered aromatic ring).

[0051] Preferably, the organic acid is selected from at least one of benzoic acid, 2-pyridinecarboxylic acid, 3-pyridinecarboxylic acid, 4-pyridinecarboxylic acid, 2H-pyran-2-carboxylic acid, 4H-pyran-4-carboxylic acid, pyridazinecarboxylic acid, pyrazinecarboxylic acid, pyrimidinecarboxylic acid, etc.; preferably benzoic acid.

[0052] According to the present invention, the organic nitrile is selected from at least one of dicyandiamide, acetonitrile, propionitrile, malononitrile, phenylacetonitrile, butyronitrile, valeronitrile, and capronitrile, preferably acetonitrile.

[0053] According to the present invention, the nitrogen-containing six-membered heterocyclic compound is selected from at least one of pyridine, pyran, pyridazine, and pyrimidine, preferably pyridine.

[0054] According to the present invention, the inorganic acid is selected from at least one of formic acid, acetic acid, chlorous acid, perchloric acid, nitric acid, sulfuric acid, boric acid, nitrous acid, metaaluminum acid, manganic acid, permanganic acid, carbonic acid, phosphoric acid, hydrochloric acid, and hypochlorous acid, preferably nitric acid.

[0055] According to the present invention, the molar ratio of the aluminum salt to the rare earth (III) salt is 1:(0.01 - 3), for example 1:(0.05 - 2), specifically 1:(0.1 - 1).

[0056] According to the present invention, the molar ratio of the aluminum salt to the rare earth (IV) salt is 1:(0.01 - 3), for example 1:(0.05 - 2), specifically 1:(0.1 - 1).

[0057] According to the present invention, the molar ratio of the aluminum salt to the organic acid is 1:(0.01 - 3), for example 1:(0.05 - 2), specifically 1:(0.1 - 1).

[0058] According to the present invention, the molar ratio of the aluminum salt to the organic nitrile is 1:(1 - 1000), for example 1:(1 - 500), specifically 1:(10 - 300).

[0059] According to the present invention, the molar ratio of the aluminum salt to the nitrogen-containing six-membered heterocyclic compound is 1:(1 - 20), for example 1:(1 - 10), specifically 1:(1 - 5).

[0060] According to the present invention, the molar ratio of the aluminum salt to the inorganic acid is 1:(1 - 20), for example 1:(1 - 10), specifically 1:(1 - 5).

[0061] In the present invention, the quaternary ammonium salt is used as a regulator to replace the rare earth (IV) salts of lanthanum, praseodymium, and neodymium, which are absent, rare, or difficult to purchase, and to promote the reaction. Its dosage is not particularly limited and can be conventionally selected by those skilled in the art. For example, it is 0.05-5 wt% of the target product aluminum oxo cluster.

[0062] According to the present invention, the temperature of the solvothermal reaction is 40-160 °C; preferably 60-130 °C, such as 70-100 °C, e.g., 80 °C. If the reaction temperature is too low, the reaction time will be longer and the crystal size will be smaller.

[0063] According to the present invention, the time of the solvothermal reaction is 72-312 hours; preferably 120-264 hours, such as 120 hours, 168 hours, 216 hours.

[0064] As an exemplary embodiment of the present invention, the reaction can be carried out at 80 °C for 192 hours or 216 hours, or at 100 °C for 144 hours or 168 hours.

[0065] According to the present invention, step 1) specifically includes: mixing the aluminum salt, rare earth (III) salt, rare earth (IV) salt, organic acid, organic nitrile, nitrogen-containing six-membered heterocyclic compound, and inorganic acid, stirring, reacting at a constant temperature, and then cooling to room temperature.

[0066] Preferably, the reaction at a constant temperature means standing reaction at a constant temperature, for example, standing reaction in an oven at a constant temperature.

[0067] According to the present invention, in step 2), the separated solid phase is washed and dried. Preferably, water, alkanes, and benzene derivatives are used to wash the separated solid phase, and it is air-dried at room temperature. The alkanes and benzene derivatives can be n-hexane, cyclohexane, or toluene.

[0068] According to the present invention, the yield of the aluminum oxo cluster a can reach 40%, and the yields of the aluminum oxo clusters b, c, and d can reach 25%.

[0069] Exemplarily, step 1) is specifically: mixing the aluminum salt, rare earth (III) salt, rare earth (IV) salt, organic acid, organic nitrile, nitrogen-containing six-membered heterocyclic compound, and inorganic acid, and carrying out a solvothermal reaction to obtain a mixture.

[0070] Exemplarily, step 1) is also specifically: mixing the aluminum salt, rare earth (III) salt, quaternary ammonium salt, organic acid, organic nitrile, nitrogen-containing six-membered heterocyclic compound, and inorganic acid, and carrying out a solvothermal reaction to obtain a mixture.

[0071] According to the present invention, for example, the rare earth (IV) salt of cerium is replaced with a quaternary ammonium salt, and the rare earth ion in the rare earth (III) salt is replaced from cerium ion with other light rare earth ions (such as La 3+ , Pr 3+ , Nd 3+ ), and isomorphic rare earth-doped aluminoxane clusters can be obtained.

[0072] According to the present invention, the aluminoxane clusters of the first aspect are prepared by the method of the second aspect.

[0073] The third aspect of the present invention provides an application of the above aluminoxane clusters for the enrichment of inorganic metal ions in wastewater pollutants and the effective capture and storage of radioactive iodine in the aqueous phase.

[0074] Advantages of the present invention:

[0075] The present invention provides an organic-inorganic hybrid cationic rare earth-doped aluminoxane cluster, which has a symmetric structure, and the cluster core size is about The rare earth-doped aluminoxane cluster has a cubic cage-like packing, as an ionic metal-oxide cluster, and has mesoporous channels and free nitrate ions, so it can be applied in the field of anion exchange; and when the rare earth ion Ce 3+ is replaced with other light rare earth ions (such as La 3+ , Pr 3+ , Nd 3+ , etc.), it can have the same wheel cluster structure and different packings.

[0076] The present invention also provides a preparation method of aluminoxane clusters, especially its large-scale preparation method, in which a solvothermal synthesis method is used, that is, a heating reaction is carried out in a solvent, the reaction raw materials are simply mixed, and through a one-step self-assembly reaction, the rare earth-doped aluminoxane clusters can be obtained. The synthesis requirements of this method are simple, the purity requirements for raw materials are low, the raw materials are easily obtained and inexpensive, the raw materials used can be purchased as chemically pure reagents without further purification, and the yield of aluminoxane cluster a can reach 40%, which is conducive to large-scale production. In addition, the post-treatment of this method is simple and easy to operate, and only needs to be separated by simple water washing, alkane washing or benzene derivative washing, and air-dried at room temperature to obtain a pure-phase crystalline product. And the raw materials of this method are extremely inexpensive and less polluting, meeting the requirements of green environmental protection. Description of the drawings

[0077] Figure 1 is the crystal structure of the crystalline product prepared in Example 1 or Example 2;

[0078] Figure 2 is the crystal packing diagram of the crystalline product prepared in Example 1 or Example 2;

[0079] Figure 3 Schematic diagram of crystal packing of the crystalline product prepared in Example 3 or Example 4 or Example 5;

[0080] Figure 4 X-ray powder diffraction pattern of the crystalline product prepared in Examples 1 and 2; among them, the "theoretical value" is the X-ray powder diffraction pattern simulated according to the crystal structure; the "experimental value 1" is the X-ray powder diffraction pattern obtained by testing on an X-ray powder diffractometer in Example 1; the "experimental value 2" is the X-ray powder diffraction pattern obtained by testing on an X-ray powder diffractometer in Example 2; the "water stability" is the X-ray powder diffraction pattern obtained by testing on an X-ray powder diffractometer after the crystal product is soaked in water for 2 weeks;

[0081] Figure 5 Infrared spectrum of the crystalline product prepared in Example 1;

[0082] Figure 6 Infrared spectrum of the crystalline product prepared in Example 2;

[0083] Figure 7 X-ray photoelectron spectroscopy analysis of the crystalline product prepared in Example 2;

[0084] Figure 8 Product photo of the crystalline product prepared in Example 2. Detailed implementation mode

[0085] The technical solution of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only for illustrative and explanatory purposes of the present invention, and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0086] Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products, or can be prepared by known methods.

[0087] The single crystal structure analysis of the present invention uses a supernova single crystal diffractometer from Rigaku, Japan.

[0088] The radiation source used for the X-ray powder diffraction pattern is Ga-Kα ray.

[0089] Example 1

[0090] Preparation of cerium-doped aluminum oxo cluster a

[0091] Put aluminum isopropoxide (0.75 mmol), ammonium cerium nitrate (0.084 mmol), cerium nitrate (0.33 mmol), benzoic acid (0.5 mmol), acetonitrile (96 mmol), pyridine (2.5 mmol) and nitric acid (1.2 mmol) into a 20 ml glass bottle, mix well at room temperature, keep it at a constant temperature of 80 °C in an oven for 5 days, take it out, naturally cool it to room temperature, separate the solid phase, rinse it with toluene, and naturally dry it at room temperature to obtain the colorless regular cube-shaped crystalline target product aluminum oxo cluster a, with the molecular formula C 56 H 60 O 43 N3Al8Ce. Among them, the crystal system of the aluminum oxo cluster a is tetragonal system, the space group is P4 / nnc, and the lattice parameter a is b is c is α is 90°, β is 90°, γ is 90°, V is

[0092] The yield of the aluminum oxo cluster a is 40%.

[0093] Example 2

[0094] Macroscale preparation of aluminum oxo cluster a

[0095] Put aluminum isopropoxide (7.5 mmol), ammonium cerium nitrate (0.84 mmol), cerium nitrate (3.3 mmol), benzoic acid (5 mmol), acetonitrile (960 mmol), pyridine (25 mmol) and nitric acid (12 mmol) into a 100 mL blue-capped bottle, mix well at room temperature, keep it at a constant temperature of 80 °C in an oven for 5 days, take it out, naturally cool it to room temperature, separate the solid phase, rinse it with toluene, and naturally dry it in the air to obtain the colorless regular cube-shaped crystalline target product aluminum oxo cluster a. The yield of the aluminum oxo cluster a is 40%.

[0096] Example 3

[0097] Preparation of lanthanum-doped aluminum oxo cluster b

[0098] Put aluminum isopropoxide (0.75 mmol), lanthanum nitrate (0.33 mmol), benzoic acid (0.5 mmol), acetonitrile (96 mmol), pyridine (2.5 mmol), nitric acid (1.2 mmol) and tetraethylammonium chloride (0.5 mmol) into a 20 ml glass bottle, mix well at room temperature, keep it at a constant temperature of 80 °C in an oven for 5 days, take it out, naturally cool it to room temperature, separate the solid phase, rinse it with toluene, and naturally dry it at room temperature to obtain the colorless block-shaped crystalline target product aluminum oxo cluster b, with the molecular formula C 56 H 60 O 43N3Al8La. Among them, the crystal system of the aluminum oxide cluster b is the tetragonal system, the space group is P4 / nnc, and the unit cell parameter a is b is c is α is 90°, β is 90°, γ is 90°, and V is

[0099] The yield of the aluminum oxide cluster b is 25%.

[0100] Example 4

[0101] Preparation of praseodymium-doped aluminum oxide cluster c

[0102] The difference between Example 4 and Example 3 is that: praseodymium nitrate is used to replace lanthanum nitrate in Example 3 to prepare the aluminum oxide cluster c, and its molecular formula is C 56 H 60 O 43 N3Al8Pr. Among them, the crystal system of the aluminum oxide cluster c is the tetragonal system, the space group is P4 / nnc, and the unit cell parameter a is b is c is α is 90°, β is 90°, γ is 90°, and V is

[0103] The yield of the aluminum oxide cluster c is 25%.

[0104] Example 5

[0105] Preparation of neodymium-doped aluminum oxide cluster d

[0106] The difference between Example 5 and Example 3 is that: neodymium nitrate is used to replace lanthanum nitrate in Example 3 to prepare the aluminum oxide cluster d, and its molecular formula is C 56 H 60 O 43 N3Al8Nd. Among them, the crystal system of the aluminum oxide cluster d is the tetragonal system, the space group is P4 / nnc, and the unit cell parameter a is b is c is α is 90°, β is 90°, γ is 90°, and V is

[0107] The yield of the aluminum oxide cluster d is 25%.

[0108] Figure 1 is the crystal structure of the crystalline product in Example 1 or Example 2 ( Figure 1 the central atom is Ce, and the surrounding eight six-coordinated atoms are Al), Figure 2 is the stacking diagram of the crystalline product in Example 1 or Example 2. FromFigure 1 It can be seen that the aluminoxane cluster has 8 aluminum atoms and 1 cerium atom. In addition to 8 benzoic acid ligands on the periphery, there are also two coordinated water molecules before and after the cerium atom. According to Figure 5 The infrared spectrum can confirm that there are free nitrate ions in the crystal. Since the outer aluminum ring is electrically neutral and there is a trivalent cerium ion in the center, the aluminoxane cluster is +3 valence, and the three free nitrate ions around it can also prove that the aluminoxane cluster of the present invention is ionic.

[0109] Figure 3 It is a schematic diagram of the crystal packing of the crystalline products in Example 3 or Example 4 or Example 5, except that the central atoms are different, representing La or Pr or Nd respectively. From Figure 3 It can be seen that the structure of the aluminoxane cluster is the same as that of the crystalline products in Examples 1 and 2, but the packing has changed.

[0110] Figure 4 It is the X-ray powder diffraction pattern of the crystalline products prepared in Examples 1 and 2. Figure 4 In the figure, the curves from top to bottom represent water stability, experimental value 1, experimental value 2, and theoretical value respectively. Among them, the "theoretical value" is the X-ray powder diffraction pattern simulated according to the crystal structure; "experimental value 1" is the X-ray powder diffraction pattern of the crystal product prepared in Example 1 tested on an X-ray powder diffractometer; "experimental value 2" is the X-ray powder diffraction pattern of the crystal product prepared in Example 2 tested on an X-ray powder diffractometer; "water stability" is the X-ray powder diffraction pattern of the crystal product prepared in Example 2 tested on an X-ray powder diffractometer after being soaked in water for 2 weeks; From Figure 4 It can be seen that the crystal products in Examples 1 and 2 are consistent, the product purity is high, and they are stable in air and water.

[0111] Figure 5 It is the infrared spectrum of the crystalline product prepared in Example 1.

[0112] Figure 6 It is the infrared spectrum of the crystalline product prepared in Example 2.

[0113] From Figure 5 and Figure 6 It can be seen that the vibration characteristic peaks of the Al-O cluster core of the aluminoxane cluster are at 1000 - 500 cm -1 , the vibration characteristic peaks of the organic ligand are at 3500 - 1000 cm -1 , and the vibration characteristic peak of the nitrate is at 1330 cm -1 .

[0114] Figure 7For the X-ray photoelectron spectroscopy analysis of the crystalline product prepared in Example 2, it can be seen from Figure 7 the presence of trivalent cerium.

[0115] Figure 8 The product photo of the crystalline product prepared in Example 2 is shown in Figure 8 which shows that this compound is colorless and cubic.

[0116] Above, the embodiments of the present invention have been described exemplarily. However, the protection scope of the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A rare earth-doped aluminum oxygen cluster compound, characterized in that, The molecular formula of the aluminoxane complex is: [Al8M(μ2-OH)8(μ3-OH)8(A)8(B)2]•xC Among them, μ2-OH represents a doubly-bridging OH, and μ3-OH represents a triply-bridging OH; M is selected from Ce 3+ , La 3+ , Pr 3+ , Nd 3+ ; A is the residue of benzoic acid; B is a water molecule; C are all nitrate ions; x is the number of free C, which is an integer between 0 and 10.

2. The aluminoxane complex according to claim 1, characterized in that, The aluminoxane complex is a pure-phase transparent colorless cubic crystalline substance.

3. The aluminoxane complex according to claim 1, wherein The aluminoxane complex is an organic-inorganic hybrid compound.

4. The aluminoxane complex according to claim 1, characterized in that, The cluster core size of the crystalline form of the aluminoxane complex is 19.6±0.2 Å.

5. The aluminoxane complex according to claim 1, characterized in that, The crystalline form of the aluminoxane complex has a symmetric structure.

6. The aluminoxane complex according to claim 1, wherein, The molecular formula of the aluminoxane complex is [Al8M(μ2-OH)8(μ3-OH)8(A)8(B)2]•3C, Among them, M is Ce 3+ ; A is the residue of benzoic acid; B is a water molecule; C is a nitrate ion.

7. The aluminoxane complex according to claim 1, wherein The molecular formula of the aluminoxane complex is C 56 H 60 O 43 N3Al8Ce, denoted as aluminoxane complex a. The crystal system of the aluminoxane complex a is tetragonal, and the space group is P4 / nnc , and the unit cell parameters a is 20.75 Å, b is 20.75 Å, c is 50.57 Å, α is 90 o , β is 90 o , γ is 90 o , and V is 21766.9 Å 3 .

8. The aluminoxane complex according to claim 7, wherein The crystal parameters of the crystalline form of the aluminoxane complex a are shown in Table 1: 。 9. The aluminoxane complex according to claim 8, wherein The aluminoxane complex a has a cubic cage-like packing structure.

10. A method for preparing the rare earth-doped aluminum oxo cluster compound according to any one of claims 1-9, characterized in that, The method includes the following steps: 1) Mix a rare earth (IV) salt or a quaternary ammonium salt, an aluminum salt, a rare earth (III) salt, an organic acid, an organic nitrile, a nitrogen-containing six-membered heterocyclic compound, and an inorganic acid, and carry out a solvothermal reaction to obtain a mixture; 2) Separate the mixture obtained after the reaction in step 1), and the solid phase obtained is the aluminoxane complex; The rare earth (III) salt is selected from nitrates of rare earth (III) ions; The organic acid is selected from benzoic acid; The aluminum salt is selected from aluminum isopropoxide; The organic nitrile is selected from acetonitrile; The nitrogen-containing six-membered heterocyclic compound is selected from pyridine; The inorganic acid is selected from nitric acid.

11. The preparation method according to claim 10, characterized in that, When the rare earth ion is a cerium ion, the rare earth (III) salt is selected from cerium (III) nitrate.

12. The preparation method according to claim 10, wherein, The quaternary ammonium salt is selected from at least one of tetramethylammonium chloride, tetramethylammonium bromide, tetraethylammonium chloride, tetraethylammonium bromide, tetrapropylammonium chloride, tetrapropylammonium bromide, and tetrabutylammonium chloride; The rare earth (IV) salt is selected from at least one of sulfates, nitrates, and oxides of rare earth (IV) ions.

13. The preparation method according to claim 10, characterized in that, The molar ratio of the aluminum salt to the rare earth (III) salt is 1:(0.01-3); The molar ratio of the aluminum salt to the rare earth (IV) salt is 1:(0.01-3); The molar ratio of the aluminum salt to the organic acid is 1:(0.01-3); The molar ratio of the aluminum salt to the organic nitrile is 1:(1-1000); The molar ratio of the aluminum salt to the nitrogen-containing six-membered heterocyclic compound is 1:(1-20); The molar ratio of the aluminum salt to the inorganic acid is 1:(1-20).

14. The preparation method according to claim 10, wherein The temperature of the solvothermal reaction is 40~160 °C; The time of the solvothermal reaction is 72~312 hours.

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