Host-guest composite materials based on metal organic framework materials and N4Py high-valent mononuclear iron complexes, as well as preparation methods and applications

Abstract

The present invention discloses a host-guest composite material based on a metal organic framework material and a N4Py high-valent mononuclear iron complex, as well as a preparation method and application, and relates to the technical field of porous coordination polymer materials. It is used to solve the technical problem that the existing biomimetic non-heme high-valent iron complex is very easy to dimerize to form an oxygen-bridged binuclear trivalent iron complex during a homogeneous reaction, thereby causing it to lose its catalytic activity. The preparation method of the host-guest composite material comprises: obtaining UiO-66-F4 powder and an acetonitrile solution containing a divalent mononuclear iron complex; adding UiO-66-F4 powder to the acetonitrile solution, and stirring until the divalent mononuclear iron complex enters the interior of the UiO-66-F4 structure to obtain FeN4Py@UiO-66-F4; placing FeN4Py@UiO-66-F4 in an acetonitrile aqueous solution containing ceric ammonium nitrate, and after standing, obtaining the above-mentioned host-guest composite material.

Description

Technical Field

[0001] The present invention relates to the technical field of porous coordination polymer materials, and more specifically to a host-guest composite material based on a metal organic framework material and an N4Py high-valent mononuclear iron complex, as well as a preparation method and application thereof. Background Art

[0002] With the accelerated advancement of global industrialization, human society's demand for various high-value chemicals continues to grow. Among them, the activation of C-H bonds is a key step in the conversion process from primary chemicals to high-value chemicals, and has always been a research hotspot in the field of chemical catalysis.

[0003] Biomimetic non-heme high-valent iron complexes show extremely high reactivity and selectivity in the activation process of hydrocarbons. One of the most representative non-heme mononuclear high-valent iron complexes ([(N4Py)Fe IV =O] 2+ ), whose C-H bond activation ability is even higher than that of its biological reference P450, and can activate high-energy C-H bonds (99.3 kcal / mol) at room temperature. However, these biomimetic non-heme high-valent iron complexes are prone to dimerization during homogeneous reactions to form oxygen-bridged dinuclear trivalent iron complexes, resulting in loss of catalytic activity. Summary of the Invention

[0004] The present invention aims to provide a host-guest composite material based on a metal-organic framework (MOF) and a high-valent mononuclear iron complex of N4Py, as well as its preparation method and application. This material addresses the technical problem that existing biomimetic high-valent non-heme iron complexes are prone to dimerization during homogeneous reactions to form oxygen-bridged dinuclear trivalent iron complexes, which in turn leads to loss of catalytic activity. In view of this, the present invention is achieved through the following technical solutions.

[0005] In a first aspect, the present invention provides a host-guest composite material based on a metal organic framework material and an N4Py high-valent mononuclear iron complex, wherein the structural expression of the host-guest composite material is:

[0006] [(N4Py)Fe IV =O]Cl2@UiO-66-F4;

[0007] Among them, UiO-66-F4 is a metal organic framework compound, [(N4Py)Fe IV =O] 2+ It is a non-heme mononuclear high-valent iron complex. The host of the host-guest composite material is UiO-66-F4, and the guest is [(N4Py)Fe IV =O]Cl2; @ indicates that the composite material is a porous coordination polymer material assembled by host and guest.

[0008] Compared with the prior art, the host-guest composite material based on metal organic framework material and N4Py high valence mononuclear iron complex of the present invention is based on UiO-66-F4 as the main component and [(N4Py)Fe IV =O]Cl2 is the guest, and the high-valent iron complex [(N4Py)Fe IV =O]Cl2 forms a strong interaction force with the pore structure of UiO-66-F4, resulting in high stability. The host-guest composite material of the present invention is used for the activation of hydrocarbons in homogeneous reactions, exhibiting high reactivity and selectivity. This solves the technical problem that existing biomimetic non-heme high-valent iron complexes are prone to dimerization during homogeneous reactions to form oxygen-bridged binuclear trivalent iron complexes, which in turn lead to loss of catalytic activity.

[0009] In a second aspect, the present invention provides a method for preparing a host-guest composite material based on a metal organic framework material and an N4Py high-valent mononuclear iron complex, which is used to prepare the host-guest composite material, comprising:

[0010] Obtaining UiO-66-F4 powder and an acetonitrile solution containing a divalent mononuclear iron complex, wherein the divalent mononuclear iron complex is FeN4Py;

[0011] The UiO-66-F4 powder is added to the acetonitrile solution and stirred until FeN4Py enters the interior of the UiO-66-F4 structure. After centrifugation and washing, FeN4Py@UiO-66-F4 is obtained;

[0012] The FeN4Py@UiO-66-F4 was placed in an acetonitrile aqueous solution containing ammonium cerium nitrate and allowed to stand for 30 to 60 minutes to obtain a structural expression of [(N4Py)Fe IV =O]Cl2@UiO-66-F4 host-guest composite material.

[0013] Compared with the prior art, the beneficial effects of the preparation method of the host-guest composite material based on metal-organic framework materials and N4Py high-valent mononuclear iron complex of the present invention are the same as the beneficial effects of the host-guest composite material based on metal-organic framework materials and N4Py high-valent mononuclear iron complex described in the above technical scheme, and will not be repeated here.

[0014] Furthermore, in the preparation method of the host-guest composite material based on the metal-organic framework material and the N4Py high-valent mononuclear iron complex of the present invention, in the process of adding the UiO-66-F4 powder to the acetonitrile solution, the molar ratio of UiO-66-F4 to FeN4Py is 1: (1~2.5).

[0015] Furthermore, in the preparation method of the host-guest composite material based on the metal-organic framework material and the N4Py high-valent mononuclear iron complex of the present invention, the FeN4Py@UiO-66-F4 is placed in an acetonitrile aqueous solution containing ammonium cerium nitrate, and the molar ratio of FeN4Py to ammonium cerium nitrate is 1:(2~2.5).

[0016] Furthermore, in the preparation method of the host-guest composite material based on the metal organic framework material and the N4Py high-valent mononuclear iron complex of the present invention, the volume ratio of water to acetonitrile in the acetonitrile aqueous solution is 1: (1~3).

[0017] Furthermore, in the preparation method of the host-guest composite material based on the metal organic framework material and the N4Py high-valent mononuclear iron complex of the present invention, the stirring rate is 100~300 rpm and the stirring time is 12~50 hours during the process of stirring until FeN4Py enters the interior of the UiO-66-F4 structure.

[0018] Furthermore, in the preparation method of the host-guest composite material based on the metal organic framework material and the N4Py high-valent mononuclear iron complex of the present invention, the obtaining of UiO-66-F4 powder comprises:

[0019] Obtain a glacial acetic acid solution with a volume concentration of 60-70%;

[0020] Adding tetrafluoroterephthalic acid and zirconium nitrate to the glacial acetic acid solution and stirring until the solid powder is completely dissolved to obtain a mixed solution; the molar ratio of the tetrafluoroterephthalic acid to the zirconium nitrate is 1:(1-2);

[0021] The mixed solution is condensed and refluxed at a temperature of 100-120° C. for 24-36 hours to form UiO-66-F4 with a cage-like porous structure; and the UiO-66-F4 is dried to obtain the UiO-66-F4 powder.

[0022] Furthermore, in the preparation method of the host-guest composite material based on the metal organic framework material and the N4Py high-valent mononuclear iron complex of the present invention, after forming the cage-like porous structure of UiO-66-F4 and before drying the UiO-66-F4, the method further comprises:

[0023] Centrifuging the mixed solution to remove the mother liquor to obtain a powdered solid material;

[0024] Washing the solid material with ultrapure water to remove the solution on the surface of the solid material;

[0025] The solid material was then immersed in methanol, dichloromethane and acetonitrile for three days, with the solvent changed every day; the solid material was UiO-66-F4.

[0026] Furthermore, in the preparation method of the host-guest composite material based on the metal organic framework material and the N4Py high-valent mononuclear iron complex of the present invention, the drying of the UiO-66-F4 comprises:

[0027] The solid material was immersed in methanol, dichloromethane and acetonitrile for exchange for three days, and then placed in a vacuum oven at 120° C. for 24 hours and cooled to room temperature to obtain the UiO-66-F4 powder.

[0028] In a third aspect, the present invention provides the application of the host-guest composite material based on the metal organic framework material and the N4Py high-valent mononuclear iron complex in the preparation of redox catalytic materials and bioinorganic chemical materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0030] Figure 1 The host-guest composite material of the present invention [(N4Py)Fe IV =O]Cl2@UiO-66-F4 synthesis schematic diagram;

[0031] Figure 2 Inventive Example 2, the UiO-66-F4 sample and [(N4Py)Fe IV =O]Cl2@UiO-66-F4 XRD comparison spectrum;

[0032] Figure 3 The UiO-66-F4 sample and [(N4Py)Fe IV =O]Cl2@UiO-66-F4 sample TGA curve comparison chart;

[0033] Figure 4 The UiO-66-F4 sample and [(N4Py)Fe IV =O]Cl2@UiO-66-F4 sample 77K nitrogen adsorption curve comparison;

[0034] Figure 5 [(N4Py)Fe IV =O]Cl2@UiO-66-F4 sample TEM-EDS spectrum; Figure A is [(N4Py)Fe IV =O]Cl2@UiO-66-F4 sample TEM image, Figure B is [(N4Py)Fe IV=O]Cl2@UiO-66-F4 sample EDS energy spectrum of fluorine element, Figure C is [(N4Py)Fe IV =O]Cl2@UiO-66-F4 sample EDS spectrum of zirconium element, Figure D is [(N4Py)Fe IV =O]Cl2@UiO-66-F4 sample’s EDS spectrum of iron;

[0035] Figure 6 The UiO-66-F4 sample and [(N4Py)Fe IV =O]Cl2@UiO-66-F4 solid UV spectrum curve comparison chart;

[0036] Figure 7 This is a diagram of the inactivation reaction pathway of existing non-heme high-valent iron complexes. DETAILED DESCRIPTION

[0037] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0038] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined. "Several" means one or more, unless otherwise specifically defined.

[0040] Biomimetic non-heme high-valent iron complexes show extremely high reactivity and selectivity in the activation process of hydrocarbons. One of the most representative non-heme mononuclear high-valent iron complexes ([(N4Py)Fe IV =O] 2+), whose C-H bond activation ability is even higher than that of its biological reference P450, and can activate high-energy C-H bonds (99.3 kcal / mol) at room temperature. However, these biomimetic non-heme high-valent iron complexes are prone to dimerization during homogeneous reactions to form oxygen-bridged dinuclear trivalent iron complexes, resulting in loss of catalytic activity.

[0041] In order to solve the above technical problems, in the first aspect, the present invention provides a host-guest composite material based on a metal organic framework material and an N4Py high-valent mononuclear iron complex, wherein the structural expression of the host-guest composite material is:

[0042] [(N4Py)Fe IV =O]Cl2@UiO-66-F4;

[0043] Among them, UiO-66-F4 is a metal organic framework compound, [(N4Py)Fe IV =O] 2+ It is a non-heme mononuclear high-valent iron complex. The host of the host-guest composite material is UiO-66-F4, and the guest is [(N4Py)Fe IV =O]Cl2; @ indicates that the composite material is a porous coordination polymer material assembled by host and guest.

[0044] In the case of adopting the above technical solution, the present invention is based on the host-guest composite material of metal organic framework material and N4Py high valence mononuclear iron complex, with UiO-66-F4 as the main body and [(N4Py)Fe IV =O]Cl2 is the guest, and the high-valent iron complex [(N4Py)Fe IV =O]Cl2 forms a strong interaction force with the pore structure of UiO-66-F4, resulting in high stability. The host-guest composite material of the present invention is used for the activation of hydrocarbons in homogeneous reactions, exhibiting high reactivity and selectivity. This solves the technical problem that existing biomimetic non-heme high-valent iron complexes are prone to dimerization during homogeneous reactions to form oxygen-bridged binuclear trivalent iron complexes, which in turn lead to loss of catalytic activity.

[0045] In the above host-guest composite materials, UiO-66-F4 is a metal organic framework material, [(N4Py)Fe IV =O]Cl2 molecular structure is shown below:

[0046] .

[0047] [(N4Py)Fe IV =O]Cl2

[0048] In a second aspect, the present invention provides a method for preparing a host-guest composite material based on a metal organic framework material and an N4Py high-valent mononuclear iron complex, which is used to prepare the host-guest composite material. The method comprises:

[0049] Obtaining UiO-66-F4 powder and an acetonitrile solution containing a divalent mononuclear iron complex, wherein the divalent mononuclear iron complex is FeN4Py;

[0050] The UiO-66-F4 powder is added to the acetonitrile solution and stirred until FeN4Py enters the interior of the UiO-66-F4 structure. After centrifugation and washing, FeN4Py@UiO-66-F4 is obtained;

[0051] The FeN4Py@UiO-66-F4 was placed in an acetonitrile aqueous solution containing ammonium cerium nitrate and allowed to stand for 30 to 60 minutes to obtain a structural expression of [(N4Py)Fe IV =O]Cl2@UiO-66-F4 host-guest composite material.

[0052] When the above technical solution is adopted, in the preparation method of the host-guest composite material based on the metal organic framework material and the N4Py high-valent mononuclear iron complex of the present invention, UiO-66-F4 is a metal organic framework (MOF) material. In the acetonitrile solution, the divalent mononuclear iron complex (such as FeN4Py) exists in a dissolved state, which is conducive to interacting with the pore structure of UiO-66-F4. Acetonitrile is used as the solvent for the divalent mononuclear iron complex, which helps to maintain the stability of the divalent mononuclear iron complex and can fully diffuse in the solvent without destroying the pore structure of UiO-66-F4. The UiO-66-F4 powder is added to the acetonitrile solution. Through stirring, the divalent mononuclear iron complex (guest) in the acetonitrile solution can diffuse and enter the pore structure of the UiO-66-F4 (host), thereby preliminarily forming a host-guest composite material FeN4Py@UiO-66-F4. Furthermore, the FeN4Py@UiO-66-F4 is placed in an acetonitrile aqueous solution containing ammonium cerium nitrate, and the divalent mononuclear iron complex (FeN4Py) is oxidized to a high-valent state [(N4Py)Fe IV =O]Cl2, and the final host-guest composite material [(N4Py)Fe IV =O]Cl2@UiO-66-F4.

[0053] The divalent mononuclear iron complex of the present invention uses FeN4Py. Compared with FeN4Py, the high-valent [(N4Py)Fe IV=O]Cl2 exhibits a stronger interaction with UiO-66-F4, resulting in greater stability for the host-guest composite. In the aforementioned process, ammonium cerium nitrate is a strong oxidant capable of oxidizing the divalent mononuclear iron complex (FeN4Py) to a higher valence state under mild conditions. The use of an aqueous acetonitrile solution allows the oxidation process to proceed under homogeneous conditions, facilitating sufficient contact between the oxidant (ammonium cerium nitrate) and the reactants. The molecular structure of FeN4Py is shown below:

[0054] .

[0055] It should be understood that in the preparation method of the host-guest composite material based on the metal-organic framework material and the N4Py high-valent mononuclear iron complex of the present invention, in order to further improve the stability, reactivity and selectivity of the prepared host-guest composite material, in the process of adding the UiO-66-F4 powder to the acetonitrile solution, the mixing ratio of UiO-66-F4 and FeN4Py should also be controlled within a reasonable range. For example, the molar ratio of UiO-66-F4 to FeN4Py can be 1: (1~2.5); for another example, the molar ratio of UiO-66-F4 to FeN4Py can be 1:1, 1:2 or 1:2.5.

[0056] It should also be understood that in the preparation method of the host-guest composite material based on the metal-organic framework material and the N4Py high-valent mononuclear iron complex of the present invention, in order to further improve the stability, reactivity and selectivity of the prepared host-guest composite material, the FeN4Py@UiO-66-F4 is placed in an acetonitrile aqueous solution containing ammonium cerium nitrate, and the mixing ratio of FeN4Py and ammonium cerium nitrate, as well as the concentration of the acetonitrile aqueous solution should be controlled within a reasonable range. For example, the molar ratio of FeN4Py to ammonium cerium nitrate can be 1: (2~2.5), and the volume ratio of water to acetonitrile in the acetonitrile aqueous solution is 1: (1~3); for another example, the molar ratio of FeN4Py to ammonium cerium nitrate can be 1:2, 1:2.2 or 1:2.5, and the volume ratio of water to acetonitrile in the acetonitrile aqueous solution can be 1:1, 1:2 or 1:3.

[0057] It should also be understood that in the preparation method of the host-guest composite material based on the metal organic framework material and the N4Py high-valent mononuclear iron complex of the present invention, in order to allow FeN4Py to fully enter the interior of the UiO-66-F4 structure and improve the preparation efficiency of the above-mentioned host-guest composite material, the stirring rate and stirring time should also be controlled within a reasonable range. For example, the stirring rate can be 100~300rpm and the stirring time can be 12~50 hours; for another example, the stirring rate can be 100rpm, 200rpm or 300rpm, and the stirring time can be 12 hours, 20 hours, 30 hours, 40 hours, or 50 hours.

[0058] As a possible embodiment, in the preparation method of the host-guest composite material based on the metal organic framework material and the N4Py high-valent mononuclear iron complex of the present invention, the obtaining of UiO-66-F4 powder includes:

[0059] Obtain a glacial acetic acid solution with a volume concentration of 60-70%;

[0060] Adding tetrafluoroterephthalic acid and zirconium nitrate to the glacial acetic acid solution and stirring until the solid powder is completely dissolved to obtain a mixed solution; the molar ratio of the tetrafluoroterephthalic acid to the zirconium nitrate is 1:(1-2);

[0061] The mixed solution is condensed and refluxed at a temperature of 100-120° C. for 24-36 hours to form UiO-66-F4 with a cage-like porous structure; and the UiO-66-F4 is dried to obtain the UiO-66-F4 powder.

[0062] In the case of adopting the above technical solution, in the preparation method of the host-guest composite material based on the metal organic framework material and the N4Py high-valent mononuclear iron complex of the present invention, glacial acetic acid in an appropriate concentration range is used to fully dissolve the solute (tetrafluoroterephthalic acid and zirconium nitrate) to form a uniform mixed solution; during the process of condensing and refluxing the mixed solution at a temperature of 100-120°C for 24-36 hours, tetrafluoroterephthalic acid is an organic ligand, and the ligand reacts with zirconium nitrate (providing metal ions Zr 4+ ) undergoes coordination reaction to form UiO-66-F4 with a metal-organic framework structure.

[0063] As a possible embodiment, in the preparation method of the host-guest composite material based on the metal organic framework material and the N4Py high-valent mononuclear iron complex of the present invention, after forming the cage-like porous structure of UiO-66-F4 and before drying the UiO-66-F4, the method further includes:

[0064] Centrifuging the mixed solution to remove the mother liquor to obtain a powdered solid material;

[0065] Washing the solid material with ultrapure water to remove the solution on the surface of the solid material;

[0066] The solid material was then immersed in methanol, dichloromethane and acetonitrile for three days, with the solvent changed every day; the solid material was UiO-66-F4.

[0067] When the above technical solution is adopted, the purity of UiO-66-F4 can be further improved and the pore environment of UiO-66-F4 can be optimized. For example, the UiO-66-F4 can be dried by immersing the solid material in methanol, dichloromethane, and acetonitrile for three days, then placing the solid material in a vacuum oven at 120°C for 24 hours and cooling it to room temperature to obtain the UiO-66-F4 powder.

[0068] In a third aspect, the present invention provides the application of the host-guest composite material based on the metal organic framework material and the N4Py high-valent mononuclear iron complex in the preparation of redox catalytic materials and bioinorganic chemical materials.

[0069] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with specific examples, but the content of the present invention is not limited to the following examples.

[0070] Unless otherwise specified, the raw materials used in the following examples are commercially available.

[0071] It should be noted that the [(N4Py)Fe IV The molecular structures of [=O]Cl2 and FeN4Py are shown above and will not be repeated in the following examples. Example 1

[0072] This embodiment provides a host-guest composite material based on a metal organic framework material and a N4Py high-valent mononuclear iron complex. The structural expression of the host-guest composite material is:

[0073] [(N4Py)Fe IV =O]Cl2@UiO-66-F4;

[0074] Among them, UiO-66-F4 is a metal organic framework compound, [(N4Py)Fe IV =O] 2+ It is a non-heme mononuclear high-valent iron complex. The host of the host-guest composite material is UiO-66-F4, and the guest is [(N4Py)Fe IV =O]Cl2; @ indicates that the composite material is a porous coordination polymer material assembled by host and guest.

[0075] This embodiment also provides a method for preparing the host-guest composite material, comprising:

[0076] S100, weigh 25 mg of FeN4Py into a glass vial and add 4 mL of acetonitrile solution;

[0077] S200, adding 100 mg of UiO-66-F4 powder to the glass vial, stirring the glass vial open for 50 hours at a stirring rate of 300 rpm, centrifuging to remove the mother liquor, and washing unreacted FeN4Py with acetonitrile to obtain an orange-yellow powder, which is FeN4Py@UiO-66-F4; wherein the molar ratio of UiO-66-F4 to FeN4Py is 1:1;

[0078] S300, weighing 15 mg of ammonium cerium nitrate and dissolving it in 0.5 mL of ultrapure water, ultrasonically dissolving it to obtain an ammonium cerium nitrate solution;

[0079] S400, weighing 100 mg of FeN4Py@UiO-66-F4 prepared in step S300, and adding it to 4.5 mL of acetonitrile aqueous solution, adding the cerium ammonium nitrate solution prepared in step S300 to the acetonitrile aqueous solution, and after standing for 30 minutes, filtering to remove the mother liquor, and obtaining a blue-green powder, which is the host-guest composite material [(N4Py)Fe IV =O]Cl2@UiO-66-F4; wherein the volume ratio of acetonitrile to ultrapure water in the acetonitrile aqueous solution is 2:1, and the molar ratio of FeN4Py to ammonium cerium nitrate is 1:2.

[0080] Furthermore, the UiO-66-F4 in step S200 of this embodiment is prepared by the following steps:

[0081] S201, weigh 1.19 g (5 mmol) of tetrafluoroterephthalic acid and 2.23 g (5.2 mmol) of zirconium nitrate (Zr(NO3)4·xH2O), and dissolve each in a solution consisting of 20 mL of glacial acetic acid and 30 mL of water to obtain a mixed solution;

[0082] S202, heating the mixed solution to 105° C. and stirring for 15 minutes until the solid powder is completely dissolved;

[0083] S203, condensing and refluxing the mixed solution at the temperature of step S202 (105°C) for 30 hours, and then centrifuging to remove the mother liquor to obtain a powdered solid material;

[0084] S204, washing the solid material with ultrapure water three times to remove the surface solution, and exchanging with methanol, dichloromethane and acetonitrile for three days respectively, replacing the solvent with fresh one every day;

[0085] S205, the solid material after solvent exchange is placed in a vacuum oven at 120° C. for 24 hours, and then cooled to room temperature to obtain white powder UiO-66-F4. Example 2

[0086] This embodiment provides a host-guest composite material based on a metal organic framework material and a N4Py high-valent mononuclear iron complex. The structural expression of the host-guest composite material is:

[0087] [(N4Py)Fe IV =O]Cl2@UiO-66-F4;

[0088] Among them, UiO-66-F4 is a metal organic framework compound, [(N4Py)Fe IV =O] 2+ It is a non-heme mononuclear high-valent iron complex. The host of the host-guest composite material is UiO-66-F4, and the guest is [(N4Py)Fe IV =O]Cl2; @ indicates that the composite material is a porous coordination polymer material assembled by host and guest.

[0089] This embodiment also provides a method for preparing the host-guest composite material, comprising:

[0090] S100, weigh 50 mg of FeN4Py into a glass vial and add 4 mL of acetonitrile solution;

[0091] S200, adding 100 mg of UiO-66-F4 powder to the glass vial, stirring the glass vial open for 24 hours at a stirring rate of 100 rpm, centrifuging to remove the mother liquor, and washing unreacted FeN4Py with acetonitrile to obtain an orange-yellow powder, which is FeN4Py@UiO-66-F4; wherein the molar ratio of UiO-66-F4 to FeN4Py is 1:2;

[0092] S300, weighing 15 mg of ammonium cerium nitrate and dissolving it in 0.5 mL of ultrapure water, ultrasonically dissolving it to obtain an ammonium cerium nitrate solution;

[0093] S400, weighing 100 mg of FeN4Py@UiO-66-F4 prepared in step S300, and adding it to 4.5 mL of acetonitrile aqueous solution, adding the cerium ammonium nitrate solution prepared in step S300 to the acetonitrile aqueous solution, and after standing for 30 minutes, filtering to remove the mother liquor, and obtaining a blue-green powder, which is the host-guest composite material [(N4Py)Fe IV =O]Cl2@UiO-66-F4; wherein the volume ratio of acetonitrile to ultrapure water in the acetonitrile aqueous solution is 1:1, and the molar ratio of FeN4Py to ammonium cerium nitrate is 1:2.

[0094] Furthermore, the UiO-66-F4 in step S200 of this embodiment is prepared by the following steps:

[0095] S201, weigh 1.19 g (5 mmol) of tetrafluoroterephthalic acid and 2.23 g (5.2 mmol) of zirconium nitrate (Zr(NO3)4·xH2O), and dissolve each in a solution consisting of 20 mL of glacial acetic acid and 30 mL of water to obtain a mixed solution;

[0096] S202, heating the mixed solution to 120° C. and stirring for 15 minutes until the solid powder is completely dissolved;

[0097] S203, condensing and refluxing the mixed solution at the temperature of step S202 (120°C) for 24 hours, and then centrifuging to remove the mother liquor to obtain a powdered solid material;

[0098] S204, washing the solid material with ultrapure water three times to remove the surface solution, and exchanging with methanol, dichloromethane and acetonitrile for three days respectively, replacing the solvent with fresh one every day;

[0099] S205, the solid material after solvent exchange is placed in a vacuum oven at 120° C. for 24 hours, and then cooled to room temperature to obtain white powder UiO-66-F4. Example 3

[0100] This embodiment provides a host-guest composite material based on a metal organic framework material and a N4Py high-valent mononuclear iron complex. The structural expression of the host-guest composite material is:

[0101] [(N4Py)Fe IV =O]Cl2@UiO-66-F4;

[0102] Among them, UiO-66-F4 is a metal organic framework compound, [(N4Py)Fe IV =O] 2+ It is a non-heme mononuclear high-valent iron complex. The host of the host-guest composite material is UiO-66-F4, and the guest is [(N4Py)Fe IV =O]Cl2; @ indicates that the composite material is a porous coordination polymer material assembled by host and guest.

[0103] This embodiment also provides a method for preparing the host-guest composite material, comprising:

[0104] S100, weigh 62.5 mg of FeN4Py into a glass vial and add 4 mL of acetonitrile solution;

[0105] S200, adding 100 mg of UiO-66-F4 powder to the glass vial, stirring the glass vial open for 12 hours at a stirring rate of 200 rpm, centrifuging to remove the mother liquor, and washing unreacted FeN4Py with acetonitrile to obtain an orange-yellow powder, which is FeN4Py@UiO-66-F4; wherein the molar ratio of UiO-66-F4 to FeN4Py is 1:2.5;

[0106] S300, weighing 19 mg of ammonium cerium nitrate and dissolving it in 0.5 mL of ultrapure water, ultrasonically dissolving it to obtain an ammonium cerium nitrate solution;

[0107] S400, weighing 100 mg of FeN4Py@UiO-66-F4 prepared in step S300, and adding it to 4.5 mL of acetonitrile aqueous solution, adding the cerium ammonium nitrate solution prepared in step S300 to the acetonitrile aqueous solution, and after standing for 30 minutes, filtering to remove the mother liquor, and obtaining a blue-green powder, which is the host-guest composite material [(N4Py)Fe IV =O]Cl2@UiO-66-F4; wherein the volume ratio of acetonitrile to ultrapure water in the acetonitrile aqueous solution is 3:1, and the molar ratio of FeN4Py to ammonium cerium nitrate is 1:2.5.

[0108] Furthermore, the UiO-66-F4 in step S200 of this embodiment is prepared by the following steps:

[0109] S201, weigh 1.19 g (5 mmol) of tetrafluoroterephthalic acid and 2.23 g (5.2 mmol) of zirconium nitrate (Zr(NO3)4·xH2O), and dissolve each in a solution consisting of 20 mL of glacial acetic acid and 30 mL of water to obtain a mixed solution;

[0110] S202, heating the mixed solution to 100° C. and stirring for 15 minutes until the solid powder is completely dissolved;

[0111] S203, condensing and refluxing the mixed solution at the temperature of step S202 (100°C) for 36 hours, and then centrifuging to remove the mother liquor to obtain a powdered solid material;

[0112] S204, washing the solid material with ultrapure water three times to remove the surface solution, and exchanging with methanol, dichloromethane and acetonitrile for three days respectively, replacing the solvent with fresh one every day;

[0113] S205, the solid material after solvent exchange is placed in a vacuum oven at 120° C. for 24 hours, and then cooled to room temperature to obtain white powder UiO-66-F4.

[0114] Through the above examples 1 to 3, host-guest composite materials [(N4Py)FeIV =O]Cl2@UiO-66-F4. In the above embodiment, the present invention synthesized [(N4Py)Fe IV =O]Cl2@UiO-66-F4 system. In simple terms, the two-step in-situ oxidation synthesis method is as follows: first, a divalent mononuclear iron complex (FeN4Py) is loaded into the pores of UiO-66-F4 by immersion, and then the oxidant ammonium cerium nitrate is diffused into the cage cavity of UiO-66-F4 in an acetonitrile aqueous solution, and the divalent mononuclear iron complex (FeN4Py) is oxidized into a tetravalent mononuclear iron complex in the cage cavity, thereby obtaining the host-guest assembled [(N4Py)Fe IV =O]Cl2@UiO-66-F4, specific assembly diagram Figure 1 [(N4Py)Fe IV =O]Cl2@UiO-66-F4 host-guest system can completely avoid the high-valent iron complexes from dimerizing easily in the homogeneous reaction process to form oxygen-bridged binuclear trivalent iron complexes, which leads to their inactivation, and solve the technical problem of their instability from the root. The specific principle is: the cage-like channels of UiO-66-F4 spontaneously transfer the high-valent iron complex ([(N4Py)Fe IV =O]Cl2) is isolated in small rooms, thus effectively blocking the reaction pathway of intermolecular dimerization inactivation. Figures 2 to 6 The host-guest composite material [(N4Py)Fe IV =O]Cl2@UiO-66-F4 is taken as an example to describe the host-guest composite material of the present invention in detail.

[0115] See also Figures 2 to 6 ,from Figure 2 It can be seen that [(N4Py)Fe IV =O]Cl2@UiO-66-F4 and UiO-66-F4, the X-ray diffraction (XRD) patterns of [(N4Py)Fe IV =O]Cl2@UiO-66-F4 has no significant change in the framework structure of UiO-66-F4, that is, the present invention loads [(N4Py)Fe IV =O]Cl2 will not destroy the pore structure of UiO-66-F4, and the framework of UiO-66-F4 remains stable. Figure 3 The TGA curve (thermal gravimetric curve) shows that compared with the framework material without encapsulated guest molecules (UiO-66-F4), the encapsulated host-guest system ([(N4Py)Fe IV=O]Cl2@UiO-66-F4) has a small weight loss in the range of 200-300 ° C, which corresponds to the weight loss of the pure tetravalent mononuclear complex, indirectly confirming that the guest molecule ([(N4Py)Fe IV =O]Cl2) was successfully encapsulated in the pores of UiO-66-F4.

[0116] In order to further verify the high-valent mononuclear complex ([(N4Py)Fe IV =O]Cl2) was successfully encapsulated in the pores of UiO-66-F4, and the host-guest composite material [(N4Py)Fe IV =O]Cl2@UiO-66-F4 was tested for nitrogen adsorption and desorption at 77K (-196℃). Figure 4 As shown, compared with UiO-66-F4 before encapsulation, the host-guest composite material [(N4Py)Fe IV =O]Cl2@UiO-66-F4 nitrogen adsorption capacity decreased significantly, which once again confirmed that the guest molecule ([(N4Py)Fe IV =O]Cl2) was successfully loaded in the pore structure of the main molecule (UiO-66-F4); the host-guest composite material of Example 2 was subjected to TEM-EDS spectrum test, as shown in FIG. Figure 5 As shown, from Figure A to Figure D, it can be seen that fluorine, zirconium and iron elements exist and are evenly distributed in the pores, proving that the guest molecules are evenly distributed in the main framework.

[0117] In order to further characterize the guest molecule ([(N4Py)Fe IV =O]Cl2) in the UiO-66-F4 pores, the host-guest system ([(N4Py)Fe IV =O]Cl2@UiO-66-F4) was tested for solid UV Figure 6 It can be seen that when the guest molecules ([(N4Py)Fe IV =O]Cl2) and a characteristic peak appeared at 692nm, which was similar to that of pure [(N4Py)Fe IV =O]Cl2, which confirms that the guest molecules in the UiO-66-F4 pores exist in the form of tetravalent mononuclear iron complexes. Figure 1 In the experiment, the guest is a non-heme high-valent iron-oxo complex, and the host is a metal-organic framework (MOF) material. The host and the guest are assembled to form a host-guest system.

[0118] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0119] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A host-guest composite material based on a metal-organic framework material and an N4Py high-valent mononuclear iron complex, characterized in that: The structural expression of the host-guest composite material is: [(N4Py)Fe IV =O]Cl2@UiO-66-F4; Among them, UiO-66-F4 is a metal organic framework compound, [(N4Py)Fe IV =O] 2+ It is a non-heme mononuclear high-valent iron complex. The host of the host-guest composite material is UiO-66-F4, and the guest is [(N4Py)Fe IV =O]Cl2; @ indicates that the composite material is a porous coordination polymer material assembled by host and guest.

2. A method for preparing a host-guest composite material based on a metal organic framework material and a N4Py high-valent mononuclear iron complex, characterized in that: For preparing the host-guest composite material according to claim 1, comprising: Obtaining UiO-66-F4 powder and an acetonitrile solution containing a divalent mononuclear iron complex, wherein the divalent mononuclear iron complex is FeN4Py; The UiO-66-F4 powder is added to the acetonitrile solution and stirred until FeN4Py enters the interior of the UiO-66-F4 structure. After centrifugation and washing, FeN4Py@UiO-66-F4 is obtained; The FeN4Py@UiO-66-F4 was placed in an acetonitrile aqueous solution containing ammonium cerium nitrate and allowed to stand for 30 to 60 minutes to obtain a structural expression of [(N4Py)Fe IV =O]Cl2@UiO-66-F4 host-guest composite material.

3. The method for preparing a host-guest composite material based on a metal organic framework material and a N4Py high-valent mononuclear iron complex according to claim 2, characterized in that: In the process of adding the UiO-66-F4 powder to the acetonitrile solution, the molar ratio of UiO-66-F4 to FeN4Py is 1: (1-2.5).

4. The method for preparing a host-guest composite material based on a metal organic framework material and a N4Py high-valent mononuclear iron complex according to claim 3, characterized in that: The FeN4Py@UiO-66-F4 is placed in an acetonitrile aqueous solution containing ammonium cerium nitrate, and the molar ratio of FeN4Py to ammonium cerium nitrate is 1: (2-2.5).

5. The method for preparing a host-guest composite material based on a metal organic framework material and a N4Py high-valent mononuclear iron complex according to claim 4, characterized in that: The volume ratio of water to acetonitrile in the acetonitrile aqueous solution is 1:(1-3).

6. The method for preparing a host-guest composite material based on a metal organic framework material and a N4Py high-valent mononuclear iron complex according to claim 5, characterized in that: During the stirring process until FeN4Py enters the interior of the UiO-66-F4 structure, the stirring rate is 100-300 rpm and the stirring time is 12-50 hours.

7. The method for preparing a host-guest composite material based on a metal organic framework material and a N4Py high-valent mononuclear iron complex according to claim 6, characterized in that: The method of obtaining UiO-66-F4 powder comprises: Obtain a glacial acetic acid solution with a volume concentration of 60-70%; Adding tetrafluoroterephthalic acid and zirconium nitrate to the glacial acetic acid solution and stirring until the solid powder is completely dissolved to obtain a mixed solution; the molar ratio of the tetrafluoroterephthalic acid to the zirconium nitrate is 1:(1-2); The mixed solution is condensed and refluxed at a temperature of 100-120° C. for 24-36 hours to form UiO-66-F4 with a cage-like porous structure; and the UiO-66-F4 is dried to obtain the UiO-66-F4 powder.

8. The method for preparing a host-guest composite material based on a metal organic framework material and a N4Py high-valent mononuclear iron complex according to claim 7, characterized in that: After forming the cage-like porous structure of UiO-66-F4 and before drying the UiO-66-F4, the method further comprises: Centrifuging the mixed solution to remove the mother liquor to obtain a powdered solid material; Washing the solid material with ultrapure water to remove the solution on the surface of the solid material; The solid material was then immersed in methanol, dichloromethane and acetonitrile for three days, with the solvent changed every day; the solid material was UiO-66-F4.

9. The method for preparing a host-guest composite material based on a metal organic framework material and a N4Py high-valent mononuclear iron complex according to claim 8, characterized in that: The drying of the UiO-66-F4 comprises: The solid material was immersed in methanol, dichloromethane and acetonitrile for exchange for three days, and then placed in a vacuum oven at 120° C. for 24 hours and cooled to room temperature to obtain the UiO-66-F4 powder.

10. Use of the host-guest composite material based on a metal organic framework material and a N4Py high-valent mononuclear iron complex according to claim 1 in the preparation of redox catalytic materials and bioinorganic chemical materials.

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