Patternable porphyrin polymer nano material with clear sequence and preparation method thereof

Abstract

The invention relates to a patterned porphyrin polymer nano material with a clear sequence and a preparation method thereof, and aims to solve the problem that accurate multi-axial control on a molecular structure and a monomer sequence is difficult to realize by the existing synthesis method. Inspired by the fact that natural macromolecule accurate sequence control results in life body structure and functional diversity, the existing synthesis method can realize single-axis sequence control, but is difficult to realize multi-axis accurate sequence control. According to the liquid-phase biaxial iterative synthesis strategy, atomic-scale precise control over biaxial chain growth can be achieved, porphyrin monomers with space controllable functional groups are used as raw materials, and the polymer nanostructure capable of being patterned and having precise atoms in the biaxial direction is successfully developed. Through the strategy, the structure and function complexity are successfully introduced into the patterned porphyrin polymer with a clear sequence, the highly adjustable optical performance of the porphyrin polymer in a solution is achieved, the porphyrin polymer is expected to be widely applied to multiple fields such as energy, information and medicine, and powerful support is provided for development of related technologies.

Description

Technical Field

[0001] The present invention belongs to the technical field of materials chemistry, and relates to a novel liquid-phase biaxial iterative synthesis strategy, and specifically to a sequence-defined patternable porphyrin polymer nanomaterial, a preparation method thereof, and an application thereof. Background Art

[0002] In nature, the complexity and sophistication of living systems largely rely on the precise control of the primary sequence of natural macromolecules, resulting in diverse structures and functions. Natural macromolecules have uniform chain lengths, specific monomer sequences, and well-defined topologies. Through strict multidimensional structural control, their intra- and intermolecular interactions are orderly governed, giving rise to diverse hierarchical nanostructures with important biological functions, such as the double helix of DNA and the secondary, tertiary, and quaternary structures of proteins. Inspired by this, chemists are committed to exploring synthetic strategies, hoping to introduce the advantages of natural macromolecules' well-defined sequences and highly controllable structures into the field of synthetic polymers, thereby expanding the application potential and value of synthetic polymers.

[0003] In recent years, certain progress has been made in the sequence control of synthetic polymers. A large number of synthetic methods have been successfully developed and have successfully achieved uniaxial sequence control in the one-dimensional (1D) structure of synthetic polymers. However, the precise synthetic polymers constructed by the above-mentioned synthetic strategies, although they can achieve a certain degree of sequence control in the one-dimensional structure, are still limited to specific sequence control in a single axis, that is, they can only arrange the monomer sequence in an orderly manner along a single axis. This limitation makes it impossible for these synthetic polymers to fully exert their structural and functional advantages when facing the complex application requirements of many scientific and technological fields, limiting their application expansion in a wider range of scenarios. Recently, with the further development of materials science and nanotechnology, people have gradually focused their attention on how to extend sequence control from one-dimensional polymers to two-dimensional (2D) nanobelt structures, aiming to give synthetic polymer nanomaterials higher-dimensional structural and functional complexity to meet more practical application needs.

[0004] However, the existing methods for synthesizing two-dimensional nanostructures still only achieve uniaxial sequence control, and cannot achieve arbitrary sequence control in the two-dimensional plane. So far, it is difficult to achieve higher-level control of the complexity of structure and function of polymer nanomaterials, and it is difficult to meet the urgent needs of many scientific and technological fields for polymer nanomaterials with high complexity and high precision sequence control. In the biomedical field, polymer nanomaterials with high complexity and high precision sequence control are expected to achieve precise drug delivery. For example, according to the specificity of different disease targets, nanocarriers that can accurately identify cancer cells can be designed to accurately transport anticancer drugs to diseased cells, avoiding damage to normal cells, thereby greatly improving the effectiveness of cancer treatment and reducing side effects. At the same time, such materials can also be used to construct biosensors, which can more sensitively detect small changes in various biomarkers in the body, helping early diagnosis of diseases. SUMMARY

[0005] To solve the above problems, the present application develops a new type of liquid biaxial iterative synthesis strategy to synthesize sequence-specific patternable porphyrin polymer nanomaterials with atomic precision, realizes controllable biaxial chain growth, and provides a new technical solution and application possibility for precise multi-dimensional nanomaterials. The preparation method makes up for the shortcomings of existing synthesis technology in sequence control of synthesized polymers, can realize full-atomic precision sequence control of synthesized polymer nanostructures in the biaxial direction, and further realize high-dimensional regulation of the complexity of structure and function, so as to break through the technical bottleneck and expand the application range of polymer nanomaterials in many fields such as biomedicine, nanotechnology, information storage, and molecular recognition.

[0006] To achieve the above purpose, the specific technical solutions adopted by the present application are as follows:

[0007] In a first aspect, the present application provides a preparation method of sequence-specific patternable porphyrin polymer nanomaterials, i.e. a liquid biaxial iterative synthesis method. First, a porphyrin monomer with site-specific functional groups is synthesized through a cyclization reaction. Then, the porphyrin monomer is connected to a three-armed polyethylene glycol star macromolecule through a Sonogashira coupling reaction. Then, the formation of poly-porphyrin is controlled through a deprotection reaction. The iterative synthesis process of coupling / deprotection is repeated to realize controllable biaxial chain growth.

[0008] The structure of the porphyrin monomer with site-specific functional groups is at least two of the following (i)-(iv) (according to the required molecular structure, two or more monomers can realize double-chain control):

[0009]

[0010] The structural formula of the three-arm polyethylene glycol star-shaped macromolecule is:

[0011]

[0012] More specifically, the method for preparing the sequence-defined patternable porphyrin polymer nanomaterial comprises the following steps:

[0013] S1. Preparation of Porphyrin Monomers with Sterilized Functional Groups

[0014] (1) Functionalized phenyl groups are cleverly installed on the spacer sites of the bipyrrole structure in a specific order;

[0015] (2) Using template synthesis, the resulting linear bipyrrole precursor with a clear sequence undergoes a cyclization reaction to synthesize a porphyrin monomer with a site-specific functional group;

[0016] S2. Generation of diverse polymer nanostructures

[0017] (1) Using three-arm polyethylene glycol star-shaped macromolecules as loading carriers (through coupling reactions, the desired porphyrin monomers are connected in a uniaxial or biaxial direction to synthesize a growing polyporphyrin structure);

[0018] (2) accurately weighing 1.5 times the molar equivalent of the para-substituted porphyrin monomer and connecting it to the three-arm polyethylene glycol star macromolecule via a Sonogashira coupling reaction;

[0019] (3) performing a deprotection reaction on the obtained linear polyporphyrin to remove the tert-butyldimethylsilyl (TBS) protecting group;

[0020] (4) Select a specific porphyrin monomer with a spatially controllable functional group and repeat the above coupling / deprotection iterative synthesis process.

[0021] Furthermore, the functional group mentioned in step (1) described in step S1 does not use trimethylsilyl (TMS), but tert-butyl (dimethyl) silyl (TBS). This is because TBS has good chemical stability during the linear precursor cyclization reaction and the Sonogashira coupling reaction, and can be easily deprotected by tetrabutylammonium fluoride (TBAF) under mild conditions. This property makes it very suitable for the protection of polymer end groups. In the different porphyrin monomers with spatially controllable functional groups, the spatial position and number of the alkynyl and iodophenyl groups protected by tert-butyldimethylsilyl (TBS) are set according to the properties of the target polymer nanostructure and the application requirements.

[0022] Furthermore, in step S1, the reaction conditions of the cyclization reaction include: the reaction temperature is room temperature, the reaction time is 1 hour, the reaction is carried out in dichloromethane solvent, and when synthesizing a bipyrrole precursor with a clear linear sequence, 2,6-di-tert-butylpyridine and scandium trifluoromethanesulfonate need to be added as catalysts before the reaction starts.

[0023] Furthermore, in step S2, the molecular weight of the three-arm polyethylene glycol star-shaped macromolecule is 1892.27 Da, and its synthesis preparation uses trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile as a protecting group for the active hydroxyl group and is achieved through a Williamson etherification reaction. It can be used as a soluble macromolecular carrier, not only as a terminal protecting group, but also facilitates the separation and purification of the product.

[0024] Furthermore, in step S2, the Sonogashira coupling reaction is carried out in tetrahydrofuran (THF) solvent at 60° C. for 24 hours under the catalysis of dichlorobis(triphenylphosphine)palladium (Pd(Ph3)2Cl2) and cuprous iodide (CuI).

[0025] Furthermore, in step S2, in the Sonogashira coupling reaction, the purity requirements of each reaction reagent are as follows: dichlorobis(triphenylphosphine)palladium (Pd(Ph3)2Cl2) purity is not less than 98%, cuprous iodide (CuI) purity is not less than 99.999%, and the water content of tetrahydrofuran (THF) solvent is less than 50 ppm, so as to ensure the efficient conduct of the coupling reaction and the quality of the product.

[0026] Furthermore, in step S2, the deprotection reaction is carried out using tetrabutylammonium fluoride (TBAF) in tetrahydrofuran (THF) at 60°C for 6 hours to ensure that the deprotection reaction is stable and proceeds fully, and the molar ratio of the tetrabutylammonium fluoride (TBAF) to the polyporphyrin is 6:1.

[0027] In a second aspect, the present invention provides a patternable porphyrin polymer nanomaterial with a clear sequence prepared by the above preparation method.

[0028] In a third aspect, the present invention provides the application of the above preparation method in preparing sequence-defined patternable porphyrin polymer nanomaterials with different optical properties.

[0029] Compared with the prior art, the advantages and uniqueness of the present invention are:

[0030] 1. The novel liquid-phase biaxial iterative synthesis strategy provided by the present invention can achieve atomic precision synthesis of sequence-defined patternable polymer nanomaterials and further precisely control biaxial chain growth.

[0031] 2. The present invention pioneered and precisely controlled the sequence and topological structure of patternable polyporphyrins with clear sequences, thereby regulating their molecular stacking patterns in solution and achieving efficient and precise control of optical properties. In the field of photodynamic therapy, this type of patternable polyporphyrin material with clear sequences also has excellent application prospects. Thanks to its optical properties that can be precisely controlled, the material is expected to have the ability to efficiently absorb light of a specific wavelength, and on this basis, it can further produce reactive oxygen species with cytotoxicity. For example, when used in tumor treatment, the high controllability of the structure of these polyporphyrin materials will provide the possibility for them to be preferentially enriched in tumor tissues. Under the irradiation of external light sources, a large amount of reactive oxygen species will be rapidly generated, accurately destroying the membrane structure, organelles and other key components of cancer cells, inducing apoptosis of cancer cells, and causing minimal damage to surrounding normal tissues. This provides a new treatment method for cancer treatment that is more precise and has fewer side effects, and is expected to improve the many problems currently faced in cancer treatment.

[0032] 3. The liquid-phase biaxial iterative synthesis strategy of the present invention has significant advantages in the synthesis, structure control, performance regulation and application expansion of polymer nanomaterials. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is the synthetic route of the three-arm polyethylene glycol star-shaped macromolecule in Example 1.

[0034] Figure 2 is the three-arm polyethylene glycol star macromolecule in Example 1 1 H NMR spectrum.

[0035] Figure 3 This is the ESI-MS spectrum of the three-arm polyethylene glycol star-shaped macromolecule in Example 1.

[0036] Figure 4 The synthetic route of the para-substituted porphyrin monomer in Example 1 is shown in FIG.

[0037] Figure 5 is the para-substituted porphyrin monomer in Example 1 1 H NMR spectrum.

[0038] Figure 6 This is the MALDI-TOF spectrum of the para-substituted porphyrin monomer in Example 1.

[0039] Figure 7 Schematic diagram of the synthesis of sequence-defined patternable polymer nanomaterials in Example 1.

[0040] Figure 8 These are the test results for characterizing the optical properties of the sequence-defined patternable porphyrin polymer nanomaterials in Example 3. Figure 8In the above, ZZ refers to a zig-zag polyporphyrin structure; J refers to a J-type polyporphyrin structure; T refers to a T-type polyporphyrin structure; and U refers to a U-type polyporphyrin structure. In MeCN, ZZ / J / T / U is dissolved in acetonitrile; and in THF, ZZ / J / T / U is dissolved in tetrahydrofuran. DETAILED DESCRIPTION

[0041] The present invention achieves controllable biaxial chain growth and synthesizes sequence-defined patternable porphyrin polymer nanomaterials through the following technical ideas:

[0042] (1) Cyclization of the corresponding linear porphyrin precursor molecules with specific sequence functional groups to synthesize porphyrin monomers with site-specific functional groups for subsequent controllable biaxial chain growth;

[0043] (2) The growing polyporphyrin is covalently coupled to a three-arm polyethylene glycol star-shaped macromolecule. The three-arm polyethylene glycol star-shaped macromolecule, as a soluble macromolecular carrier, can not only serve as a terminal protecting group of the polyporphyrin, but also can serve as a highly polar label to facilitate the efficient separation of the growing polyporphyrin molecules;

[0044] (3) The above-mentioned porphyrin monomers with spatially controllable functional groups are subjected to liquid-phase biaxial iterative synthesis operations through the Sonogashira coupling reaction, thereby achieving the controllable synthesis of atomically precise patternable porphyrin polymer nanostructures and realizing efficient and controllable biaxial chain growth.

[0045] Among them: three-arm polyethylene glycol star-shaped macromolecules can be analyzed by nuclear magnetic resonance technology (NMR), electrospray ionization mass spectrometry (ESI-MS), etc. Porphyrin monomers with spatially controllable functional groups can be analyzed by nuclear magnetic resonance technology

[0046] The sequence-defined patternable polymer nanostructures can be analyzed using nuclear magnetic resonance (NMR), matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF-MS), and scanning tunneling microscopy (STM).

[0047] In order to introduce the technical solution of the present invention more clearly and in detail, it will be described below in conjunction with specific embodiments.

[0048] Example 1

[0049] S1. Preparation of Porphyrin Monomers with Sterilized Functional Groups

[0050] Diphenyl-4-yl)methyl)-1H-pyrrol-2-yl)(phenyl)methyl)-1H-pyrrol-2-yl)(4-((tert- butyldimethylsilyl)ethynyl)phenyl)methanone (0.528 g, 0.5 mmol, 1.0 eq) was weighed out and dissolved in 5 mL of anhydrous toluene. Subsequently, 1,8-diazabicycloundec-7- ene (DBU, 0.76 g, 0.75 mL, 5 mmol, 10.0 eq) was added to the solution and stirred at room temperature for 5 min. After the color of the reaction mixture was observed to darken significantly, magnesium bromide (MgBr2, 0.28 g, 1.5 mmol, 3.0 eq) was added. Next, the reaction solution was refluxed under atmospheric conditions for 3 h, after which it was allowed to cool naturally to room temperature.

[0051] After the reaction was completed, the reaction mixture was concentrated and then passed through an alumina column to remove excess metal. The main porphyrin-containing component, which included free porphyrin and magnesium porphyrin, was collected. The collected porphyrin- containing component was dissolved in 50 mL of dichloromethane, and 0.5 mL of trifluoroacetic acid (TFA) was added. The reaction was stirred at room temperature for 1 h. After the reaction was completed, the reaction mixture was diluted with 100 mL of dichloromethane, and then washed with half-saturated brine (30 mL each, for a total of 3 times). The washed solution was dried with anhydrous sodium sulfate, and then concentrated under reduced pressure. The obtained crude product was purified using a silica gel column chromatography method, with a mixture of ethyl acetate and heptane as the eluent, and the volume percentage of ethyl acetate gradually increased from 0 to 5, to finally obtain the free porphyrin.

[0052] The obtained free porphyrin (110 mg, 0.1152 mmol) and zinc acetate (Zn(OAc)2, 189 mg, 0.864 mmol) were added to a 250 mL round-bottom flask equipped with a condenser, and 60 mL of chloroform and 30 mL of methanol were added to completely dissolve them. The mixed solution in the flask was heated to reflux for 2 h, and then cooled to room temperature. After the solvent was removed by distillation under reduced pressure, the crude product was again purified and separated by silica gel column chromatography, with chloroform as the eluent. The target compound, para-substituted porphyrin monomer (116 mg, yield 22%), was finally obtained as a purple solid. The synthesis route of the compound is shown in Figure 4 1 H NMR spectrum Figure 5 ) and MALDI-TOF spectrum Figure 6 The synthesized porphyrin monomer molecular structure was characterized by H NMR spectrum

[0053] S2. Generation of linear porphyrin polymer nanomaterials

[0054] ​First, a three-arm polyethylene glycol star-shaped macromolecule was synthesized. The molecular weight of the three-arm polyethylene glycol star-shaped macromolecule was 1892.27 Da. The synthetic preparation route was as follows: Figure 1 As shown, trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile is used as a protective group for the active hydroxyl group and the etherification reaction is achieved by Williamson reaction. 1 H NMR spectrum ( Figure 2 ) and ESI-MS spectra ( Figure 3 ) The structure of the synthesized three-arm polyethylene glycol star-shaped macromolecule was characterized to verify the successful synthesis of the product.

[0055] Then, a 50 ml Shrek flask was added to which a three-arm polyethylene glycol star macromolecule (24.7 mg, 0.013 mmol) and a para-substituted porphyrin monomer (i) (20 mg, 0.020 mmol, 1.5 mol equivalents) synthesized in step S1 were added. 10 ml of acetonitrile was then added and the solvent was azeotropically removed to remove residual water. This operation was repeated three times. Subsequently, dichlorobis(triphenylphosphine)palladium (Pd(PPh3)2Cl2, 0.46 mg, 0.00065 mmol, a 5% molar ratio of the reactants) and cuprous iodide (CuI, 0.25 mg, 0.0013 mmol, a 10% molar ratio of the reactants) were added to the flask. Subsequently, the flask was evacuated and then filled with nitrogen. This operation was repeated three times to completely deoxygenate the reaction system to ensure that the reaction system was in an inert gas environment. Next, a degassed tetrahydrofuran-N,N-diisopropylethylamine mixed solvent (8 ml, 3:1 volume ratio) was added. The flask was tightly sealed and heated at 60°C for 24 hours. After the reaction, the solvent was removed from the reaction system under vacuum, and the resulting residue was redissolved in dichloromethane. The product was then extracted with semi-saturated saline solution, using 10 ml of semi-saturated saline solution each time for a total of three extractions. The dichloromethane layers from each extraction were combined, dried over sodium sulfate, and the solvent was removed. The crude product was purified by silica gel column chromatography using a methanol-chloroform mixture as the eluent, with the volume ratio gradually adjusted from 5:95 to 20:80. The resulting linear polyporphyrin (24.6 mg, 67.5% yield) consisted of a three-arm polyethylene glycol star macromolecule attached to a porphyrin monomer.

[0056] Next, linear polyporphyrin (12.9 mg, 0.0046 mmol) was weighed and dissolved in 5 mL of tetrahydrofuran. Tetrabutylammonium fluoride (TBAF, 0.028 mL, 6.0 molar equivalents in a 1.0 mol / L tetrahydrofuran solution) was then added. The reaction mixture was stirred at 60°C for 6 hours. After completion, the tetrahydrofuran was removed under vacuum. The residue was redissolved in dichloromethane and extracted three times with 10 mL of semi-saturated brine. The organic phases from each extraction were combined, dried over anhydrous sodium sulfate, and then concentrated under vacuum. The crude product was purified again by silica gel column chromatography using a methanol-chloroform mixture with the eluent adjusted from 5:95 to 20:80 by volume. The target compound (10.0 mg, 80.8% yield) was obtained.

[0057] This embodiment is a linear polyporphyrin model reaction, and an iterative synthesis reaction cycle is established. According to the iterative reaction cycle, linear porphyrin polymer nanomaterials can be synthesized through four uniaxial "coupling + deprotection" iterative reaction cycles.

[0058] Example 2

[0059] Based on Example 1, through the screening and design of porphyrin monomers, 4-6 biaxial "coupling + deprotection" iterative reaction cycles can be used to synthesize sequence-defined patternable polymer nanomaterials (such as ZZ / J / T / U-patterned porphyrin polymers), as shown in the schematic diagram. Figure 7 As shown, the present invention uses porphyrin monomers (a) with spatially controllable functional groups as raw materials and adopts three-arm polyethylene glycol star-shaped macromolecules (b) as the loading carrier of growing polyporphyrins to successfully develop biaxially atomically precisely controllable patternable polymer nanostructures (three products J / T / U are listed in c), as follows Figure 7 The preparation process of three patterned porphyrin polymers J / T / U.

[0060] 1. Preparation of J-type patterned porphyrin polymers

[0061] Using three-arm polyethylene glycol star-shaped macromolecules and two porphyrin monomers (i) and (iv) as raw materials, J-shaped patterned porphyrin polymers were prepared according to the following method:

[0062] (Coupling Reaction Method) A 50 ml Shrek flask was charged with a three-arm polyethylene glycol star macromolecule (24.7 mg, 0.013 mmol) and a para-substituted porphyrin monomer (i) (20 mg, 0.020 mmol, 1.5 mol equivalents). 10 ml of acetonitrile was then added and the solvent was azeotropically removed to remove residual water. This operation was repeated three times. Dichlorobis(triphenylphosphine)palladium (Pd(PPh3)2Cl2, 0.46 mg, 0.00065 mmol, 5% by mole ratio of the reactants) and cuprous iodide (CuI, 0.25 mg, 0.0013 mmol, 10% by mole ratio of the reactants) were then added to the flask. The flask was then evacuated and filled with nitrogen. This operation was repeated three times to completely deoxygenate the reaction system to ensure that the reaction system was in an inert atmosphere. Next, a degassed tetrahydrofuran-N,N-diisopropylethylamine mixed solvent (8 ml, 3:1 volume ratio) was added. The flask was tightly sealed and heated at 60°C for 24 hours. After the reaction, the solvent was removed from the reaction system under vacuum, and the resulting residue was redissolved in dichloromethane. The product was then extracted with semi-saturated saline solution, using 10 ml of semi-saturated saline solution each time for a total of three extractions. The dichloromethane layers from each extraction were combined, dried over sodium sulfate, and the solvent was removed. The crude product was purified by silica gel column chromatography using a methanol-chloroform mixture as the eluent, with the volume ratio gradually adjusted from 5:95 to 20:80. The resulting linear polyporphyrin (24.6 mg, 67.5% yield) consisted of a three-arm polyethylene glycol star macromolecule attached to a porphyrin monomer.

[0063] (Deprotection Reaction Method) Linear polyporphyrin (12.9 mg, 0.0046 mmol) was weighed and dissolved in 5 mL of tetrahydrofuran. Tetrabutylammonium fluoride (TBAF, 0.028 mL, prepared at a 1.0 mol / L tetrahydrofuran solution, 6.0 molar equivalents) was then added. The reaction mixture was stirred at 60°C for 6 hours. After completion of the reaction, the tetrahydrofuran was removed under vacuum. The residue was redissolved in dichloromethane and extracted three times with 10 mL of semi-saturated brine. The organic phases from each extraction were combined, dried over anhydrous sodium sulfate, and then concentrated under vacuum. The crude product was purified again by silica gel column chromatography using a methanol-chloroform mixture with the eluent adjusted from 5:95 to 20:80 by volume. The target compound (10.0 mg, 80.8% yield) was obtained.

[0064] Afterwards, a J-type patterned porphyrin polymer can be synthesized through one (iv) "coupling + deprotection" iterative reaction cycle using a porphyrin monomer as a raw material and two (i) "coupling + deprotection" iterative reaction cycles using a porphyrin monomer as a raw material.

[0065] 2. Preparation of T-shaped patterned porphyrin polymers

[0066] Using a three-arm polyethylene glycol star-shaped macromolecule and two porphyrin monomers (i) and (iii) as raw materials, a J-shaped patterned porphyrin polymer was prepared according to the following method:

[0067] T-shaped patterned porphyrin polymers can be synthesized by subjecting the three-arm polyethylene glycol star-shaped macromolecule to two "coupling + deprotection" iterative reaction cycles with (i) porphyrin monomer, then subjecting it to one "coupling + deprotection" iterative reaction cycle with (iii) porphyrin monomer, and finally subjecting it to one "coupling + deprotection" iterative reaction cycle with (i) porphyrin monomer.

[0068] 3. Preparation of U-shaped patterned porphyrin polymers

[0069] Using three-arm polyethylene glycol star-shaped macromolecules and two porphyrin monomers (i) and (iv) as raw materials, J-shaped patterned porphyrin polymers were prepared according to the following method:

[0070] U-shaped patterned porphyrin polymers can be synthesized by subjecting the three-arm polyethylene glycol star-shaped macromolecule to two "coupling + deprotection" iterative reaction cycles with (i) porphyrin monomer, then subjecting it to two "coupling + deprotection" iterative reaction cycles with (iv) porphyrin monomer, and finally subjecting it to two "coupling + deprotection" iterative reaction cycles with (i) porphyrin monomer.

[0071] Example 3

[0072] Optical tests were performed on four patterned porphyrin polymer nanomaterials: ZZ / J / T / U. The specific sample testing methods and results are as follows:

[0073] (1) UV-Vis absorption spectroscopy: The samples were dissolved in tetrahydrofuran (THF) and acetonitrile (MeCN) to prepare single-molecule sample solutions and aggregated sample solutions, respectively. UV-Vis absorption spectra were recorded using a Shimadzu UV 3600 spectrometer. The slit width was set to 1 nm, the scan speed was set to 480 nm / min, and the wavelength range was scanned from 300 to 700 nm.

[0074] The characteristic absorption peaks of the aggregated states of ZZ-type, J-type, T-type and U-type motifs in acetonitrile (MeCN) all showed different degrees of blue shift compared with their single molecule states in tetrahydrofuran (THF), accompanied by peak broadening, which indicates that they have different stacking behaviors in acetonitrile. Among them, the peak broadening of the J-type motif is the most significant, followed by the T-type motif, which indicates that the stacking modes of the J-type and T-type motifs are conducive to the formation of longer delocalized structures ( Figure 8 a).

[0075] (2) Steady-state fluorescence spectroscopy: The samples were dissolved in tetrahydrofuran (THF) and acetonitrile (MeCN) to prepare single-molecule sample solutions and aggregated sample solutions, respectively. Fluorescence emission spectra were collected using a Shimadzu RF-6000 fluorescence spectrophotometer. The excitation wavelength of the sample was set to 425 nm, the slit width was set to 2 nm, the scanning speed was set to 480 nm / min, and the fluorescence scanning range was 500 to 800 nm.

[0076] The fluorescence spectra of various patterned polymer nanostructures in their aggregated states showed different degrees of characteristic red shifts (i.e., 7.4, 4.2, 9.6, and 7.9 nm for ZZ-type, J-type, T-type, and U-type motifs, respectively) and broader emission peaks, which further confirmed that the obtained patterned polymer nanostructures had diverse stacking configurations ( Figure 8 b).

[0077] (3) Transient time-resolved fluorescence spectroscopy: The samples were dissolved in tetrahydrofuran (THF) and acetonitrile (MeCN) to prepare single-molecule sample solutions and aggregated sample solutions, respectively. The fluorescence lifetime was measured using a HORIBA Delta Flex time-correlated single-photon counting (TCSPC) system equipped with a pulsed nano-LED light source. The excitation wavelength was selected as 425 nm, and the photoluminescence signal was collected at 605 nm. The photon decay curves of different channels were fitted with a three-exponential tail until the chi-square value (χ 2 ), standard deviation and residual reach optimal values.

[0078] The difference in the lifetime of these patterned polymer nanostructures can be attributed to the following reasons: both ZZ-type and U-type motifs present a more twisted structure with higher rotational and torsional freedom in space, which allows them to produce more intermediate states during stacking in a poor solvent (MeCN), ultimately resulting in a slight decrease in lifetime. In sharp contrast, J-type and T-type motifs have a rigid conformation with lower rotational and torsional freedom in space, which further promotes their direct stacking in MeCN with fewer intermediate states. In this case, the excited state electrons relax to the ground state faster, resulting in a significant shortening of the lifetime of the J-type and T-type motifs in the aggregated state ( Figure 8 c, d).

[0079] From this example, it can be concluded that different patterning structures of poly-porphyrin have an impact on the stacking mode in solution, thereby affecting its optical properties.

[0080] Comparative Example 1

[0081] This example provides a preparation method of porphyrin polymer nanomaterial, which is basically the same as example 1, the difference is only that the molecular structure of porphyrin monomer is different, specifically, it is not tetraphenylporphyrin, that is, there is no benzene ring structure, and the result is that the coupling activity is very low.

[0082] Comparative Example 2

[0083] This example provides a preparation method of porphyrin polymer nanomaterial, which is basically the same as example 1, the difference is only that the protecting group of the alkynyl group in the porphyrin monomer is different, specifically, TMS is used instead of TBS protecting group, and the result is that the TMS protecting group is unstable under the coupling reaction conditions.

[0084] Comparative Example 3

[0085] This example provides a preparation method of porphyrin polymer nanomaterial, which is basically the same as example 1, the difference is only that the process operation of the coupling reaction is different, specifically, there is no complete oxygen removal, and the result is that the alkynyl group is coupled with the alkynyl group instead of the alkynyl group and iodine.

[0086] The specific embodiments of the present application are described above. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor belong to the scope of protection of the present application.

Claims

1. A method for preparing a patternable porphyrin polymer nanomaterial with a clear sequence, characterized in that: This is a liquid-phase biaxial iterative synthesis method. First, a porphyrin monomer with a site-specific functional group is synthesized through a cyclization reaction. Then, the porphyrin monomer is connected to a three-arm polyethylene glycol star-shaped macromolecule through a Sonogashira coupling reaction. The formation of the polyporphyrin is then controlled by a deprotection reaction. The iterative coupling / deprotection synthesis process is repeated to achieve controllable biaxial chain growth. The structural formula of the porphyrin monomer having a site-specific functional group is selected from at least two of the following (i)-(iv): The structural formula of the three-arm polyethylene glycol star-shaped macromolecule is:

2. The method for preparing a patternable porphyrin polymer nanomaterial with a well-defined sequence according to claim 1, wherein: The following steps are involved: S1. Preparation of Porphyrin Monomers with Sterilized Functional Groups (1) installing a functionalized phenyl group on the spacer site of the bipyrrole structure; (2) Using a template synthesis method, the obtained linear bipyrrole precursor with a clear sequence is subjected to a cyclization reaction to synthesize a porphyrin monomer with a site-specific functional group; S2. Generation of diverse polymer nanostructures (1) Using three-arm polyethylene glycol star-shaped macromolecules as loading carriers; (2) accurately weighing 1.5 times the molar equivalent of the para-substituted porphyrin monomer and connecting it to the three-arm polyethylene glycol star macromolecule via a Sonogashira coupling reaction; (3) performing a deprotection reaction on the obtained linear polyporphyrin to remove the tert-butyldimethylsilyl protecting group; (4) Select a specific porphyrin monomer with a spatially controllable functional group and repeat the above coupling / deprotection iterative synthesis process.

3. The method for preparing a patternable porphyrin polymer nanomaterial with a well-defined sequence according to claim 2, wherein: In step S1, the functional group is butyl(dimethyl)silyl.

4. The method for preparing a patternable porphyrin polymer nanomaterial with a well-defined sequence according to claim 2, wherein: In step S1, the reaction conditions of the cyclization reaction include: reaction temperature is room temperature, reaction time is 1 hour, the reaction is carried out in dichloromethane solvent, and 2,6-di-tert-butylpyridine and scandium trifluoromethanesulfonate can be added as needed.

5. The method for preparing a patternable porphyrin polymer nanomaterial with a well-defined sequence according to claim 2, wherein: In step S2, the molecular weight of the three-arm polyethylene glycol star-shaped macromolecule is 1892.27 Da, and its synthesis is achieved by using trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile as a protecting group for the active hydroxyl group and by Williamson etherification reaction.

6. The method for preparing a patternable porphyrin polymer nanomaterial with a well-defined sequence according to claim 2, wherein: In step S2, the Sonogashira coupling reaction is carried out in tetrahydrofuran solvent at 60° C. for 24 hours under the catalysis of dichlorobis(triphenylphosphine)palladium and cuprous iodide.

7. The method for preparing a patternable porphyrin polymer nanomaterial with a well-defined sequence according to claim 6, wherein: In step S2, in the Sonogashira coupling reaction, the purity requirements of each reaction reagent are: the purity of dichlorobis(triphenylphosphine)palladium is not less than 98%, the purity of cuprous iodide is not less than 99.999%, and the water content of tetrahydrofuran solvent is less than 50 ppm.

8. The method for preparing a patternable porphyrin polymer nanomaterial with a well-defined sequence according to claim 2, wherein: In step S2, the deprotection reaction is carried out using tetrabutylammonium fluoride in tetrahydrofuran at 60°C for 6 hours, and the molar ratio of the tetrabutylammonium fluoride to the polyporphyrin is 6:

1.

9. A patternable porphyrin polymer nanomaterial with a well-defined sequence obtained by the preparation method according to any one of claims 1 to 8.

10. Use of the preparation method according to any one of claims 1 to 8 in preparing sequence-defined patternable porphyrin polymer nanomaterials with different optical properties.

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