A method for studying the reaction mechanism of photosensitizers with ros

Abstract

The application discloses a method for researching reaction mechanism of photosensitizer and ROS. 1 The application obtains reaction rate coefficients of photosensitizer and ·OH and O2, reaction mechanism of photosensitizer and ROS by computer software calculation. 1 The application obtains secondary reaction rate coefficients of photosensitizer and ·OH and O2, activation energy of reaction of photosensitizer and ·OH, reaction mechanism of photosensitizer and ·OH and life of photosensitizer by experiment. 1 The application obtains reaction mechanism of photosensitizer and ·OH and O2 by calculation and experiment, simulates and predicts reaction kinetics of photosensitizer and ROS in water environment, fills the blank of reaction mechanism of photosensitizer and ROS in water environment and provides basis for degradation evaluation of photosensitizer in environment.

Description

Technical Field

[0001] This invention belongs to the field of liquid phase chemical reaction kinetics technology, specifically relating to a method for studying the reaction mechanism of photosensitizers and ROS. Background Technology

[0002] Brown carbon, as an important class of chromogenic compounds, can form excited triplet states, thereby inducing a new chemical pathway, namely photosensitization. In recent years, photosensitization reactions in the field of environmental photochemistry have received increasing attention. Many photochemical transformation processes in atmospheric water phase are initiated by photooxidants (such as hydroxyl radicals, peroxy radicals, etc.) rather than direct photolysis. The photosensitization effect known from surface water chemistry has been discussed as a potential reaction pathway for SOA formation in water / partic phase (Atmospheric evolution of molecular-weight-separated brown carbon from biomass burning. Atmospheric Chemistry and Physics, 2019.19(11):p.7319-7334.). Several organic compounds in ambient air, including non-phenolic aromatic carbonyl groups, quinones, aromatic ketones, and nitrogen-containing heterocyclic compounds, can form SOA after absorbing light. 3 C*, these compounds are called photosensitizers (Glyoxal induced atmosphericphotosensitized chemistry leading to organic aerosol growth. Environmentalscience&technology, 2014.48(6):p.3218-3227; Photooxidants from brown carbon and other chromophores in illuminated particle extracts. Atmospheric Chemistry andPhysics, 2019.19(9):p.6579-6594; Aqueous-phase secondary organic aerosolformation via reactions with organic triplet excited states—a shortreview. Current Pollution Reports, 2018.4:p.8-12).

[0003] Excited triplet photosensitizers can undergo different types of reaction pathways to generate various ROS (reactive oxygen species).1 O2, OH, etc. 3 C* can react with O2 to produce singlet oxygen, superoxide radicals, and various reactive oxygen species (ROS), and has a significant impact on… 3Aqueous-phase reactions initiated by C* (Kinetics and mass yields of aqueous secondary organic aerosol from highly substituted phenols reacting with a triplet excited state. Environmental Science & Technology, 2021. 55(9): p. 5772-5781; Reactive species in advanced oxidation processes: Formation, identification and reaction mechanism. Chemical Engineering Journal, 2020. 401: p. 126158; Uncertainty and misinterpretation over identification, quantification and transformation of reactive species generated in catalytic oxidation processes: A review. Journal of hazardous materials, 2021. 408: p. 124436). And it is the source of the formation of hydrogen peroxide radicals.Excited triplet photosensitizers can undergo different types of reaction pathways, such as energy transfer with oxygen, collision with water, electron transfer, and chemical reactions with organic compounds such as volatile organic compounds, alkenes, and phenols. (Five-membered heterocycles as potential photosensitizers in the tropospheric aqueous phase: Photophysical properties of imidazole-2-carboxaldehyde, 2-furaldehyde, and 2-acetylfuran. The Journal of Physical Chemistry A, 2020. 124(48): p. 10029-10039; Quenching of excited-state xanthone and thioxanthone by inorganic anions. Journal of the Chemical Society, Perkin Transactions 2, 1985(8): p. 1279-1283; Secondary organic aerosol formation from anthropogenic air pollution: Rapid and higher than expected. Geophysical Research) Letters, 2006, 33(17)). These reaction pathways play an important role in photochemical processes and are of great significance for understanding the complex reaction mechanisms initiated by photosensitizers.

[0004] Current research on photosensitizers largely focuses on gas-phase conditions, lacking understanding of the formation of secondary organic aerosols in atmospheric aqueous / particulate phases, and even more so on the photosensitization process. Therefore, studying the photochemical properties, kinetics, and reaction mechanisms of photosensitizers to understand the photosensitization process in atmospheric aqueous / particulate phases and assess its impact on SOA formation is of greater significance.

[0005] Investigating whether aromatic carbonyl compounds can serve as potential photosensitizers to trigger photosensitizing reactions in the environment, and their potential and persistence as photosensitizers in the environment, is of great significance in terms of their contribution to the formation of SOA in the environment. However, there is currently a lack of systematic research methods on the reaction kinetics and reaction mechanisms of aromatic carbonyl photosensitizers with ROS in aqueous phases, and many gaps remain regarding the optical properties and formation process of brown carbon. Therefore, designing a scheme that can predict the kinetics and reaction mechanisms of their reactions with ROS in aqueous environments is particularly important. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method for studying the reaction mechanism of photosensitizers and ROS.

[0007] The objective of this invention is achieved through the following technical solutions.

[0008] A method for studying the reaction mechanism between photosensitizers and ROS, including computational and experimental methods;

[0009] The calculation method includes the following steps:

[0010] (1) Input the photosensitizer structure into Chem3D, perform structure optimization, and find the optimal structural state;

[0011] (2) Input the optimized atomic coordinates of the structure from step (1) into Gaussian 16, and perform calculations using the selected basis set and density functional theory method to obtain the photosensitizer and ·OH. 1 The reaction rate coefficient of O2 and the reaction mechanism between photosensitizer and ROS;

[0012] If the transition state is calculated to have more than two imaginary frequencies, the calculation result is inaccurate. Adjust the basis set and density functional theory method and repeat step (2).

[0013] If the calculated transition state has only one imaginary frequency and the vibrational mode is normal, then the calculation result is accurate, and the photosensitizer and ·OH are obtained. 1 The reaction rate coefficient of O2 and the reaction mechanism between photosensitizer and ROS;

[0014] The experimental method includes the following steps:

[0015] (a) Experimental testing revealed the interaction between the photosensitizer and ·OH groups. 1 The second-order reaction rate coefficient of O2;

[0016] (b) Calculate the activation energy of the reaction between the photosensitizer and ·OH by using the second-order reaction rate coefficient obtained from the experiment in step (a) to determine the reaction mechanism between the photosensitizer and ·OH;

[0017] (c) Estimate the diffusion constant based on the molecular radius of the photosensitizer and calculate the diffusion limiting rate coefficient of the photosensitizer; determine the reaction mechanism of the photosensitizer and ·OH based on the diffusion limiting rate coefficient of the photosensitizer and the second-order reaction rate coefficient of the photosensitizer and ·OH obtained from the experimental test in step (a);

[0018] (d) Calculate the lifetime of the photosensitizer by using the second-order reaction rate coefficient between the photosensitizer and ·OH obtained from the experiment in step (a).

[0019] Preferably, step (a) experimentally tests to obtain the photosensitizer and1 The method for determining the second-order reaction rate coefficient of O2 is as follows:

[0020] In a multi-stage photochemical reaction chamber, the relative rate method was used to determine the photosensitizer and... 1 The second-order reaction rate coefficient of O2.

[0021] Further preferred, step (a) experimentally tests to obtain the photosensitizer and 1 The specific steps for determining the second-order reaction rate coefficient of O2 are as follows:

[0022] The reference material was used separately. 1 A mixed solution of O2 sensitizer and photosensitizer was placed together in a photochemical reaction chamber under the same environmental conditions and irradiated. After different reaction times, samples were taken to measure the photolysis rates of the reference material and the photosensitizer. The results were then compared with those of the O2 sensitizer. 1 The competitive reaction relationship between O2 and photosensitizer and 1 The second-order reaction rate of O2.

[0023] More preferably, the light source in the photochemical reaction chamber is a light source with an emission spectrum of 550-700nm; it can be a high-pressure mercury lamp with a 290nm cutoff filter to filter out light below 290nm, or it can be an LED light source with an emission spectrum of 550-700nm.

[0024] More preferably, 1 The O2 sensitizer chosen is Bengal rose red, and the reference compound chosen is FFA, which is similar to... 1 The second-order reaction rate of O2 is 9.4 × 10⁻⁶. 7 M -1 s -1 (Aqueous singlet oxygen reaction kinetics offurfuryl alcohol: effect of temperature, pH, and salt content. Environmental Science: Processes & Impacts, 2017.19(4):p.507-516); The entire apparatus is used to fully dissolve oxygen by magnetic stirring.

[0025] More preferably, because both the photosensitizer and the reference material react with each other in the same solution environment... 1 O2 produces a competitive reaction, and both the photosensitizer and the reference react only with substances in the solution. 1 Degraded by O2 reaction, reference material and 1 The second-order reaction rate of O2 is known, meaning that based on this competitive kinetic relationship, the photosensitizer and... 1 The formula for calculating the second-order reaction rate coefficient of O2 is Eq.1:

[0026]

[0027] in, For the APs to be tested and 1 The second-order rate constant for the O2 reaction; [A]0, [A] t [FFA]0, [FFA] t The concentrations of the photosensitizer and the reference FFA at time zero and time t, respectively; For reference FFA and 1 The second-order reaction rate constant of O2.

[0028] Preferably, the method for obtaining the second-order reaction rate coefficient between the photosensitizer and ·OH in step (a) is as follows:

[0029] The rate coefficient and activation energy of the second-order reaction between a photosensitizer and a hydroxyl radical (·OH) under a temperature gradient were determined using pulsed laser flash photolysis.

[0030] A further preferred method for obtaining the second-order reaction rate coefficient between the photosensitizer and ·OH in step (a) is as follows:

[0031] (A) Prepare a free radical precursor solution and use a circulating water pump to pump the free radical precursor solution into a quartz reaction tube;

[0032] (B) The free radical precursor solution in the quartz reaction tube is irradiated with pulsed excitation light emitted by a laser to generate free radicals, and then photosensitizer stock solution is added to the free radical precursor solution in batches.

[0033] (C) A continuous diode laser is used as the detection light. The change in free radical concentration caused by the reaction of photosensitizers with hydroxyl radicals at different concentrations is monitored online using the spectral absorption method. The signal of free radical concentration change is then converted by an oscilloscope and averaged multiple times before being sent to a computer to collect data.

[0034] More preferably, the free radical precursor solution comprises SCN. - Inorganic salts and H2O2. When determining the second-order reaction rate of the photosensitizer with ·OH, since the absorption wavelength of ·OH radicals is around 230 nm, the absorption spectra of many substances in the solution overlap, making direct spectroscopic detection impossible. Therefore, this invention uses SCN, a commonly used reagent with a known second-order reaction rate with ·OH radicals. -As a reference (see the literature Tropospheric Aqueous-Phase Free-Radical Chemistry: Radical Sources, Spectra, Reaction Kinetics and Prediction Tools. Chemphyschem 2010, 11, 3796-3822), a certain amount of SCN will be determined. - When added to an aqueous H₂O₂ solution as a free radical precursor solution, the generated ·OH radicals rapidly react with SCN⁻ to form (SCN)₂. ·- Free radicals; of which SCN - For containing SCN - Inorganic salts such as KSCN and NaSCN can be used.

[0035] More preferably, the activation energy of the reaction is calculated using the Arrhenius equation based on the temperature and the second-order reaction rate coefficient between the photosensitizer and ·OH.

[0036] Preferably, the formula for calculating the diffusion limiting rate coefficient in step (c) is Eq.9:

[0037]

[0038] Preferably, the formula for calculating the lifetime of the photosensitizer in step (d) is Eq.10:

[0039]

[0040] Preferably, the photosensitizer is an aromatic carbonyl photosensitizer; the basis set and density functional theory method in step (2) is M062X / 6-311++G(2df,2p).

[0041] Preferably, the photosensitizer is an aromatic carbonyl photosensitizer; the structural formula of the aromatic carbonyl photosensitizer is as follows:

[0042]

[0043] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0044] (1) This invention is the first to measure the second-order reaction rate coefficient of APs and ·OH using pulsed laser flash photolysis technology, and to measure the reaction rate coefficient of APs and ·OH in a photochemical reaction chamber. 1 The second-order reaction rate coefficient of O2.

[0045] (2) The determination of APs and ·OH as described in this invention 1The method for determining the second-order reaction rate constant of O2 is simple, has few interfering factors, can quickly acquire data, has high measurement accuracy, and provides accurate detection results. This method is also applicable to other photosensitizers reacting with ·OH, 1 The determination of the second-order reaction rate constant of O2 is important for the reaction between photosensitizers and ·OH groups in aquatic environments. 1 The study of O2 reaction kinetics is of great value.

[0046] (3) This invention is the first to calculate the relationship between APs and ·OH. 1 The reaction mechanism of O2 was simulated and predicted, and the reaction kinetics of APs with ROS in the aquatic environment were predicted. This fills the current gap in the understanding of the reaction mechanism of aromatic carbonyl photosensitizers with ROS in the aquatic environment and provides a basis for evaluating the environmental degradation effect of aromatic carbonyl photosensitizers. Attached Figure Description

[0047] Figure 1 Logarithmic plot of APs vs FFA concentrations in the reaction solution with singlet oxygen generated from rose red;

[0048] Figure 2 To add different concentrations of APs (SCN)2 ·- Transient absorption spectrum under 460 nm detection light ([H2O2]=170 mM, [KSCN]=0.5 Mm, 25℃);

[0049] Figure 3 for Line graph; smaller graph is lnk 2nd Arrhenius spectrum of vs1 / T;

[0050] Figure 4a and Figure 4b For APs and 1 Energy level orbital diagram of the O2 reaction;

[0051] Figure 5 The bar chart shows the reaction rates of methyl salicylate with six APs. Detailed Implementation

[0052] The present invention will be further described in detail below with reference to embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. All reagents used in the following embodiments are commercially available.

[0053] The Aps structure used in this embodiment is as follows:

[0054]

[0055] Example 1

[0056] In a multi-stage photochemical reaction chamber, the relative rate method was used to determine the interaction between APs and singlet oxygen. 1 The rate coefficient of the second-order reaction of O2. The specific implementation process is as follows:

[0057] (1) Prepare 100 mL of a mixed solution containing 20 μM FFA, 50 μM RB and 50 μM APs.

[0058] (2) Take 30 mL of the prepared mixed solution and add it to a quartz reaction tube with a radius of 1.5 cm. Place them together in a photochemical reaction chamber and use a high-pressure mercury lamp with a 400 nm cutoff filter as the light source for the light experiment.

[0059] (3) Take 2 mL of sample every 4 hours and use high performance liquid chromatography to test the changes in APs and FFA concentrations in the reaction solution.

[0060] In the system, FFA will compete with APs. 1 O2, therefore APs can be calculated using formula Eq.1. 1 The second-order rate coefficient of the O2 reaction:

[0061]

[0062] in, For the APs to be tested and 1 The second-order rate constant of the O2 reaction; [APs]0, [APs] t [FFA]0, [FFA] t The concentrations of APs and reference FFA at time zero and time t, respectively; For reference FFA and 1 The second-order reaction rate constant of O2. Figure 1 To obtain the logarithmic plot of reference FFA and APs concentrations at the same reaction time, the APs and APs concentrations were calculated based on the plot slope. 1 The second-order rate coefficient of the O2 reaction is: (4.09±0.16)×10 7 ~(1.90±0.05)×10 8 between.

[0063] Example 2

[0064] The rate coefficient and activation energy of the second-order reaction between APs and hydroxyl radicals (·OH) under a temperature gradient were determined using pulsed laser flash photolysis. The specific procedure is as follows:

[0065] (1) The laser energy of the 266nm pulsed excitation light was set to 20mJ, the pulsed excitation light wavelength was 266nm, and the pulse width was 2ns. The operating temperature was room temperature (25℃). A mixed solution of 170mM H2O2 and 0.5mM KSCN was prepared as (SCN)2 ·- The precursor solution was prepared by using the mixed solution as a solvent to prepare a 1 mM APs stock solution.

[0066] (2) Take 500mL (SCN)2 ·- The precursor solution was poured into a beaker and pumped to a quartz reaction tube using a circulating water pump, with continuous circulation. A 266nm laser was emitted horizontally into the quartz reaction tube, and 5mL of APs stock solution was added sequentially. Simultaneously, a 460nm secondary laser was activated as a detection beam, overlapping with the excitation beam to form a single optical path that illuminated the reaction tube. Monitoring was performed using (SCN)2. ·- The changes in the intensity of the 460nm detection light detected by the photodetector due to concentration changes were studied. An oscilloscope was connected to a computer to acquire the data in real time.

[0067] Detected signal changes such as Figure 2 As shown, the intensity of the detection light instantly drops from its initial value I0 to its minimum value I immediately before and after the excitation light is triggered. t＝0 The reason is that a large amount of ·OH was generated in the reaction tube at this time, and the light intensity signal gradually rose afterward because the ·OH generated at this time was gradually physically quenched or consumed by reacting with APs of different concentrations.

[0068] Under a 266nm laser, H2O2 decomposes to produce ·OH, while SCN is detected using a 460nm continuous laser. - The product generated after reacting with ·OH The concentration changes of APs and SCN during the experiment - All of them participate in the reaction with ·OH, therefore, as the concentration of the analyte increases, the amount of ·OH generated also increases. The concentration will also change accordingly, which in turn will cause a change in the detected light intensity. According to formula Eq.2:

[0069]

[0070] in and These represent the effects of laser irradiation. The absorbance after adding different concentrations of APs and Initial absorbance at 460 nm. k APs k is the rate constant for the reaction of ·OH with APs. R For ·OH and SCN -The rate constant of the reaction is 1.1 × 10⁻⁶. 10 M -1 s -1 .

[0071] Since APs also exhibit absorption at 266 nm, the experiment observed that the reaction solution almost completely absorbed the 266 nm excitation light. Therefore, the addition of APs will compete with H₂O₂ for photons, causing the ·OH concentration to change with the APs concentration. This will affect (SCN)₂. ·- This shielding effect can be corrected using formula Eq.3:

[0072]

[0073] in, After laser irradiation Absorbance after adding different concentrations of APs; and These represent the absorbance intensities of the reaction solution at 266 nm, with and without APs, respectively. Therefore, Eq.2 can be transformed into Eq.4:

[0074]

[0075] in, for Initial absorbance at 460 nm.

[0076] Figure 3 Showing different temperatures The absorbance intensity and the corrected absorbance intensity as a function of AP concentration, and the reference SCN - Since the reaction rate with ·OH is known, the second-order reaction rate coefficient k between APs and ·OH can be determined according to Eq. 4. It can be observed that the reaction rates are all around 10. 10 M -1 s -1 A large order of magnitude.

[0077] The activation energy of the reaction was calculated using the Arrhenius equation Eq.5.

[0078]

[0079] Where k is the rate coefficient of the second-order reaction between APs and ·OH, T is the absolute temperature, Ea is the experimental activation energy, and R is the molar gas constant.

[0080] Example 3

[0081] Theoretical calculations were performed on APs and singlet oxygen. 1The reaction mechanism of O2 and hydroxyl radical ·OH, and the specific implementation process are as follows:

[0082] (1) Input the APs structure in Chem3D, perform structure optimization, and find the optimal structure state;

[0083] (2) The optimized atomic coordinates of the structure were input into Gaussian 16. Appropriate basis sets and models were selected, and the M062X / 6-311++G(2df,2p) method based on density functional theory and basis sets were used to optimize the structure and calculate the frequencies of the reaction in the liquid phase. An integral equation-based polarization continuity model (IEFPCM) was used to simulate the solvation effect.

[0084] MO62X is a functional method, and 6-311++G(2df,2p) is a basis set based on 6-311G, with diffuse functions added to heavy atoms and H atoms, two d functions and one f function added to heavy atoms, and one p function added to H atoms.

[0085] If the calculated transition state has more than two imaginary frequencies, or if the vibration mode is incorrect, readjust the atomic coordinates and recalculate.

[0086] (3) The reaction rate coefficient was calculated using the multiconfigurational transition state theory:

[0087]

[0088] Among them, Q ≠ (T) is the partition function of the transition state, Q R (T) is the partition function of the reactants having multiple conformations, k B κ is Boltzmann's constant, h is Planck's constant, E0 represents the energy barrier height of the classical transition state, and κ is... i (T) is the tunneling correction factor.

[0089]

[0090] Among them, Q j Let represent the partition function of reactant conformation j, where the relative energy difference between conformation j and the lowest energy conformation is limited to no more than 10 kJ / mol. Therefore, the summation of the partition functions only includes conformations whose energies are close to the lowest energy conformation. This yields the results for APs and ·OH. 1 The reaction rate coefficient and reaction mechanism of O2.

[0091] Generally, reactions in solution can be modeled as Eq.8 processes.

[0092]

[0093] Where, kD k is the rate coefficient of a chemical reaction. r The diffusion reaction rate coefficient

[0094] Figure 4a and Figure 4b APs+ were showcased 1 Different reaction pathways of O2 in the liquid phase. Theoretical calculations revealed that, except for 3-O2N-AP, the transition state energy barrier of the other APs is lowest at the (3,6) position with [4+2] cycloaddition, while that of 3-O2N-AP is lowest at the (2,5) position with [4+2] cycloaddition. For AP, 3-HO-AP, 3-H2N-AP, 3-H3C-AP, and 3-H3CO-AP, theoretical calculations suggest that the [4+2] cycloaddition at the (3,6) position is the pathway with [4+2] cycloaddition. 1 The main reaction pathway of O2, 3-O2N-AP and 1 The primary reaction pathway for O2 is the [4+2] cycloaddition at the (2,5) position, explaining why 3-O2N-AP reacts with... 1 The O2 reaction is the slowest. In the reaction between APs and ·OH, ·OH primarily attacks site 2. The theoretically calculated trend of the reaction rate coefficient of APs is consistent with the experimentally measured trend, and the calculated k... r Much greater than k D Furthermore, the theoretical rate coefficients for this reaction all exceed 10. 10 The magnitude indicates that this reaction is a typical diffusion-controlled process.

[0095]

[0096] Example 4

[0097] The reaction type between APs and hydroxyl radicals (·OH) is determined using the diffusion limiting rate coefficient; the specific implementation process is as follows:

[0098] Estimate the diffusion constant based on the molecular radius, (2) and substitute it into the diffusion limiting rate coefficient k. D .

[0099]

[0100] Where, k B η is the Boltzmann constant. s Let r be the dynamic viscosity of the solution, and T be the reaction temperature. A and r B Let A and B be the molecular volumes.

[0101] Table 1 lists the molecular radius, diffusion coefficient, and estimated k of the six APs. D k was measured experimentally at 25℃ exptAnd the activation energy of the reaction. According to the description in the literature (Herrmann H., Hoffmann D., Schaefer T., et al. Tropospheric aqueous-phase free-radical chemistry: Radical sources, spectra, reaction kinetics and prediction tools[J]. ChemPhysChem, 2010, 11(18):3796-3822.), SCN - Activation energy (E) of the reaction with ·OH a The activation energy is 14.1 kJ / mol. Therefore, the activation energy calculated by formula Eq.5 already includes SCN. - E reacting with ·OH a In practice, this part needs to be subtracted from the activation energy of the reaction between APs and ·OH. Table 1 lists the activation energies of the reaction between APs and ·OH. a The range of 12.1–41.6 kJ / mol indicates that this is a typical diffusion-controlled activation energy. This preliminarily confirms that the reaction between APs and ·OH is diffusion-controlled. Furthermore, based on molecular volume and diffusion constant, the kJ / mol values ​​for various APs reactions are... D The value is 7.56 × 10 9 ~7.70×10 9 M –1 s –1 Within the range. The experimentally measured values ​​are in the range of 10. 10 M –1 s –1 The magnitude of the apparent rate coefficient, which is larger than the range predicted by the diffusion rate coefficient, further indicates that the reaction is close to diffusion-controlled.

[0102] Table 1. Diffusion constant (D), rate coefficient (k) at 25℃, and activation energy (E) of APs α )

[0103]

[0104] Example 5

[0105] Using the experimentally measured second-order reaction rate coefficients between APs and ROS, and the concentration of ROS in the environment, the lifetime of APs in typical liquid particles in the atmosphere is further predicted according to Eq.10.

[0106] Taking the reaction rate coefficients of APs with ·OH as an example, Table 2 clearly shows that under daytime conditions, APs, whether in stationary particles or cloud droplets, degrade rapidly due to their reaction with ·OH radicals. This indicates that APs survive in the atmosphere for less than one hour, and their reaction with ·OH occurs extremely rapidly.

[0107]

[0108] Table 2. Estimated lifetimes (τ, in hours) of APs in typical droplets under the influence of hydroxyl radicals.

[0109]

[0110] Example 6

[0111] To verify the actual photosensitizing performance of APs, the common drug residue methyl salicylate (MeSa) was directly degraded experimentally. Figure 5 The results showed that methyl salicylate degraded under UV irradiation after the addition of APs, and the degradation rate was significantly increased with the addition of APs. APs were effective in degrading MeSa, according to Examples 1, 2, and 3-HO-AP with ·OH and 1 O2 exhibits the fastest reaction rate and highest reactivity, making it more effective at degrading MeSa. Furthermore, theoretical calculations show that 3-HO-AP has the shortest lifetime, allowing it to react with MeSa to a greater extent, making it an excellent photosensitizer. 3-O2N-AP reacts with ·OH and... 1 O2 has the slowest reaction rate, the worst effect in degrading MeSa, a long lifespan in the environment, and low reactivity, making it a poor type of photosensitizer.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description and ideas. For example, after obtaining the basic dynamic parameters according to Embodiments 1-2, other dynamic results can be simulated in Gaussian software. It is neither necessary nor possible to exhaustively list all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for studying the reaction mechanism between photosensitizers and ROS, characterized in that, Including computational methods and experimental methods; The calculation method includes the following steps: (1) Input the photosensitizer structure into Chem3D, perform structure optimization, and find the optimal structural state; (2) Input the optimized atomic coordinates of the structure from step (1) into Gaussian 16, and perform calculations using the selected basis set and density functional theory method to obtain the photosensitizer and ·OH. 1 The reaction rate coefficient of O2 and the reaction mechanism between photosensitizer and ROS; If the transition state is calculated to have more than two imaginary frequencies, the calculation result is inaccurate. Adjust the basis set and density functional theory method and repeat step (2). If the calculated transition state has only one imaginary frequency and the vibrational mode is normal, then the calculation result is accurate, and the photosensitizer and ·OH are obtained. 1 The reaction rate coefficient of O2 and the reaction mechanism between photosensitizer and ROS; The experimental method includes the following steps: (a) Experimental testing revealed the interaction between the photosensitizer and ·OH groups. 1 The second-order reaction rate coefficient of O2; experimental tests were conducted to obtain the photosensitizer and... 1 The method for determining the second-order reaction rate coefficient of O2 is as follows: In a multi-stage photochemical reaction chamber, the relative rate method was used to determine the photosensitizer and... 1 The second-order reaction rate coefficient of O2; The experimental method for obtaining the second-order reaction rate coefficient between the photosensitizer and ·OH is as follows: The rate coefficient and activation energy of the second-order reaction between a photosensitizer and a hydroxyl radical (·OH) under a temperature gradient were determined using pulsed laser flash photolysis. The specific steps for experimentally obtaining the second-order reaction rate coefficient between the photosensitizer and ·OH are as follows: (A) Prepare a free radical precursor solution and use a circulating water pump to pump the free radical precursor solution into a quartz reaction tube; (B) The free radical precursor solution in the quartz reaction tube is irradiated with pulsed excitation light emitted by a laser to generate free radicals, and then photosensitizer stock solution is added to the free radical precursor solution in batches. (C) A continuous diode laser is used as the detection light. The spectral absorption method is used to monitor the changes in free radical concentration caused by the reaction of different concentrations of photosensitizer with hydroxyl free radicals online. The free radical concentration change signal is then converted by an oscilloscope and averaged multiple times before being sent to a computer to collect data. (b) Calculate the activation energy of the reaction between the photosensitizer and ·OH by using the second-order reaction rate coefficient obtained from the experiment in step (a) to determine the reaction mechanism between the photosensitizer and ·OH; (c) Estimate the diffusion constant based on the molecular radius of the photosensitizer and calculate the diffusion limiting rate coefficient of the photosensitizer; determine the reaction mechanism of the photosensitizer and ·OH based on the diffusion limiting rate coefficient of the photosensitizer and the second-order reaction rate coefficient of the photosensitizer and ·OH obtained from the experimental test in step (a); (d) Calculate the lifetime of the photosensitizer by using the second-order reaction rate coefficient between the photosensitizer and ·OH obtained from the experiment in step (a); The photosensitizer is an aromatic carbonyl photosensitizer; the structural formula of the aromatic carbonyl photosensitizer is as follows:

2. The method for studying the reaction mechanism between photosensitizers and ROS according to claim 1, characterized in that, Step (a) Experimental testing yielded photosensitizer and 1 The specific steps for determining the second-order reaction rate coefficient of O2 are as follows: The reference material was used separately. 1 A mixed solution of O2 sensitizer and photosensitizer was placed together in a photochemical reaction chamber under the same environmental conditions and irradiated. After different reaction times, samples were taken to measure the photolysis rates of the reference material and the photosensitizer. The results were then compared with those of the O2 sensitizer. 1 The competitive reaction relationship between O2 and photosensitizer and 1 The second-order reaction rate of O2.

3. The method for studying the reaction mechanism between photosensitizers and ROS according to claim 2, characterized in that, The light source in the photochemical reaction chamber is a light source with an emission spectrum of 550-700nm; 1 The O2 sensitizer chosen was Bengal rose red, and the reference material chosen was FFA; the entire device was used to fully dissolve oxygen through magnetic stirring; Photosensitizer and 1 The formula for calculating the second-order reaction rate coefficient of O2 is Eq.1: in, For the APs to be tested and 1 The second-order rate constant for the O2 reaction; [A]0, [A] t [FFA]0, [FFA] t The concentrations of the photosensitizer and the reference FFA at time zero and time t, respectively; For reference FFA and 1 The second-order reaction rate constant of O2.

4. The method for studying the reaction mechanism between photosensitizers and ROS according to claim 1, characterized in that, The free radical precursor solution includes SCN. - Inorganic salts and H2O2; The activation energy of the reaction was calculated using the Arrhenius equation based on the temperature and the rate coefficient of the second-order reaction between the photosensitizer and ·OH.

5. The method for studying the reaction mechanism between photosensitizers and ROS according to claim 1, characterized in that, Step (c) uses the formula Eq.9 to calculate the diffusion limiting rate coefficient of the photosensitizer: Where, k B η is the Boltzmann constant. s Let r be the dynamic viscosity of the solution, T be the reaction temperature, and r be the dynamic viscosity. A and r B Let A and B be the molecular volumes.

6. The method for studying the reaction mechanism between photosensitizers and ROS according to claim 1, characterized in that, Step (d) uses the formula Eq.10 to calculate the lifetime of the photosensitizer:

7. The method for studying the reaction mechanism between photosensitizers and ROS according to claim 1, characterized in that, The photosensitizer is an aromatic carbonyl photosensitizer, and the basis set and density functional theory method in step (2) is M062X / 6-311++G(2df,2p).

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