A pentazolium lead complex, its preparation method and application

Abstract

This invention provides a pentaazole lead complex, its preparation method, and its application, relating to the field of laser-initiated ignition technology. The molecular formula of the pentaazole lead complex is Pb(N5)(N3), and its characterization is as follows: decomposition peak temperature: 120℃; characteristic wavenumbers detected by attenuated total reflectance infrared spectroscopy are: 3369.11, 3330.71, 3258.58, 3170.41, 1986.73, 1601.30, 1214.97 cm⁻¹. ‑1 The characteristic wavenumbers detected by Raman spectroscopy excited by 785 nm near-infrared laser are: 226.17, 573.48, 1184.74, 1342.18, and 1481.11 cm⁻¹. ‑1 Elemental analysis: PbN8: calcd N 35.10%, Found: N 35.15%. This invention discloses a novel pentazolium lead complex Pb(N5)(N3) and its preparation method. It has a low laser initiation threshold, is environmentally friendly, and experimentally determined to be successfully initiated at excitation energies of 3–100 mJ. The pentazolium lead complex described in this application does not contain ClO4. ‑ The pentazolium lead complex described in this application has higher energy than the conventional initiating explosive lead azide (Pb(N3)2), and can use a smaller amount of explosive under the same conditions.

Description

Technical Field

[0001] This invention relates to the field of laser-induced detonation and ignition technology, specifically to a pentazolium lead complex, its preparation method, and its application. Background Technology

[0002] Laser-initiated ignition technology, as a novel ignition technology developed in recent years, has attracted widespread attention in the military and aerospace fields due to its advantages such as strong anti-interference capability, high safety, and reliable ignition. Laser-initiated ignition technology can effectively improve the safety and reliability of traditional ignition methods. However, in the development of laser-initiated ignition technology, exploring laser-ignited primary explosives with low laser ignition energy and high explosive performance is a challenging problem that needs to be solved in this field.

[0003] Coordination compounds are a class of compounds with special properties and structures, typically formed by the central atom and surrounding molecules or ions bonded together by coordinate bonds. Due to their rich assembly patterns and flexible design, they usually possess special physical or chemical properties, thus becoming a research hotspot for researchers in the field of laser-induced detonation and ignition.

[0004] Pentazole anions are all-nitrogen species with aromatic planar structures, possessing a certain degree of stability and capable of releasing a large amount of energy. Furthermore, the combustion products of pentazole anions are entirely environmentally friendly nitrogen gas. Since the first isolation and synthesis of room-temperature stable pentazole anion salts at Nanjing University of Science and Technology in 2017, research on pentazole anions has deepened, and various pentazole derivatives have been studied and synthesized. Pentazole anions possess excellent coordination ability and five potential coordination sites, offering advantages such as abundant coordination sites and diverse coordination modes. They are excellent ligands for constructing energetic coordination compounds. As excellent high-energy ligands, pentazole anions hold promise for designing laser-responsive and highly explosive energetic coordination compounds. Moreover, compared to traditional energetic coordination compounds suitable for laser ignition, pentazole lead complexes do not contain ClO4. - The ions decompose into a large amount of nitrogen gas, making them a new type of environmentally friendly energetic complex.

[0005] The existing technology does not disclose pentaazole lead complexes applied in the field of laser-initiated detonation and ignition technology. Summary of the Invention

[0006] This invention provides a pentazolium lead complex, its preparation method, and its application, in order to solve the technical problems mentioned in the background.

[0007] To address the aforementioned technical problems, this invention discloses a pentazolium lead complex with the molecular formula Pb(N5)(N3), characterized as follows: Decomposition peak temperature: 120℃; The characteristic wavenumbers detected by attenuated total reflectance infrared spectroscopy are: 3369.11, 3330.71, 3258.58, 3170.41, 1986.73, 1601.30, and 1214.97 cm⁻¹. -1 ; The characteristic wavenumbers detected by Raman spectroscopy excited by 785 nm near-infrared laser are: 226.17, 573.48, 1184.74, 1342.18, and 1481.11 cm⁻¹. -1 ; Elemental analysis: PbN8: calcd N 35.10%, Found: N 35.15%.

[0008] This invention also discloses a method for preparing a pentazolium lead complex, comprising: Step 1: At room temperature, dissolve sodium azide solid in deionized water, then add lead acetate trihydrate solid to the sodium azide solution. After stirring at room temperature for a second time, add saturated sodium acetate solution dropwise to the solution while continuing to stir until the solution becomes clear. Step 2: At room temperature, add sodium pentaazole solid to the clear solution obtained in Step 1, cool to the first temperature and stir for the first time, then filter to obtain a white lead pentaazole complex.

[0009] Preferably, the first temperature is 5~20℃ and the room temperature is 20~25℃.

[0010] Preferably, the first time duration is 15~24 h; the second time duration is 0.5~1 h; the stirring speed in step one is 300~500 r / min; and the stirring speed in step two is 100~200 r / min.

[0011] Preferably, in step one, the ratio of sodium azide to deionized water is 0.1 mol : 20~30 mL.

[0012] Preferably, in step one, the molar ratio of lead acetate trihydrate to sodium azide is 1:1 to 1.1.

[0013] Preferably, in step two, the molar ratio of sodium pentazolate to sodium azide is 1:1.

[0014] This invention also discloses an application of a pentaazole lead complex, wherein the pentaazole lead complex as described in claim 1 is used as a laser-initiated ignition propellant, and can be effectively initiated with laser energy ≥3 mJ.

[0015] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention discloses a novel pentaazole lead complex Pb(N5)(N3) and its preparation method. It has a low laser initiation threshold and is environmentally friendly. Experimental results show that it can be successfully initiated at excitation energies of 3 to 100 mJ.

[0017] (2) The pentazolium lead complex described in this application does not contain ClO4. - Since it contains ions, the decomposition products do not contain Cl, which is beneficial to human health and the sustainable development of the ecological environment.

[0018] (3) The pentaazole lead complex described in this application has higher energy than the conventional initiating explosive lead azide (Pb(N3)2), and less explosive can be used under the same conditions. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic flowchart of the preparation method of the present invention; Figure 2 The DSC curve of the pentaazole lead complex of the present invention is shown.

[0020] Figure 3 This is the infrared spectrum of the pentazolium lead complex of the present invention.

[0021] Figure 4 This is the Raman spectrum of the pentazolium lead complex of the present invention.

[0022] Figure 5 This is a schematic diagram of the laser-initiated detonation and ignition testing device used in this invention.

[0023] Figure 6 The diagram illustrates the initiation of the pentazolium lead complex prepared in this invention as a laser-initiated ignition propellant at an excitation energy of 100 mJ.

[0024] Figure 7 The diagram illustrates the initiation of the pentazolium lead complex prepared in this invention as a laser-initiated ignition propellant at an excitation energy of 3 mJ.

[0025] Figure 8 A schematic diagram of the initiation of lead pentazolium, prepared as a comparative example, as a laser-initiated ignition propellant at an excitation energy of 100 mJ. Detailed Implementation

[0026] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0027] Furthermore, in this invention, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions and features of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0028] The present invention provides the following embodiments: This invention provides a pentazolium lead complex with the molecular formula Pb(N5)(N3), characterized as follows: Decomposition peak temperature: 120℃; The characteristic wavenumbers detected by attenuated total reflectance infrared spectroscopy are: 3369.11, 3330.71, 3258.58, 3170.41, 1986.73, 1601.30, and 1214.97 cm⁻¹. -1 ; The characteristic wavenumbers detected by Raman spectroscopy excited by 785 nm near-infrared laser are: 226.17, 573.48, 1184.74, 1342.18, and 1481.11 cm⁻¹. -1 ; Elemental analysis: PbN8 (319.256): calcd N 35.10%, Found: N 35.15%.

[0029] See Figure 1 The present invention also provides a method for preparing a pentazolium lead complex, comprising: Step 1: Dissolve sodium azide solid in deionized water at room temperature, then add lead acetate trihydrate solid to the sodium azide solution and stir at room temperature (300~500 r / min) for a second time. Then, while stirring continuously, add saturated sodium acetate solution dropwise to the solution until the solution is clear. Step 2: At room temperature, add sodium pentaazole solid to the clear solution obtained in Step 1, cool to the first temperature and stir (100~200 r / min) for the first time, then filter to obtain a white lead pentaazole complex.

[0030] The first temperature is 5~20℃, the first duration is 15~24 h, and the room temperature is 20~25℃.

[0031] In step one, the ratio of sodium azide to deionized water is 0.1 mol : 20~30 mL.

[0032] In step one, the second duration is 0.5~1 hour; In step one, the molar ratio of lead acetate trihydrate to sodium azide is 1:1 to 1.1.

[0033] In step two, the molar ratio of sodium pentazolate to sodium azide is 1:1.

[0034] This invention also discloses an application of a pentaazole lead complex, which is used as a laser-initiated igniter and can effectively detonate with a laser energy ≥3 mJ.

[0035] Example 1:

[0036] Step 1: At room temperature (20~25℃), dissolve 0.1 mol sodium azide solid (6.5 g) in 25 mL of deionized water, then add 0.1 mol lead acetate trihydrate solid (37.9 g) to the solution. Stir at room temperature (500 r / min) for 1 h, then add saturated sodium acetate solution dropwise to the solution while stirring continuously until the solution is clear.

[0037] Step 2: At room temperature (20~25℃), add 0.1 mol of sodium pentaazole solid (9.3 g) to the clear solution obtained in Step 1, cool to 5℃ and stir (200 r / min) for 24 h, filter to obtain 26.5 g of white lead pentaazole complex, yield 83%.

[0038] The product obtained in Example 1 was characterized by the following methods: infrared spectrometer: Thermo Nicolet iS10; Raman spectrometer: ATR3110, excitation wavelength: 785 nm; elemental analyzer: Vario EL III; differential scanning calorimeter: NETZSCH DSC 204 F1 Phoenix, heating rate: 5 K / min.

[0039] Its DSC (differential scanning calorimetry), infrared spectrum, and Raman spectrum are as follows: Figure 2 , Figure 3 and Figure 4 As shown.

[0040] DSC: 120 scan (decomposition peak temperature); Infrared (ATR): 3369.11, 3330.71, 3258.58, 3170.41, 1986.73, 1601.30, 1214.97 cm-1 Among them, 1214.97 cm -1 The peak represents the characteristic infrared absorption of the pentazolium anion.

[0041] Raman (785 nm): 226.17, 573.48, 1184.74, 1342.18, 1481.11 cm⁻¹ -1 Among them, 1184.74 is the Raman characteristic absorption peak of the pentaazole anion.

[0042] Elemental analysis: PbN8 (319.256): calcd N 35.10%, Found: N 35.15%.

[0043] The product obtained in Example 1 was subjected to... Figure 5 The laser-initiated ignition device shown was tested by placing a sample (approximately 2 mg) in an alumina crucible. The excitation voltage of the laser (Dawa-100) was adjusted to irradiate the sample at a specific excitation energy. As the excitation voltage decreased, the output laser energy also decreased accordingly. After multiple tests, it was finally determined that the sample could be stably initiated at the minimum adjustable laser energy (3 mJ). High-speed photographic images at the maximum (100 mJ) and minimum (3 mJ) laser energies are shown below. Figure 6 and Figure 7 As shown.

[0044] Example 2:

[0045] Step 1: At room temperature (20~25℃), dissolve 0.1 mol sodium azide solid (6.5 g) in 25 mL of deionized water, then add 0.1 mol lead acetate trihydrate solid (37.9 g) to the solution. Stir at room temperature (500 r / min) for 1 h, then add saturated sodium acetate solution dropwise to the solution while stirring continuously until the solution is clear.

[0046] Step 2: At room temperature (20~25℃), add 0.1 mol of sodium pentaazole solid (9.3 g) to the clear solution obtained in Step 1, cool to 15℃ and stir (150 r / min) for 15 h, filter to obtain 25.4 g of white lead pentaazole complex, yield 80%.

[0047] The product obtained in Example 2 was structurally characterized, and the results were the same as those in Example 1.

[0048] Comparative Example 1: Step 1: At room temperature (20~25℃), dissolve 0.1 mol of lead pentaazole solid (9.3 g) in 25 mL of deionized water, then add 0.1 mol of lead acetate trihydrate (37.9 g) solid to the solution. Stir at room temperature (500 r / min) for 1 h, then add saturated sodium acetate solution dropwise to the solution until the solution is clear while stirring continuously.

[0049] Step 2: At room temperature (20~25℃), add 0.1 mol of sodium pentaazole solid (9.3 g) to the clear solution obtained in Step 1, cool to 5℃ and stir (200 r / min) for 24 h, filter to obtain 10.4 g of solid product, yield 30%.

[0050] The product obtained in Comparative Example 1 was obtained by... Figure 5 The laser-initiated ignition device shown in the test indicated that the solid product obtained from Comparative Example 1 (2 mg) could not be initiated as a laser-initiated ignition propellant at a laser energy of 100 mJ. Figure 8 ).

[0051] The beneficial effects of the above technical solution are as follows: (1) This invention discloses a novel pentaazole lead complex Pb(N5)(N3) and its preparation method. It has a low laser initiation threshold and is environmentally friendly. Experimental results show that it can be successfully initiated at excitation energies of 3 to 100 mJ.

[0052] (2) The pentazolium lead complex described in this application does not contain ClO4. - Since it contains ions, the decomposition products do not contain Cl, which is beneficial to human health and the sustainable development of the ecological environment.

[0053] (3) The pentaazole lead complex described in this application has higher energy than the conventional initiating explosive lead azide (Pb(N3)2), and less explosive can be used under the same conditions.

[0054] In one embodiment, a first pre-reaction test is performed before step one when changing raw material batches, which includes: Step 011: Obtain the time-standard conductivity fitting curve (the time-actual conductivity fitting curve below is a reference), divide the time-standard conductivity fitting curve into multiple curve segments, wherein the characteristic ratio of each curve segment is less than the first preset value, and the time of the curve segment is continuous. Step 012: Obtain the minimum slope of each curve segment 1, determine the curve segment 1 with a minimum slope greater than the minimum active slope threshold as the target curve segment 1, and determine the maximum end time of all target curve segment 1 as the first test duration. Step 013: Dissolve the sodium azide solid sample in the deionized water sample, then add the lead acetate trihydrate solid sample to the sodium azide solution, stir at room temperature for the first test time, and measure the conductivity multiple times to construct a time-actual conductivity fitting curve; the ratio of each sample meets the requirements, wherein the molar ratio of lead acetate trihydrate solid sample to sodium azide solid sample is 1:1; Step 014: Divide the time-actual conductivity fitting curve into multiple continuous curve segments (the time of curve segments two is continuous), and determine the curve segment two with the minimum slope greater than the minimum activity slope threshold as the target curve segment two; Step 015: Align the curve formed by segment one of the target curve with the curve formed by segment two of the target curve in time; analyze and determine the characteristic matching value, conductivity matching value, and slope matching variation value; determine the active state value based on the characteristic matching value, conductivity matching value, and slope matching variation value; issue an early warning when the active state value is not within the corresponding state value range.

[0055] Among them, the abscissa of the time-standard conductivity fitting curve and the time-actual conductivity fitting curve is the average time, and the time after adding lead acetate trihydrate solid to the solution is 0; The characteristic ratio is: |maximum slope of curve segment one (or two) - minimum slope of curve segment one (or two)| ÷ absolute value of the minimum slope of curve segment one (or two); The characteristic ratio of each curve segment 2 is less than the first preset value; The feature matching value S is the ratio of the average slope of curve segment two with the largest average slope to that of curve segment one with the largest average slope. The conductivity matching value U = the ratio of the final conductivity of segment two of the last target curve to the final conductivity of segment one of the last target curve.

[0056] Determine the slope matching variation value G; ; N represents the total number of all remaining target curve segments 2, excluding the target curve segment 2 with the largest average slope. The average slope of segment two of the i-th remaining target curve; The average slope of segment two of the target curve with the largest average slope; The average slope of segment one of the target curve with the largest average slope; The average slope of the time-standard conductivity fitted curve for the time segment of the i-th remaining target curve; Active state value = ; They are respectively The evaluation weights corresponding to U (all values ​​are greater than 0 and less than 1); The sum is 1; based on experimental production experience or general industry knowledge, the importance of each indicator in different reaction systems is judged to determine the weight; the more important it is, the larger the value.

[0057] The time-standard conductivity fitting curve is a curve obtained by fitting the "time-actual conductivity" when sodium azide and lead acetate trihydrate raw materials with superior / optimal activity are used, after experimental and historical production verification, and when step one (the key initial step in the preparation of pentaazole lead complex) is performed with satisfactory results. It serves as a "standard reference" for subsequent pre-reaction testing, reflecting the ideal law of conductivity change over time when high-quality raw materials participate in the reaction.

[0058] The first preset value ranges from 1 to 1.2, reflecting the stability of the conductivity change rate of each target curve segment 1. The minimum activity slope threshold is the average slope of the corresponding curve segment within the nearest preset time period (ranging from 3 min to 10 min) before the conductivity of the time-standard conductivity fitting curve finally remains unchanged (the stage where the reaction enters a stagnant or equilibrium state). The beneficial effects of the above technical solution are as follows: The time-standard conductivity fitting curve serves as an ideal reference for the reaction of "superior / optimal raw materials." It is a "benchmark" validated through experiments and historical production, accurately depicting the change in conductivity over time when high-quality raw materials participate in the reaction. This provides an absolute standard reference for subsequent activity testing of different batches of raw materials, ensuring a clear "high-quality benchmark" and avoiding ambiguity in judgment due to the lack of a standard, thus guaranteeing the accuracy of activity testing from the source. Its time anchoring method, which sets the time after the addition of lead acetate trihydrate to the solution as 0, completely aligns the time dimension of the actual reaction with the standard reaction, eliminating the interference of time misalignment on conductivity change analysis. This ensures strict comparability of the reaction processes of different batches of raw materials in the time dimension, providing a unified time benchmark for subsequent segmented matching, slope analysis, and other methods.

[0059] The characteristic ratio (maximum slope ÷ minimum slope of curve segments) requires that "the characteristic ratio of each curve segment 2 is less than the first preset value (greater than or equal to 1 and less than 1.2)", which can strictly limit the fluctuation range of the rate of change of conductivity. By screening out the raw material segments with stable reactivity from the "rate fluctuation dimension", the subsequent reaction can be prevented from getting out of control due to sudden increases or decreases in conductivity.

[0060] The feature matching value S focuses on the "curve segment with the largest average slope," which is the core manifestation of the most active phase in the reaction. By comparing the actual and standard average slopes of this phase, the "activity matching degree of the fastest reaction phase" can be accurately captured. If the matching degree is high, it indicates that the activity of the raw materials is consistent with that of high-quality raw materials during the most critical period of the reaction, providing a key guarantee for the subsequent reaction to achieve the expected high efficiency; if there is a mismatch, it can provide an early warning of "insufficient / excessive activity in the core reaction phase," facilitating timely intervention.

[0061] The conductivity matching value U is selected as the "final conductivity of the last target curve segment," which is a core indicator of the final state of the reaction, reflecting the total ion concentration and binding state of the system after the reaction. Matching the final conductivity indicates that the final ion equilibrium state of the actual reaction is consistent with that of a high-quality reaction, meaning that the final state of the product formation is stable. This ensures that the final state indicators such as the amount and purity of the pentazolium lead complex meet expectations, thus guaranteeing product quality from the "reaction endpoint dimension."

[0062] The slope matching variation value G analyzes the slope deviation from the standard for the remaining target segments excluding those with the highest average slope, covering the activity stability throughout the entire reaction cycle. The reaction is not limited to a single "maximum activity phase"; the activity stability of the remaining segments is equally crucial (e.g., a smooth transition in the middle stage and an orderly finish in the later stage). This value can detect "activity fluctuations in non-core segments." A small variation indicates that the activity of the raw materials consistently matches the standard throughout the reaction cycle, and the entire reaction process is controllable. A large variation can provide an early warning of "abnormal activity in localized stages of the reaction," facilitating targeted optimization (e.g., adjusting stirring, temperature, or other conditions at a specific stage).

[0063] By determining the maximum value of the end time of all target curve segments as the first test duration, it can be ensured that the pre-reaction test time covers the complete cycle of activity manifestation in the standard reaction.

[0064] Setting activity thresholds (such as minimum activity slope thresholds) provides a clear and objective standard for determining whether a curve segment belongs to the target curve segment. This eliminates interference from segments with excessively low slopes (insufficient reactivity) in determining the activity state, allowing activity analysis to focus on the effective reaction range and improving the accuracy of activity assessment.

[0065] An early warning is issued when the activity state value is outside the corresponding range, enabling timely detection of deviations from the standard reaction activity when raw material batches are changed. This warning is based on a comprehensive judgment of multi-dimensional indicators (characteristic matching value, conductivity matching value, and slope matching variation value), making it highly targeted and accurately indicating whether the problem lies in the core stage of the reaction, the final state, or overall stability, providing clear guidance for subsequent adjustments. Based on the specific characteristics of the characteristic matching value S, conductivity matching value U, and slope matching variation value G, adjustments can be made to the ratio of sodium azide solid sample to lead acetate trihydrate solid sample.

[0066] In one embodiment, when changing raw material batches, a second pre-reaction test is performed before step two. The second pre-reaction test includes: Step 021: First test: Add the solid sample of sodium pentaazole to the clear solution sample obtained based on the amount of raw materials used in Step 1 of the current batch production. After the sodium pentaazole sample is completely dissolved, control the cooling device of the reaction vessel (the reaction vessel for the second pre-reaction test) to make the cooling rate of the solution the first cooling rate. During the cooling process, the temperature and conductivity of the solution are detected simultaneously multiple times. Stir for a first time after cooling to the first temperature. During the first time, the temperature and conductivity of the solution are detected simultaneously multiple times. Step 022: Based on the temperature and conductivity detection results, construct the time-solution temperature fitting curve and the time-solution conductivity fitting curve (both x-axis are time, with the initial cooling time as 0). Combine the time-solution temperature fitting curve and the time-solution conductivity fitting curve to select the first effective time period of the cooling process, and combine the time-solution temperature fitting curve and the time-solution conductivity fitting curve to select the second effective time period of the isothermal process. Step 023: Align the time-temperature fitting curve and the time-conductivity fitting curve of the solution with time to obtain the time-temperature fitting curve and the time-conductivity fitting curve of the solution for the first effective time period, and the time-conductivity fitting curve of the solution for the second effective time period. Based on the time-solution temperature fitting curve and time-solution conductivity fitting curve of the first effective time period, and the time-solution conductivity fitting curve of the second effective time period, the temperature-conductivity coupling coefficient of each first effective time period and the temperature-conductivity coupling coefficient of the equivalent second effective time period are determined. Step 024: When any one of the temperature-conductivity coupling coefficients in the first effective time period or the equivalent temperature-conductivity coupling coefficient X in the second effective time period is abnormal, an alarm is triggered to remind the user to adjust the first cooling rate (first adjustment method: the adjustment direction for different temperature-conductivity coupling coefficient values ​​can be determined experimentally, and the cooling rate adjustment gradient can be set according to the value of the temperature-conductivity coupling coefficient to gradually adjust the temperature). An anomaly occurs when the temperature-conductivity coupling coefficient corresponding to the first effective time period exceeds a preset ratio (ranging from 0.4 to 0.7) and is outside the allowable range of the corresponding temperature-conductivity coupling coefficient. If the temperature-conductivity coupling coefficient of the equivalent second effective time period is not within the allowable range of the corresponding temperature-conductivity coupling coefficient, then it is abnormal; Optionally, the second adjustment method also uses the following method to adjust the first cooling rate: Obtain the equivalent arithmetic mean Y of the slopes of the temperature-conductivity coupling coefficients for all first effective time periods in step 023 (the number of positive slopes in the temperature-conductivity coupling coefficients for all first effective time periods is greater than the number of negative slopes, so the arithmetic mean of all positive slopes is the equivalent arithmetic mean; the number of positive slopes in the temperature-conductivity coupling coefficients for all first effective time periods is less than the number of negative slopes, so the arithmetic mean of all negative slopes is the equivalent arithmetic mean; if the number of positive slopes in the temperature-conductivity coupling coefficients for all first effective time periods is equal to the number of negative slopes, then the arithmetic mean of the slopes of the temperature-conductivity coupling coefficients for all first effective time periods is the equivalent arithmetic mean). Based on the current value of the first cooling rate, and according to the preset adjustment rules (i.e., through multiple sets of controlled variable experiments, the deviation range of the coupling coefficient between Y and the equivalent second effective time period was clarified, as well as the adjustment direction and specific adjustment value of the cooling rate corresponding to each range; for example, when the deviation is all in the "slight range", the cooling rate needs to be increased), the specific adjustment range is determined to obtain the adjusted first cooling rate, thereby ensuring that the solution crystallization process meets expectations and that the final pentaazole lead complex meets the requirements. The preset adjustment rules are derived from the summary of the system's historical experiments.

[0067] First cooling rate: Using sodium azide and lead acetate trihydrate raw materials with superior / optimal activity, after experimental and historical production verification, if step one (the key initial step in the preparation of pentaazole lead complex) is performed and the results are qualified, step two is continued. The cooling rate of the solution cooling process in the actual step when the product of step two is qualified is obtained, and the corresponding actual time-solution temperature fitting curve and actual time-solution conductivity fitting curve are obtained. Using the division form of step 023 above, the time-solution temperature fitting curve and time-solution conductivity fitting curve of the first effective time period and the time-solution conductivity fitting curve of the second effective time period are obtained. A cooling temperature segment is determined based on a first effective time period, and the average slope of the time-solution conductivity fitting curve corresponding to the cooling temperature segment is determined as the reference conductivity slope of the cooling segment. The average conductivity slope of the second effective time period is determined as the reference conductivity slope of the isothermal process.

[0068] The first effective time period is the solution cooling process. The slope fluctuation of the time-solution conductivity fitting curve must be less than the allowable fluctuation (the slope fluctuation is the standard deviation of the slope within the continuous time period ÷ the average slope of the continuous time period; the allowable fluctuation is 0.1). There can be multiple such continuous time periods (i.e., multiple first effective times). This indicates that the conductivity-related processes in the solution (such as ion migration, solvation, etc.) are in a relatively stable dynamic equilibrium state within this time period. There is no situation where the conductivity change rate fluctuates drastically due to local overheating, overcooling, or other abnormal factors. This can provide stable basic data for subsequent analysis of the impact of cooling on solution crystallization and other behaviors. At the same time, the initial stage of cooling should be excluded (when the solution has just entered the cooling process, the conductivity change rate may still be in an unstable transitional state).

[0069] The second effective time period: From the time-solution temperature fitting curve, select continuous time periods where the temperature is within the target isothermal temperature range (determined by the set isothermal center temperature and the allowable fluctuation range); at the same time, within these continuous time periods, the slope fluctuation of the time-solution conductivity fitting curve must be less than the allowable fluctuation (the slope fluctuation is the standard deviation of the slope within the continuous time period ÷ the average slope of the continuous time period; the allowable fluctuation is such as 0.01), and the stage at the end of the isothermal period where the conductivity hardly changes should be excluded; The temperature-conductivity coupling coefficient for each first effective time period is specifically as follows: ; The average slope of the time-solution conductivity fitting curve for the h-th first effective time period obtained in step 023; The reference conductivity slope for the temperature segment corresponding to the h-th first effective time period obtained in step 023; The temperature-conductivity coupling coefficient N for the equivalent second effective time period is calculated based on the following formula: ; The average slope is determined based on the time-solution conductivity fitting curve obtained in step 023 for the second effective time period. The slope of the baseline conductivity during the isothermal process; If the temperature-conductivity coupling coefficients for all first effective time periods and the equivalent temperature-conductivity coupling coefficients for the second effective time period are within the corresponding allowable range, then it is determined that the first cooling rate does not need to be adjusted.

[0070] The beneficial effects of the above technical solution are as follows: For step 20 (single test and data acquisition): By strictly controlling the cooling rate and simultaneously detecting temperature and conductivity multiple times, comprehensive and accurate raw data are provided for subsequent analysis. This ensures that subsequent process adjustments based on this data have a reliable basis and can truly reflect the changes in the solution during the cooling process, laying the foundation for the study and optimization of the crystallization process.

[0071] For step 21 (screening of effective time periods): Based on the temperature and conductivity fitting curves, the first effective time period of the cooling process and the second effective time period of the isothermal process are screened out. The initial unstable stage of cooling and the meaningless stage at the end of isothermal process are excluded. This ensures that the conductivity-related processes in the solution (such as ion migration and solvation) are in a relatively stable dynamic equilibrium state during the subsequent analysis period. This allows the analysis results to more accurately reflect the key stage characteristics of crystallization and to indicate the core effective range for process adjustment.

[0072] For step 22 (coupling coefficient calculation): calculate the temperature-conductivity coupling coefficient of the first effective time period and the equivalent second effective time period, quantify the relationship between temperature and conductivity, accurately capture the degree of influence of temperature on conductivity during cooling and isothermal stages, provide quantitative indicators for judging whether the crystallization process is normal and for subsequent cooling rate adjustment, and make process adjustment move from qualitative to quantitative, improving the accuracy of adjustment.

[0073] Regarding step 23 (abnormal alarm and rate adjustment): When the coupling coefficient is abnormal, an alarm is triggered and a reminder is given to adjust the first cooling rate. This can promptly detect abnormalities in the crystallization process and prevent product defects caused by the continued abnormality.

[0074] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A pentazolium lead complex, characterized in that: The molecular formula is Pb(N5)(N3), and its characterization is as follows: Decomposition peak temperature: 120℃; The characteristic wavenumbers detected by attenuated total reflectance infrared spectroscopy are: 3369.11, 3330.71, 3258.58, 3170.41, 1986.73, 1601.30, and 1214.97 cm⁻¹. -1 ; The characteristic wavenumbers detected by Raman spectroscopy excited by 785 nm near-infrared laser are: 226.17, 573.48, 1184.74, 1342.18, and 1481.11 cm⁻¹. -1 ; Elemental analysis: PbN8: calcd N 35.10%, Found: N 35.15%.

2. A method for preparing a pentazolium lead complex, used to prepare the pentazolium lead complex as described in claim 1, characterized in that: include: Step 1: At room temperature, dissolve sodium azide solid in deionized water, then add lead acetate trihydrate solid to the sodium azide solution. After stirring at room temperature for a second time, add saturated sodium acetate solution dropwise to the solution while continuing to stir until the solution becomes clear. Step 2: At room temperature, add sodium pentaazole solid to the clear solution obtained in Step 1, cool to the first temperature and stir for the first time, then filter to obtain a white lead pentaazole complex.

3. The method for preparing a pentazolium lead complex according to claim 2, characterized in that: The first temperature is 5~20℃, and the room temperature is 20~25℃.

4. The method for preparing a pentazolium lead complex according to claim 2, characterized in that: The first time duration is 15~24 h; the second time duration is 0.5~1 h; the stirring speed in step one is 300~500 r / min; the stirring speed in step two is 100~200 r / min.

5. The method for preparing a pentazolium lead complex according to claim 2, characterized in that: In step one: the ratio of sodium azide to deionized water is 0.1 mol : 20~30 mL.

6. The method for preparing a pentazolium lead complex according to claim 2, characterized in that: In step one, the molar ratio of lead acetate trihydrate to sodium azide is 1:1 to 1.

1.

7. The method for preparing a pentazolium lead complex according to claim 2, characterized in that: In step two, the molar ratio of sodium pentazolate to sodium azide is 1:

1.

8. The application of a pentazolium lead complex, characterized in that, When the pentaazole lead complex as described in claim 1 is used as a laser-initiated igniter, it can effectively initiate detonation with a laser energy ≥ 3 mJ.

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