Figures (10)  Tables (8)

    • Figure 1. 

      DSC heat flow curves for H4-PTZ at 2.0, 5.0, 8.0, 10.0, and 15.0 °C·min−1.

    • Figure 2. 

      Conversion rate data for H4-PTZ at 2.0, 5.0, 8.0, 10.0, and 15.0 °C·min−1.

    • Figure 3. 

      Regression of H4-PTZ using Starink method.

    • Figure 4. 

      Dependence between activation energy and conversion rate.

    • Figure 5. 

      Scatter diagrams of the experimental y'(α) and corresponding fitting curves.

    • Figure 6. 

      Optimized configuration of H4-PTZ (Note: The atomic number in the molecule has been labeled, and there are the same number of atoms).

    • Figure 7. 

      Potential electrostatic distribution of H4-PTZ (Note: Blue represents a positive electrostatic potential and red represents a negative electrostatic potential).

    • Figure 8. 

      The reasonable initiation reactions and corresponding decomposition pathways of H4-PTZ. (a) Representing four superficially reasonable initiation reactions; (b) corresponding ecomposition pathways.

    • Figure 9. 

      Optimized configuration and bond lengths (Å) of transition states and products at B3LYP/6-311+G(d, p) level.

    • Figure 10. 

      Energy barriers corresponding to four decomposition reaction pathways.

    • Β (°C·min–1)T0 (°C)Tp (°C)Tend (°C)ΔHd (J/g)
      2249.03251.3253.31147.33
      5258.19261.45264.71055.02
      8262.71267.38272.88924.26
      10264.03268.78273.581084.23
      15270.07275.37284.96929.36

      Table 1. 

      Thermal decomposition parameters at different heating rates for H4-PTZ.

    • KissingerOzawa
      Eα (kJ·mol–1)lnA (s–1)Eα (kJ·mol–1)
      Tp194.3542.82193.29
      T0––220.07

      Table 2. 

      Apparent activation energy using different methods.

    • No.Expression of f(α)No.Expression of f(α)
      1αm6(1–α)n[–ln(1–α)]p
      2(1–α)n7(1–α)m[1–(1–α)n]p
      3[–ln(1–α)]p8(1–α)m[(1–α)n–1]p
      4αm(1–α)n9n(1–α)[–ln(1–α)]1–1/n
      5αm[–ln(1–α)]p10(1–α)n(1+kα)

      Table 3. 

      Several common forms of f(α).

    • Eoe
      (kJ·mol−1)      		Eop
      (kJ·mol−1)      		Te0
      (°C)      		Tp0
      (°C)      		TSADT
      (°C)      		TTIT
      (°C)      		Tb
      (°C)
      5-(4-Pyridyl)tetrazolate220.07193.29244.15245.32244.15254.68257.43

      Table 4. 

      Thermal safety evaluation parameters.

    • ΔS≠ (J·mol−1·K−1)ΔH≠ (kJ·mol−1)ΔG≠ (kJ·mol−1)
      5-(4-Pyridyl)tetrazolate106.52194.35139.13

      Table 5. 

      Thermodynamic parameters.

    • AtomChargeAtomCharge
      N1−0.219N9−0.285
      N2−0.111C10+0.071
      N3−0.010C11−0.123
      N4−0.266H12+0.260
      C5+0.352H13+0.117
      C6−0.070H14+0.115
      C7−0.122H15+0.113
      C8+0.071H16+0.108

      Table 6. 

      Mulliken atomic charges of H4-PTZ at B3LYP/6-311G(d, p) level(e).

    • TSTS1TS2TS3TS4
      Frequencies517.64i438.40i450.68i1744.57i

      Table 7. 

      Negative imaginary frequencies of transition states at B3LYP/6-311+G(d, p) level (cm−1).

    • E/B2PLYPZPE/B3LYPEtot
      R−504.5296620.082568−504.447094
      TS1−504.4171690.074990−504.342179
      TS2−504.4523780.075044−504.377334
      TS3−504.3446750.073984−504.270691
      TS4−504.4320170.075664−504.356353
      P1−504.4895910.055047−504.434544
      P2−504.5075720.054567−504.453005
      P3−504.4556780.048981−504.406697
      P4−504.5247420.081559−504.443183

      Table 8. 

      Energy values of H4-PTZ and each stagnation points (Hartree).