Context Density functional theory (DFT) calculations at the M06-2X/def2-TZVP level were employed to design bis-six-membered nitrogen-rich fused ring energetic materials. Six neutral derivatives (I-2–4, I-3–4, I-3–5, II-2–4, II-3–4, and II-3–5) achieved energy densities exceeding 2.0 g/cm3, with energetic salts reaching unprecedented values up to 3.3 g/cm3. Non-covalent interaction isosurfaces quantified van der Waals forces in crystal packing, while decomposition pathway simulations for II-3–2 identified a low O-NO2 BDE (20.24 kcal/mol) coexisting with high thermal stability (<InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="894_2025_6453_Article_IEq1.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="25" /> </InlineMediaObject> <EquationSource Format="TEX">${T}_{\text{bp}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>T</mi> <mtext>bp</mtext> </msub> </math></EquationSource> </InlineEquation> = 765.3 °C), governed by autocatalytic kinetics (<InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="894_2025_6453_Article_IEq2.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="31" /> </InlineMediaObject> <EquationSource Format="TEX">$\Delta G$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi mathvariant="normal">Δ</mi> <mi>G</mi> </mrow> </math></EquationSource> </InlineEquation> = 24.7 kcal/mol and <InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="894_2025_6453_Article_IEq2.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="31" /> </InlineMediaObject> <EquationSource Format="TEX">$\Delta G$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi mathvariant="normal">Δ</mi> <mi>G</mi> </mrow> </math></EquationSource> </InlineEquation> = 8.44 kcal/mol). The DFT-derived performance matrix (<InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="894_2025_6453_Article_IEq4.gif" Format="GIF" Height="12" Rendition="HTML" Resolution="72" Type="Linedraw" Width="13" /> </InlineMediaObject> <EquationSource Format="TEX">$\rho$</EquationSource> <EquationSource Format="MATHML"><math> <mi>ρ</mi> </math></EquationSource> </InlineEquation> > 2.02 g/cm3, <InlineEquation ID="IEq5"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="894_2025_6453_Article_IEq1.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="25" /> </InlineMediaObject> <EquationSource Format="TEX">${T}_{\text{bp}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>T</mi> <mtext>bp</mtext> </msub> </math></EquationSource> </InlineEquation> > 600 °C, HOFs > 3500 kJ/mol) provides a transferable protocol for balancing energy and safety in molecular modeling of advanced energetics. Method The DFT-based geometric optimization and frequency analyses of the designed molecules were determined using M06-2x/def2-TZVP method at Gaussian 09 package suite of programs. The heats of formation (HOF) for all molecules were obtained using an atomization reaction. The kinetic energy (<InlineEquation ID="IEq6"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="894_2025_6453_Article_IEq6.gif" Format="GIF" Height="17" Rendition="HTML" Resolution="72" Type="Linedraw" Width="110" /> </InlineMediaObject> <EquationSource Format="TEX">$\Delta {E}_{\text{HOMO}-\text{LUMO}}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi mathvariant="normal">Δ</mi> <msub> <mi>E</mi> <mrow> <mtext>HOMO</mtext> <mo>-</mo> <mtext>LUMO</mtext> </mrow> </msub> </mrow> </math></EquationSource> </InlineEquation>), electrostatic potential (ESP), and other related calculations were computed using Multiwfn_3.8_dev software. The visualization of the weak interaction between dimers was accomplished using VMD 1.9.3 program.

Design and performance evaluation of nitrogen-rich bis-six-membered fused ring energetic materials via density functional theory

期刊论文
发表日期：

2025年8月1日

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Qian Zhang,
You-Xiang Guo,
Tao Long,
Lan-Ying Xu,
Yan Huang

摘要

Context

Density functional theory (DFT) calculations at the M06-2X/def2-TZVP level were employed to design bis-six-membered nitrogen-rich fused ring energetic materials. Six neutral derivatives (I-2–4, I-3–4, I-3–5, II-2–4, II-3–4, and II-3–5) achieved energy densities exceeding 2.0 g/cm³, with energetic salts reaching unprecedented values up to 3.3 g/cm³. Non-covalent interaction isosurfaces quantified van der Waals forces in crystal packing, while decomposition pathway simulations for II-3–2 identified a low O-NO₂ BDE (20.24 kcal/mol) coexisting with high thermal stability ( ${T}_{\text{bp}}$ $T_{bp}$ = 765.3 °C), governed by autocatalytic kinetics ( $\Delta G$ $Δ G$ = 24.7 kcal/mol and $\Delta G$ $Δ G$ = 8.44 kcal/mol). The DFT-derived performance matrix ( $\rho$ $ρ$ > 2.02 g/cm³, ${T}_{\text{bp}}$ $T_{bp}$ > 600 °C, HOFs > 3500 kJ/mol) provides a transferable protocol for balancing energy and safety in molecular modeling of advanced energetics.

Method

The DFT-based geometric optimization and frequency analyses of the designed molecules were determined using M06-2x/def2-TZVP method at Gaussian 09 package suite of programs. The heats of formation (HOF) for all molecules were obtained using an atomization reaction. The kinetic energy ( $\Delta {E}_{\text{HOMO}-\text{LUMO}}$ $Δ E_{HOMO - LUMO}$ ), electrostatic potential (ESP), and other related calculations were computed using Multiwfn_3.8_dev software. The visualization of the weak interaction between dimers was accomplished using VMD 1.9.3 program.