Molecular dynamics method was employed to study the binding energies of the selected crystal planes of the 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane（HMX）/1,3-dimethyl-2-imidazolidinone（DMI） cocrystal in differ...Molecular dynamics method was employed to study the binding energies of the selected crystal planes of the 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane（HMX）/1,3-dimethyl-2-imidazolidinone（DMI） cocrystal in different molecular molar ratios. The mechanical properties were estimated in different molar ratios. Solvent effects were evaluated and the cooperativity effects were discussed in the HMX···HF···DMI ternary by using the M06-2x/6-311＋G（2df,2p） and MP2（full）/6-311＋G（2df,2p） methods. The results indicate that the substituted patterns（020） and（100） own the highest binding energies. The stabilities of cocrystals in the 1：1 and 2：1 ratios are the greatest, and thus the HMX/DMI cocrystals prefer cocrystallizing in the 1：1 and 2：1 molar ratios, which have good mechanical properties. The sensitivity change of cocrystal originates from not only the formation of intermolecular interaction but also the increment of bond dissociation energy of the N–NO2 bond. The cooperativity effect appears in the linear complex while the anti-cooperativity effect is found in the cyclic system. DMI binding to HMX is not energetically and structurally favored in the presence of HF. This is perhaps the reason that the solvent with large dielectric constant weakens the stability of the HMX/DMI cocrystals. Therefore, the solvents with low dielectric constants should be chosen in the preparation of HMX/DMI cocrystals.展开更多
为设计硝基吡唑炸药经物理吸附方式进行废水处理的方案,借助DFT-M06-2X和MP2(full)方法在6-311++G(2d,p)基组水平上研究了Cl–···3,4-二硝基吡唑(3,4-DNP)自由基···H2O体系阴离子氢键诱导协同效应。结果...为设计硝基吡唑炸药经物理吸附方式进行废水处理的方案,借助DFT-M06-2X和MP2(full)方法在6-311++G(2d,p)基组水平上研究了Cl–···3,4-二硝基吡唑(3,4-DNP)自由基···H2O体系阴离子氢键诱导协同效应。结果表明,随着3,4-DNP自由基···H2O体系中Cl–的引入和三聚体的形成,不仅3,4-DNP自由基与H2O之间常规O–H···O和H–O···H氢键的距离、相互作用能、电子密度发生了较大改变,而且Cl–与3,4-DNP自由基或H2O之间形成的H···Cl–阴离子氢键与N···Cl–、C···Cl–、O···Cl–相互作用的相应值也发生了明显改变,从而导致了显著的阴离子氢键诱导协同或反协同效应,形成了稳定的复合物。由此可推断,依据阴离子诱导氢键协同效应,Cl–可用于硝基吡唑类炸药的废水处理。AIM (atom in molecules)、电子密度转移、RDG (reduced density gradient)和NBO (natural bonding orbital)分析揭示了协同效应的本质。展开更多
文摘Molecular dynamics method was employed to study the binding energies of the selected crystal planes of the 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane（HMX）/1,3-dimethyl-2-imidazolidinone（DMI） cocrystal in different molecular molar ratios. The mechanical properties were estimated in different molar ratios. Solvent effects were evaluated and the cooperativity effects were discussed in the HMX···HF···DMI ternary by using the M06-2x/6-311＋G（2df,2p） and MP2（full）/6-311＋G（2df,2p） methods. The results indicate that the substituted patterns（020） and（100） own the highest binding energies. The stabilities of cocrystals in the 1：1 and 2：1 ratios are the greatest, and thus the HMX/DMI cocrystals prefer cocrystallizing in the 1：1 and 2：1 molar ratios, which have good mechanical properties. The sensitivity change of cocrystal originates from not only the formation of intermolecular interaction but also the increment of bond dissociation energy of the N–NO2 bond. The cooperativity effect appears in the linear complex while the anti-cooperativity effect is found in the cyclic system. DMI binding to HMX is not energetically and structurally favored in the presence of HF. This is perhaps the reason that the solvent with large dielectric constant weakens the stability of the HMX/DMI cocrystals. Therefore, the solvents with low dielectric constants should be chosen in the preparation of HMX/DMI cocrystals.
文摘为设计硝基吡唑炸药经物理吸附方式进行废水处理的方案,借助DFT-M06-2X和MP2(full)方法在6-311++G(2d,p)基组水平上研究了Cl–···3,4-二硝基吡唑(3,4-DNP)自由基···H2O体系阴离子氢键诱导协同效应。结果表明,随着3,4-DNP自由基···H2O体系中Cl–的引入和三聚体的形成,不仅3,4-DNP自由基与H2O之间常规O–H···O和H–O···H氢键的距离、相互作用能、电子密度发生了较大改变,而且Cl–与3,4-DNP自由基或H2O之间形成的H···Cl–阴离子氢键与N···Cl–、C···Cl–、O···Cl–相互作用的相应值也发生了明显改变,从而导致了显著的阴离子氢键诱导协同或反协同效应,形成了稳定的复合物。由此可推断,依据阴离子诱导氢键协同效应,Cl–可用于硝基吡唑类炸药的废水处理。AIM (atom in molecules)、电子密度转移、RDG (reduced density gradient)和NBO (natural bonding orbital)分析揭示了协同效应的本质。
