Theoretical Studies on Intermolecular Interactions of 4-Amino-5-nitro-1,2,3-triazole Dimers

Seven optimized configurations and their electronic structures of 4-amino-5-nitro- 1,2,3-triazole dimers on their potential energy surface have been obtained by using density functional theory （DPT） method at the B3LYP/6-311＋＋G＊＊ level. The maximum intermolecular interaction energy is -35.42 kJ/mol via the basis set superposition error-correction （BSSE） and zero point energy-correction （ZPE）. Charge transfers between the two subsystems are small. The vibration analysis of optimized configurations was performed, and the thermodynamic property changes from monomer to dimer have been obtained with the temperature ranging from 200 to 800 K on the basis of statistical thermodynamics. It is found that the hydrogen bonds contribute to the dimers dominantly, and the extent of intermolecular interaction is mainly determined by the hydrogen bonds＇ strength rather than their number. The dimerization processes of Ⅳ, Ⅴand Ⅵ can occur spontaneously at 200 K.

Crystal Structure and Thermal Decomposition Kinetics of 3-Nitro-4-diazo-5-oxygenpyrazole

A novel compound 3-nitro-4-diazo-5-oxypyrazole was synthesized by the nitration of 4-amino-3,5-dinitropyrazole using nitrification agents of fuming nitric acid and trifluoroacetic anhydride. The compound was purified by column chromatography and characterized by IR, NMR, MS and elemental analysis. Two different single crystals obtained by culturing with ethyl acetate as a solvent were measured by X-ray single-crystal diffractometer. The molecular weight of C3HN5O3 is 155.09 and the two crystals belong to monoclinic system, space groups P21/n and P21/c. For 1： a = 5.5007（2）, b = 9.0691（4）, c = 11.4158（4） A, β = 92.710°, V = 568.85 A3, Z = 4, Dc = 1.811 g/cm3, μ = 0.162 mm-1, F（000） = 312 and the final deviation factor is 0.0213. Crystals 1 and 2 have similar unit cell parameters, except that a = 10.1828（12）, b = 5.5925（6）, c = 10.5574（10） A and β = 108.330（4）° in crystal 2. The thermal behavior of the compound was studied by TG-DSC and melting endothermic peak and decomposition exothermic peak are at 425.7 and 534.5 K in DSC curve. The activation energy and pre-exponential factor of the exothermic decomposition reaction of the title compound obtained by Kissinger method and Flynn-Wall-Ozawa method are 50.38 k J/mol, 4.59 × 1022 s^（-1） and 55.89 k J/mol.

Non-isothermal Kinetics of the Thermal Decomposition of 3-Nitro-1,2,4-triazol-5-one Magnesium Complex

The thermal decomposition of 3-nitro-1,2,4-triazol-5-one magnesium complex and its kinetics were studied under the non-isothermal condition by DSC and TG/DTG methods. The kinetic parameters were obtained from analysis of the DSC and TG/DTG curves by the Kissinger method,the Ozawa method,the differential method and the integral method. The most probable mechanism functions for the thermal decomposition of the first stage,the second stage and the third stage were suggested by comparing the kinetic parameters. The entropy of activation (ΔS ≠),enthalpy of activation (ΔH ≠) and free energy of activation (ΔG ≠) at Tpdo are -66.74 J·mol -1 ·K -1 ,119.2 kJ·mol -1 and 152.44 kJ·mol -1 ,respectively.

Molecular Design and Property Prediction of High Density 4-Nitro-5-(5-nitro-1,2,4-triazol-3-yl)-2H-1,2,3-triazolate Derivatives as the Potential High Energy Explosives

To search for potential energetic materials with large energy density and acceptable thermodynamics and kinetics stability,twelve derivatives of 4-nitro-5-(5-nitro-1,2,4-triazol-3-yl)-2H-1,2,3-triazolate(named A~L)are designed and analyzed by using density functional theory(DFT)calculations at the B3LYP/6-311G**level of theory.The molecular heats of formation(HOF),electronic structures,impact sensitivity(H_(50)),oxygen balance(OB)and density(ρ)are investigated by isodesmic reaction method and physicochemical formulas.Furthermore,the detonation velocity(D)and detonation pressure(P)are calculated to study the detonation performance by Kamlet-Jacobs(K-J)equation.These results show that new molecule J(H_(50)=36.9 cm,ρ=1.90g/cm^(3),Q=1912.46 cal/g,P=37.82 GPa,D=9.22 km/s,OB=0.00),compound A(H_(50)=27.9 cm,ρ=1.93 g/cm^(3),Q=1612.93 cal/g,P=38.90 GPa,D=9.19 km/s)and compound H(H_(50)=37.3 cm,ρ=1.97 g/cm^(3),Q=1505.06cal/g,P=37.20 GPa,D=9.01 km/s)present promising effects that are far better RDX and HMX as the high energy density materials.Our calculations can provide useful information for the molecular synthesis of novel high energy density materials.

A novel derivative of Genistein inhibits proliferation of ovarian cancer HO-8910 cells by regulating reactive oxygen species

Objective To investigate the anticancer effect of a novel derivative of genistein(5-hydroxy-4’-nitro-7-propionyloxy-genistein,HNPG)on human ovarian cancer HO-8910 cells and its possible molecular mechanism.Methods HO-8910 cells were cultured in vitro,and the inhibitory effect of HNPG on proliferation was determined using MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]assay.The effect of HNPG on inducing apoptosis was examined using FCM with Annexin V-FITC and propidium iodide staining.The effect of HNPG on regulating reactive oxygen species(ROS)was measured using FCM with 2’,7’-di chlorodihydro-fluorescein diacetate staining.The effect of HNPG on modulating mitochondrial membrane potential(MMP)was determined using FCM with lipophilic cationic dye 2(6 Amino 3 imino 3H xanthen 9 yl)benzoic acid methyl ester(Rh123)staining.The bioactivity of superoxide dismutase(SOD)and catalase(CAT)and the content of glutathione(GSH)and malondialdehyde(MDA)were detected using enzymelinked immunosorbent assay.The related apoptotic proteins,including bcl-2,bax,cyt-c,and cleavedcaspase-3,were assessed using western blotting.Results HNPG exhibited dramatic antitumor activity against HO-8910 cells in vitro,inhibited proliferation,and induced apoptosis in a time-and dose-dependent manner.These effects were accompanied by reduced bioactivity of SOD and CAT,reduced GSH content,and enhanced MDA content.Simultaneously,the amount of ROS was increased and the level of MMP was reduced,along with upregulation of mitochondrial apoptosis pathway-related proteins,bax,cyt-c,and cleaved-caspase-3;bcl-2 protein was downregulated.Conclusion HNPG inhibited proliferation of human ovarian cancer HO-8910 cells in vitro,which might be related to decreased bioactivity of SOD and CAT.HNPG also reduced GSH content,which resulted in ROS accumulation in cells,damaged the integrity of mitochondrial membrane,and induced cell apoptosis.

Theoretical Study on the Nitrogen-rich Derivatives Based on 1,2,4-Triazole and 1,2,3-Triazole Rings:an Extended Family of Power Performance Energetic Materials

The geometric and electronic structures of the derivatives of 4-nitro-5-(5-nitroimino-1,2,4-triazol-3-yl)-2H-1,2,3-triazolate(named A~J)are explored employing density functional theory(DFT)calculations at the B3LYP/6-311G^(**)level of theory.Based on the optimized molecular structures,the heats of formation(HOF)are obtained,and the electronic properties,density and molecular sensitivity by characteristic heights(H_(50))are discussed.Besides,the detonation performances(detonation velocity,detonation pressure)are estimated via Kamlet-Jacobs(K-J)formula.Compounds B(H50=29.4 cm,ρ=1.91 g/cm^(3),Q=1563.04 cal/g,P=36.05 GPa,D=8.95 km/s)and H(H_(50)=31.9 cm,ρ=1.80 g/cm^(3),Q=1610.09 cal/g,P=37.31 GPa,D=9.12 km/s)have positive HOFs and remarkable insensitivity and good detonation performance,strongly suggesting them as the acceptable new-type explosive.The initiating power surpasses conventional primary explosives,such as HMX.The outstanding detonation power of compounds B and H contributes to its future prospects as a promising green primary explosive.

Designing energetic covalent organic frameworks for stabilizing high-energy compounds

As an emerging high-energy compound,3-nitro-1,2,4-triazol-5-one(NTO)is used in military explosives and rocket propellants.However,the strong acidic corrosion of NTO,and the high sensitivity and poor thermostability of its salts,severely restrict their practical applications.Therefore,a novel strategy to design and construct energetic covalent organic frameworks(COFs)is proposed in this study.We have successfully prepared a two-dimensional crystalline energetic COF(named ECOF-1)assembled from triaminoguanidine salt,in which NTO anions are trapped in the porous framework via the ionic interaction and hydrogen bonds.The results show that ECOF-1 exhibits superior thermal stability than energetic salt of NTO.It also exhibits insensitivity and excellent heat of detonation of 7,971.71 kJ·kg−1.ECOF-1 greatly inhibits the corrosiveness of NTO.In prospect,energetic COFs are promising as a functional platform to design high-energy and insensitive energetic materials.