Jiaping Zhu

Molecular dynamics simulations for 5,5′-bistetrazole-1,1′-diolate (TKX-50) and its PBXs

Molecular dynamics has been carried out to simulate the well-known new explosive compound 5,5′-bistetrazole-1,1′-diolate (TKX-50) and TKX-50 based polymer bonded explosives (PBXs) with four kinds of polymer binders, such as, fluorine (F2311), fluorine resin (F2641), polyethylene glycol (PEG) and ethylene-vinyl acetate copolymer (EVA). The isotropic mechanical properties (tensile modulus, bulk modulus, shear modulus and Poisson’s ratio), moldability, and bonding energy are reported for first time for TKX-50 crystal and TKX-50 based PBXs. The mechanical properties of the explosive can be effectively raised by adding polymer binders in small amounts and the ability of different polymer binders improving the plasticity of TKX-50 in the increasing order PEG > EVA > F2641 = F2311. The moldability of TKX-50 based PBXs is better than that of pure TKX-50, and the increasing order is PEG > EVA > F2311 > F2641. The interaction between each of the crystalline surfaces and each of the polymers is different, the order of the abilities of different binders to combine TKX-50 crystal decreases as follows: F2311 > PEG ≈ F2641 > EVA. The calculated detonation performances for pure TKX-50 and TKX-50 based PBXs show that both of them are comparable with those of HMX. Ultimately, as for the four polymer binders, PEG is considered the best one for explosive TKX-50.

A new multifunctional Schiff-based chemosensor for mask-free fluorimetric and colorimetric sensing of F− and CN−

A Schiff-based chemosensor DSS was designed for selective and simultaneous detection and/or determination of F(-) and CN(-) by distinguishable changes in both solution color and spectroscopic responses within same sample due to the strong emission enhancement at distinct emission bands without any mask. In addition, the sensing mechanism was evaluated by NMR titration and DFT calculations.

A simple ratiometric and colorimetric chemosensor for the selective detection of fluoride in DMSO buffered solution.

A derivative of squaramide (cyclobuta[b]quinoxaline-1, 2(3H, 8H)-dione) has been synthesized for the ratiometric and colorimetric sensing of F(-) in aqueous solution in competitive fashion. With F(-), probe 1 showed a highly selective naked-eye detectable color change along with a characteristic UV-Vis absorbance over other tested ions, which probably originates from the deprotonation occurred between 1 and F(-), as proved by the (1)H NMR titration experiments and DFT calculations.

Preparation, crystal structure, thermal behavior, and theoretical studies of N,N′-dinitro-4, 4′-azo-bis(1,2,4-triazolone) (DNZTO)

Abstract N,N′-Dinitro-4,4′-azo-bis(1,2,4-triazolone) (DNZTO) is synthesized by the reaction of 4,4′-azo-bistriazolone (ZTO) with a mixture of nitric acid and acetic anhydride. The product was fully characterized by IR, NMR, matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry, and single-crystal X-ray analysis. The explosive performance including detonation pressures (P), velocities (D) of DNZTO, and heats of formation were predicted using gaussian 09 at B3LYP/6-311+G**.

Crystal structure of tetraqua((E)-4,4′-(diazene-1,2-diyl)bis(5-oxo-4,5-dihydro-1,2,4-triazol-1-ide)-κ2N:O)barium(II), C4H10N8O6Ba

Abstract C4H10BaN8O6, triclinic, P1̅ (No. 2), a = 7.6249(18) Å, b = 7.8460(16) Å, c = 11.723(3) Å, α = 70.520(8)°, β = 85.079(10)°, γ = 64.007(7)°, V = 592.792 Å3, Z = 2, Rgt(F) = 0.0332, wRref(F2) = 0.0734, T = 153 K.

Crystal structure of poly[diaqua-µ2-(E)-5-oxo-4-((5-oxo-1,5-dihydro-4H- 1,2,4-triazol-4-yl)diazenyl)-4,5-dihydro-1,2,4-triazol-1-ide-κ3O:O:N) sodium], C4H7N8NaO4

Abstract C4H7N8NaO4, monoclinic, C2/c (no. 15), a = 19.42(2) Å, b = 6.514(5) Å, c = 15.38(1) Å, β = 93.23(2)°, V = 1942.9 Å3, Z = 8, Rgt(F) = 0.0631, wRref(F2) = 0.1660, T = 293 K.