Haixia Ma

Preparation, non-isothermal decomposition kinetics, heat capacity and adiabatic time-to-explosion of NTO·DNAZ

NTOxDNAZ was prepared by mixing 3,3-dinitroazetidine (DNAZ) and 3-nitro-1,2,4-triazol-5-one (NTO) in ethanol solution. The thermal behavior of the title compound was studied under a non-isothermal condition by DSC and TG/DTG methods. The kinetic parameters were obtained from analysis of the DSC and TG/DTG curves by Kissinger method, Ozawa method, the differential method and the integral method. The main exothermic decomposition reaction mechanism of NTOxDNAZ is classified as chemical reaction, and the kinetic parameters of the reaction are E(a)=149.68 kJ mol(-1) and A=10(15.81)s(-1). The specific heat capacity of the title compound was determined with continuous C(p) mode of microcalorimeter. The standard mole specific heat capacity of NTOxDNAZ was 352.56 J mol(-1)K(-1) in 298.15K. Using the relationship between C(p) and T and the thermal decomposition parameters, the time of the thermal decomposition from initialization to thermal explosion (adiabatic time-to-explosion) was obtained.

Synergistic actions between tebuconazole ligand and Cu(II) cation: reasons for the enhanced antifungal activity of four Cu(II) complexes based on the fungicide tebuconazole

Four Cu(II) complexes, namely, [CuL2(SO4)(DMF)]n1, [CuL2(CH3COO)2] 2, [CuL4Cl2]·2DMF·3H2O 3 and [CuL4(ClO4)2] 4, (L = ((RS)-1-(4-chloro-phenyl)-4,4-dimethyl-3-(1,2,4-triazole-1-ylmethyl)pentan-3-ol), tebuconazole) have been synthesized and their structures were identified by elemental analysis (EA), infrared (IR) spectroscopy and single crystal X-ray diffraction (XRD). Moreover, the four obtained complexes were screened for antifungal activities against four selected fungi using the mycelial growth rate method. Structural analysis indicates that the different coordination modes of the ligands and counter anions contribute to a one-dimensional polymer chain structure in complex 1 and zero-dimensional mononuclear structures in complexes 2–4. The results of the antifungal activities show that all the complexes synthesized show better antifungal activities than the ligand L. In addition, the mechanism of the increased antifungal activities of the title complexes in comparison with the ligand was discussed preliminarily and the synergistic interaction between Cu2+ and tebuconazole was also investigated by the Wadley approach.

Synthesis, crystal structure, biological activity and theoretical calculations of novel isoxazole derivatives.

Series of isoxazole derivatives were synthesized by substituted chalcones and 2-chloro-6-fluorobenzene formaldehyde oxime with 1,3-dipolar cycloaddition. The target compounds were determined by melting point, IR, (1)H NMR, elemental analyses and HRMS. The crystal structure of compound 3a was detected by X-ray diffraction and it crystallizes in the triclinic space group p2(1)/c with z=4. The molecular geometry of compound 3a was optimized using density functional theory (DFT/B3LYP) method with the 6-31G+(d,p) basis set in the ground state. From the optimized geometry of the molecule, FT-IR, FT-Raman, HOMO-LUMO and natural bond orbital (NBO) were calculated at B3LYP/6-31G+(d,p) level. Finally, the antifungal activity of the synthetic compounds were evaluated against Pythium solani, Gibberella nicotiancola, Fusarium oxysporium f.sp. niveum and Gibberella saubinetii.

Molecular structure and thermal behavior of N-Benzoyl-3,3-dinitroazetidine

N-Benzoyl-3,3-dinitroazetidine (BDNAZ) has been synthesized and characterized by elemental analysis, FT-IR spectroscopy, 1H NMR and X-ray single crystal diffraction technique. BDNAZ crystallizes in the monoclinic space group P21/c. Its thermal behavior was studied under a non-isothermal condition by DSC and TG/DTG methods, the value of Ea and A of the exothermic decomposition reaction of BDNAZ are 143.19 kJ mol−1 and 1014.34 s−1, respectively. The specific heat capacity of BDNAZ was determined with a continuous Cp mode of micro-calorimeter and theoretical calculation. The adiabatic time-to-explosion was evaluated as 109.9–124.4 s.

A new Co(II) complex of diniconazole: synthesis, crystal structure and antifungal activity.

A new Co(II) complex of diniconazole, namely diaqua[(E)-(RS)-1-(2,4-dichlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl-κN(4))pent-1-en-3-ol]cobalt(II) dinitrate dihydrate, [Co(C15H17Cl2N3O)3(H2O)2](NO3)2·2H2O, was synthesized and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Crystal structural analysis shows that the centrosymmetric Co(II) cation is coordinated by four diniconazole ligands and two water molecules, forming a six-coordinated octahedral structure. There are also two free nitrate counter-anions and two additional solvent water molecules in the structure. Intermolecular O-H...O hydrogen bonds link the complex cations into a one-dimensional chain. In addition, the antifungal activity of the complex against Botryosphaeria ribis, Gibberella nicotiancola, Botryosphaeria berengriana and Alternariasolani was studied. The results indicate that the complex shows a higher antifungal activity for Botryosphaeria ribis and Botryosphaeria berengriana than diniconazole, but a lower antifungal activity for Gibberella nicotiancola and Alternariasolani.

Thermal Properties of 1-Amino-1-hydrazino-2,2-dinitroethylene Cesium Salt

A new high-energy organic cesium salt, 1-amino-1-hydrazino-2,2-dinitroethylene cesium salt [Cs(AHDNE)], was synthesized by reacting of 1-amino-1-hydrazino-2,2-dinitroethylene (AHDNE) and cesium chloride in alkali methanol aqueous solution. The thermal behavior and nonisothermal decomposition kinetics of Cs(AHDNE) were studied. The kinetic equation obtained is . The self-accelerating decomposition temperature (TSADT) and critical temperature of thermal explosion (Tb) of Cs(AHDNE) are 152.9 and 163.5°C, respectively. The specific heat capacity of Cs(AHDNE) was determined with a micro-differential scanning calorimetry (DSC) method, and the molar heat capacity was 223.62 J mol−1 K−1 at 298.15 K. The adiabatic time to explosion of Cs(AHDNE) was 93.5 s. Cs(AHDNE) has higher thermal stability than AHDNE. Cs(AHDNE) is sensitive to impact and friction.

1-(2,4-Dinitro-phen-yl)-3,3-dinitro-azetidine.

In the title compound, C9H7N5O8, the dihedral angle between the mean plane of the azetidine ring and that of the benzene ring is 26.1 (1)°; the planes of the two nitro groups of the azetidine ring are aligned at 88.7 (1)°.

Two novel Co(II) and Ni(II) complexes of tebuconazole with enhanced antifungal activities

Two transition metal complexes, [CoL4Cl2]·4MeOH 1 and [NiL4Cl2]·4MeOH 2 (L = (RS)-1-(4-chloro-phenyl)-4,4-dimethyl-3-(1,2,4-triazole-1-ylmethyl)pentane-3-ol), tebuconazole were synthesized and their structures were determined using single crystal X-ray diffraction (XRD). Crystal structural analysis shows that complexes 1 and 2 have similar structures, both with the metal cation lying on a crystallographic inversion center and coordinated with four triazole groups and two chloride anions. The antifungal activities of L and its complexes against four selected plant pathogenic fungi were evaluated. The results show that both complexes have stronger bioactivities than the ligand L and that complex 2 has slightly higher bioactivities than complex 1. To elucidate the mechanisms behind the increased antifungal activities of the title complexes in comparison with L, cumulative release studies in static water and theoretical investigations of the complexes were carried out. The results indicate that there are three factors contributing to the enhanced bioactivities: attractive controlled release properties, synergic interaction between metal cations and L, and improved penetration into the lipid membranes.

Synthesis, crystal structure and antifungal activity of a divalent cobalt(II) complex with uniconazole.

Azole compounds have attracted commercial interest due to their high bactericidal and plant-growth-regulating activities. Uniconazole [or 1-(4-chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)pent-1-en-3-ol] is a highly active 1,2,4-triazole fungicide and plant-growth regulator with low toxicity. The pharmacological and toxicological properties of many drugs are modified by the formation of their metal complexes. Therefore, there is much interest in exploiting the coordination chemistry of triazole pesticides and their potential application in agriculture. However, reports of complexes of uniconazole are rare. A new cobalt(II) complex of uniconazole, namely dichloridotetrakis[1-(4-chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl-κN(4))pent-1-en-3-ol]cobalt(II), [CoCl2(C15H18ClN3O)4], was synthesized and structurally characterized by element analysis, IR spectrometry and X-ray single-crystal diffraction. The crystal structural analysis shows that the Co(II) atom is located on the inversion centre and is coordinated by four uniconazole and two chloride ligands, forming a distorted octahedral geometry. The hydroxy groups of an uniconazole ligands of adjacent molecules form hydrogen bonds with the axial chloride ligands, resulting in one-dimensional chains parallel to the a axis. The complex was analysed for its antifungal activity by the mycelial growth rate method. It was revealed that the antifungal effect of the title complex is more pronounced than the effect of fungicide uniconazole for Botryosphaeria ribis, Wheat gibberellic and Grape anthracnose.

Molecular structure, quantum chemical investigation, and thermal behavior of (DNAZ-CO)2

Bis-(3,3-dinitroazetidinyl)-oxamide ((DNAZ-CO)2) is an acyl derivative of 3,3-dinitroazetidine (DNAZ). It is prepared and its crystal structure is determined. The crystal is orthorhombic, Fdd2 space group, a = 13.136(14) Å, b = 19.48(3) Å, c = 10.326(14) Å, V = 2642 (6) Å3, Z = 8. A density functional theory (DFT) method of the Amsterdam Density Functional (ADF) package is used to calculate the geometry, frequencies, and properties. The optimized geometry, frontier orbital energy, and main atomic orbital percentage are obtained. The thermal behavior is studied under a non-isothermal condition by DSC and TG/DTG methods. The apparent activation energy (Ea) and pre-exponential factor (A) of the exothermic decomposition reaction of (DNAZ-CO)2 are 164.10 kJmol−1 and 1013.38 s−1 respectively. The critical temperature of thermal explosion is 272.20°C. The values of ΔS≠, ΔH≠, and ΔG≠ of this reaction are 6.44 Jmol−1·K−1, 163.76 kJmol−1 and 160.34 kJmol−1 respectively.