Synthesis,characterization, crystal structure,and reactivity of heterobimetallic dioxovanadium(V) complexes containing multidentate hydrazone ligands

Two new heterobimetallic complexes of the composition [(VO₂)₂(μ₃-slsch){Na₂(μ-H₂O)₂(H₂O)₂}]_n (1) and [(VO₂)₂(μ₃-npsch){Na₂(μ-H₂O)₂(H₂O)₂}(DMF)]_n (2) were obtained by reaction of the ligand and vanadium pentoxide in a 1:1 molar ratio in methanol in the presence of Na₂CO₃ (2 equivalents). The complexes obtained were characterized using various spectroscopic studies. The structures of both the complexes were established by single crystal X-ray crystallographic study. We have also explored the catalytic behavior of the complexes in oxidative bromination of phenol red, which is the bio-inspired reaction catalyzed by an enzyme haloperoxidase.     

Peroxidative catalytic oxidation of alcohols catalyzed by heterobinuclear vanadium(V) complexes using H2O2 as terminal oxidizing agents

Here we report the catalytic oxidation of benzylic alcohol, hetero‐aryl alcohols and propargylic alcohols to their corresponding carbonyl compound using heterobimetallic sodium‐dioxidovanadium(V) complexes. The present catalytic oxidation studies proceed at 70 °C using H₂O₂ as terminal oxidant. During the whole process, the complexes react with hydrogen peroxide to form peroxo‐vanadium(V) species. The present study shows the heterogeneity of pre‐catalyst which could be easily recovered and moreover isolation of product is very simple.     

丙二酰二腙衍生的二氧化二钼(Ⅵ)配合物的合成、表征和晶体结构

本文报道了二氧杂钼(Ⅵ)配合物[MoO₂(H₂L)(H₂O)]的合成、表征和分子结构。该配合物是由马来酰二腙配体双(2-羟基-1-萘醛)丙二酰二腙(H₄L)与双(乙酰丙酮)二氧钼(Ⅵ)在甲醇中以1∶1的物质的量之比反应得到的。通过各种光谱(如IR、MS和NMR)对该配合物进行了表征。通过单晶X射线晶体学确定了配合物的结构。该配合物属于单斜晶系P2₁/c空间群。金属中心具有扭曲的八面体配位环境,与H₂L^2-的1个甲亚胺氮原子、2个末端氧基团、H₂L^2-的2个氧原子和配位水分子的1个氧原子相连。     

Numerical simulation of long-duration blast wave evolution in confined facilities

The objective of this research effort was to investigate the quasi-steady flow field produced by explosives in confined facilities. In this effort we modeled tests in which a high explosive (HE) cylindrical charge was hung in the center of a room and detonated. The HEs used for the tests were C-4 and AFX 757. While C-4 is just slightly under-oxidized and is typically modeled as an ideal explosive, AFX 757 includes a significant percentage of aluminum particles, so long-time afterburning and energy release must be considered. The Lawrence Livermore National Laboratory (LLNL)-produced thermo-chemical equilibrium algorithm, “Cheetah”, was used to estimate the remaining burnable detonation products. From these remaining species, the afterburning energy was computed and added to the flow field. Computations of the detonation and afterburn of two HEs in the confined multi-room facility were performed. The results demonstrate excellent agreement with available experimental data in terms of blast wave time of arrival, peak shock amplitude, reverberation, and total impulse (and hence, total energy release, via either the detonation or afterburn processes.