川北某黑色页岩型铼矿工艺矿物学研究

通过矿相显微镜、扫描电镜、电子探针、X射线能谱元素面分析等多种手段综合研究了川北某黑色页岩型铼矿中铼的赋存状态。样品为黑色页岩,有机碳含量较高。粘土矿物总量为14.6%,黄铁矿含量16.2%,石英含量37.7%。样品具典型的粘土结构,矿物粒度微细。铼有两种赋存状态,一种呈类质同象形式赋存于黄铁矿内,另一种则以分散形式存在。典型黄铁矿测点Re平均含量为0.024%。黄铁矿是Re的重要载体矿物。建议通过浮选分离黄铁矿,从而实现Re的富集。      

High efficient OLEDs based on novel Re(I) complexes with phenanthroimidazole derivatives

Novel rhenium(I) [Re(I)] complexes with phenanthroimidazole ligands were successfully designed, synthesized and characterized. The Re(I) complexes displayed intense phosphorescence with yellow or orange color around 540–580 nm at room temperature with relatively short lifetimes. The phosphorescent simple-structure OLEDs using these Re(I) complexes as dopants exhibited low turn-on voltage of 3.5–3.6 V, maximum current efficiencies of 18.7–21.1 cd A⁻¹ and maximum power efficiencies of 13.3–18.9 lm W⁻¹, which were amongst the highest reported for OLEDs based on Re(I) complexes with phenanthroline ligands as emitters. The excellent performances are due to the bulky steric Re(I) complexes with short lifetime and good electron-transporting ability, which may improve the electron injection and result in greater balance between electron and hole fluxes. The results suggest that these complexes have potential application in OLEDs.     

从铜冶炼烟气酸洗液中分离富集铼

铜冶炼烟气酸洗液经D296阴离子交换树脂吸附后,再依次采用氨水解吸Sb,NaOH和酒石酸混合溶液解吸Bi,NH₄SCN溶液解吸Re,实现Re/Sb/Bi的分步解吸并获得铼富集液。结果表明：酸洗液电位对Re、Sb、Bi吸附率没有明显影响,适宜的酸洗液H₂SO₄浓度为43.81 g·L^-1,Re、Sb、Bi吸附率分别为100%、6.55%和89.05%;D296树脂吸附Re的穿透容量和饱和容量分别为1.308和1.773 g·L^-1,且树脂利用率为73.77%;先采用12.5%氨水解吸Sb,16%NaOH+140 g·L^-1酒石酸混合溶液解吸Bi,通过添加酒石酸可有效抑制Bi水解,再采用10%NH₄SCN溶液解吸Re,得到铼富集液,其Cu、As、Sb、Bi浓度均降至1 mg·L^-1以下,且使酸洗液中Re富集了4倍。     

Formation of rhenium diboride via mechanochemical–annealing processing of Re and B

Rhenium diboride (ReB₂) powder was prepared by mechanochemical processing of Re–B powder mixtures with subsequent annealing at temperatures of 600 °C to 1200 °C. Reactive evolution during the synthesis was investigated; furthermore, the effects of the amount of excess B on the reactions that occurred during the synthesis were assessed. The substantial reaction of Re with B occurred at 700 °C to form Re₇B₃ with a small amount of ReB₂. At 800 °C, Re₇B₃ converted into ReB₂; this conversion was enhanced with increasing temperature and increasing amount of excess B. At 1000 °C or above, single-phase ReB₂ powder without trace quantities of Re₇B₃ was obtained for compositions with 15 wt% or greater excess B. The synthesized ReB₂ powder particles were submicrometer with the vast majority being ∼500 nm. In addition, the resulting ReB₂ powders were consolidated by hot pressing or spark plasma sintering to examine the sinterability of the powders.     

铼(Ⅶ)催化烯丙醇移位/去对称化串联反应

使用Re_2O_7和手性磷酸为共催化剂,实现了催化不对称的环己二烯酮烯丙醇移位/氧杂-Michael加成串联反应。通过这一反应,可以一步构建带有三个手性中心的环己烯酮骨架结构,为合成带有这一类骨架的天然产物和药物分子提供了高效的合成方法。同时,通过分析条件的优化,找到了合适的手性拆分条件,为光学活性环己烯酮化合物提供了分析方法。     

Influence of preparation method on the catalytic performances of Re2O7/SiO2-Al2O3 catalysts in the metathesis of ethylene and 2-pentene

The metathesis of ethylene and 2-pentene for propylene production was investigated over Re₂O₇/SiO₂-Al₂O₃ catalysts. The SiO₂-Al₂O₃ (50 wt% Al₂O₃) were obtained by co-precipitation, physical mixing, and sol–gel coating. The presence of isolated layers/grains γ-Al₂O₃ either in bulk (physical mixing) or on the surface (sol–gel coating) resulted in isomerization-free metathesis. On the contrary, the Re₂O₇ catalysts supported on co-precipitated SiO₂-Al₂O₃ or the direct synthesis showed both metathesis and double-bond shift isomerization activities and as a consequence, higher propylene yield was obtained via the secondary metathesis reaction. The catalytic properties were also correlated with the Al-atom rearrangements and the acidic characters/strengths.     

ICP-AES法快速测定铜冶炼废酸中铼、钼、硒含量的研究

采用硝酸处理试样,建立电感耦合等离子体发射光谱法同时测定铜冶炼废酸中铼、钼、硒含量的分析方法。通过实验选择各元素最佳分析谱线,并对基体干扰进行探讨。在选定的实验条件下,方法的检出限为0.6～7.0ng/mL,加标回收率为95.24%~104.83%。该方法应用于三种废酸中三种元素的分析,相对标准偏差为0.26%~4.67%。     

Electrochemical synthesis and characterization of mixed molybdenum-rhenium oxides

The electrodeposition of Mo_xRe_1−xO_y films (0.6 ≤ x ≤ 1) on indium-tin oxide (ITO) coated glass substrates from acidic peroxo-polymolybdo-perrhenate solutions is described. Trends in film growth were established as a function of potential from +0.4 V to −0.7 V vs Ag/AgCl by analyzing the composition and stoichiometry of the deposit using inductively coupled plasma mass spectrometry (ICPMS) and X-ray photoelectron spectroscopy (XPS). These experiments show that the concentration of rhenium increases linearly with the deposition potential and that the deposits are mixed-valent containing up to five different metal oxidation states (i.e., Mo^IV, Mo^V, Mo^VI, Re⁰, Re^IV). Electroanalytical techniques were used to explore the deposition mechanism, including chronocoulometry, cyclic voltammetry, spectroelectrochemistry, and electrochemical quartz crystal nanogravimetry (EQCN). At potentials positive to −0.26 V, perrhenate (Re^VIIO₄⁻) behaves as a redox mediator to accelerate the deposition of a mixed-valent molybdenum oxide, but at more negative potentials mixed molybdenum-rhenium oxides are produced.     

Synthesis and electrochemiluminescence studies of tricarbonylrhenium(I) complexes with a cationic 2,2′-bipyridyl ligand

Two new rhenium(I) carbonyl complexes with cationic 2,2′-bipyridyl ligands were synthesized and characterized. The electrogenerated chemiluminescence (ECL) of the rhenium(I) carbonyl complexes was first investigated in aqueous solution using the co-reactant tri-n-propylamine (TPrA). The ECL behavior of the complexes was also studied in the presence of several surfactants. The oxidation of both TPrA and the rhenium(I) complexes was facilitated in the presence of Triton X-100, and the ECL intensity was enhanced 300-fold at a Au electrode.     

Synthesis, crystal structures, and electronic spectra of (1,8-naphthyridine)Re(CO)3Cl and [(1,8-naphthyridine)Cu(DPEPhos)]PF6

Two 1,8-naphthyridine (nap) metal complexes (nap)Re^I(CO)₃Cl (1) and [(nap)Cu^I(DPEPhos)]PF₆ (2) were synthesized and characterized by NMR-, emission, and absorption spectroscopy, elemental analysis, mass spectrometry, and X-ray structural analysis. In both complexes, the nap ligand coordinates with both N atoms to the metal centre in a bidentate manner. 1 and 2 exhibit a broad phosphorescence in solid state at T = 300 K, which is completely quenched in solution at r.t. In addition, the gas-phase structures of both complexes were optimized at the B3LYP/6-31G(d,p) level of theory.