Highly efficient visible-light photocatalytic ethane oxidation into ethyl hydroperoxide as a radical reservoir

Photocatalytic ethane conversion into value-added chemicals is a great challenge especially under visible light irradiation. The production of ethyl hydroperoxide (CH₃CH₂OOH), which is a promising radical reservoir for regulating the oxidative stress in cells, is even more challenging due to its facile decomposition. Here, we demonstrated a design of a highly efficient visible-light-responsive photocatalyst, Au/WO₃, for ethane oxidation into CH₃CH₂OOH, achieving an impressive yield of 1887 μmol g_cat⁻¹ in two hours under visible light irradiation at room temperature for the first time. Furthermore, thermal energy was introduced into the photocatalytic system to increase the driving force for ethane oxidation, enhancing CH₃CH₂OOH production by six times to 11 233 μmol g_cat⁻¹ at 100 °C and achieving a significant apparent quantum efficiency of 17.9% at 450 nm. In addition, trapping active species and isotope-labeling reactants revealed the reaction pathway. These findings pave the way for scalable ethane conversion into CH₃CH₂OOH as a potential anticancer drug.

Highly efficient visible-light driven photocatalytic oxidation of ethane into ethyl hydroperoxide was realized for the first time over Au/WO₃.     

新型手性Salen双核锌配合物的分子识别研究

合成了新型手性Salen配体（H3L）及新型手性Salen双核锌配合物（主体）.通过研究主体对咪唑类客体及氨基酸酯类客体的分子识别行为,测定了这些配位反应的缔合常数.主体对咪唑类客体分子识别的缔合常数顺序为:K(Im) >K(2-MeIm) >K(2-Et-4-MeIm).主体对氨基酸酯类客体分子识别的缔合常数顺序为:K(LeuOCH3) >K(ValOCH3) >K(AlaOCH3) >K(SerOCH3),配位数均为2.主体与D、 L型氨基酸酯分子识别反应在不同温度下的缔合常数结果表明,随着温度的升高,对映选择性下降.实验发现反应体系中存在焓熵补偿关系. CD光谱的研究结果也反映了主体对不同客体识别能力的差异.     

Powering the analytical glow discharge

The glow discharge may be powered by direct current (dc), radio frequency (rf) and pulsed discharge sources. Each has specific advantages and special features that should be considered by analysts using the various forms of glow discharge spectroscopy. This paper reviews some of the factors that contribute to the selection of a power source for the glow discharge.     

Aerobic oxidation of methyl p-tolyl sulfide catalyzed by a remarkably labile heteroscorpionate RuII-aqua complex,fac-[RuII(H2O)(dpp)(tppm)]2+

fac-[RuII(Cl)(dpp)(L3)]+ (L3 = tris(pyrid-2-yl)methoxymethane (tpmm) = [1A]+ and tris(pyrid-2-yl)pentoxymethane (tppm) = [1B]+ and dpp = di(pyrazol-1-yl)propane) rapidly undergo ligand substitution with water to form fac-[RuII(H2O)(dpp)(L3)]2+ (L3 = tpmm = [2A]2+ and tppm = [2B]2+). In the structure of [2A]2+, the distorted octahedral arrangement of ligands around Ru is evident by a long Ru(1)-O(40) of 2.172(3) A and a large angle O(40)-Ru(1)-N(51) of 96.95(14) degrees . The remarkably short distance between O(40) of H2O and H(45a) of dpp confirms the heteroscorpionate ligand effect of dpp on H2O. [2B]2+ aerobically catalyzes methyl p-tolyl sulfide to methyl p-tolyl sulfoxide in 1,2-dichlorobenzene at 25.0 +/- 0.1 degrees C under 11.4 psi of O2. Experimental facts in support of this aerobic sulfide oxidation are the absence of H2O2 and the oxidative reactivity of the putative Ru(IV)-oxo intermediate toward methyl p-tolyl sulfide, 2-propanol, and allyl alcohol. This study provides the first documented example of aerobic-sulfide oxidation catalyzed by the remarkably labile heteroscorpionate Ru(II)-aqua complex without the formation of a highly reactive peroxide as an intermediate.     

葫芦脲：分子识别与组装

综述了葫芦脲这一类合成受体的最新研究进展，包括葫芦脲的分子设计与合成 ，离子和分子识别，键合的热力学性质，分子组装及其功能的最新研究概况。     

带电胶体离子扩散与交换动力学的比较

Taking soil colloid and hydrated silica (quartz sand) as the experimental material, the comparative study has been made on the kinetics of ion diffusion and ion exchange in charged colloid and charged coarse disperse systems. The results showed that ion exchange kinetics in the two systems conform to the kinetic law of ion diffusion. Besides, through this comparative study on the kinetics of ion exchange and ion diffusion, a method has been advanced theoretically to estimate the quantity of adsorbed ion that is located in the inner of the Helmholtz layer. As far as hydrated silica is concerned , there were about 33 per cent of the total adsorbed quantity of Mg2+that were located in the inner of the Helmholtz layer under the given experimental conditions, bu tfor soil colloid the percentage was only 7.5.     

Zs－93硒剂对移植性小鼠S＿（180）肉瘤的抑制作用及其免疫活性

用硒与尿素化合，新生的由杂环有机硒所组成的Ｚｓ－９３硒剂治疗移植性Ｓ１８０肉瘤，有显著的抑瘤作用（Ｐ＜０．０１），其作用表现出一定的剂量效应，以５μｇ／只小鼠为最适，抑瘤率达６０．７６％，治疗组小鼠的Ｔ细胞、ＳＯＤ活性均有增强。     

A DNA-mediated crosslinking strategy to enhance cellular delivery and sensor performance of protein spherical nucleic acids

Intracellular delivery of enzymes is essential for protein-based diagnostic and therapeutic applications. Protein-spherical nucleic acids (ProSNAs) defined by protein core and dense shell of oligonucleotides have been demonstrated as a promising vehicle-free enzyme delivery platform. In this work, we reported a crosslinking strategy to vastly improve both delivery efficiency and intracellular sensor performance of ProSNA. By assembling individual ProSNA with lactate oxidase (LOX) core into a nanoscale particle, termed as crosslinked SNA (X-SNA), the enzyme delivery efficiency increased up to 5–6 times higher. The LOX X-SNA was later demonstrated as a ratiometric probe for quantitative detection of lactate in living cells. More importantly, X-SNA probe showed significantly improved sensor performance with signal-to-noise ratio 4 times as high as ProSNA when detecting intracellular lactate.

By crosslinking protein spherical nucleic acid (SNA) into a supramolecular architecture X-SNA, the intracellular enzyme delivery efficiency was significantly enhanced, showing 3–4 times higher signal-to-noise ratio in detecting intracellular lactate.     

微孔配位聚合物作为新型储氢材料的研究

微孔配位聚合物性质独特、结构多样，具有广泛的应用前景，它已成为近几年来一个热门的研究领域。本文简要介绍该类化合物作为一种新型的储氢材料，在合成、结构和储氢性能方面的研究进展。     

Cu, Zn─SOD酶模型化合物催化O2－歧化作用的研究

为了解Ｃｕ，Ｚｎ－ＳＯＤ酶结构和功能关系，尤其是Ｃｕ周围配位构型对催化Ｏ＾－２歧化活性的影响，本文用ＮＢＴ法测定了Ｃｕ，Ｚｎ－ＳＯＤ酶和两个Ｃｕ－ｉｍ－Ｚｎ模型配合及相应单核配合物催化Ｏ＾＿２歧化的活性，结果表明不同咪唑桥联方式和不同配位构型的化合物催化Ｏ＾－２歧化的活性明显不同。