A New Tetranuclear Cobalt Cluster with （1H-Benzimidazol-2-yl）-methanol Synthesis and Crystal Structure

A new tetranuclear cluster [Co4(bm)6Cl2]·(H2O)2·(CH3OH)(1, Hbm is(1H-benzimidazol-2-yl)-methanol) has been synthesized by solvothermal method and structurally determined by IR, elemental analysis, and single-crystal X-ray diffraction. Complex 1 belongs to monoclinic space group P21/n with a = 21.1713(5), b = 12.7948(3), c = 24.0195(9) , β = 95.309(3)°, V = 6478.6(3) 3, Z = 4, F(000) = 2568, Dc = 1.289 g·cm–3, Mr = 1257.63, μ = 9.096 mm–1, S = 1.000, the final R = 0.0861 and wR = 0.2552 for 4956 observed reflections with I 2σ(I). Two connected face-sharing cubes are observed in the framework of 1, each with one vertex missing. Complex 1 forms a 2-D network through N–H···O hydrogen bonds. The apparent holes can be observed.     

ZIF-67 derived carbon wrapped discontinuous CoxP nanotube as anode material in high-performance Li-ion battery

Transition metal phosphides (TMPs) are prospective anode materials for lithium-ion batteries (LIBs) due to their high theoretical capacities and low redox voltages. Herein, we report a template directing method to develop a tube-sheath hybrid composing of cobalt phosphide particles encapsulated in metal organic frameworks (MOFs) derived N-doped carbon sheaths (Co_xP@NC). The utilization of directing template leads to a homogenous distribution of the subsequently formed cobalt phosphide particles, restrains the aggregation of cobalt phosphides, and thus results in the superb rate capability and cyclability. Contributable to the integrated merits of the interior downsized cobalt phosphide particles and the outer ZIF-67 derived porous carbon sheath, the volume expansion during cycling is effectively suppressed. The Co_xP@NC hybrid shows superb electrochemical performance as anode material for LIB, with good reversible capacity of 928 mAh·g^?1 after 100 cycles at 0.1 A g^?1, and high stability of 526 mAh·g^?1 after 600 cycles at 1.0 A g^?1. This work provides a route for rational design of MOF derived carbon-based anode material for LIB, which could also be applied as a promising platform in diverse field.     

Antimicrobial tunicamycin derivatives from the deep sea-derived Streptomyces xinghaiensis SCSIO S15077

Abstract

Tunicamycin E (1), featuring a methyl substitution at C-10′, was isolated from marine-derived Streptomyces xinghaiensis SCSIO S15077 originated from the South China Sea sediment together with six known compounds, tunicamycin B (2), tunicamycin X (3), tunicamycin A (4), streptovirudin D₂ (5), tunicamycin C (6), and tunicamycin C₃ (7). The structure of compound 1 was elucidated by detailed spectroscopic data analyses. All the compounds exhibited strong to moderate antibacterial activity against Gram-positive bacteria Bacillus thuringiensis BT01 and B. thuringiensis W102 with MIC values ranging from 0.008 to 2 μg/mL. Moreover, compounds 1–7 exhibited moderate antifungal activity against Candida albicans ATCC 96901 and C. albicans CMCC (F) 98001 with MIC values ranging from 2 to 32 μg/mL. This is the first report that tunicamycins exhibit antimicrobial activities against B. thuringiensis, C. albicans CMCC (F) 98001 and a fluconazole resistant strain C. albicans ATCC 96901.     

微气相色谱法分析氢氘同位素组分气体

该文建立了聚变堆燃料循环系统中氢氘组分的微气相色谱定量分析方法。采用MnCl2溶液改性的氧化铝色谱柱(4～6 m×0.53 mm)为分离柱,考察了改性液含量、色谱柱长和载气流量对氢氘组分分析的影响,在液氮低温(77 K)条件下实现了H₂、HD和D₂混合物的分离。结果表明,19%MnCl2溶液处理的色谱柱分离氢同位素的效果优于15%MnCl₂溶液处理的色谱柱;柱越长,H₂和HD的分离效果越好,当色谱柱长度大于5 m时,H2和HD组分可以完全分离,分离度大于1.5;HD和D2的最小理论塔板高度分别为0.013 cm和0.016 cm。He中H2、HD、D23组分氢同位素在0%～10%含量范围内的线性相关系数均不低于0.993,检出限(LOD)分别为600.1、343.8、654.5μL/L。方法的相对标准偏差为0.34%～1.5%。该法是一种快速、准确、实用的氢同位素分析方法,有望用于聚变堆D/T燃料循环系统氢同位素气体的测定。     

Magnetron sputtering deposition of silicon nitride on polyimide separator for high-temperature lithium-ion batteries

To date,lithium-ion batteries are becoming increasingly significant in the application of portable devices and electrical vehicles,and revolutionary progress in theoretical research and industrial application has been achieved.However,the commercial polyolefin separators with unsatisfying electrolytes affinity and poor thermal stability have extremely restricted the further application of lithium-ion batteries,especially in the high-temperature fields.In this work,magnetron sputtering deposition technique is employed to modify the commercial polyimide separator by coating silicon nitride on both sides.Magnetron sputtering deposition modified polyimide(MSD-PI)composite separator shows high thermal stability and ionic conductivity.More importantly,compared with the cells using Celgard separator,the cells with MSD-PI separator exhibit superior electrochemical performance,especially long-term cycle performance under high temperature environment,owing to the high thermal conductivity of surface Si3 N4 particles.Hence,lithium-ion batteries with MSD-PI separator are capable of improving thermal safety and capacity retention,which demonstrates that magnetron sputtering deposition technique could be regarded as a promising strategy to develop advanced organic/inorganic composite separators for high-temperature lithium-ion batteries.     

离子型聚合物修饰电极的电化学发光特性

通过静电相互吸引作用对导电玻璃电极表面进行聚乙烯亚胺和聚丙烯酸分子层修饰,比较了修饰电极对中性介质中鲁米诺电化学发光的影响.结果表明,聚乙烯亚胺修饰层对电极反应的影响相对较小,而对鲁米诺分子的电化学发光具有极大的增强效应.荷正电的聚乙烯亚胺修饰分子与鲁米诺激发态3-氨基邻苯二甲酸阴离子间静电相互作用而导致的激发态稳定性增加,对鲁米诺分子的电化学发光的增强起着关键作用.     

基于蛋白模板金纳米簇及羟基氧化钴纳米片的激活型荧光纳米探针用于免标记和灵敏检测生物硫醇

该文基于牛血清白蛋白模板金纳米簇（BSA@AuNCs）与羟基氧化钴（CoOOH）纳米片构建了一种激活型荧光纳米探针用于生物硫醇的检测。带负电的BSA@AuNCs能通过静电吸附作用组装到带正电的CoOOH纳米片表面,与此同时,BSA@AuNCs的荧光由于内滤效应（IFE）有效地被CoOOH纳米片猝灭,形成BSA@AuNCs－CoOOH纳米探针。当向纳米探针溶液加入生物硫醇（0.05～150 μmol/L）时,生物硫醇与纳米探针中的CoOOH纳米片发生氧化还原反应,CoOOH纳米片被降解生成Co2+,同时释放出BSA@AuNCs,BSA@AuNCs荧光信号恢复。结果表明,该纳米探针可以检测低浓度的生物硫醇,对生物硫醇（半胱氨酸、谷胱甘肽和高半胱氨酸）的检出限为30 nmol/L。相对于其他的氨基酸、金属离子及糖类化合物,该纳米探针对生物硫醇具有较高的选择性并成功应用于人血清样品中生物硫醇的检测。     

Polydopamine-Assisted Rapid One-Step Immobilization of L-Arginine in Capillary as Immobilized Chiral Ligands for Enantioseparation of Dansyl Amino Acids by Chiral Ligand Exchange Capillary Electrochromatography

Herein, a novel L-arginine (L-Arg)-modified polydopamine (PDA)-coated capillary (PDA/L-Arg@capillary) was firstly fabricated via the basic amino-acid-induced PDA co-deposition strategy and employed to constitute a new chiral ligand exchange capillary electrochromatography (CLE-CEC) method for the high-performance enantioseparation of D,L-amino acids (D,L-AAs) with L-Arg as the immobilized chiral ligand coordinating with the central metal ion Zn(II) as running buffer. Assisted by hydrothermal treatment, the robust immobilization of L-Arg on the capillary inner wall could be facilely achieved within 1 h, prominently improving the synthesis efficiency and simplifying the preparation procedure. The successful preparation of PDA/L-Arg coatings in the capillary was systematically characterized and confirmed using several methods. In comparison with bare and PDA-functionalized capillaries, the enantioseparation capability of the presented CLE-CEC system was significantly enhanced. Eight D,L-AAs were completely separated and three pairs were partially separated under the optimal conditions. The prepared PDA/L-Arg@capillary showed good repeatability and stability. The potential mechanism of the greatly enhanced enantioseparation performance obtained by PDA/L-Arg@capillary was also explored. Moreover, the proposed method was further utilized for studying the enzyme kinetics of L-glutamic dehydrogenase, exhibiting its promising prospects in enzyme assays and other related applications.     

以四氟对苯二甲酸为配体构建的两个铅的配位聚合物：合成、晶体结构和荧光性质

在4-甲基咪唑/三氮唑存在下,利用四氟对苯二甲酸为配体、与Pb(NO3)2作用,得到了2种配位聚合物{[Pb(tfbdc)(H2tfbdc)0.5]·(4-MI)·(H2O)}n(1)和{[Pb(tfbdc)(H2O)2]}n(2)(H2tfbdc=四氟对苯二甲酸,4-MI=4-甲基咪唑),并用红外光谱、元素分析和X-单晶衍射对其进行了表征。化合物1属于单斜晶系,空间群为P21/n,化合物2属于三斜晶系,空间群为P1。配合物1中,铅离子依靠正常的Pb-O键和次级键Pb…O,与7个氧原子配位;tfbdc2-阴离子和H2tfbdc分别采用不同的配位方式桥联铅离子,导致1个具有孔道的三维结构的形成。而4-甲基咪唑和游离水分子通过氢键作用嵌在这三维结构的孔道中。π-π堆积作用的存在增强了1的稳定性。配合物2中,铅离子是位于8个氧原子的配位环境中,tfbdc2-阴离子以螯合和桥联的方式与铅离子作用,导致1个二维层状结构的形成。此外还考察了1和2的热稳定性和固体荧光性质。