一种新的16金属笼状物[HN(C_2H_5)_3]_4-[Mo_3~VMo_6~(VI)V_7~(IV)O_(40)(PO_4)]·2[N(C_2H_5)_3]的水热合成和结构

报道了一种新的杂多化合物[HN(C_2H_5)_3]_4-[Mo_3~VMo_6~(VI)V_7~(IV)O_(40)(PO_4)]·2[N(C_2H_5)_3]的合成,并用元素分析、EPR、IR谱、及X--射线单晶衍射等手段进行了表征。结果表明,该杂多酸盐属于单斜晶系,空间群P21/n,a=14.0841(3),b=14.2505(3),c=19.6089(3)?b=94.213(1),V=3925.0(1)?,Z=2,Dc=2.171g/cm3,Mr=2566.18,m=2.284mm-1,F(000)=2516,R=0.0477,wR=0.0945.杂多阴离子是1个16金属笼状物,笼中心包含1个PO4四面体客体。     

Asymmetric reduction of representative ketones with a bis-chiral oxazaborolidine system

In recent years, many optically active β-amino alcohols, mostly derived from naturally occurring α-amino acids, have been incorporated into the asymmetric synthesis as chiral auxiliaries or ligands.1 An effective asymmetric catalysts, the oxazaborolidine-borane reagents, which were originally pioneered by Itsuno and Corey,2 were generally prepared from chiral β-amino alcohols by the reaction with boric acid or formed in situ in the presence of borane. These reagents provide excellent enanti…     

[C6N2H18]2[Mo5O15(HPO4)2]·H2O的水热合成与结构表征

通过水热法合成了一个新化合物[C6N2H18]2[Mo5O15(HPO4)2]·H2O,并通过IR光谱、ICP、元素分析、差热与热重分析和X射线单晶衍射分析等手段进行了表征.结果表明,晶体属三方晶系,P3(2)21空间群,a=1.1231(1)nm,c=2.2802(5)nm,V=2.4911(7)nm3,Dx=2.835Mg/m3,Z=6,最后的一致性因子R=0.0227,wR=0.0675.阴离子中Mo5O15构成一环状结构,2个HPO4一个连在环的下方,一个连在环的上方,形成类似于“飞碟”状的结构,阳离子为2个质子化的四甲基乙二胺.     

再谈磷的同素异形体(1)——块体磷的同素异形体

结合最新研究进展，全面介绍了块体状磷的同素异形体——白磷、红磷、黑磷等，包括存在、组成、性质、结构、制备、应用等，同时明确了紫磷、希拖夫磷、灰磷、褐磷等概念，提出了大学本科化学教学的建议。     

Synthesis and Crystal Structure of[Fe_2V (μ_3-O) (μ-O_2CCH_3)_6 (THF)_3]Cl· 3H_2O

lmTR0DUCTI0NTrivanadium(III)ox0-carb0xylat0complexeshaveattractedmuchinterestre-cently"~".Manyc0mp0unds0fthiskindhavebeensynthesizedandtheirstructural,physicalandspectr0sc0picpr0pertieshavebeenstudied.Butnone0fthiskindofcom-plexeswithmixedmeta1shavebeensynthesized.Hereinwereportthecrystalstruc-tureofthefirstmixedmeta1carboxylatocomp0undofvanadium.2EXPERIMENTAL2.1Synthesis0.l6g(lmmol)VCl3,0.32g(2mmol)FeCl3and0.48g(6mm0l)NaCO,CH,wasdisso1vedinaso1uti0n0ft0luerie(20ml),THF(lOml),ac…     

N，N，N′，N′-四丁基丙二酰胺从硝酸盐介质中萃取铈(Ⅲ)

Study on the extraction and separation of rare earth with new extractants is important in the rare earth chemistry and nuclear reprocessing. In this work， the extraction of Ce(Ⅲ) with N，N，N′，N′-tetrabutylmalonamide (TBMA) in toluene from nitrate media has been investigated. The effect of the concentration of nitric acid， TBMA and salt-ing-out agent (LiNO₃) and also the temperature on the distribution ratios was examined. The stoichiometries of the extracted complexes were determined to be Ce(NO₃)₃·3TBMA and Ce(NO₃)₃·4TBMA， respectively. The ap-parent extraction constants and the enthalpy of the extraction were calculated based on the extraction data， which are logK_ex1=3.97， logK_ex2=4.75 and Δ_rH_m^?=-31.25kJ·mol^-1， respectively. The IR spectra of the loaded organic phase supported the suggested extraction mechanism.     

Novel Water Soluble Fluorescent Trimethine Indocyanines Containing N-ρ-Carboxybenzyl Group

Indocyanine dyes as fluorescent labeling reagents have been used in bioanalysis1,2. Arylsulfonate indocyanine dyes 1d and 1e developed by Waggoner A. S. et al.3,4 have excellent fluorescent properties combined with good aqueous solubility, are a new generation of fluorescent label compounds for proteins, oligonucleotides and other compounds containing hydroxyl, mercaptol or primary amine groups5. However, photostability of these dyes has been a problem. Z. G. YAO et al.6 reported that p…     

文理兼收护理学专业医用化学课程的改革

护理学专业文理兼收模式下，通过优化教学内容，采用“基于团队的导学教学法”和实现课堂微课化等改革措施，达到了培养学生团队协作能力、自主学习能力，提高学习效果的目的。     

Effect of active control on optimal structures in wall turbulence

The effect of active control imposed at the wall on optimal structures in wall turbulence is studied by using a linear transient growth model.When the detection plane of the control is located in the buffer layer,the influence of the control on the transient growth of large scale motion becomes negligible as Reynolds number increases.However,if the control signal is detected at the plane located in the logarithm region,the transient growth at large scale can be greatly suppressed.New peak values of transient growth resulting from the strong blowing and suction on the wall exist.The study indicates that a proper selection of control imposed on the wall can suppress the large scale motion in the logarithmic region.     

0Interacting model of new agegraphic dark energy:observational constraints and age problem

Many dark energy models fail to pass the cosmic age test because of the old quasar APM 08279+5255 at redshift z=3.91,the ΛCDMmodel and holographic dark energy models being no exception.Inthis paper,we focus onthe topic of the age problem inthe new agegraphic dark energy(NADE)model.We determine the age of the universe in the NADE model by fitting the observational data,including type Ia supernovae(SNIa),baryon acoustic oscillations(BAO)and the cosmic microwave background(CMB).We find that the NADE model also...