一种新型的催化反应及其机理

通过对金属冠醚[Fe_6~Ⅲ(C_(12)H_9N_2O_5)_6(H_2O)_2(CH_3OH)_4]和[Fe_6(C_(12)H_8N_2O_5Cl)_6(H_2O)_4(CH_3OH)_2]反应体系的分析,认为水杨酸基双酰肼羧酸的酯化是一种新型的由金属冠醚自身进行的内部酯化反应,并将这种酯化反应定义为内部自催化反应.对于18-MC-6金属冠醚[Fe_6(C_(12)H_9N_2O_5)_6(H_2O)_2(CH_3OH)_4],在其内部自催化反应中,反应物为[Fe_6(C_(10)H_6N_2O_3-COOH)_6(H_2O)_2(CH_3OH)_4],其中主要配体(Z)-H_4shcpa具有羧酸基团(—COOH).作为酯化反应的功能基团—COOH,通过与铁离子的配位,再与具有活性的配位甲醇结合,生成酯化合物(Z)—H_3mshcp,最终得到内部自催化反应产物[Fe_6~Ⅲ(C_(10)H_6N_2O_3—COOCH_3)_6(H_2O)_2(CH_3OH)_4].其中,内部自催化反应的催化中心应是铁离子.     

簇合物[(C_2H_5)_4N]_3[W_2FeS_6(SCH_2CH_2S)_2]的合成、结构和性质研究

用两种不同的合成路线制备了标题化合物单晶,该化合物晶体为P2_1/c空间群,α=1.4256(5)nm,b=3.6007(9)nm,c=1.8075(4)nm,β=99.15(2)°,Z=8,对结构精修得到最后的一致性因子R=0.069,在[W_2FeS_6(SCH_2CH_2S)_2]~(3-)中存在端基双键S、端基单键螯合配位S和桥μ_2—S。Fe通过桥S分别与两个W相连,构成双齿非线型的W—Fe—W硫桥式结构。用EHMO方法对簇合物的电子结构进行了量子化学计算得到了与结构研究一致的规律。对簇合物进行了红外光谱、紫外可见光谱和电化学研究,并与所合成的其它化合物进行比较。     

含桥联配体的双核铁羰基簇合物的合成和结构研究

Fe_3(CO)_(12)与亚磷酸三硫代苯酯P(SC_6H_5)_3在温和条件下反应给出三个具有桥联原子的双核铁羰基簇合物(μ-SC_6H_5)_2Fe_2(CO)_5,(μ-SC_6H_5)(μ-P(SC_6H_5)_2)Fe_2(CO)_5和(μ-SC_6H_5)(μ-P(SC_6H_5)_2))Fe_2(CO)_5(P(SC_6H_5)_3).本文对这三个簇合物进行了IR,~1HNMR和MS谱的表征工作,并用z-ray衍射技术测定了它们的单晶结构.     

簇合物Co6(μ3-S)2(μ4,η2-SPR)(CO)14(R=Fc,naphthyl

用P2S5分别与萘和二茂铁反应，得到两种配位基前体：(L1，C10H7为naphthyl萘基)和(L2，Fc为二茂铁基).L1和L2分别与Co2(CO)8反应，得到两种新的含S、P桥基的六核钴羰基簇合衍生物：Co6(μ3-S)2(μ4,η2-SPC10H7)(CO)14(Ⅰ)和Co6(μ3-S)2(μ4,η2-SPFc)(CO)14(Ⅱ).L1与Ru3(CO)12反应得到Ru3(μ3-S)(μ-H)2(CO)9(Ⅲ)和Ru4(μ3-S)(μ3-PC10H7)(CO)10(Ⅳ).通过元素分析和谱学表征，对簇合物Ⅰ～Ⅳ的结构进行了推测.     

四核链型M—Fe—S（M=Mo,W）原子簇化合物的成键特征

用MAD—SCC—EHMO法计算了3个4核链型M—Fe—S(M=Mo,W)原子簇化合物[Fe_2S_2(MoS_4)_2]~(4-)、[Fe_2S_2(MoS_2O_2)_2]~(4-)和[Fe_2S_2(WS_4)_2]~(4-)的电子结构,根据计算所得的分子轨道能级、轨道特征和Mulliken约化重叠集居等数据,对其成键性质进行了分析。指出了在簇合物的成簇过程中,由于电子从Fe原子转移到M原子,使得簇合物中M的表观氧化态低于碎片M_2S_2X_2~(2-)中M的表观氧化态,本文还根据Mulliken约化重叠集居和电荷密度变化的分析,给出簇合物电子的离域性顺序([Fe_2S_2(MoS_4)_2]~(4-)>[Fe_2S_2(MOS_2O_2)_2]~(4-)>[Fe_2S_2(WS_4)_2]~(4-))。     

新型含胺基膦配体的钌羰基簇合物HRu_3{μ_3-η~2-P(NEt_2)_2}(CO)_9的合成和结构

本文用 Ru_3(CO)_(12)和二(二乙胺)氯化膦(Er_2N)_2PCl 在较温和条件下反应得到了一个具有新结构和新配位方式的三核簇合物 HRu_3{μ_3-η~2-P(NEt_2)_2}(CO)_3.该簇合物的结构特点是由于配体中磷原子和一个氮原子组成桥参与配位而形成一千五员 Ru_3PN 稳定骨架结构,我们对该簇合物进行了元素分析和 IR,HNMR,MS 表征工作,并进行了 x-光单晶结构分析     

簇合物Co6（μ3—S）2（μ4,η^2—SPR）（CO）14（R=Fc,naphthyl C10H7）、Ru3（μ3—S

用P2S5分别与萘和二茂铁反应,得到两种配位基前体：C10H7－P＝S－S－S＝S－P－S－S－C10H7（L1,C10H7为naphthyl萘基)和Fe-P＝S－S＝S－P－Fc-S(L2,Fc为二茂铁基）。L1和L2分别与Co2(CO)8反应,得到两种新的含S,P桥基的六核钴羰基簇合衍生物：Co6(μ3-S)2(μ4,,η^2-SPC10H7)(CO)14(Ⅰ)和Co6(μ3-S)2(μ4,η^2-SPFc)(CO)14(Ⅱ).L1与Ru3(CO)12)反应得到Ru3(μ3-S)(μ-H)2(CO)9(Ⅲ)和Ru4(μ3-S)(μ3-PC10H7)(CO)10(Ⅳ).通过元素分析和谱学表征,对族合物Ⅰ－Ⅳ的结构进行了推测。     

含氮宾或卡宾的金属羰基簇合物的结构化学研究Ⅱ——Fe_2(CO)_6(PhNCONPh)的合成和结构

Fe_2(CO)_6(PhNCONPh)簇合物是由[Et_3NH][HFe_3(CO)_(11)]和C_6H_5NCO在苯中反应获得。应用四园衍射仪测定了该簇合物的晶体结构。晶体学数据:C_(19)H_(10)O_7N_2Fe_2,空间群P2_1/n,a=8.5062(1),b=13.2752(1),c=18.9038(2)(?),β=98.96(2)°,Z=4和D_c=1.643gcm~(-3)。结构系用直接法解出,最后R 因子为0.031.结果表明,题目簇合物分子是由苯代脲基C_6H_6—N—C(O)—N—C_6H_5中的N 原子,分别和(OC)_3Fe—Fe(CO)_3中的两个Fe 原子键合而成。使各两Fe 与N 原子和一个C 原子形成变形的双三角锥构型。     

含卡宾或烯酮基铁簇合物作为乙醇合成机理模型的研究

用含卡宾或烯酮的铁簇合物为模型,在模拟多相反应的条件下,研究了它们与H_2,H_2/CO,H_2/CO/CH_3OH 和H_2/CO/CD_3OD 的反应行为。在95℃和2.0 MPa的条件下,Fe_2(μ-CH_2)(CO)_8/SiO_2与含有合成气的甲醇反应可得 43％的醋酸甲酯,同时伴有甲烷、乙烷、乙烯、乙醛和乙醇等产物。与引入全氘代甲醇的合成气反应后,可得到氘代产物DCH_2COOCD_3和CH_3 COOCD_3.DCH_2 COOCD_3与A_cOCD_3(=DCH_2COOCD_3+CH_3COOCD_3)的相对丰度比随CD_3OD与H_2比值的减小而降低,由此可推测烯酮加成与烯酮氢化成乙酰基中间体这一对竞争反应。     

含半填隙磷原子配体六核钴羰合簇的P（OEt）3和PPh3取代衍物的合成和表征

用P（OEt)e)和PPh3分别与Co6(μ6-P)（μ,η^2-SCH2CH2CH2S)(μ-PSCH2CH2CH2S)(CO)12进行取代反应,首次得到了4－取代和1个二取代含半填隙磷原子配体六核钴羰基簇合物的取代衍生物,化学式如下：Co6(μ,η^2-SCH2CH2CH2S)(μ－PSCH2CH2CH2S）（CO）11[P(OEt)3](Ⅰa和Ⅰb,同分异体）Co6（μ6－P）(μ,η^2-SCH2CH2CH2S)(μ－PSCH2CH2CH2S）（CO）11[P(OEt)3]2（Ⅱ）,Co6（μ6－P）(μ,η^2-SCH2CH2CH2S)(μ－PSCH2CH2CH2S）（CO）11（PPh3)( Ⅲa),Co6（μ6－P）(μ,η^2-SCH2CH2CH2S)(μ－PSCH2CH2CH2S）（μ-CO）（CO）(PPh3)(Ⅲb),对5个合成的簇合衍生物通过元素分析,IR（vco),^1HNMR,^31PNMR和MS谱学表征,发现ⅠaⅡb,Ⅲa,Ⅲb是一取代的同分异构体,P（OEt)3和PPh3可能代母体钴簇合物基底不同钴原子上的一个CO。Ⅱ是二取代物,两个P(OEt)3分子可能各取代母体钴簇合物在顶端的两个钴原子上的一个CO。     

某些杂环偶氮试剂结构与性能的理论研究

用PPP方法研究了某些杂环偶氮试剂的结构.在计算结果的基础上,讨论了结构与性能之间的关系.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that