活泼配盐[(μ-RE)(μ-E′)Fe_2(CO)_6][Et_3NH][E,E′=S,Se]的亲电反应研究——蝶状Fe_2SSe及Fe_2Se_2簇合物的合成及表征

本文由［（μｔＢｕＳ）（μＣＯ）Ｆｅ２（ＣＯ）６］［Ｅｔ３ＮＨ］和硒粉形成的［（μｔＢｕＳ）（μＳｅ）Ｆｅ２（ＣＯ）６］［Ｅｔ３ＮＨ］，分别与溴化苄，二碘甲烷及邻一、间一、对一双（溴甲基）苯反应，合成了蝶状Ｆｅ２ＳＳｅ单簇物（μｔＢｕＳ）（μＰｈＣＨ２Ｓｅ）Ｆｅ２（ＣＯ）６（３ａ）和双簇物［（μｔＢｕＳ）Ｆｅ２（ＣＯ）６］２（μＳｅＺＳｅμ）［Ｚ＝ＣＨ２，ｏ．ｍ．ｐ双（亚甲基）苯］（４ａｄ）。类似地，由［（μＰｈＳｅ）（μＣＯ）Ｆｅ２（ＣＯ）６］［Ｅｔ３ＮＨ］和硫粉或硒粉所形成的［（μＰｈＳｅ）（μＳ）Ｆｅ２（ＣＯ）６］［Ｅｔ３ＮＨ］或［（μＰｈＳｅ）（μＳｅ）Ｆｅ２（ＣＯ）６］［Ｅｔ３ＮＨ］分别与对一双（溴甲基）苯反应合成了蝶状Ｆｅ２ＳＳｅ和Ｆｅ２Ｓｅ２双簇物［（μＰｈＳｅ）Ｆｅ２（ＣＯ）６］２［μＳ（ｐＣＨ２Ｃ６Ｈ４ＣＨ２）Ｓμ］（５ａ）及［（μＰｈＳｅ）Ｆｅ２（ＣＯ）６］２［μＳｅ（ＰＣＨ２Ｃ６Ｈ４ＣＨ２）Ｓｅμ］（５ｂ）。所有产物均经元素分析、ＩＲ和１ＨＮＭＲ表征。     

（四甲基二硅撑）双（3－三甲硅基环戊二烯基）－四羰基二铁的反应性

标题化合物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２］_２／（μ－ＣＯ）_２（Ａ）分子中的Ｆｅ－Ｆｅ键被钠汞齐还原断裂，生成相应的双铁负离子，分别与ＭｅＣＯＣｌ、ＰｈＣＯＣｌ、ＰｈＣＨ_２Ｃｌ、ＣｌＣＨ_２ＣＯＯＣ_２Ｈ_５和Ｐｈ_３ＳｎＣｌ进行亲核取代反应，生成在铁原子上引入相应取代基的产物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２Ｒ］_２（Ｒ：ＭｅＣＯ（１），ＰｈＣＯ（２），ＰｈＣＨ_２（３），ＣＨ_２ＣＯＯＣ_２Ｈ_５（４），Ｐｈ_３Ｓｎ（５），Ｉ（６））。Ａ在氯仿中与碘反应，得到Ｆｅ－Ｆｅ断裂的双铁碘化物，但在苯中与过量碘反应，则得到Ｆｅ－Ｉ－Ｆｅ桥联的离子型化合物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２］_２Ｉ·Ｉ（７）。化合物６的晶体和分子结构经Ｘ射线衍射测定，６属单斜晶系，Ｐ２１／ｃ空间群，ａ＝１．７２１７（４）ｎｍ，ｂ＝０．７７５３（２）ｎｍ，Ｃ＝１．３６２９（７）ｎｍ，β＝１０３．８０（３）°，Ｖ＝１．７６７（２）ｎｍ３，Ｚ＝４，Ｄｃ＝１．６２９９·ｃｍ－１，最终偏差因子Ｒ＝０．０５４。     

金属硼化物结构与稳定性的理论研究

用ＨＦ／３－２１Ｇａｂｉｎｉｔｉｏ法对金属硼化物ＭＢ２／ＭＢ２（Ｍ＝Ｌｉ，Ｎａ，Ｂｅ，Ｍｇ，Ａｌ）的７５个电子态结构进行能量梯度法优化，再用大基组二次且上互作用ＱＣＩＳＤ（Ｔ）／６－３１１Ｇ进行单点计算，得到了结构参数总能量，为了考察各原子簇的稳定性，还对２４个碎片的７０多个电子态，求得相应的ＱＣＩＳＤ（Ｔ）能量，在此基础上计算了原子化能、电离能、离解通道和碎片化能，得到了原子簇的稳定性规律。     

THE EXCITED STATES AND VIBRATIONAL FREQUENCIES OF Bli_2~e（e＝0，＋1，－1）CLUSTERS

ＴＨＥＥＸＣＩＴＥＤＳＴＡＴＥＳＡＮＤＶＩＢＲＡＴＩＯＮＡＬＦＲＥＱＵＥＮＣＩＥＳＯＦＢｌｉ：（ｅ＝０，＋１，－１）ＣＬＵＳＴＥＲＳＴＨＥＥＸＣＩＴＥＤＳＴＡＴＥＳＡＮＤＶＩＢＲＡＴＩＯＮＡＬＦＲＥＱＵＥＮＣＩＥＳＯＦＢｌｉ：（ｅ＝０，＋１，－１）Ｃ...     

蝶状铁硒簇合物双（μ—p—甲苯硒基）六羰基二铁双膦取代…

测得并解析了２个蝶状铁硒取代衍生物（μ－ｐ－ＭｅＣ６Ｈ４Ｓｅ）２Ｆｅ２（ＣＯ）２（Ｐｈ２ＰＣＨ２ＣＨ２ＰＰｈ２）（Ａ）和（μ－ｐ－ＭｅＣ６Ｈ４Ｓｅ）２Ｆｅ２（ＣＯ）４（ｃｉｓ－Ｐｈ２ＰＣＨ＝ＣＨＰＰＨ２）（Ｂ）的＾１Ｈ－＾１ＨＣＯＳＹ谱和＾１Ｈ－＾１５ＣＣＯＳＹ谱以及Ａ的＾１Ｈ－＾１ＨＮＯＥＳＲ谱，从而进一不确证了它们的结构。     

精确模型化学中MPn微扰外推的一个问题

通过对ＢＨ、ＡｌＨ、ＢＦ和ＡｌＦ的高级别ａｂ ｉｎｉｔｉｏ势能曲线计算和理论分析,发现在分子的几何构型偏离平衡时,由于参考态级成不充分的问题,Ｈａｒｔｒｅｅ－Ｆｏｃｋ单参考态的ＭＰｎ微扰计算可能给出错误的能量值。从而表明,目前的精确模型化学方法（Ｇ１、Ｇ２、Ｇ３和ＣＢＳ系列）中用ＭＰｎ微扰外推的办法拟合高级别ａｂ ｉｎｉｔｉｏ,对偏离平衡构型体系（如动力学研究中的过渡态、中间体等）的能量计算,在一     

碳基铁—硫醇（硫酚）—格氏试剂体系与芳酰氯反应的研究：…

通过Ｆｅ３（ＣＯ）１２、硫醇（硫酚）和ＥｔＭｇＢｒ所形成的络盐［（μ－ＣＯ）（μ－ＲＳ）Ｆｅ２（ＣＯ６）》－Ｍｇ＾＋Ｂｒ与氯代芳酰氯的原位反应，合成了通式为（μ－ＲＳ）（μ－ｏ－ＣｌＣ６Ｈ４ＣＯ）Ｆｅ２（ＣＯ６）和（μ－ＲＳ）（μ－ｍ－ＣｌＣ６Ｈ４ＣＯ）Ｆｅ２（ＣＯ）６（Ｒ＝ｎ－Ｂｕ，ｔ－Ｂｕ，Ｐｈ）的６个新桥芳酰基铁硫配合物，并用Ｃ／Ｈ分析、ＩＲ和＾１ＨＮＭＲ表征了它们的结构。     

高电势铁硫蛋白的模型化合物：2,4,6—三苯基苯硫酚的4Fe4S簇合 …

新型簇合物（ｎ－Ｂｕ４Ｎ）２「Ｆｅ４Ｓ４（ｔｐｂｔ）４」（ｔｐｂｔ－２，４，６－三苯基苯硫酚基）通过２，４，６－三苯基苯硫酚和（ｎ－Ｂｕ４Ｎ）２「Ｆｅ４Ｓ４９Ｓ－ｔ－Ｂｕ０４」在ＤＭＦ中进行配体交换反应合成得到。该簇合物在ＣＨ３ＣＮ溶液中的「Ｆｅ４Ｓ４」＾３＋／２＋和「Ｆｅ４Ｓ４」＾２＋１／＋的氧化还原电位分别为－０．１４和－１．３１ＶｖｓＳＣＥ。     

羰基铁－硫醇（硫酚）－格氏试剂体系与芳酰氯反应的研究──某些μ－芳酰基铁硫配合物的合成及结构

通过Ｆｅ３（ＣＯ）（１２）、硫醇（硫酚）和ＥｔＭｇＢｒ所形成的络盐［（μ－ＣＯ）（μ－ＲＳ）Ｆｅ２（ＣＯ）６］－Ｍｇ＋Ｂｒ与氯代芳酰氯的原位反应，合成了通式为（μ－ＲＳ）（μ－ｏ－ＣｌＣ６Ｈ４ＣＯ）Ｆｅ２（ＣＯ）６和（μ－ＲＳ）（μ－ｍ－ＣｌＣ６Ｈ４ＣＯ）Ｆｅ２（ＣＯ）６（Ｒ＝ｎ－Ｒｕ，ｔ－Ｂｕ，Ｐｈ）的６个新桥芳酰基铁硫配合物，并用Ｃ／Ｈ分析、ＩＲ和１ＨＮＭＲ表征了它们的结构。     

A NOVEL REACTION BETWEEN Ge－Ge AND Fe－Fe BONDS IN COMPLEX （Me_2GeGeMe_2）［（η~5－C_5H_4）Fe（CO）］_2（μ－CO）_2 AND CRYSTAL STRUCTURE OF THE PRODUCT

ＡＮＯＶＥＬＲＥＡＣＴＩＯＮＢＥＴＷＥＥＮＧｅ－ＧｅＡＮＤＦｅ－ＦｅＢＯＮＤＳＩＮＣＯＭＰＬＥＸ（Ｍｅ_２ＧｅＧｅＭｅ_２）［（η~５－Ｃ_５Ｈ_４）Ｆｅ（ＣＯ）］_２（μ－ＣＯ）_２ＡＮＤＣＲＹＳＴＡＬＳＴＲＵＣＴＵＲＥＯＦＴＨＥＰＲＯＤＵＣＴ￥ＸｉｕＴ?..     

On determination of the strength of local electric fields at the bromine atoms in the series of compounds BrCH2R by79Br NQR spectroscopy

The values of changes in the strength of local electric fields at the bromine atoms for a series of compounds BrCH₂R were determined from a hyperbolic equation relating the⁷⁹Br NQR frequencies to their field constants. The totalities of electron-acceptor and electrodonor substituents R are described by equations of the same type differing in their parameters. Deceased. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1150–1154, June, 1998.     

A Theoretical Investigation of Surface‐enhanced Sum‐frequency Generation

Following the surface enhanced Raman scattering (SERS), we shall investigate the possibility of observing surface‐enhanced sum‐frequency generation (SESFG), which refers to the transformation of ordinary vibrational SFG (i.e. singly resonant) into SESFG. Two mechanisms of SESFG will be studied; one is due to the transformation of singly‐resonant vibrational SFG into doubly resonant vibrational SFG (that is, both vibrationally resonant and Raman‐scattering resonant) and the other is due to the enhancement of the polarizability in addition to the original vibrational resonance in vibrational SFG.     

Molecular relaxations in dual-frequency nematic liquid crystals

The preparation of nematic liquid crystals mixtures results in changing of molecular relaxations in comparison to pure substances. Typical example is the creation of dual-frequency nematic liquid crystals using a base mixture and functional admixtures. In this paper, we present how dielectric properties of starting compounds change at mixture preparation. Three dual-frequency nematic mixtures of different composition were prepared and examined by means of dielectric spectroscopy in a wide frequency (100 Hz to 10 MHz) and temperature range (170°C to ?60°C). Parameters of detected modes for pure compounds and final mixtures were calculated and their relationships with crossover frequency are discussed.     

Wavelet frequency spectrum and its application in analyzing an oscillating chemical system

Based on the continuous wavelet transform (CWT), three types frequency spectra, wavelet frequency spectrum (WFS), point frequency spectrum (PFS) and time frequency spectrum (TFS), were developed. Two data sets were simulated and treated with the proposed spectra, the results indicated that WFS could extract the frequency information, which was like Fourier analysis but more accurate, PFS could obtain the frequency at any moment, TFS could show frequency change with time. These abilities of PFS and TFS were impossible for Fourier analysis. An oscillating chemical signal was processed with WFS and TFS. From the processed results, two points could be learned about the oscillating chemical reaction: one was the oscillating chemical reaction was a mixture one including two or more complex kinetics processes, the velocity of the switch from the reduced state (RS) to the oxidized state (OS) was faster than the reverse switch (from OS to RS); the other was increase of KBrO₃ could decrease the velocities of both switches, which led to the oscillating period became longer.     

Investigations of dual-frequency nematic liquid crystals doped with dichroic dye

In this work, we studied and analysed a particular variety of liquid crystals, the so-called dual-frequency nematic liquid crystals (DFNLCs). The interest was to perform dielectric spectroscopy and optical characterisation with two pure and doped mixtures of DFNLCs. By means the dielectric spectroscopy we observed a low value of crossover frequency at room temperature for one dye doped mixture. Additionally, in the spectra studies, a scattering of light at cross-frequency, and a stable and unstable focal conical state was observed, respectively, for the investigated mixtures.     

Everything you wanted to know about phase and reference frequency in one- and two-dimensional NMR spectroscopy

The fundamental concept of phase discussed in this tutorial aimed at providing students with an explanation of the delays and processing parameters they may find in nuclear magnetic resonance (NMR) pulse programs. We consider the phase of radio-frequency pulses, receiver, and magnetization and how all these parameters are related to phases and offsets of signals in spectra. The impact of the off-resonance effect on the phase of the magnetization is discussed before presenting an overview of how adjustment of the time reference of the free induction decay avoids first-order correction of the phase of spectra. The main objective of this tutorial is to show how the relative phase of a pulse and the receiver can be used to change the reference frequency along direct and indirect dimensions of NMR experiments. Unusual of phase incrementation with non-90° angles will be illustrated on one- and two-dimensional NMR spectra.     

刚球粒子碰撞频率和距离关系的计算机模拟

用Montecallo方法模拟了由两个刚球粒子组成的体系，得到了碰撞频率和粒子间距的定量关系。模拟结果显示，碰撞频率随着粒子间距的增大急剧下降。这一特性为文献[1]中描述的两个粒子体系的聚集过程的碰撞反应动力学提供了有用的旁证。     

Dielectric behaviour of binary dual-frequency nematics with low crossover frequencies

Binary dual-frequency nematic liquid crystals synthesised at the Military University of Technology were measured by dielectric means. All the investigated materials exhibit low crossover frequency. They were composed of only two molecules with longitudinal and transverse dipole moments. The main difference is the molecular weight of the molecules. Results of relaxation parameters of detected mode and crossover frequency are shown. The influence of structure on ion conductivity is discussed. The broad phase transition from an isotropic phase to a nematic one was observed.     

THE TRANSFER OF LOW FREQUENCY SIGNAL BY THE NONNEUTRAL ELECTRON PLASMA IN EV DEVICE

The transfer of low frequency signal by the nonneutral electron plasma in EV deviceis investigated in this paper.The experiment results are consistent with approximate theoryand numerical calculation of rigorous theory,showing that the transfer is due to the wholemovement of the electron plasma.This work provides a practical method for measuring thetotal nonneutral electron plasma energy in similar EV device without destroying the plasmaState.