Structure, Stability and Vibrational Spectra of LaC_5~n(n=-1,0,+1) Clusters

用密度泛含方法研究了ＬａＣ５ｎ（ｎ＝－１，０，＋１）分子簇的结构和稳定性及振动光谱，对这个六原子体系提出了三种可能构型，点群结构为Ｃ２ｖ对称性．第一个构型为Ｌａ接在弯曲的Ｃ５链上，第二个是Ｌａ通过二个键与Ｃ５环相连第三个是Ｌａ通过一个键与Ｃ５环相连；结果表明，第一个构型即当Ｌａ接在弯曲的Ｃ５链上时能量最低．振动光谱分析指出，当ｎ＝－１时，第二个构型为局域极小值；当ｎ＝＋１时，第一个和第二个构型为局域极小值；对ｎ＝０，局域极小值没有找到．     

GC/MS法分析奶油中的脂肪酸

利用气相色谱/质谱/计算机联用技术分析人造奶油、天然奶油和新西兰奶油中的脂肪酸,从中鉴定出7种酸:棕榈酸、棕榈油酸、硬脂酸、油酸、亚油酸、亚麻油酸及花生酸。人造奶油含亚油酸比天然奶油含的高。     

STUDY ON THE SYNTHESIS OF A NEW TYPE OF PHOSPHORUS HETEROCYCLIC COMPOUNDS-PYRAZOLO[3, 4-d]-1, 3, 2-DIAZAPHOSPHORIN-6-ONE

1-substituted-5-benzoylamino-4-pyrazolecarboxamides(2)were prepared by the reaction of 1-substituted pyrazolo[3, 4-d]-oxazinone(1)with amines in benzene.The compound 2 was refluxed with excess LiAlH₄ in a mixture of THF and ether, one of the two carbamoyl groups in the molecule 2 was reduced selectively.As the results, 1-substituted-5-benzylamino-4-pyrazolecarboxamides (3) were obtained.Compounds 3reacted with Cl₂PPh-X, or P(NET₂)3, producing the title compounds(4).The conditions of the reactions were studied.     

锗（Ⅳ）─苯基荧光酮体系差分脉冲吸附伏安法的研究

在１．４１×１０－２ｍｏｌ／Ｌ的硫酸介质中，锗与苯基荧光酮试剂反应在－０．５７Ｖ（ＶＳ．ＳＣＥ）电位处产生灵敏的络合吸附波．用差分脉冲极谱法测定．该络合吸附波的峰高与锗（Ⅳ）浓度在３．２×１０－８ｍｏｌ／Ｌ－４．０×１０－７ｍｏｌ／Ｌ范围内成正比，检测下限是８．５×１０－９ｍｏｌ／Ｌ．本文详细讨论了测定的最佳条件及电极反应的机理，并用该法测定了人参中锗的含量。     

鲁米诺－亮绿SF－过氧化氢－铜（Ⅱ）化学发光体系的研究

本文报道了鲁米格亮绿ＳＦ－过氧化氢。铜（Ⅱ）化学发光体系，建立了测定微量铜的化学发光新方法。相对标准偏差为２．４％（ｎ＝１０），检出限为１．６×１０￣－９ｍｏｌ·Ｌ￣－１。用于人发、茶叶及铜精矿样品中微量铜的测定，结果令人满意。     

Synthesis and biological evaluation of 3-{[4-(4-[18F]fluorophenyl)methyl] piperazin-1-yl}-methyl-1H-pyrrolo[2,3-b]pyridine for in vivo studies of dopamine D4 receptor

The compound 3-{[4-(4-[¹⁸F]fluorophenyl)methyl]piperazin-1-yl}-methyl-1H-pyrrolo[2,3-b]pyridine ([¹⁸F]3), which is an analogue of L-745,870 binding D₄ This revised version was published online in July 2006 with corrections to the Cover Date.     

Theoretical investigation of the decarbonylation of acetaldehyde by Fe+ and Cr+.

We report a comprehensive theoretical study on the decarbonylation of acetaldehyde by Fe+ and Cr+. Various intermediates, transition states, and products involved in the decarbonylation reactions are fully optimized at the B3LYP/6-311+G(2df,2pd) level of theory. The potential energy surfaces (PESs) corresponding to [M,O,C2,H4]+(M=Cr and Fe) are examined in detail using B3LYP and CCSD(T) methods, respectively. The validity of these theoretical methods is calibrated with respect to the available thermochemical data. Calculations suggest that the Cr+ mediated decarbonylation of acetaldehyde takes place in four steps on the sextet surface: encounter complexation, C-C activation, aldehyde H-shift, and nonreactive dissociation, in good accordance with the Co+ mediated decarbonylation of acetaldehyde [Zhao, Zhang, Guo, Wu, Lu, Chem. Phys. Lett. 2005, 414, 28], while for the Fe+/acetaldehyde system decarbonylation can occur on both the quartet and the sextet PESs. The quartet pathway, which experiences spin-orbit coupling between the two surfaces, is energetically more favorable; whereas along the sextet decarbonylation coordinate several high-energy barriers are revealed. The theoretical results are compared with the experimental product kinetic energy and angular distributions of decarbonylation of acetaldehyde by Fe+ and Cr+ measured using a crossed-beam technique [Sonnenfroh, Farrar, J. Am. Chem. Soc. 1986, 108, 3521].     

Fluorimetric determination of ascorbic acid with o-phenylenediamine

A simple and sensitive fluorimetric method for the determination of ascorbic acid (AA) is described. The method is based on the condensation reaction between AA and o-phenylenediamine (OPDA) in the absence of the oxidant. The fluorescence intensity is measured at excitation and emission wavelengths of 360 and 430 nm, respectively. Under optimum condition, a linear relationship is obtained between the fluorescence intensity and the concentration of AA in the range of 0.05-40 μg ml⁻¹. The detection limit is 0.006 μg ml⁻¹, which is obviously lower than that of other fluorimetric methods reported.     

Mo－Cu－S原子簇化合物［Mo_2Cu_6S_6（SCMe_3）_2（O）_

基于标题簇合物的快原子质谱研究，提出该二簇合物在质谱过程中的可能断裂途径及其簇骼转换的相关性。