有机磷化合物的质谱研究 Ⅹ.1,2-二苯基-3,3-二烷基-2,5-二氧-1,4,2-二氮磷杂环戊烷的EI质谱研究

应用EI质谱和联动扫描技术研究了13个有机磷杂环化合物,讨论了主要离子的形成过程,分子离子在EI条件下的各种重排反应和取代基对不同解离反应产物离子相对强度的影响。

η~3-2-甲基烯丙基稀土配合物的合成及其催化性质的研究

1975年CouPs和Wailes首次合成了第一个η~3-烯丙基稀士配合物——Cp_2Sc(η~3-C_3H_5)。由于该类配合物稳定性差难于合成,目前为止文献上仅有几篇报道。其中代表性的例子是1991年吴文玲等人合成的(η~3-cC_3H_5)_2CeCl_5Mg_2(tmed)_2,并测定了其晶

A MASS-SPECTROMETRIC STUDY OF ORGANIC PHOSPHORUS-COMPOUNDS .5. EI SPECTRA OF 1, 3, 2-OXAZAPHOSPHOLIDINE 2-SULFIDES DERIVATES

The mass spectral behaviour of 15 new type of organic phosphorus compounds with a considerable insecticidal activity, 1, 3,2-oxazaphospholidine 2-sulfides derivatives, under 70 eV electron impact has been studied by means of high and low resolution mass spectrometry as well as by B/E linked scan and MIKES/CID analysis. Discussion is focused into the isomerization between oxygen and sulphur in molecules and some rearrangement reactions.

有机磷化合物的质谱研究——Ⅴ.2-硫-1,3,2-氧氮磷杂环戊烷衍生物

本文报道15种新合成的2-硫-1,3,2-氧氮磷杂环戊烷衍生物的 EI 谱.在质量分析离子动能谱、碰撞诱导分解谱、B/E 联动扫描及高分辨精确质量测量的基础上,讨论了这类化合物的质谱裂解机理及特征.着重讨论上述化合物的氧硫异构现象及几种重排反应.

汉语四声的数学奥秘——频率变比3∶2

本论文采用音乐物理和数学方法揭示了汉语四声的奥秘——频率变比3∶2,这个比例被命名为“宝石配比”.这一发现为语音研究、语音教学以及计算机语音识别提供了一条重要的科学依据.

A combined DFT and SCRF study of solvent effects on 4-methyl-3-penten-2-one

The IR spectrum of 4-methyl-3-penten-2-one is interpreted with the aid of normal coordinate calculations within the Onsager self-consistent reaction field (SCRF) model, using a density functional theory (DFT) method at the Becke3LYP/6-31G* level. The solvent effects on the geometry, energy, dipole moment, and vibrational frequencies of 4-methyl-3-penten-2-one in the solution and in the liquid phase are calculated using the Onsager SCRF model. The calculated vibrational frequencies in the liquid-phase are in good agreement with the experimental values. The solvent reaction field has generally weak influence. For the two main bands of C=C and C=O mixed vibrational modes, small frequency shifts (5-6 cm(-1)), but relatively large changes in IR intensities (up to 101 km mol(-1) in the liquid phase) are found. (C) 1999 Elsevier Science BV. All rights reserved.

Bifunctional AgOAc-catalyzed asymmetric [3+2] cycloaddition of azomethine ylides

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新型结构的1.3μm GexSi（1-x）/Si MQW 波导探测器的优化设计

首次提出了一种新型的环形1.3μm Ge_xSi_(1-x)/Si波导探测器结构.器件的主体由3μm宽环形波导构成.器件的输入端是8μm宽的波导.这两部分通过劈形波导过渡连接.各部分经过优化设计,可以同时实现高的耦合效率和高内量子效率.对于器件的材料结构、电学和光学特性进行了仔细的分析与设计.结果表明,优化设计的器件其外量子效率可达28%,比已经报道的直波导探测器的外量子效率提高2～3倍.而上升下降时间仍然保持在110ps左右.

Syntheses, crystal structures, visible and near-IR luminescent properties of ternary lanthanide (Dy3+, Tm3+) complexes containing 4,4,4-trifluoro-1-phenyl-1,3-butanedione and 1,10-phenanthroline

The ligands 4,4,4-trifluoro-1-phenyl-1.3-butanedione (Hbfa) and 1,10-phenanthroline (phen) were used to prepare ternary lanthanide (Ln) complexes [Dy(bfa)(3)phen and Tm(bfa)(3)phen]. Crystal data: Dy(bfa)(3)phen C(42)H(26)FqN(2)O(6)Dy, triclinic, P (1) over bar, a= 9.9450(6) angstrom, b = 14.0944(9) angstrom, c = 14.6043(9) angstrom, alpha = 82.104(1)degrees, beta = 87.006(1)degrees, gamma = 76.490(1)degrees, V = 1971.1(2)angstrom(3), Z = 2; Tm(bfa)(3)phen C42H26F9N2O6Tm, triclinic, P (1) over bar, a = 9.898(5)angstrom, b = 13.918(5)angstrom, c = 14.753(5)angstrom, a = 83.517(5)degrees, alpha = 86.899(5)degrees, gamma = 76.818(5)degrees, V = 1965.3(14)angstrom(3), Z = 2. The coordination number of the central Ln(3+) (Ln = Dy, Tm) ion is eight, with six oxygen atoms from three Hbfa ligands and two nitrogen atoms from the phen ligand.

New process for the preparation of 3,5-dihydroxy-1-pentylbenzene

A new process for the preparation of 3,5-dihydroxy-1-pentylbenzene, which is used as medicinal intermediate and raw material for the synthesis of HIV restrainer, is proposed in this paper. Technical 3,5-dimethoxybenzoic acid reacted with lithium hydride to form a salt (I) which acylated n-butyllithium directly to give 1-(3,5-dimethoxyphenyl)-1-pentanone (II) in 85.06% yield. Then (II) was reduced through a Wolff-K-Huangminglong reaction at 210 degrees C to give 3,5-dimethoxy-1-pentylbenzene (III). Finally, (III) refluxed with melt pyridine hydrochloride at 200 degrees C for 2 h to afford the target product 3,5-dihydroxy-1-pentylbenzene (IV). The total yield of (IV) amounted to 61.50% and its mass percentage was 98.22%. The products were characterized by means of IR, H-1-NMR, GC and HLPC-MS. The results indicated that this synthetic route was feasible, characterized by simple process and higher yield, and superior to the published ones.