MCM-41-supported bidentate phosphine palladium(0) complex: a highly active and recyclable catalyst for the Sonogashira reaction of aryl iodides

The first MCM-41-supported bidentate phosphine palladium(0) complex has been prepared. This complex is a highly efficient catalyst for Sonogashira reaction and can be reused at least 10 times without any decrease in activity.     

锰（Ⅱ）—邻菲口罗啉配合物极谱吸附波及其应用

在ｐＨ９．５ＮＨ３ＮＨ４Ｃｌ缓冲溶液中，Ｍｎ（Ⅱ）与邻菲口罗啉形成的配合物在－１．３６Ｖ（ｖｓ．ＳＣＥ）处产生一灵敏的吸附波，一阶导数峰电流与Ｍｎ（Ⅱ）浓度在５×１０－８５×１０－６ｍｏｌ／Ｌ范围内呈线性关系，检出限为２×１０－８ｍｏｌ／Ｌ对极谱性质及反应机理进行了研究，用该法测定了大豆和茶叶中的微量锰，结果满意     

Volume and compressibility changes of complex formation between 18-Crown-6 and NaCl,KCl, and CsCl in water

The apparent molal volumes and compressibilities of NaCl, KCl, and CsCl in mixtures of 18-Crown-6 and water have been calculated from density and speed-of-sound measurements at 25°C. The partial molal volumes and compressibilities of the salts when all cations have formed complexes with 18-Crown-6 molecules have been evaluated. The sign and magnitude of the volume and compressibility changes of complex formation strongly suggest that the charge of the cation becomes very effectively screened by the crown ether.     

四元缔合物体系薄层树脂相分离与光度法联用测定痕量钴

提出了在酸性条件下 (pH=5.0),利用阳离子交换树脂-丁二酮肟-碘-钴四元体系,通过薄层树脂相光度法测定钴的新方法。本法灵敏度高 (e454=1.7105L/molcm),比水相光度法提高14倍,精密度理想 (测定2.0礸/ml Co(II) 6次,RSD=1.3%),选择性好。实测药品VB12及天然水中钴,线性范围0.024~2.0礸/ml (定容50ml),检出限10.4ng/ml。     

双核银络合物[Ag_2(dppm)_2(Py)_2(μ-Cl)]ClO_4的合成与结构

二-(二苯基膦)甲烷(dppm)是一种易与金属形成多核络合物的有机膦配体。我们用dppm作为配体合成了一系列银的多核络合物,并对其结构进行了研究。本文报导了其中一个双核化合物[Ag_2(dppm)_2(Py)_2(μ-Cl)]ClO_4的合成及晶体结构、分子结构的测定。     

Inclusion of Nonopiate Analgesic Drugs in Cyclodextrins. I. X-Ray Structure of a 1 : 1 β-Cyclodextrin-p-bromoacetanilide Complex

The preparation and X-ray crystal structure of a 1 : 1 complex between -cyclodextrin (-CD) and the analgesic p-bromoacetanilide are reported. Thermogravimetric and UV spectrophotometric analyses of single crystals grown from an aqueous solution containing host and guest in 1 : 1 molar ratio yielded the composition -CD p-bromoacetanilide $ 13.5H2O. Crystals of the complex are triclinic, space group P1, with a = 15.197(3), b = 15.613(2), c = 15.743(4) Å, = 87.16(2), = 98.29(2), = 103.39(1)° and Z = 2 crystallographically independent complex units per unit cell. The -CD molecules form head-to-head dimers which pack in the channel-mode. Each dimer contains two guest molecules whose acetylamino substituents are located at the dimer interface while the bromine atoms protrude from the -CD primary faces. The acetyl residues of both guest molecules were found to be disordered but the X-ray data permitted     

Studies on the Chemistry of Thienoannelated O , N - and S , N -Containing Heterocycles, 28 [1]. Synthesis of Imidazo[1,5- d ]thieno[2,3- b ][1,4]thiazine Derivatives as GABA -Receptor Ligands

Summary.  GABA-receptor-ligands are still very interesting in drug-development. Usually benzodiazepines are used in the treatment but they have serious side-effects. Thus, a recently synthesized quioxaline derivative which showed reduced side-effects in an animal model was used as a model-substance. The cyclus was modified to optimize the pharmacological profile. Accordingly, a series of imidazo-thieno-thiazines was synthesized starting from 5-acetyl-2-chloro-3-nitrothiophene to yield 6-ethyl-2,3-dihydro-1H-thieno[2,3-b][1,4]thiazine-2-one. Reaction with potassium tert-butoxide and diethylchlorophosphate gave an intermediate, which resulted in the desired ring system after adding the corresponding isocyanides and potassium tert-butoxide. Corresponding author. E-mail: thomas.erker@univie.ac.at Received August 6, 2002; accepted August 13, 2002     

Waugh-型镍钼杂多酸的量子化学计算

采用半经验INDO法，完成了Waugh-型镍钼杂多酸（NH44）6〔NIMO9O32〕·6H2O的量子化学计算，得到146个成键轨道和78个反键轨道，轨道能级，电荷和键序等数据。通过对这些数据的分析，表明杂多酸分子中端氧和Ni都可能为化学活性中心，各原子轨道在分子轨道中都占有一定比例，其HOMO和LUMO能级皆为负值，其体系具有进一步接受电子的能力。这些结论与实验事实一致。     

Mercury(II) complex with terpyridine: structure of the 2∶1 solvate of [Hg(terpy)2](CF3SO3)2 with acetone

[Hg(terpy)₂](CF₃SO₃)₂·0.5(CH₃)₂CO crystallizes in the triclinic space group witha=14.631(6),b=15.258(4),c=18.785(7) Å, =69.66(2), =70.72(1), =88.55(1)°. The crystal structure consists of two independent [Hg(terpy)₂]²⁺ cations, four trifluoromethanesulfonate anions and an acetone molecule in the asymmetric unit. Each mercury atom is coordinated by two tridentate terpyridine ligands forming an irregular six-coordination polyhedron. The Hg–N bond lengths range from 2.27(2) to 2.53(2) Å.     

Preparative Separation and Analysis of Complex Mixtures of Leucomycins and Desmycarosyl Leucomycins Using HPLC and Mass Spectrometry

Composition and hydrolysis products of a biotechnical available complex of macrolides were analyzed by HPLC and ESI-CID-MSⁿ. Major components are leucomycin-type antibiotics (leucomycins A₁ (5), A₇ (3), A₉ (2), 9-desoxy-9-oxo-turimycin H₃ (4) and niddamycin B (6). Hydrolysis of the complex mixture yielded 9-, 13-isoforocidins (7, 8, 9, 11) and 9-oxo-forocidin (10). A preparative separation procedure was elaborated furnishing compounds 3 - 11 for semisynthetic experiments.Prof. Dr. Udo Gräfe deceased on 14.2.2003. For obituarity see: Schlegel B (2003) J Peptide Sci 9: 661–661.