Spaltung von 1,2,4-Thiadiazol-3-onen mit Triphenylphosphan: Triphenylphosphonio-thioimidazolate und ihre Folgereaktionen

Fission of 1,2,4-Thiadiazol-3-ones by Triphenylphosphane: gewidinet Triphenylphosphonio Thioimidazolates and Their Consecutive Reactions Treatment of benzimidazo[1,2-d][1,2,4]thiadiazol-3(2H)-ones ( 1 ) and imidazo[1,2-d]-[1,2,4]thiadiazol-3(2H)-ones ( 17 ) with triphenylphosphan leads to the liberation of isocyanate and the formation of triphenylphosphonio-thiobenzimidazolat ( 4 ) and triphenylphosphonio-thioimidazolat ( 18 ), respectively. 2,4-Diphenyl-5-phenylimino-1,2,4-thiadiazol-3-one ( 23 ) is desulfurized with Ph₃P and decomposed into phenyl isocyanate and diphenylcarbodiimide whereas the N-unsubstituted imino-thiadiazol-3-one ( 25 ) is attacked at the exocyclic imino group by Ph₃P to give the N-phosphoranylidene thiourea ( 26 ). The structure of 4 can be rationalized as a dynamic system between polar and apolar valence isomeres. Reactions of 1 and 17 with cyanates, isocyanates, carbon disulfide, acetic anhydride, amines, benzyl chloride, grignard compounds, and CH acidic compounds are described.     

Zur Radikalischen Copolymerisation ungesättigter Isocyanate mit Vinylchlorid

On the Free Radical Copolymerization of Unsaturated Isocyanates with Vinylchloride The free radical copolymerization of vinyl-, isopropenyl- and p-vinyl-phenylisocyanate with vinylchloride in mass and tetrahydrofurane solution at 50°C is investigated. The incorporation of the isocyanate monomers in the copolymers is favoured. These monomers effect a great decrease of the rate of copolymerization and a crosslinking of the formed homo- and copolymers, whose extent depends on the kind and the quantity of the incorporated monomers. The crosslinking is caused by the forming of isocyanurate units.     

Säurekatalysierte Umsetzungen von Aromaten mit Alkanen und Cycloalkanen. IX. Alkylierungen mit 2,2,4-Trimethylpentan (Isooctan)

Acid-catalyzed Reactions of Aromatic Hydrocarbons with Alkanes and Cycloalkanes. IX. Alkylations with 2,2,4-Trimethylpentane (Isooctane) The non-conventional alkylation of benzene, toluene, ethyl- and isopropylbenzene, fluoro- and chlorobenzene with 2,2,4-trimethylpentane in the presence of acid catalysts is described. The composition of the rather complex reaction mixtures is determined by gas-liquid chromatography and mass spectrometry, tert. butylarenes being the main products beside alkylsubstituted indanes and tetralines. Their formation is interpreted as a competition between fragmentation and isomerization of the alkylating agent. By use of trifluoromethanesulfonic acid or combinations of catalysts from HF or HSO₃F with variant metallic fluorides at lower temperatures the selectivity of the reaction may be partially raised.     

在机床研发中基于职能单位的产品开发理论与实践

通过调查得知,包括虚拟现实技术在机床制造中应用可能性的应用方法、策略和工具在产品开发中的现状.对调查结果进行了讨论,考虑到研究理论的可移植性和对企业内部实战的依赖性.讨论的结果为基础研究领域的命题"基于职能单位的产品开发"提供结论.     

Über die Reaktionen von Benzimidazol-2-carbonsäurehydrazid mit Elektrophilen

About the Reactions of Benzimidazole-2-carbohydrazide with Electrophilic Compounds Benzimidazole-2-carbohydrazide ( 1 ) reacts with aldehydes and ketones to form N-alkylidene-benzimidazole-2-carbohydrazides( 2a–j ). With carbon disulfide, diphenyl carbonate and cyanates, ring closure takes place to afford 1,2,4-triazines and 1,3,4-oxadiazoles. Attempts to synthezise 2-isocyanato-benzimidazole failed. ¹H-n.m.r. and ¹³C-n.m.r. spectroscopic data of the compounds are given.     

3D-FE-Analysis of CT-specimens including viscoplastic material behavior and nonlocal damage

In order to describe the time-dependent inelastic behavior of steel structures up to failure, a material model is developed within the framework of thermodynamics considering viscoplastic material behavior, isotropic hardening, softening, and isotropic ductile damage. Since softening and damage lead to localization of deformations, the model is extended by a non-local implicit gradient formulation. An additional gradient equation is formulated for the local damage variable in order to achieve results independent of the finite-element discretization. The approach is verified by 3D-structural analysis of CT-specimens.     

The development of a high throughput reactor for the catalytic screening of three phase reactions

The design and utilisation of a reactor for the optimisation of multiple heterogeneous catalytic reactions in liquid phase is described. With the ability to screen up to 25 samples simultaneously at a maximum pressure of 50 bar, the reactor is one of the first to be designed specifically for what is termed stage II, the optimisation phase, of catalytic high throughput experimentation (HTE). Experiments demonstrating the reliability and reproducibility of the reactor are described, including the use of the reactor to study the catalytic hydrogenation of crotonaldehyde (CrAld) over bimetallic samples based on a commercial 5 wt.% Pt on activated carbon catalyst. Modification of the mono-metallic Pt sample by the impregnation of aqueous metal salts and various pre-treatments, resulted in 140 bimetallic catalysts that were used in the hydrogenation study. The changes observed in both selectivity and reactivity of the modified catalysts are described and show, by way of example, how the speed of catalyst screening can be increased by at least an order of magnitude.