Die photochemische reaktion von decacarbonyl-dirhenium mit cyclischen und acyclischen olefinen

Re₂(CO)₁₀ reacts on photochemical induction with acyclic or cyclic olefins with one to four CC bonds. The main products are octacarbonyl-μ-hydrido-μ-olefinyl-dirheniumm complexes. Isomerism of the olefinyl ligands is observed. In some cases the simple substitution products enneacarbonyl-η-olefindirhenium can be isolated. With cyclopentadiene and cycloheptatriene tricarbonyl-η⁵-cyclodienylrhenium compounds are the favoured side products. Ethylene yields Re₂(CO)₈H complexes with vinyl and 1-buten-1-yl bridges. Additionally trinuclear complexes with one and two vinyl bridges are obtained. The complexes are characterized spectroscopically.     

Zur reaktion von N-Hydroxysuccinimid mit dicyclohexylcarbodiimid

N-Hydroxysuccinimide reacts with dicyclohexylcarbodiimid in molar-proportion (3:1) forming dicyclohexylurea and succinimide oxycarbonyl-β-alanin-hydroxysuccinimid ester 7. The structure of 7 has been confirmed by NMR and chemical methods.     

Zur reaktion von tricyclopentadienyl-lanthanoid-komplexen mit 1-alkinen

Contrary to the prediction based on published pK₃-data (for cyclopentadiene and phenylethyne), Cp₃Ln^III-complexes react readily with various 1-alkynes, HCCR, by liberating cyclopentadiene. While for Ln = Yb and R = n-alkyl the formation of the novel metallacycles [Cp₂YbCCR]₃ involving

bridges and quite exceptional ¹H NMR spectroscopic features is preferred, the “lighter” Ln-element Nd apparently avoids the formation of corresponding {Cp₂NdCCR} moieties with still intact μ-(CCR) ligands in favour of a partial regeneration of Cp₃Nd.     

Die Kernresonanzspektren von N-substituierten 2.6-Dimethylmorpholinen

The NMR spectra of N-substituted 2,6-dimethylmorpholines after separation into cis- and trans-isomers by VPC have been investigated. The spectral parameters (chemical shift and coupling constants) are evaluated by a mathematical analysis. The spectra of the cis-compounds show some special features so far unexplainable. The difference of the chemical shift of the protons in 3-position of the cis-isomers depends strongly on the nature of the N-substituent.     

Zum mechanismus der reaktion von alkylierten aromaten mit dichlorcarben

Tropylium halides (type B) are not stable. When trying to prepare these from 4 resp. 7 subsequent products are obtained. Makosza reaction of 4 gives the same product 1 as from 2-methyl naphthaline. Thus, B is an intermediate.     

Arylvanadium-verbindungen XI. Zur reaktion von trimesitylvanadium mit ketonen

Trimesitylvanadium in solution reacts with a series of ketones. Depending upon the structures of the ketones these reactions yield olefins, alcohols or a radical, respectively. Sterically hindered ketones only form coordination compounds with trimesitylvanadium or do not react at all.     

Über die reaktion von pyridin mit maleinsäureanhydrid-I

The reaction between pyridine and maleic anhydride was studied thermoanalytically. With reagents of high purity, the reaction proceeds very slowly with formation of oligomeric and polymeric products. Protic reagents (such as water, maleic acid, acetic acid or pyridinium hydrochloride) catalyse the reaction during which polymerization occurs at a later stage.Radical inhibitors (such as sulphur, 2,2-diphenyl-1-picryl hydrazyl or anthracene) have no influence on the reaction rate.Ultra-violet spectroscopic studies on solutions of maleic anhydride and some derivatives in pyridine and dimethyl sulphoxide show a charge-transfer absorption for the maleic anhydride/pyridine system at 303 nm.