Intra- und intermolekulare elektronische und Schwingungsrelaxation

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Synthese und Eigenschaften einigerp-tolyl-phenylsubstituierter Di- und Trisilane und von 1,1,1,3,3,3-Hexaphenyltrisilan

The synthesis and properties of [Ph ₂ p-TolSi]₂, [Ph ₂ p-TolSi]₂SiPh ₂, [Ph ₃ Si]₂Si(p-Tol)₂, [Ph ₂ p-TolSi]₂Si(p-Tol)₂ and (SiPh ₃)₂SiH₂ are described. The silanes are identified using IR,Ra- and²⁹Si-NMR-spectroscopy.

     

Nachweis und Bestimmung von Hydrastin und Berberin in Drogen und Extrakten

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Physikalische und physikochemische Mikromethoden und -apparate

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Titan und Eisen in Titan-, Eisen- und Zirkoniumerzen und -konzentraten

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Darstellung und strukturuntersuchungen von dimethylmetallacet- und acetimidohydrazinderivaten des galliums und indiums

Trimethylgallium and trimethylindium react with N′,N$\text{-}\text{?}$ dimethylacethydrazine and N′,N″,N′″-trimethylacetimidohydrazine, respectively, to form as a first step, monomeric dimethylmetal derivatives with five-membered ring skeletons. These heterocyclic compounds immediately add a further alkylmetal molecule. The ¹H NMR, IR and Raman spectra of these compounds are discussed and the results of X-ray structure determinations of two of the adducts are given.     

Acyclische und cyclische Silylhydrazone und Hydrazonylsilane

Acyclic and Cyclic Silylhydrazones and Hydrazonylsilanes Dimethylketone-di-tert-butylmethylsilylhydrazone ( 1 ) is obtained in the reaction of the silylhydrazine and dimethylketone by condensation. Di-tert-butyldifluorosilane reacts with lithiated hydrazones to give fluorosilylhydrazones 2–4 , (CMe₃)₂SiF? NH? N = CRR′, ( 2 : R=Me, R′=CMe₃; 3 : R,R′=CHMe₂; 4 : R,R′=Ph). The bis(hydrazonyl)silane 5 , (CMe₃)₂Si(NH? N=CPh₂)₂, is formed in a molar ratio 1:2. Tris( 6 )- and tetrakis(hydrazonyl)silanes ( 7 ) are obtained from CMe₃SiF₃ ( 6 ), SiF₄ ( 7 ), and lithiated tert-butylmethylketon-hydrazone. The lithium derivatives 8–11 are formed in the reaction of 1–4 with butyllithium. Bis(silyl)hydrazones ( 12–15 ) are the result of the reaction of halogensilanes and the lithium derivatives of 1(8), 2(9) and 3(10); 12 : (CMe₃)₂SiMe(CMe₃SiF₂)-N? N=CMe₂, 13 : (CMe₃)₂MeSi(PhSiF₂)N? N=CMe₂, 14 : (CMe₃)₂SiF(Me₃Si)N? N=C(Me)(CMe₃), 15 : (CMe₃)₂SiF (SiMe₃)N? N=C(CHMe₂)₂. Saltelimination out of 10 und 11 leads to the formation of the first bis(imino)-2,2,4,4-cyclodisilazanes, 16 :[(CMe₃)₂ SiN? N=C(CHMe₂)₂]₂, 17 : [(CMe₃)₂SiN? N=CPh₂]₂. Cyclisation occurs in the reaction of 12 und 14 with tert-butyllithium, 2-silyl-1,2-diaza-3-sila-5-cyclopentenes ( 18 and 19 ) are formed. Dilithiated 1 reacts with SiF₄ to give the spirocyclic compound 20 . HF-elimination from 18 and dimerisation of the intermediate diazasilacyclopentadiens lead to the formation of the tricyclus 21 .     

Herstellung und Charakteristika von o-Acryloyloxy- und o-Methacryloyloxybenzoes?ure und ihren Polymeren

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Fluorsilyl- und Fluorboryl-substituierte Cyclotetrasilazane Synthese und Kristallstrukturen

Fluorosilyl and Fluoroboryl Substituted Cyclotetrasilazanes. Synthesis and Crystal Structures Mono- and dilithiated octamethylcyclotetrasilazanes ( 1, 6 ) react with fluorosilanes and F₂BN(SiMe₃)₂, respectively, under retention of the cyclotetrasilazane structure yielding the mono- and disubstituted compounds 2–5 and 7–13 . In the reaction of the dilithium compound 6 with a fluorsilane in equivalent amounts, the bicyclic compounds 14 and 15 are obtained. Crystallographic investigations of the compounds 2, 3, 8 , and 9 indicate that the monosilylated eight-membered ring has a cradle conformation while the disilylated ring has a chair conformation. The X-ray structure of the bicyclic system 14 indicates that the nitrogen atoms of the Si₃N-units have a pyramidal environment.     

Herr Kessler und die Oxydation's- und Reductions-Erscheinungen

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