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Reactions of π-Organonickel Complexes with Tertiary Phosphanes In a hexane solution Ni(C5H5)2 reacts with PBu3 or Ph2PBu forming the nickel(O) complexes Ni(PBu3)4 or Ni(Ph2PBu)4 (A). Under the same conditions only one cyclopentadienyl ligand is substituted by PhPBu2 and the nickel(I) compound (C5H5)Ni (PhPBu2)2 (B) is obtained. Products of the reactions between B and α,α′-dipyridyl, hydrogen chlorid in ether, or Ni(PhPBu2),Cl2 are Ni(dipy)2, [PhPHBu2]2[NiCl4], or (C5H5) Ni(PhPBu2)2Cl. By the reaction with HgCl2 a cyclopentadienyl compound of an unknown structur is formed. The compound Ni(PhPBu2)4 which is analogous to A is synthesized by the reduction of bis(acety1acetonato)-nickel with Et2AlOEt in the presence of PhPBu2 or by the reaction of bis (cyclooctadiene-1,5)-nickel with PhPBu2. 相似文献
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The mass spectra of the pyrrolidides of some long-chain carboxylic acids with alicyclic residues attached to their ω-end are discussed and compared with the spectra of the corresponding esters. Fragmentation triggered by the pyrrolidide group generates a series of peaks, which clearly exhibits the size and the structure of the carbon chain. 相似文献
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Walther Lamprecht und Hubert Katzlmeier 《Fresenius' Journal of Analytical Chemistry》1961,181(1):216-229
Zusammenfassung An kristallisierten Enzymen des biologischen Stoffwechsel wird gezeigt, daß bei der Polarographie nur die schwefelhaltigen Proteine katalytische Wasserstoffwellen geben. Von den in der Literatur beschriebenen Doppelstufen der Proteine besitzt nur die im negativeren Potentialbereich liegende Welle die eigentliche katalytische Funktion. Die erste Vorwelle von Proteinen verschwindet, wenn die polarographische Messung bei 0° C durchgeführt wird.In Proteinen sind nur Disulfidgruppen katalytisch wirksam. Sogenannte reine Sulfhydryl-Enzyme haben keinen katalytischen Effekt. Typische SH-Enzyme können jedoch polarographisch als p-Chloromercuribenzoatkomplexe gemessen werden.Durch Harnstoffzusatz bei der polarographischen Messung von Proteinen gelingt es, zwischen maskierten und freien Sulfhydryl- oder Disulfidgruppen an Enzymen zu definieren.Auszug aus der Dissertationsschrift H. Katzlmeier, Technische Hochschule München (1959). 相似文献
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A measuring system is described which permits study of all stages of combustion processes as functions of carrier gas, temperature, residence time and tube filling. The organic sample is fed at constant speed into a stream of carrier gas. The mixture reaches the combustion chamber within a few milliseconds via a transfer capillary. With the help of a viscous inlet system, a sample of the resulting reaction products is taken and fed into a mass spectrometer. Reaction time and temperature can be adjusted within wide ranges or varied continuously. A plot of the extent of reaction of the various combustion products against temperature at a chosen reaction time yields an oxidation-thermogram which gives a clear picture of the combustion process. It is evident from thermograms of selected compounds that the samples decompose in the presence of oxygen at appreciably lower temperatures than in inert gas. The primary step of the decomposition is “oxidative pyrolysis” which often leads to other products than “inert pyrolysis”. The intermediate products found are partly structurally specific and, especially with nitrogen-containing samples, are numerous and long-lived (for example, carbon monoxide, nitric oxide, cyanogen, hydrocyanic acid, cyanic acid and methyl cyanate). The notorious “difficult combustibility” is largely due to the fact that carbon monoxide, cyanic and hydrocyanic acids undergo complete combustion only at very high temperature. The combustion properties of the “empty tube” can be improved noticeably by a filling of quartz wool and markedly by partly filling with platinum wool. 相似文献
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A. Zschunke H. Meyer I. Heidlas B. Messbauer B. Walther H.-D. Schdler B. Thomas 《无机化学与普通化学杂志》1983,504(9):117-127
31P and 195Pt N.M.R. Investigations on Diplatinum (I) Complexes of the Type [Pt2(μ-SPR2)2L2] (L = PR3, PhP(OPh)2, P(OPh)3, CNR) 31P-, 195Pt-chemical shifts and 195Pt–31P- resp. 31P–31P-coupling constants of a series of doubly bridged diplatinum(I) complexes are reported. 31P-coordination chemical shifts of the terminal ligands of complexes of type [Pt2(μ-SPR2)2(P′R3′)2] and some of the various coupling constants are strongly influenced by the π-acceptor strength of these ligands. J(195Pt–195Pt) is found to change the sign among the series of complexes investigated. Thermal singlett triplet exitation giving rise to the paramagnetism of these complexes observed by preliminary EPR-measurements and confirmed by EHT-calculations is deduced from the large values of 2J(P–P′) and 3J(P′P′) as well as the unusually high temperature dependence of some coupling constants and other NMR features. The chemical stability of the doubly bridged core, the coordination shifts of the bridging phosphorus atoms and EHT-calculations suggest a view of aromaticity of the [Pt2(μ-SPR2)2](M–M) unit of these complexes. 相似文献
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