Schlüsselbruchstücke in den Massenspektren von Alkaloiden, 3. Mitt.

Zusammenfassung Die wichtigsten massenspektrometrischen Abbaureaktionen, die zur Bildung von Schlüsselbruchstücken in den Chinolizidinalkaloiden der Lupinin-, Cytisin- und Sparteinklasse führen, werden in der folgenden Arbeit erläutert. An Beispielen aus der Cytisinreihe wird demonstriert, wie durch Änderung der Basizität^** von Stickstoffatomen die Bruchstückbildung so gelenkt werden kann, daß einmal aus dem einen und einmal aus dem anderen Teil der Verbindung Schlüsselbruchstücke entstehen.Mit 12 AbbildungenHerrn Prof.Hayek zum 60. Geburtstag gewidmet.2. Mitt.:G. Spiteller undM. Spiteller-Friedmann, Tetrahedron Letters1962, 153.     

C3N6H6(H3BO3)2的合成及晶体结构

以三聚氰胺和硼酸为原料在水溶液中反应合成出了一种新的BCN化合物先驱体C3N6H6(H3BO3)2。XRD表征结果表明三聚氰胺和硼酸的最佳配比为1∶3(物质的量比)。用单晶X-射线衍射分析法测定了该化合物的晶体结构。该化合物属单斜晶系,空间群为P21/C,晶胞参数为a=0.3597(7)nm,b=2.0105(4)nm,c=1.4112(3)nm,α=90,°β=92.07(3),°γ=90,°V=1.0199(3)nm3,Z=4,D c=1.627g.cm-3,μ(MoKα)=0.144mm-1,F(000)=520。晶体结构经全矩阵最小二乘法修正,最终可靠因子R1=0.0519,wR2=0.1361。该化合物是由C3N6H6分子和H3BO3分子通过氢键加合组装形成的三维超分子结构化合物。     

GdB_3O_6-CeB_3O_6二元体系中Tb~(3+)的光致发光

研究了组成对Tb~(3+)激活的GdB_3O_6-CeB_3O_6二元体系的发光亮度、发光光谱和激发光谱的影响。结果表明:在紫外光激发下,Ce~(3+)和Gd~(3+)对Tb~(3+)的发光均有敏化作用,特别是Ce~(3+)对Tb~(3+)的发光敏化效果十分显著;Gd~(3+)在该体系中还能起能量传递的中间体作用;Ce~(3+)→Tb~(3+)能量传递的机理为电多极相互作用的共振传递。     

Füllvorrichtung für einfache Mikrobüretten

Ohne Zusammenfassung     

Vergleich der phenolischen Lösungsmittel für Poly-6-capronamid

Zusammenfassung Mit Hilfe der viskosimetrischen Angaben wurden einige phenolische Lösungsmittel für Polyamide verglichen. Die Lösungsmittelgüte dieser Lösungsmittel sinkt in der Reihe:m-Kresol,p-Kresol, Phenol undo-Kresol.     

Synthesis of C6-to-C6 and C3-to-C3 diamide linked γ-cyclodextrin dimers

The syntheses of three new diamide-linked γ-cyclodextrin dimers joined by substitution at either a glucopyranose C6^A or C3^A carbon are reported. The syntheses involve the reaction of either C6^A or C3^A amino-substituted γ-cyclodextrin with bis(4-nitrophenyl)succinate to form succinamide linked γ-cyclodextrin dimers or reaction of C6^A azide-substituted γ-cyclodextrin with carbon dioxide to form a urea linked γ-cyclodextrin dimer.     

Die erste fluormethylidin-verbrückte molybdän-cluster-verbindung: darstellung und struktur von [(C5H5)3(CO)6Mo3(μ3-CF)]

Treatment of [Cp(CO)₃Mo]⁻ with ClCOCF₂COCl gave [Cp(CO)₃MoCOCF₂COMo(CO)₃Cp] (1), which, by loss of CO gave [Cp(CO)₃MoCOCF₂Mo(CO)₃Cp] (2). Further loss of CO moieties from 2 resulted in a mixture of different molybdenum complexes. The trinuclear complex [Cp₃(CO)₆Mo₃(μ₃-CF)] (3) was considered the most interesting one. The crystal structure of 3 is presented. The compound appears as two crystallographical independent molecules of identical structure, which crystallize in two enantiomeric forms.     

Os3(CO)9(μ3-AsC6H4CH3)(μ3-C6H3CH3) synthesis and crystal structure

One of the products of the reaction of the activated cluster Os₃(CO)₁₁(NCMe) with As(p-tol)₃ in refluxing nonane has been shown by spectroscopic and X-ray crystallographic methods to be Os₃(CO)₉(μ₃-AsC₆H₄CH₃)(μ₃-C₆H₃CH₃), which contains a benzyne moiety bonded asymmetrically from one carbon to one osmium via a σ bond and from a second carbon to form a bridge between the remaining two osmium atoms.     

Arene complexes of zirconium containing triangular cluster cations [(η6-C6H6Me3)3Zr3(μ-Cl)6]n+,n = 2,3

Ionic -mesitylene zirconium complexes (1–4) have been obtained by a reaction between ZrCl₄ and a metal reducer (Al, Zn or Mg) in the presence of AlCl₃ in mesitylene. An X-ray study has shown that in the triangular cluster cations [(-C₆H₃Me₃Zr₃(-Cl₆)]ⁿ⁺ an increase in the charge from 2+ (1,2) to 3+ (3,4) is accompanied by shortening of the Zr-Zr distances from 3.32–3.33 A to 3.27–3.28 Å. AlCl₄ ^– (1), Al₂Cl₇ ^– (1–3), and Mg[(-Cl)₂AlCl₂]₃ ^– (4), the latter found here for the first time, are present in the complexes studied as counterions.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 134–142, January, 1994.     

Tieftemperatur-flüssigphasefluorierung von pentafluorphenyl-element-Verbindungen. Darstellungen und eigenschaften von (C6F5)3AsF2, (C6F5)3SbF2, (C6F5)2SeF2, (C6F5)2SeO,C6F5TeF3 und Cs[(C6F5)3EF3] (E = As,Sb) [1]

The fluorination reactions of (C₆F₅)₃E (E = As, Sb) with elemental flourine yield (C₆F₅)₃EF₂ in high yields. From the reactions of (C₆F₅)₃EF₂ with CsF the new salts Cs[(C₆F₅)₃EF₃] are obtained. (C₆F₅)₂SeF₂ and C₆F₅TeF₃ are formed for the first time by reacting (C₆F₅)₂SeF and (C₆F₅)₂TeF₂ with elemental flourine and XeF₂, respectively. (C₆F₅)₂SeF₂ rapidly reacts with glass, and the new compound (C₆F₅)₂SeO is isolated. The preparations, properties and ¹⁹F NMR spectra of the new compounds are described.