Extraktion und photometrische bestimmung von zinn und blei mit 2-(o-hydroxyphenyl)benzthiazolin

The reaction of 2-(o-hydroxyphenyl)benzthiazoline with tin(II) gives bis-(salicylidenamino-2-thiophenolato)-tin(IV); with lead(II), (salicylidenamino-2-thio-phenolato)-lead(II) is formed. The composition of the complexes in solution was determined by the molar ratio, and the gradient ratio methods; the oxidation state of tin was proved by the use of Mössbauer spectroscopy. Both complexes are suitable for the extraction-photometric determination of traces of these metals. The effects of many diverse ions were examined and procedures are given for the determination of tin and lead.     

Studies on bis(3,5-di-t-butyl-1,2-benzoquinone 1-oximato)manganese(II) and its mixed-ligand complexes

The synthesis, spectroscopy, and redox-reactivity towards PPh(3) of bis(3,5-di-t-butyl-1,2-benzoquinone 1-oximato)manganese(II), Mn(ox)(2), and its mixed-ligand complexes, Mn(ox)L(x) [L(x)=8-hydroxyquinolinato (L(1)), 2,2'-bipyridine (bpy) (L(2)), 1,10-Phenanthroline (phen) (L(3)) and N-(2-hydroxyphenyl)-3,5-di-t-butylsalicylaldiminato (L(4))] complexes, are presented. While some complexes exhibit solid-state ESR spectra they were ESR-silent in toluene or CHCl(3) at 300 K. The reduction of all ESR-silent complexes with an excess of PPh(3), independently from the nature of secondary L(x) ligands, results in the appearance of a six-line hyperfine coupling of 55Mn (I=5/2) (A(Mn)=95-100 G) and a seven-line radical signal, which was assigned to phosphiniminophenoxyl type radicals (g=2.0056-2.0075, A(P)=8. 5 G and A(N)=1.875 G).     

Die sauer katalysierte Umlagerung von 1-Allyl-cyclohexadien-(3,5)-1,2-diolen

Zusammenfassung 1-Allyl-cyclohexadien-(3,5)-diole-(1,2) vom Typ I geben bei Säurebehandlung unter intermediärem Auftreten von 2-Allyl-cyclohexadien-(3,5)-onen (Typ VII_ vornehmlich o- oder p-allyl-substituierte Phenole. Deren Bildungsweise wird diskutiert.     

Die gaschromatographische Trennung von Zinn(IV)- und Titan(IV)-chlorid

Ohne Zusammenfassung     

双[4,6-二叔丁基-2-(3,5-二叔丁基-2-羟苄基)酚]二酯抗氧剂的微波合成及其热稳定性

以2,4-二叔丁基苯酚和二酰氯为原料,利用微波技术设计并合成了5个具有高分子量和高稳定性的新型酚二酯抗氧剂--双[4,6-二叔丁基-2-(3,5-二叔丁基-2-羟苄基)酚]二酯(3a～3e),其结构经1H NMR,13C NMR,IR和元素分析表征.初步热稳定分析(TGA)表明,与传统抗氧剂2246相比,3a和3d具有更好的热稳定性.     

Synthese und Struktur von Vanadium(III)- und Vanadium(IV)-silanolaten

Synthesis and Structures of Vanadium(III) and Vanadium(IV) Silanolates The syntheses of the new and partially known vanadium(III)-silanolate complexes [{V(OSiMe^t₂Bu)₃}₂(THF)] ( 1 ), [Li(THF)₂V(OSiMe^t₂Bu)₄] ( 2 ), [V(OSiMe^t₂Bu)(lut)] ( 3 ), V(OSiPh₃)₃(THF)₃ ( 4 ), [Li(THF)₄][V(OSiPh₃)₄](THF)₂ ( 5 ), [Li(DME)VMes(OSiMe^t₂Bu)₃] ( 7 ), [Li(THF)₄][VMes · (OSiPh₃)₃] ( 8 ), [Li(THF)₄][VMes₃(OSiMe^t₂Bu)] ( 9 ), and Na[VMes₃(OSiPh₃)](THF)₄ ( 10 ) as well as the vanadium(IV) compounds [V(OSiPh₃)₄] ( 6 ), [VMes₃(OSiMe^t₂Bu)] ( 11 ) and [VMes₃(OSiPh₃)] ( 12 ) are reported. In most cases the vanadium atom displays a coordination number of four. The dimeric structure of 1 with coordination numbers of four and five, respectively, has been deduced from molecular mass measurements, mass spectrometry and its magnetic properties. The crystal structures of compounds 2 , 4 , 5 , 9 and 11 were resolved. Complex 2 resembles a bridged contact ion pair in which both metal centres are in a tetrahedral coordination environment. In 4 the ligands are arranged trigonal bipyramidally with the THF molecules in the axial positions. Complexes 5 and 9 crystallize in separated ion paires with the vanadium in a tetrahedral coordination sphere. The crystal structure of 11 is analogous to that of 9 but with consequences due to the higher oxidation state. Oxidation of the vanadates(III), e. g. 5 , 9 and 10 , yields the corresponding vanadium(IV) compounds 6 , 11 and 12 .     

Zur synthese und struktur von pentacarbonylmetall(0)-Komplexen intramolekular basenstabilisierter zinn(III)-verbindungen

The synthesis and structure of pentacarbonylmetal(0) complexes of the types (C0)₅MSn(XCH₂CH₂)₂E (M = Cr, Mo, W; X = O, S; E = NR, PPh, O, S) and (CO)₅ WSn(SCH₂CH₂)₂E · py (E = NMe, O, S) are reported.¹¹⁹Sn and ¹³C NMR studies show the compounds with X = O and E = NR to be dimeric whereas the derivatives with X = S have been found to be monomeric. The π-acceptor behaviour of the ligands Sn(XCH₂CH₂)₂E is comparable to that of the phosphanes. The barriers to internal rotations about the nitrogencarbon bonds have been determined for the NBu^t derivatives.     

Über das thermische Verhalten von Zinn(IV)- und Blei(IV)-Diphosphat

The thermal behaviour of SnP₂O₇ and PbP₂O₇ were investigated. The tin compound is stable at least at temperatures up to 1150°, whereas PbP₂O₇ begins to loss oxygen around 400°. The spectroscopic and roentgenographic analysis of the decomposition product, shows that it is the known polymeric lead(II) metaphosphate.     

Reaktionen von o-halogenacetophenonen mit schwefelkohlenstoff und phenylisothiocyanat

O-Haloacetophenones 1 react with carbon disulfide in the presence of sodium hydride and an alkylating reagent to ketene S,S-acetals 3 and 4. The formation of 1-thiochromones 5 is possible, when the reaction is carried out at 100°. Treatment of 3a with aniline and guanidine, respectively, leads to the ketene N,N-acetal 6 and the 2-aminopyrimidine 7, respectively Reaction of 1 with phenyl isothiocyanate/sodium hydride and following alkylation gives ketene S,N-acetals 9, thiazolidones 14 and thiazolidine 15. Cyclisation of 9 in a basic medium forms the 4(1H)-quinolones 11. The physical properties of synthesized compounds are characterized by means of mass, ¹H NMR, and IR spectra. The possible modes of formation are discussed.     

Darstellung und spektroskopische Charakterisierung von bindungsisomeren Halogenoselenocyanato-Osmaten(IV) und -Rhenaten(IV)

Preparation and Spectroscopic Characterization of Bond Isomeric Halogenoselenocyanato-Osmates(IV) and -Rhenates(IV) By oxidative ligand exchange of appropriate chloro-iodo complexes of Os^IV or Re^IV with (SeCN)₂ in CH₂Cl₂ or by heterogeneous reaction with Pb(SeCN)₂ or AgSeCN in CH₂Cl₂ the new complexes cis-[OsCl₄(NCSe)(SeCN)]^2?, tr.-[OsCl₄Br(NCSe)]^2?, tr.-[OsCl₄Br(SeCN)]^2?, [ReCl₅(NCSe)]^2?, [ReCl₅(SeCN)]^2?, tr.-[ReCl₄I(NCSe)]^2?, tr.?[ReCl₄(NCSe)(SeCN)]^2? and tr.?[ReCl₄(NCSe)₂]^2? are formed and isolated as pure compounds by ion exchange chromatography on DEAE-cellulose. The bond isomers are significantly distinguished by the frequencies of innerligand vibrations: n?_CN(Se) > n?_CN(N); n?_CSe(N) > n?_CSe(Se); δ_NCSe > δ_SeCN. The electronic spectra (10 K) of the solid salts reveal a bathochromic shift for the charge transfer bands of the Se isomers as compared with the corresponding N isomers. The intra-configurational transitions are observed for the Os^IV complexes at 600 to 2400 and for the Re^IV complexes at 500 to 1600 nm. The ⁷⁷Se nmr signals of the Os^IV bond isomers are registrated for Se binding in the region 970 to 1040 ppm, for N coordination downfield at 1540 to 1640 ppm.     

Herstellung,Kristallstruktur und magnetische Eigenschaften von Bis (1,2-benzochinondiimid)-1,2-benzosemichinondiimidokobalt (II)-tetraphenylborat-pentahydrat

Synthesis, Crystal Structure, and Magnetic Properties of Bis(1,2-benzoquinonediimide)-1,2-benzosemiquinonediimidocobalt (II)-tetraphenylborate-pentahydrate Co (II)-salts catalyze the autoxidation of 1,2-diaminobenzene in slightly alkaline solution. Deeply coloured metal complexes are formed during the reaction suggesting intermediate radical or semiquinonediimide stages of the aromatic ligands. Starting from [Co^II (1,2-diaminobenzene)₃] (ClO₄)₂ two different intermediate complexes can be isolated, the magnetic properties of which point to a high-spin cobalt (II)-complex and a low-spin cobalt (II)-complex with a radical ligand respectively. The X-ray structure determination of the latter complex yielded a square pyramidal arrangement, the Co-N₄-plane distance being only 0.5 Å. The dark blue coloured complex is diamagnetic. Two of the aromatic ligands have the oxidation state of a benzoquinonediimide while the third, coordinated by one amino group only, is pseudosemiquinonoid. Crystals of C₄₂H₄₈BCoN₆O₅ are monoclinic, a = 14.493 (5), b = 18.341 (7), c = 15.492 (5) Å, β = 99.198 (5), space group P2¹/n. D_obs. = 1.290, D_calc. = 1.289 g/cm³ for Z = 4. The structure was solved by Patterson's method and refined by least-squares techniques to R = 0.088 for 2866 of 5014 independent reflexions.     

Darstellung und Eigenschaften von Blei(IV)-arsenat-Gelen und kristallinem Blei(IV)-hydrogenarsenat-monohydrat

Lead(IV) acetate reacts with aqueous arsenic acid to yield lead(IV) arsenates, the state of which depends on the conditions of precipitation. At room temperature amorphous precipitates or gelatinous masses are obtained. Also clear solutions are obtained, which need sometime to become gelatinous. At 90°C colourless crystalline lead(IV) hydrogenarsenate-monohydrate, Pb(HAsO₄)₂ · H₃O, is obtained, isotypic with lead(IV) hyrdrogen-phosphate-monohydrate.     

Systematische Untersuchungen zur Polarographie von Nitrosobenzol und von den Mono- und Di-oximen von 1,4-Benzochinon (I). 1.4- und 1.2- Naphthochinon (II) und (III) sowie von 9,10-Anthraehinon (IV)

Ohne Zusammenfassung     

Gasometrische Bestimmung von Hydrazin und einigen seiner Derivate unter Anwendung von Blei(IV)- und Blei(II, IV)-oxid als Oxydationsmittel

Zusammenfassung Die Oxydation von Hydrazin und einigen seiner Derivate mit Blei(IV) und Blei(II, IV) oxid wurde untersucht, und die Bedingungen für die gasometrische Bestimmung von Hydrazinsulfat, Isonicotinsäurehydrazid, Benzoylhydrazin und Semicarbazidhydrochlorid wurden ausgearbeitet.

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Summary The oxidation of hydrazine and some of its derivatives with lead(IV)-oxide and lead(II, IV) oxide has been studied and conditions for the gasometric determination of hydrazine sulphate, isonicotinic acid hydrazide, benzoyl hydrazine, and semicarbazide hydrochloride have been ascertained.

     

Trennung und Charakterisierung von Chloro-aquo-hydroxo-oxo-osmaten(IV)

Separation and Characterization of Chloro-aquo-hydroxo-oxo-osmates(IV) As a result of the acidic hydrolysis of hexachloroosmate(IV), OsCl₆^2?, and/or the careful reduction of osmium tetroxide with iron(II) sulfate in hydrochloric acid products have been obtained which have been separated by column chromatography using diethylaminoethyl cellulose. On the basis of the analytically determined Os:Cl ratios, the ionic charges that could be deduced from the elution behaviour, and the absorption spectra the products have been characterized as the monomers OsCl₅(H₂O)^?, cis-OsCl₄(OH)(H₂O)^?, fac-OsCl₃(OH)₂(H₂O)^? and mer-OsCl₃(OH)(H₂O)₂, the O-bridged dimers Cl₅Os? O? OsCl₅^4?, cis-(H₂O)Cl₄Os? O? OsCl₄(H₂O)^2?and fac-(H₂O)(OH)Cl₃Os? O? OsCl₃(OH)(H₂O)^2? and the hydrogen bridges forming OH-bridged dimers shown in “Inhaltsübersicht”.