Strukturen und reaktionen von methylantimondihalogeniden und versuche zur darstellung von methylantimon

MeSbCl₂ (1) and SbCl₃ give the adduct MeSbCl₂·0.6SbCl₃ (1a). MeSbBr₂ (2) reacts with NaI to form MeSbI₂ (3) and with Cr(CO)₅ THF to give Me(Br)₂SbCr(CO)₅ (4). The crystal structures of 1a, 2 and 4 are reported. Derivatives of methyl antimony are obtained by reaction of 2 or 4 with Mg in tetrahydrofuran.     

Synthese und Kristallstruktur von KMnP und KMnAs

Synthesis and Crystal Structure of KMnP and KMnAs KMnP and KMnAs have been prepared from the elements at 800-°C in a closed system. X-ray investigations suggest a layer-type structure where the manganese atoms are tetrahedrally coordinated by the phosphorus or arsenic atoms. The coordination polyhedra share common edges in two dimensions. The compounds crystallize in the space group P4/nmm with a = 4.275, c = 7.668 Å for KMnP and a = 4.391, c = 7.791 Å for KMnAs, respectively; z = 2. The structural relations to the ternary arsenides with transition metals and lithium, t o Mn₂As, to the oxidehalides of the lanthanides and to ternary sulfides are discussed.     

Umsetzungen von Δ-triazolinen und von ringketon-anilen mit isocyanaten und isothiocyanaten

Δ²-Triazolines, derived from cyclopentene and aryl azides, react with isocyanates and isothiocyanates giving 1-arylamino-2-carboxamido- and 1-arylamino-2-thiocarboxamido-cyclopentenes respectively. Cyclopentanone anils, which are formed from the triazolines by thermal loss of nitrogen, are intermediates. In contrast, the Δ²-triazoline from norbornene and phenyl azide undergoes induced loss of nitrogen on treatment with phenylisocyanate. The product, a 1:1 adduct less N₂, has been investigated chemically and spectroscopically; the final structural elucidation however requires further experiments.     

Chelometrische Bestimmung von Calcium und Magnesium in Erzen und Konzentraten von Schwermetallen

Zusammenfassung Bei der Bestimmung von Calcium und Magnesium in Konzentraten von Schwermetallen entfernt man Makromengen der störenden Elemente (Fe, Zn, Cu, Pb, u. a.) durch eine einzige Operation, nÄmlich durch die gruppenweise Abscheidung der Metalle mit NatriumdiÄthyldithiocarbamidat aus Acetatlösung bei pH5,5 und anschlie\ende Extraktion mit Chloroform. Das zurückgebliebene Aluminium maskiert man mit TriÄthanolamin und bestimmt durch Titration mit ÄDTA gegen Eriochromschwarz T die Summe von Calcium und Magnesium, dann durch Titration gegen Fluorexon den Calciumgehalt. Bei Proben von Erzen, die in der Regel grö\ere Mengen Titan enthalten, wird vor dem Trennverfahren das Titan gemeinsam mit Eisen mit einer Chloroformlösung von Nitrosophenylhydroxylamin extrahiert.Die Proben schlie\t man mit Salz- und SalpetersÄure auf. KieselsÄure entfernt man durch Abrauchen mit Flu\- und SchwefelsÄure, Antimon durch Abrauchen mit Bromwasserstoff- und SchwefelsÄure.

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Summary Macro-amounts of elements interfering with the determination of calcium and magnesium in concentrates of heavy metals (Fe, Zn, Cu, Pb, etc.) are removed by a single operation, a group precipitation of these metals from their acetate complexes at pH5.5 with sodium diethyldithiocarbamidate and extraction with chloroform. The remaining aluminium is masked with triethanolamine, afterwards Ca and Mg are titrated together with EDTA using Eriochrome Black T. Calcium is then titrated using fluorexone as an indicator. The extraction of titanium and iron with a chloroform solution of nitrosophenylhydroxylamine prior to the procedure is used, if the ores contain larger amounts of titanium.The samples are decomposed by hydrochloric and nitric acids; silica is removed by evaporation with hydrofluoric and sulphuric acids, antimony by evaporation with hydrobromic and sulphuric acids.

     

Erzeugung von sieben- und sechsring-alkinen durch photolyse und thermolyse von cyclopropenonen

A six-membered and two seven-membered cycloalkynes, namely 1 – 3, are generated by matrix photolyses of the corresponding cyclopropenones 4 – 6 at about 15 K and characterized by spectroscopic means and in two cases by identification of the trimerization products 9 and 10.     

Amidometallate von Lanthan und Gadolinium und Umsetzung von Lanthan,Gadolinium und Scandium mit Ammoniak

Amidometallates of Lanthanum and Gadolinium and the Conversion of Lanthanum, Gadolinium, and Scandium with Ammonia By reaction of the metals with NsNH₂ and NH₃ in the hightemperature- autoclave Na₃[La(NH₂)₆], Na₃[Gd(NH₂)₆], and Na[Gd(NH₂)₄] were prepared, but not any compound of Sc. By corresponding experiments with NH₄I only La(NH₂)₃, GdN, and ScH₂ were obtained. Na₃[La(NH₂)₆] and Na₃[Gd(NH₂)₆] are isotypic with Na₃[Y(KH₂)₆], Na[Gd(NH₂)₄] with Na[Yb((NH₂)₄]. The thermal behaviour of the prepared amides was characterized by DTA and tensimetry.     

Synthese und Isolierung von Heptafulven und Sesquifulvalen

The synthesis and isolation of heptafulvene ( 1 ) and sesquifulvalene ( 2 ) is reported: Acetoxy-tropylium-fluoroborate ( 10 ) may be prepared by addition of tropone to acetyl-fluoroborate at low temperatures. The tropylium salt reacts easily with methyllithium and sodium cyclopentadienide to give the acetoxy-methyl-cycloheptatrienes 11 and the acetoxy-cyclopentadienyl-cycloheptatrienes 12 respectively. Gas-phase pyrolysis of 11 and 12 affords in remarkably good yields heptafulvene ( 1 ) and sesquifulvalene ( 2 ), which are isolated in cristalline form at low temperatures. Spectroscopic as well as chemical evidence of the title compounds is presented.     

Matrixreaktionen von AlF und AlCl mit o-atomen: IR-spektren von OAlF und OAlCl

It is possible to synthesize OAlF and OAlCl in an argon matrix by co-condensation of AlF and AlCl with oxygen atoms. The stretching vibrations of these compounds are found at 1148 and 740 cm⁻¹ (¹⁶OAlF), respectively 1094 and 490.5 cm⁻¹ (¹⁶OAlCl). As ¹⁶O/¹⁸O isotopic splitting of all frequencies can be observed, an exact calculation of the force constants f(AlF), f(AlO) and f(AlCl) is possible. The force constant f(AlO) is 6.6 [10² Nm⁻¹] for both compounds. This is the first time, that structural data of molecules, containing aluminium with the formal charge 3+ with an AlO bond, have been obtained.     

Bildung und Eigenschaften von Aoylphosphinen. III. Molekül- und KristallStruktur von Dipivaloylphosphin

Syntheses and Properties of Acylphosphines. III. Molecular and Crystal Structure of Dipivaloylphosphine In the reaction of tris(trimethylsilyl)phosphine with pivaloyl chloride two Si? P bonds are cleaved and dipivaloyltrimethylsilylphosphine is formed. Reaction with methanol yields dipivaloylphosphine. N.m.r. investigations show a tautomeric equilibrium between keto and enol form as in β-diketones. The substance crystallizes in the orthorhombic space group Pmmn with molecules in two crystallographically different sites [cell parameters: a = 14.04(1), b = 13.82(1), c = 6.28(2) Å]. An X-ray structure determination (R = 5.0%) proves the existence of the enol form in the solid, in that (1.) the molecular symmetry is mm 2(C_2v), (2.) P? C bonds are shortened and C? O bonds are elongated, and (3.) we find a symmetric hydrogen bridge with a very short O? O distance. Bond lengths and angles are compared with those of other β-diketones. The packing of molecules is studied in detail.     

Borchelate von Salicylaldoxim und Derivaten

Formation and structure of boron chelates of salicylaldoxime are studied with O-alkyloximes and O-acyloximes of salicylaldehyde. The six-membered ring chelates thus obtained are synthesized also by alkylation resp. acylation of the preformed salicylaldoxime boron chelates. Thermolysis of the difluoroboron or diphenylboron chelates gives fluoroboronic resp. phenylboronic acid derivatives of salicylaldoxime that are isolated as dimeric compounds.     

Kristallstrukturen von Kalium- und Silbercyanamidonitrat

Pseudoelement Compounds. XV Crystal Structure Analysis of Potassium and Silver Cyanamidonitrate The crystal structures of potassium and silver cyanamidonitrate are reported. In both the potassium and the silver salt metal anion contacts via the atoms cyano-N, amide-N and oxygen are observed. The structural parameters of the ion [NO₂NCN]^– are only slightly influenced by the different environments (potassium, silver). K[NO₂NCN] forms a coordination lattice in which the nearest neighbours of the potassium ion are nine N and O atoms belonging to seven different anions. Ag[NO₂NCN] has a layer structure; the silver atoms are arranged in zickzack chains running perpendicular to the layers with an Ag–Ag distance of 3.169(1) Å.     

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.     

Methyl-Dichlorophosphate von Zinn und Blei

Methyl Dichlorophosphates of Tin and Lead The compounds (CH₃)₃M(O₂PCl₂) (I), (M = Sn, Pb) and (CH₃)₂Sn(O₂PCl₂)₂ (II), formed by the reaction of the corresponding methyltin and methylleadchlorides with P₂O₃Cl₄ are described. The IR and Mössbauer spectra suggest that the tin compounds are polymerized through O? P? O bridges, whereby (I) and (II) contain metal atoms with coordination numbers five (D_3h) and six (D_4h), respectively.     

Versuche zur Synthese von Nonafulvenen und von Nonaheptafulvalen

Attempted Synthesis of Nonafulvenes and of Nonaheptafulvalene The reaction of cyclononatetraenide with α-bromobenzyl acetate ( 6 ) as well as with 1,1-dihalodimethylether gives at ?50°, instead of the expected cyclononatetraenes, bicyclo[6.1.0]nona-2,4,6-triene derivatives 10d and 16 (Scheme 3 and 5, respectively). It seems that in some cases the well known thermally disrotative valence isomerization of cyclononatetraenes 7 to 3a, 7a-dihydroindenes 8 is much slower than the formation of bicyclo[6.1.0]nona-2,4,6-trienes of the type 10 and 16 . This type of reaction hurts the Woodward-Hoffmann rules. Possible precursors of the attractive nonaheptafulvalene are prepared by reaction of acetoxy-tropylium fluoborate ( 19a ) as well as of bromo-tropylium bromide ( 19b ) with lithium-cyclononatetraenide (Scheme 8). So far, the attempted gas-phase pyrolysis of the precursors 21a and 21b failed to give nonaheptafulvalene (5).     

Synthese von Betenamin und von Betalain-Modellsubstanzen

Synthesis of Betenamine and of Betalaine Model Substances For comparisons of color, spectroscopic properties, pK_a values, and stabilities, a number of model substances containing the 1,7-diazaheptamethinium chromophore 8 of the yellow and red betalaine plant pigments were prepared by the thermal or photolytic ring opening of simple pyridine derivatives (such as 2 and 14-16 ), followed by the introduction of amines. Among the novel compounds prepared were betenamine perchlorate ( 5 ), the ‘naked’ ring system of the beet-pigment betanine ( C ) as well as two 1,7-diazaheptamethinium salts 25 and 27 with terminal amono acids. The synthesis of 5 started with 4-(2-aminoethyl)pyridine ( 1 ) and proceeded via 2 , ring opening with indoline to 4 , saponification, and intramolecular amine replacement (Scheme 1). The syntheses of 25 and 27 involved only one step, namely ring opening of γ-picoline using (S)-cyclodopa ( 24 ) and (S)-proline ( 26 ), respectively (Scheme 3).     

Synthese und Struktur von assoziiertem μ-Phosphinodiboran und von phosphorsubstituierten Derivaten

Associated -phosphinodiborane, (-H₂PB₂H₅) _n , is formed in the reaction of H₂P(BH₃)₂Na with HCl in diethyl ether solution at –96°C. The formation of B–H–B bridges is demonstrated by IR and¹¹B-NMR spectra. (-H₂PB₂H₅) _n decomposes thermally to diborane and polymeric phosphinoborane analogous to -H₂NB₂H₅. Other phosphorus substituted -phosphinodiboranes associated via B–H–B bridges are formed in the reaction of the salts (CH₃)PH(BH₃)₂Li, (CH₃)₂P(BH₃)₂Li, andPhPH(BH₃)₂Li with HCl.

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Mit 6 Abbildungen

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Herrn Professor Dr.E. Hayek zum 70. Geburtstag gewidmet.     

Untersuchung und Beurtheilung von Gerbmaterialien und von Leder

Ohne Zusammenfassung     

Untersuchung von Fleisch und Wurst und von Bouillonersatzmitteln

Ohne Zusammenfassung     

Synthese und eigenschaften von dialkylaminodifluorarsinen

The reactions of secondary amines with AsF₃ lead to the formation of dialkylaminodifluorarsines F₂As-NR₂. Eight aminoarsines have been prepared by this method and are describe. IR, ₁₉F and ₁H-NMR and mas spectral data are presented for these compounds and discussed. The fluorination of aminodicholorarsines Cl₂As-Nr₂ with SbF₃ or ZnF₂ produces only small yields of the difluorarsines F₂As-NR₂; fluorination of AsCl₃ under the same conditions, however, is a suitable preparative method for the synthesis of AsF₃.     

Bestimmung von Niob- und Zirkoniumspuren in Titandioxid und in Ilmenit

For the determination of traces of niobium and zirconium, TiO₂ and ilmenite are decomposed by fusion with boric acid and NaKCO₃. The mass is dissolved in 8 N HCl and Fe(III) extracted with di-iso-propylether. Thereafter Nb and Zr are separated from Ti by solvent extraction with tri-n-octyl phosphine oxide in cyclohexane. Both elements are backextracted with aqueous oxalic acid and determined by X-ray fluorescence or photometry with sulphochlorophenol S (Nb) or arsenazo III (Zr).