NMR-spektroskopische Untersuchungen zur Solvatation von Tetraphenylimidodiphosphatokomplexen der Lanthanoiden

NMR-spectroscopic Investigations on Solvation of Lanthanoide Complexes of Tetraphenylimidodiphosphate The additional coordination of solvent molecules to chelate complexes LnA₃ of rare earth ions (Ln³⁺) and tetraphenylimidodiphosphate ions (A^?) has been studied by ¹H-NMR spectroscopy. The nature of the solvent has a great influence on the spectra observed especially in the case of paramagnetic Ln³⁺ ions. In acetone as solvent TmA₃ forms a disolvate preferably. The brutto stability constants for the additional coordination of acetone as ligands by TmA₃ are β₁ = (0.013 ± 0.003) mol^?1 · l and β₂ = (0.016 ± 0.001) mol^?1 · l².     

Untersuchungen zur Konstitution und Entwässerung von Natriumtetramethylammoniumsilicathydrat

Investigations of the Constitution and Dehydratation of the Sodium Tetramethylammonium Silicate Hydrate Sodium tetramethylammonium silicate hydrates have a different composition in dependence of the mole-relation silicon dioxide: sodium oxide: tetramethylammonium oxide. The constitution is in all cases a sodium tetramethylammonium tetraanhydrido-bis-cyclotetrasilicate hydrate (double-four-ring silicate hydrate). Investigations of dehydration show that at first double-four-ring silicates with lower water contents are formed before condensation occurs.     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. 62. Darstellung und NMR-spektroskopische Untersuchung von Komplexen des Tetramethyltitans

Contributions to the Chemistry of Transition Metal Alkyl Compounds. 62. Preparation and NMR-spectroscopic Characterization of Tetramethyltitanium Complexes Complexes of tetramethyltitanium with THF and oxygen, nitrogen and phosphorous containing chelating ligands were synthesized and characterized by low temperature n.m.r. spectroscopy. The obtained complexes show a dynamic behaviour in solutions. The results of semiempirical MO calculations favour octahedral and not a trigonal prismatic configuration of the complexes.     

29Si-NMR-Spektroskopie an Silicatlösungen. IV. Untersuchungen zur Kondensation der Monokieselsäure

²⁹Si-NMR Spectroscopy of Silicate Solutions. IV. Investigations on the Condensation of Monosilicic Acid Condensation reactions of the monosilicic acid prepared by hydrolysis of Si(OCH₃)₄ in diluted HCl are investigated by ²⁹Si-n.m.r. spectroscopy. It is shown that the first product of the condensation, which is stable for some time, is not di- but cyclotrisilicic acid. The condensation then proceeds via higher monocyclic and polycyclic acids to branched and crosslinked polymer products. The kinetics of the condensation reactions is investigated in the dependence on SiO₂ concentration and pH value. The mechanism of the condensation, particularly that in the low molecular range, is discussed.     

Beiträge zur Chemie der Übergangsmetall-Diolefinkomplexe. IV. Synthese von Koordinationsverbindungen des Kobalts mit perdeuteriertem Butadien-1,3

Contributions to the Chemistry of Transition Metal Diolefin Complexes. IV. Synthesis of Cobalt Coordination Compounds of Butadiene-d₆ The synthesis and characterization of two cobalt complexes of butadiene-1, 3-d₆ with the empirical formula CoC₁₂D₁₉ and CoC₁₂D₁₈H will be described. The results of the mass spectroscopy and the ¹H-NMR studies lead to the proposed structure:.

• 1 (π-butadiene-1, 3-d₆)(π-3-methyl-d₃-heptadienyl-d₁₀)cobalt.
• 2 (π-butadiene-1, 3-d₆)(π-3-methyl-d₂-heptadienyl-d₁₀)cobalt.

. The mechanism of synthesis of the named complexes will be reported.     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. XIV. Untersuchungen über Benzylwolframverbindungen-Darstellung und Charakterisierung des Wolframtetrabenzyls

Contributions to the Chemistry of Transition Metal Alkyl Compounds. XIV. Investigations on Benzyl Tungsten Compounds. – On the Formation and Characterization of Tetrabenzyl Tungsten Unstable benzyl tungsten pentachloride is formed from tribenzyl boron and tungsten hexachloride. Other benzylating agents yield only less defined reduction products. – Reacting WCl₄ · 2 THF with dibenzyl magnesium W(CH₂C₆H₅)₄ can be obtained. The new compound is stable at room temperature and is thoroughly characterized.     

Schwingungs- und NMR-spektroskopische Untersuchungen von Trivinylen und Trivinyldihalogeniden des Arsens und Antimons

The i.r. and Raman spectra of monomeric AsVi₃, SbVi₃, Vi₃AsHal₂ and Vi₃SbHal₂ (Vi = CH₂ = CH-, Hal = F, Cl) have been recorded and assigned. According to these data the compounds have trigonal pyramidal and trigonal bipyramidal structures, respectively, probably with slightly twisted vinyl groups. The ¹H- and ¹³C-NMR spectra of the products have been measured in different solvents and at different temperatures. For the quantum mechanical calculations of these NMR spectra a modified BASIC version of the known fortran programme LAOCOON III was used.     

NMR-spektroskopische Untersuchungen zur Thiolyse von Decachlorocyclopentaphosphazen,N5P5Cl10

NMR Spectroscopic Studies on the Thiolysis Reaction of Decachlorocyclopentaphosphazenen, N₅P₅Cl₁₀ A series of different but exclusively geminally substituted products, N₅P₅Cl_10?n(SR)_n, is formed by reactions of decachlorocyclopentaphosphazene, N₅P₅Cl₁₀, with sodium ethanethiolate, NaSEt, or benzenethiolate, NaSPh, in benzene or ether. The degree of substitution is low (mainly up to n = 4); intensified conditions do not result in further substitution but in decomposition. The compounds were separated by column chromatography and identified by ³¹P NMR spectroscopy. ³¹P chemical shifts and P—P coupling constants of the investigated compounds systematically change with the progressive substitution by SR groups. The chlorine-replacement pattern is discussed.     

Untersuchungen zur molekulargewichtsverteilung von polyäthylenterephthalat

The molecular weight distribution of carefully prepared thermostabilized poly(ethylene terephthalate) was determined immediately after polycondensation in vacuo (P?_n = 121) and after the melt was stirred at 280°C for 5.5 hr under nitrogen (P?_n = 123). The fractionation was carried out by successive precipitation in liquid phases. The samples were separated into 25 fractions including refractionation. The Flory distribution was observed in all samples.     

Die Anwendung des Nitrometers zur Ermittlung der Konstitution und zur Bestimmung des Stickstoffs in einer Klasse von Nitroverbindungen (Nitroamine)

Ohne Zusammenfassung     

NMR-spektroskopische Untersuchungen an Mercaptophosphazenen. II. NMR-spektroskopische Untersuchungen an 15N-markierten Mercaptophosphazenen

N.M.R. Spectroscopic Investigations of Thiophosphazenes. II. N.M.R. Spectroscopic Investigations of ¹⁵N Labelled Thiophosphazenes Completely ¹⁵N labelled compounds of the type ¹⁵N₃P₃Cl_6?n(SR)_n, R = Et or Ph; n = 0, 2, 4, or 6, and of the type ¹⁵N₄P₄Cl_8?n(SR)_n, R = Et; n = 0, 4, or 8, were prepared and investigated by means of both ³¹P n.m.r. spectroscopy and ¹⁵N n.m.r. spectroscopy respectively. The coupling constants ²J_PP, in some cases only found by simulating the spectra, and the coupling constants ¹J_PN are given. The values of these coupling constants and their relation are discussed. The general tendency is visible, that with increasing coupling constant ¹J_PN the coupling constant ²J_PP decreases. With increasing grade of substitution n the ¹⁵N chemical shifts are changed to higher fields.     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. XLII. Untersuchungen über Norbornylverbindungen des Titans,Zirconiums und Hafniums

Contributions to the Chemistry of Transition Metal Alkyl Compounds. XLII. Investigations on Norbornyl Compounds of Titanium, Zirconium, and Hafnium It is reported about ¹³C-NMR, IR, and mass spectroscopic measurements of (1-Nor)₄M derivatives of Ti, Zr, and Hf and unsuccessful efforts for synthesis of 1-norbornyl titanium halides Furthermore, (2-Nor)₄Ti and (2-Nor)₄Zr were synthesized. These compounds are remarkably less stable than the corresponding 1-norbornyl derivatives and appear to be exo/endo isomer mixtures. At thermolyses of (2-Nor)₄Ti stable (2-Nor)₂Ti is formed. The stability of (7-Nor)₄Ti is comparable with that of (2-Nor)₄Ti.     

NMR-spektroskopische Untersuchungen an 15N-markierten N-Methyl-imidodiphosphorsäure-Derivaten

NMR Spectroscopic Studies of ¹⁵N Labelled N-Methyl-imidodiphosphoric Acid Derivatives ¹⁵N labelled compounds (EtO)_mCl_2?m(O)P? NMe? P(O)(OEt)_nCl_2?n (m = 0–2, n = 0–2) were prepared as a mixture and investigated by means of ³¹P and ¹⁵N NMR spectroscopy. The chemical shift values δ_P and δ_N, and the coupling constants ¹J_PN and ²J_PP are discussed and interpreted qualitatively by semiempirical quantumchemical calculations (CNDO/2) using POPLE 'S ΔE-model.     

NMR-spektroskopische Untersuchungen an Mercaptophosphazenen. I. Verlauf der Reaktion von Natriumethylmercaptid mit Hexachlorocyclotriphosphazatrien bzw. Octachlorocyclotetraphosphazatetraen

N.M.R. Spectroscopic Investigations of Thiophosphazenes. I. Reactions of Sodium Ethylthiolate with Hexachlorocyclotriphosphazatriene and Octachlorocyclotetraphosphazatetraene By reactions of hexachlorocyclotriphosphazatriene with an excess of sodium ethylthiolate as a suspension in ether all of the possible geminal derivatives N₃P₃Cl_6?n(SEt)_n; n = 1–6, are formed in different quantities. Products from reactions of octachlorocyclotetraphosphazatetraene with sodium ethylthiolate, N₄P₄Cl_8?n(SEt)_n, likewise contain all of the geminally substituted derivatives up to n = 8 with the exception of the derivatives with n = 1 and n = 7. Compounds with n = 3, 4, or 5 exist in two geminal isomers respectively. Nongeminal ethylthiochlorophosphazenes were not found by any reaction. The formed compounds were isolated by chromatographic methods and studied by ³¹P n.m.r. spectroscopy.     

Zum Nachweis des Germaniums mit Phenylfluoron und zur Konstitution der Komplexverbindung

Zusammenfassung Durch Adsorption des ausfallenden Niederschlages an der Phasengrenzfläche zwischen Tetrachlorkohlenstoff und wäßriger Lösung konnte die Empfindlichkeit des Germaniumnachweises mit Phenylfluoron von 3,3g Ge/ml bis auf 0,02 g Ge/ml gesteigert werden. Die Zusammensetzung des Germanium-Phenylfluoronkomplexes wurde ermittelt. Danach entfallen auf ein Germaniumatom zwei Molekel Phenylfluoron.Herrn Prof. Dr. A. Kurtenacker zum 70. Geburtstag gewidmet.     

Anwendungsbeispiele der Hochspannungselektrophorese zur Trennung von Radionukliden. IV

Microchimica Acta - Über die quantitative Bestimmung von Seltenen Erden mittels Radioreagensverfahren wurde berichtet. Die Elemente 57 bis 71 werden in wenigen Minuten elektrophoretisch...     

Untersuchungen zur Anwendung ternärer Komplexe in der Photometrie—II Die Bestimmung des Titanium(IV) mit Tiron in Gegenwart von Iminodiessigsäure, Nitrilotriessigsäure bzw. Diethylentriaminpentaessigsäure

As part of a study to evaluate the use of ternary complexes in photometric methods of analysis, three model systems involving titanium(IV) and tiron plus iminodiacetic acid, nitrilotriacetic acid or diethylenetriaminepenta-acetic acid have been investigated. The methods were compared in terms of working range, molar absorptivity, standard deviation, coefficient of variation, slope of calibration line, limit of detection and limit of determination. The extent of interference from 20 other ions was also examined. The nitrilotriacetic acid system was shown to have better selectivity than the other two.     

Untersuchungen der Zersetzungsgleichgewichte und zur Phasenbreite der Molybdäntelluride

Investigation of Decomposition Equilibria and the Phase Fields of Molybdenum Tellurides The Te₂-pressure over Mo₃Te₄ and MoTe₂ as well as over equilibrium mixtures of Mo+Mo₃Te₄, Mo₃Te₄+MoTe₂, and MoTe₂+Te.l, respectively, has been measured directly between 1100 and 1373 K. No remarkable deviations from stoichiometry exist for MoTe₂ as well as for Mo₃Te₄. The coexistence pressures are for Mo/Mo₃Te₄: lg p/10⁵ Pa = 5.56—9879/T, and for Mo₃Te₄/MoTe₂: lg p/10⁵ Pa = 8.398—11790 /T. Third law enthalpies are derived: Δ_fH°(298, Mo₃Te₄) = —195.5±10 with S°(298) = 268, and Δ_fH°(298, αMoTe₂) = —89.5 ± 11 with S°(298) = 115.3 (values in kJ/mol and J mol^?1 K^?1, respectively).