Acyl- und Alkylidenphosphane. XVIII. Monoacetyl- und Diacetylphosphan

Acyl- and Alkylidenephosphines. XVIII. Monoacetyl- and Diacetylphosphine When triacetylphosphine 3a is treated with methanol 4 or benzyl alcohol 6 P? C(O) bonds are cleaved and a mixture of diacetyl- 2a and monoacetylphosphine 1a is formed. The thermally labile phosphine 1a decomposes completely within a few hours at +20°C; but 2a also reacts slowly within days to give triacetylphosphine 3a and further unknown compounds. As it is found by nmr-spectroscopic studies the acidic hydrogen atoms of monoacetylphosphine 1a are both bound to phosphorus. In liquid diacetylphosphine 2a or in solutions of this compound, However, there exists an equilibrium between the keto tautomer K- 2a with a PH and the enol tautomer E- 2a with an O? H? O group; compared with pentane-2,4-dione 8a the keto tautomerpredo minates in 2a . As in 1,3-diketones a low temperature and a small dielectric constant of the solvent increase the amount of enol tautomer E- 2a present. The ¹H-nmr resonance of the enolic hydrogen atom is observed at very low field (δ = 18,3 ppm).     

Feldionen- und Elektronenstoß-Massenspektrometrie von Polymeren und Copolymeren. 5. Mitt. Aliphatische und aromatische Polyamide und Polyimide

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Sila-Riechstoffe und Riechstoffe-Isostere. 11. Mitt. Vergleich von Carbinolen und Silanolen mit Thiocarbinolen und Silanthiolen

The thiocarbinolsRC(CH₃)₂SH withR=C₆H₅CH₂ and C₆H₅CH₂CH₂ were prepared via reactions 2–5 and compared in their odors (very unpleasant) with the fragrances of the analogous carbinolsRC(CH₃)₂OH and silanolsRSi(CH₃)₂OH. Silanethiols, prepared by reactions 6–8, smell less unpleasant than thiocarbinols but decompose easily in the presence of catalytic amounts of ammonium salts (eq. 9). Very pure hexenyl-methyl-vinylsilanethiol (silathiolinalool) decomposes contrarily under cyclization to a 1-sila-2-thia-cyclopentane derivative (E 1). The differences of odors, in spite of very similar structures, are discussed in the light of the theory ofAmoore (Size and structure of molecules rule their odor qualities).

Prof. DDDr. DDr. h. c.Viktor Gutmann zum 65. Geburtstag gewidmet.     

Glasumwandlungs-Verhalten von statistischer und Block-Copolymeren und von Polymerblends aus Styrol und Cyclododecylacrylat. 1. Mitt. Glastemperaturen

Ohne Zusammenfassung     

Funktionelle Monomere und Polymere. 26. Mitt Synthese und Polymerisation von Vinylcholat und Vinyldehydrocholat

Ohne Zusammenfassung     

Metallboranate und Boranato-metallate. V. Solvate des Cadmiumboranats und Boranatocadmate

The reaction of CdCl₂ or CdBr₂with LiBH₄, in ether yields no pure Cd(BH₄)₂, but Li₂Cd(BH₄)₄ was isolated as an oily etherate. Similarly, NaCd(BH₄)₃ was obtained from CdCl₂ and NaBH₄ in ether and tetrahydrofurane as solvents. LiCd(BH₄)₃ and NaCd(BH₄)₃ were also formed from the components in ether solution. In these solutions Cd migrates to the anode confirming their formulation as tetrahydroborato-cadmates. Cadmiumtetrahydroborate was formed in the reaction of cadmium methoxide with diborane in tetrahydrofurane (THF) and isolated as crystalline solvates. It reacts with pyridine to give Cd(BH₄)₂ · 3 NC₅H₅ and with NH₃ to yield Cd(NH₃)₆(BH₄)₂.     

Metallboranate und Boranatometallate. 14. Chlorid-tetrahydridoborate des Calciums und Strontiums

Metal Tetrahydridoborates and Tetrahydridoborato Metalates. 14. Chloro Tetrahydridoborates of calcium and Strontium The action of hydrogen chloride on E(BH₄)₂ (E ? Ca, Se) in a 1:1 mole ratio in tetrahydrofuran yields the title compounds isolated as their tetrahydrofuran adducts. No intermediates were detected by ¹¹B n.m.r. spectroscopy in the reaction of methanol with Ca(BH₄)₂. The final product is Ca[B(OCH₃)₄]₂ · THF.     

Chalkogenolat-lonen und ihre Derivate. I. Darstellung und Eigenschaften salzartiger Chalkogenophenolate

Chalcogenolates and their Derivatives. I. Syntheses and Properties of Ionic Chalcogenophenolates The syntheses and properties of ionic chalcogenophenolates are described. Using liquid ammonia as solvent the alkali chalcogenophenolates M[EPh] (M = Na, K; E = Se, Te; Ph = C₆H₅) have been synthesized via reduction of the diphenyl dichalcogenides with alkali metals. Similarly, the tetraphenylphosphonium chalcogenophenolates [Ph₄P][EPh] (E = S, Se, Te) have been obtained by reacting alkali chalcogenophenolates with tetraphenylphosphonium chloride.     

Zur Chemie und Strukturchemie der Phosphide und Polyphosphide. 20. Darstellung,Struktur und Eigenschaften der Alkalimetallmonophosphide NaP und KP

Chemistry and Structural Chemistry of Phosphides and Polyphosphides. 20. Preparation, Structure, and Properties of the Alkali Metal Monophosphides NaP and KP The monophosphides NaP and KP were prepared by reaction of the elements in sealed glass ampoules at 725 K and 765 K, respectively. NaP yields as black reflecting needles, whereas KP is formed as microcrystalline substance with colour of coke. The compounds react very rapidly with aqueous reagents forming solid polymeric yellow phosphanes (PH)_x and partially gaseous products. NaP and KP crystallize in the novel orthorhombic NaP type (P 2₁2₁2₁; a = 603,8 pm; b = 564.3 pm; c = 1 014.2 pm and a = 650.0 pm; b = 601.6 pm; c = 1 128.8 pm; Z = 8, respectively) characterized by onedimensional infinite ¹∞(P^?) helices of covalent twofold bonded P-atoms with mean bond length P? P = 223.9 pm. The compounds can be described as Zintl-phases with M⁺ and P^? with respect to the structure. The range of existence of the NaP type and the LiAs type structure can be separated by the radii ratios. The volume increment for P^? is V(P^?) = 18.0 cm³mol^?1. For the bond energy E(P? P) in the monophosphides a value of 248 kJ · mol^?1 is calculated. The structures are discussed in detail together with related compounds.     

Komplexe von Acetylaceton und Acetonylaceton mit Alkali- und Erdalkaliionen. MO-SCF-Berechnungen und UV-Spektroskopie

In analogy to previous investigations on main group metal ion complexes with diacetyl², model calculations within the LCGO MO SCF framework using minimal basis sets are used in combination with UV spectrocopy in order to investigate complex formation tendencies, eventual ion specifities and ion binding energies of Li, Na, K, Mg and Ca ions with dicarbonyl ligands. The influence of the separation of the coordinative centers by methylene groups on the interaction with these metal ions is discussed. The simple quantum chemical models seem to work in the case of diacetyl and acetylacetone, whereas they fail in the prediction of the experimentally observed interaction of acetonylacetone with the metal ions.

     

Gymnemagenin,Struktur und O-Isopropylidenderivate Glykoside und Aglykone. 313. Mitteilung

Several O-isopropylidene derivatives of gymnemagenin ( 5 ), a hexahydroxytriterpene from the leaves of Gymnema sylvestre R. Br. have been prepared, which may perhaps be useful to correlate gymnemagenin with other triterpenes. From the data obtained we conclude that gymnemagenin is 3β, 16β, 21β, 22α, 23, 28-hexahydroxy-olean-12-ene.     

Zur Chemie und Strukturchemie der Phosphide und Polyphosphide. 12. Die Pentaphosphide des Lanthans und Neodyms,LaP5 und NdP5

Chemistry and Structure Chemistry of Phosphides and Polyphosphides. 12 Pentaphosphides of Lanthanum and Neodymium, LaP₅ and NdP₅ LaP₅ and NdP₅ are formed on heating (750°C, evacuated silica ampoules) filings of La or Nd metal with red phosphorus. LaP₅ crystallizes in the monoclinic space group P2₁/m with a = 9.768, b = 9.679, c = 5.576 Å, β = 105.25° and Z = 4 formula units. NdP₅ crystallizes in the monoclinic space group P2₁/m with a = 4.938, b = 9.551, c = 5.444 Å, β = 103.27° and Z = 2 formula units. The structure of LaP₅ is a superstructure variant of NdP₅. La or Nd atoms and P atoms form layers which alternate along [100]. Within a layer the P atoms are connected to a net of condensed 12-rings. The number of 2-valent and 3-valent P atoms corresponds with the formula . The P? P distances vary from 2.16 to 2.22 Å. Each metal atom is linked with 8 P atoms (averages: La? P = 3.071 or Nd? P = 3.016 Å).     

Isomere Tritolylphosphine und deren Derivate. UV-Spektren und Dipolmomente

The UV spectra of tris(2-methylphenyl)phosphine (I), tris(3-methylphenyl)phosphine (II), tris(4-methylphenyl)phosphine (III), and of their phosphine oxides, phosphine sulfides, and methyl phosphonium iodides are given. The dipole moments of I–III in benzene at 20° C were also determined. I absorbs at the longest wavelength and this result may be interpreted by a broadening of the angle on phosphorus in I. This results also from the measured dipole moment, assuming a constant phosphorus ring moment and neglecting other ortho-effects.     

Über Cyanatverbindungen und deren reaktives Verhalten. XLIII. Darstellung und Eigenschaften von Organomagnesiumthiocyanat- und -selenocyanat-Verbindungen

Cyanates and their Reactive Behaviour. XLIII. Synthesis and Properties of Organomagnesium Thiocyanate and Selenocyanate Compounds RMgX and RMgX · 2 L compounds react with KYCN in tetrahydrofurane via halide pseudohalide exchange reactions to give RMgNCY solutions (R = alkyl or aryl groups; X ? Cl, Br, I; L ? O-donors; Y ? S, Se), from which compounds of the type RMgNCY · 2 THF have been isolated in a crystalline form. The prepared compounds are characterized by analytical data, IR absorption spectra, concentration dependent conductivity measurements and reactive behaviour in relation to classic Grignard reagents.     

Funktionelle Monomere und Polymere. 37. Mitt. Zur Synthese und Polymerisation von Styrolderivaten,die Adenin und Cytosin enthalten

Ohne Zusammenfassung     

Funktionelle Monomere und Polymere. 37. Mitt. Zur Synthese und Polymerisation von Styrolderivaten, die Adenin und Cytosin enthalten

Ohne Zusammenfassung     

Acyl- und Alkylidenphosphane. XXXIII. Lithoxy-methylidenphosphan · DME und -methylidinphosphan · 2 DME — Synthese und Struktur

Acyl- and Alkylidenephosphines. XXXIII Lithoxy-methylidenephosphine · DME and -methylidynephosphine · 2DME — Syntheses and Structures Lithium dihydrogenphosphide · DME(¹) and ethyl formate in a molar ratio of 2 : 1 react in 1,2-dimethoxyethane to give liquid lithium formylphosphide · DME in 87% yield. Since lithium complexed by the chelate ligand DME is bound to the oxygen atom of the carbonyl group, the compound has to be considered as lithoxy-methylidenephosphine · DME ( 1 ). According to x-ray structure analyses of crystalline derivatives [5, 6], molecules of this type dimerize forming a four membered Li O Li O ring. Characteristic nmr-data show the presence of an E- and Z-isomer (δ¹ H  P: 3.87 and 4.49; ¹ J _HP: 150.8 and 136.5; δ¹ H  C: 11.4 and 10.05; ² J _HP: 6.1 and 81.2; ³ J _HH: 6.6 and 13.9; δ³¹ P : 38.6 and 8.8; δ¹³ C P: 225.0 and 215.4 ppm; ¹ J _CP: 41.2 and 65.0 cps); in 1,2-dimethoxyethane an E : Z ratio of 1.86 : 1 is found. In a similar reaction of lithium bis (trimethylsilyl)phosphide · 1.6 THF(¹) with excess dimethyl carbonate lithoxy-methylidynephosphine · 2DME ( 2 ) is formed via an up to now poorly understood mechanism. The compound can also be prepared from lithium dihydrogenphosphide · DME; it crystallizes in the monoclinic space group P2₁/n {a = 880.6(2); b = 1296.6(2); c = 1267.4(2) pm; β = 96.07(2)° at −100 ± 3°C; Z = 4}. An x-ray structure analysis (R_w = 0.052) gives a P C distance of 155.5 pm which is typical for a triple bond. The C O bond length of 119.8 pm, however, is extremely short compared to the standard value of a single bond (139 pm). Angles of 178.5° and 170.7° at the carbon and oxygen correspond with the expected linear configuration of the PC O Li backbone of the molecule, Characteristic nmr-data are as follow: δ³¹ P -384.2; δ¹³ C 166.6ppm; ¹J_cp 41.5 cps.     

Cyclopolymerisation. 11. Mitt. Polyelektrolyte und Polyampholyte aus N-Alkyl-N, N-diallylaminen und Methacrylamid

Ohne Zusammenfassung