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  • 1
    Electronic Resource
    Electronic Resource
    Untersuchungen über die Tautomerie von Dialkylestern der 1-Cyano-2-oxo-alkanphosphonsäuren durch die Methode der σϱ-Analyse und die LCAO-MO-Methode (1975)
    Springer
    Monatshefte für Chemie 106 (1975), S. 1533-1541 
    Details
    ISSN: 1434-4475
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The applicability of the principle of linear free energies to the tautomerism of dialkyl esters of 1-cyano-2-oxo-alkanephosphonic acids is studied. Correlations between the tautomeric equilibrium constants andTaft's inductive constants, as well asKabachnik's σ ϕ constants of the substituents in RO-groups at the phosphorus atom and those at the carbonyl group in some series of compounds of this type are found. The dominating inductive influence of the R-substituents on the position of tautomeric equilibrium in these compounds is proved also by model quantum chemical investigation of the effects of conjugation in the corresponding tautomeric forms byHückel's LCAO—MO-method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00913628
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  • 2
    Electronic Resource
    Electronic Resource
    Darstellung, Struktur und Reaktionsfähigkeit von Metallderivaten des 1-Propinphosphonsäure-diethylesters (1980)
    Springer
    Monatshefte für Chemie 111 (1980), S. 1351-1358 
    Details
    ISSN: 1434-4475
    Keywords: Allene-acetylene isomerization ; Metal derivatives ; Phosphonic acid derivatives
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Metallation of diethyl ester of 1-propynephosphonic acid (1-DEPP) is achieved by treatment with alkaline amides, calcium amid and calcium in liquid ammonia, with isopropylmagnesium chloride in ether or via metal exchange from the potassium derivative of 1-DEPP with copper(II) and cobalt(II) chloride resp. On the basis of IR-and1H-NMR-spectra the calcium derivative appears as a mixture of an allene and its isomeric acetylene. The IR-spectrum of the lithium derivative is consistent with an analogous phenomenon while an acetylene structure is attributed only to the cobalt and copper derivatives. The alkylation of the potassium derivative with alkyl halides and the hydroxy-alkylation with benzaldehyde occur with low yield at the γ-position of the parent compound.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00903662
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  • 3
    Electronic Resource
    Electronic Resource
    Darstellung, Struktur und Reaktionsfähigkeit des Magnesium-diäthylphosphono-acetons. IR-Spektroskopische Angaben über seine Kationotropie in Lösung (1967)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 100 (1967), S. 3139-3145 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Magnesium reagiert mit dem Diäthylester des Phosphono-acetons in flüssigem Ammoniak in hoher Ausbeute zu Magnesium-diäthylphosphono-aceton, das mit Acetylchlorid das O -Acetylderivat, mit Äthyljodid hingegen das C-Äthylderivat des Diäthylphosphono-acetons liefert. Aus den IR-Spektren folgt, daß Magnesium-diäthylphosphono-aceton in kristallinem Zustand ein Enolat mit Chelatbildung zwischen dem Magnesium und dem Sauerstoff der P=O-Gruppe darstellt, während in CCl4-Lösung Kationotropie zwischen der Chelat- und der Carbeniatform besteht.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19671001002
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  • 4
    Electronic Resource
    Electronic Resource
    Magnesium-acetylacetonat, Mg3[MeC(O)CHC(O)Me]6, und Magnesium-(diethoxyphosphinyl)acetonat, Mg3[(EtO)2P(O)CHC(O)Me]6, dreikernige Chelatkomplexe (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 3529-3534 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Magnesium Acetylacetonate, Mg3[MeC(O)CHC(O)Me]6, and Magnesium (Diethoxyphosphinyl)acetonate, Mg3[(EtO)2P(O)CHC(O)Me]6- Trinuclear Chelate ComplexesThe title compounds 1 and 2 have been investigated by X-ray structure analysis and found to be trimeric. Each Mg atom is coordinated by six O atoms with a distorted octahedral array. The bridging of the central Mg atom with the terminal ones is achieved by common O atoms of the carbonyl groups. Whereas the preparation of magnesium (diethoxyphosphinyl)acetonate (2) has been reported previously, magnesium acetylacetonate (1) has been obtained for the first time by dehydration of Mg(acac)2(H2O)2.
    Notes: Röntgenuntersuchungen ergaben für die Titelverbindungen 1 und 2 trimere Strukturen. Jedes Mg-Atom ist von sechs O-Atomen verzerrt oktaedrisch koordiniert. Die Verbrückung des zentralen Mg-Atoms mit den endständigen erfolgt durch gemeinsame O-Atome der Car-bonyl-Gruppen. Magnesium-(diethoxyphosphinyl)acetonat (2) wurde nach Literaturangaben hergestellt, die Darstellung von Magnesium-acetylacetonat (1) erfolgte erstmals durch Entwässerung von Mg(acac)2(H2O)2.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180909
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  • 5
    Electronic Resource
    Electronic Resource
    IR-Spektroskopische Untersuchungen über die Kinetik der kationotropen Umwandlung von Magnesium-diäthylphosphono-aceton in Lösung (1970)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 3190-3195 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: IR-Spectroscopic Studies on the Kinetics of the Cationotropic Conversion of Magnesium-diethylphosphonoacetone in SolutionThe kinetics of the cationotropic conversion of magnesium-diethylphosphonoacetone in tetrachloromethane solution has been studied by means of IR-spectra. The kinetic curves of the formation of the C-form 2 show complete conversion of the chelate 1 into 2. The rate of conversion increases with decreasing concentration of the solution. An empirical relationship between the starting concentration and half-time conversion has been found. The influence of various solvents on the rate of conversion has been investigated. A precise assignment of the fundamental frequencies of both forms has been made.
    Notes: Die Kinetik der kationotropen Umwandlung von Magnesium-diäthylphosphono-aceton in Tetrachlorkohlenstofflösung wird IR-spektroskopisch gemessen. Die kinetischen Kurven für die Bildung der C-Form weisen auf die vollständige Umwandlung des Chelats 1 in die C-Form 2. Mit der Abnahme der Lösungskonzentration nimmt die Umwandlungsgeschwindigkeit zu. Es wurde eine empirische Abhängigkeit der Anfangskonzentration von der Halbumwandlungszeit festgestellt und der Einfluß unterschiedlicher Lösungsmittel auf die Umwandlungsgeschwindigkeit untersucht. Ferner wurde die Zuordnung der grundlegenden, die beiden Formen kennzeichnenden Frequenzen präzisiert.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19701031022
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  • 6
    Electronic Resource
    Electronic Resource
    Darstellung, Struktur und Reaktionsfähigkeit einiger Metallderivate der Cyan-methanphosphonsäure-dialkylester (Dialkylphosphonoacetonitrile) (1971)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 104 (1971), S. 3073-3079 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis, Structure and Reactivity of Some Metal Derivatives of Dialkyl Cyanomethanephosphonate (Dialkylphosphonoacetonitrile)By direct metallation of diethyl cyanomethanephosphonate (diethylphosphonoacetonitrile, DÄPAN) with magnesium in liquid ammonia, with sodium or potassium in ether//dioxane (1:1), as well as the dipropylester the metallic derivatives have been obtained. The i.r. and 1H n.m.r. spectroscopic investigation indicates a slow isomerisation. By reaction of magnesium-diethylphosphonoacetonitrile with alkyl halides or acyl chlorides the C-alkyl or C-acyl derivatives have been obtained in 10-44% yields.
    Notes: Durch direkte Metallierung von Cyan-methanphosphonsäure-diäthylester (Diäthylphosphonoacetonitril, DÄPAN) mit Magnesium in flüssigem Ammoniak bzw. Natrium bzw. Kalium in Äther//Dioxan (1:1) sowie des Dipropylesters derselben Säure wurden die Metallderivate erhalten. Die 1R- und 1H-kernresonanzspektroskopische Untersuchung ihrer Struktur weisen auf eine Isomerisierung hin. Mit Alkylhalogeniden bzw. Acylchloriden wurden aus Magnesium-diäthylphosphonoacetonitril die C-Alkyl- bzw. C-Acyl-Derivate in 10-44 proz. Ausbeute erhalten.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19711041011
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