Condensations at the Methyl Groups of N-Acetylbenzamide and Diacetylimide by Means of Potassium Amide in Liquid Ammonia

1964 ◽  
Vol 86 (5) ◽  
pp. 872-876 ◽  
Author(s):  
Stewart D. Work ◽  
David R. Bryant ◽  
Charles R. Hauser
Keyword(s):  
Liquid Ammonia ◽  
Methyl Groups

Tetraalkyldibismutane/Tetraalkyldibismutanes

1983 ◽  
Vol 38 (2) ◽  
pp. 125-129 ◽  
Author(s):  
Hans Joachim Breunig ◽  
Ditmar Müller
Keyword(s):  
Spectral Data ◽  
Nmr Spectra ◽  
Liquid Ammonia ◽  
Methyl Groups ◽  
H Nmr

Abstract The tetraalkyldibismutanes R2BiBiR2 (R = Et, Pr, iPr, Bu) were synthesized by reactions of 1,2-dibromoethane with sodium dialkylbismutides, which were produced by cleavage of the corresponding trialkylbismutanes with sodium in liquid ammonia. The dibismutanes were isolated in good yields as air sensitive red liquids. Spectral data of dibismutanes and some bismutanes are compared with data of their antimony analogues. 1H NMR spectra reveal, that the methylene protons in Et4Bi2 as well as the methyl groups in iPr4Bi2 are diastereotopic.

C-Aroylations of imides and N-aroylations of β-keto amides with aromatic esters by means of sodium hydride to form β-keto imides

1968 ◽  
Vol 46 (15) ◽  
pp. 2561-2566 ◽  
Author(s):  
James F. Wolfe ◽  
George B. Trimitsis ◽  
Charles R. Hauser
Keyword(s):  
Liquid Ammonia ◽  
Sodium Hydride ◽  
Amide Group ◽  
Methyl Groups ◽  
Aromatic Esters ◽  
Synthetic Utility ◽  
C And N ◽  
Hydride Method ◽  
Better Than

Aroylations at the methyl groups of N-acetylbenzamide and p-benzoylaminoacetophenone, and at a methylene position of succinimide with appropriate aromatic esters were effected by means of sodium hydride in refluxing monoglyme. Benzoylation at the amide group of α-benzoylacetamide and salicylamide were accomplished similarly. The yields of β-keto imides from these C- and N-aroylations by sodium hydride, with which intermediate dianions were evidently not formed, were generally much better than those obtained through dianions produced by means of an alkali amide in liquid ammonia. The synthetic utility of the sodium hydride method is discussed.

Ammonolysis of titanium tetrachloride in liquid ammonia

1976 ◽  
Vol 73 ◽  
pp. 849-851 ◽  
Author(s):  
Thomas Kottarathil ◽  
Gérard Lepoutre
Keyword(s):  
Liquid Ammonia ◽  
Titanium Tetrachloride

Reduction of carbon impurities in aluminium nitride from time-resolved chemical vapour deposition using trimethylaluminum

2020 ◽  
Author(s):  
Polla Rouf ◽  
Pitsiri Sukkaew ◽  
Lars Ojamäe ◽  
Henrik Pedersen
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Aluminium Nitride ◽  
Methyl Groups ◽  
Time Resolved ◽  
Thermally Induced ◽  
Light Emitting ◽  
Carbon Impurities ◽  
Wide Range

<p>Aluminium nitride (AlN) is a semiconductor with a wide range of applications from light emitting diodes to high frequency transistors. Electronic grade AlN is routinely deposited at 1000 °C by chemical vapour deposition (CVD) using trimethylaluminium (TMA) and NH<sub>3</sub> while low temperature CVD routes to high quality AlN are scarce and suffer from high levels of carbon impurities in the film. We report on an ALD-like CVD approach with time-resolved precursor supply where thermally induced desorption of methyl groups from the AlN surface is enhanced by the addition of an extra pulse, H<sub>2</sub>, N<sub>2</sub> or Ar between the TMA and NH<sub>3</sub> pulses. The enhanced desorption allowed deposition of AlN films with carbon content of 1 at. % at 480 °C. Kinetic- and quantum chemical modelling suggest that the extra pulse between TMA and NH<sub>3</sub> prevents re-adsorption of desorbing methyl groups terminating the AlN surface after the TMA pulse. </p>

Detection of Chemical Exchange in Methyl Groups of Macromolecules

2019 ◽  
Author(s):  
Michelle Gill ◽  
Andrew Hsu ◽  
Arthur G. Palmer, III
Keyword(s):  
Relaxation Rate ◽  
Chemical Exchange ◽  
Double Quantum ◽  
Methyl Groups ◽  
Multiple Quantum ◽  
Relaxation Data ◽  
E Coli ◽  
Methyl Trosy ◽  
Dynamics Simulations ◽  
Exchange Broadening

<div> <div> <div> <p>The zero- and double-quantum methyl TROSY Hahn-echo and the methyl <sup>1</sup>H-<sup>1</sup>H dipole- dipole cross-correlation nuclear magnetic resonance experiments enable estimation of multiple quantum chemical exchange broadening in methyl groups in proteins. The two relaxation rate constants are established to be linearly dependent using molecular dynamics simulations and empirical analysis of experimental data. This relationship allows chemical exchange broadening to be recognized as an increase in the Hahn-echo relaxation rate constant. The approach is illustrated by analyzing relaxation data collected at three temperatures for <i>E. coli </i>ribonuclease HI and by analyzing relaxation data collected for different cofactor and substrate complexes of <i>E. coli </i>AlkB. </p> </div> </div> </div>

Solubility of argon, and gaseous mixture argon-methane-nitrogen in liquid ammonia

1970 ◽  
Vol 35 (12) ◽  
pp. 3757-3761 ◽  
Author(s):  
J. Matouš ◽  
J. Šobr ◽  
J. P. Novák
Keyword(s):  
Liquid Ammonia ◽  
Gaseous Mixture

The synthesis and stereochemistry of the ternary cobalt(III) complex with a stereospecific ligand derived from (S)-leucine

1986 ◽  
Vol 51 (2) ◽  
pp. 318-326 ◽  
Author(s):  
Milan Strašák ◽  
Pavol Novomeský
Keyword(s):  
Ir Spectroscopy ◽  
Aqueous Medium ◽  
Absorption Spectroscopy ◽  
Absolute Configuration ◽  
Nmr Spectra ◽  
Methyl Groups ◽  
Electron Absorption Spectroscopy ◽  
Electron Absorption ◽  
C Nmr

A new stereospecific ligand, ethylenediamine-N,N'-di(S)-α-isocapronic acid, was synthesized by condensation of (S)-leucine with 1,2-dibromoethane in alkaline aqueous medium. It follows from the 1H and 13C NMR spectra that the terminal methyl groups are chemically and magnetically nonequivalent. Of the four theoretically possible isomers of the ternary cobalt (III) complex with ethylenediamine, separation on catex yielded only one, whose absolute configuration was determined by a combination of 1H and 13C NMR, electron absorption spectroscopy and CD and IR spectroscopy.

Preparation, properties and structure of some intermediate nido- and arachno-monocarbaboranes

1981 ◽  
Vol 46 (10) ◽  
pp. 2345-2353 ◽  
Author(s):  
Karel Baše ◽  
Bohumil Štíbr ◽  
Jiří Dolanský ◽  
Josef Duben
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Nmr Spectra ◽  
Liquid Ammonia ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Starting Compound

The 6-N(CH3)3-6-CB9H11 carbaborane reacts with sodium in liquid ammonia with the formation of 6-CB9H12- which was used as a starting compound for preparing the 4-CB8H14, 9-L-6-CB9H13 (L = (CH3)2S, CH3CN and P(C6H5)3), 1-(η5-C5H5)-1,2-FeCB9H10-, and 2,3-(η5-C5H5)2-2,31-Co2CB9H10- carboranes. The 4-CB8H14 compound was dehydrogenated at 623 K to give 4-(7)-CB8H12 carborane. Base degradation of 6-N(CH3)3-6-CB9H11 in methanol resulted in the formation of 3,4-μ-N(CH3)3CH-B5H10. The structure of all compounds was proposed on the basis of their 11B and 1H NMR spectra and X-ray diffraction was used in the case of the transition metal complexes.

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