Isomers of bis(trifluoromethyl)phosphinomethylhydrazine, (CF3)2PNHNHMe and (CF3)2PN(Me)NH2

1969 ◽  
Vol 47 (22) ◽  
pp. 4281-4283 ◽  
Author(s):  
L. K. Peterson ◽  
G. L. Wilson
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Vapor Phase ◽  
Mass Spectra ◽  
Electronic Effects ◽  
Nuclear Magnetic

The synthesis of isomers of bis(trifluoromethyl)phosphinomethylhydrazine, (CF3)2PNHNHMe, 1, and (CF3)2PN(Me)NH2, 2, and their characterization by infrared, nuclear magnetic resonance, and mass spectra, and by vapor phase molecular weight measurements are described. The significance of the formation of both isomers is discussed in terms of steric and electronic effects.

scholarly journals Cleavage of the Graft Bonds in PVDF–g–St Films by Boiling Xylene Extraction and the Determination of the Molecular Weight of the Graft Chains

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1098 ◽  
Author(s):  
Chen ◽  
Seko
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Thermal Degradation ◽  
Gel Permeation Chromatography ◽  
Extraction Time ◽  
Gel Permeation ◽  
Irradiation Graft ◽  
Nuclear Magnetic

To determine the molecular weight of graft chains in grafted films, the polystyrene graft chains of PVDF–g–St films synthesized by a pre-irradiation graft method are cleaved and separated by boiling xylene extraction. The analysis of the extracted material and the residual films by FTIR, nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC) analyses indicates that most graft chains are removed from the PVDF–g–St films within 72 h of extraction time. Furthermore, the molecular weight of the residual films decreases quickly within 8 h of extraction and then remains virtually unchanged up to 72 h after extraction time. The degradation is due to the cleavage of graft bonds, which is mainly driven by the thermal degradation and the swelling of graft chains in solution. This allows determination of the molecular weight of graft chains by GPC analysis of the extracted material. The results indicate that the PVDF–g–St prepared in this study has the structure where one or two graft chains hang from each PVDF backbone.

Spectroscopic and Chromatographic Identification of Precursors, Intermediates, and Impurities of 3,4-Methylenedioxyamphetamine Synthesis

1978 ◽  
Vol 61 (4) ◽  
pp. 951-967 ◽  
Author(s):  
Theodore Lukaszewski
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Thin Layer ◽  
Mass Spectra ◽  
Test Results ◽  
Chromatographic Data ◽  
Nuclear Magnetic

Abstract The ultraviolet, infrared, nuclear magnetic resonance, and mass spectra of a number of precursors, intermediates, and impurities of 3,4-methylenedioxyamphetamine (MDA) synthesis are presented as well as gas-liquid and thin layer chromatographic data. Test results are given on the precursors safrole, isosafrole, and piperonal; the intermediates isosafrole glycol, N-formyl-MDA, and l-(3,4-methylenedioxyphenyl)- 2-nitro-l-propene; the impurities di[l- (3,4-methylenedioxyphenyl) -2-propyl] amine, di[l - (3,4 - methylenedioxyphenyl) -2- propyl] methylamine, and 3,4-methylenedioxyphenyIpropane; and the product MDA. The data are discussed and 2 methods of MDA synthesis are summarized, in which the precursors, intermediates, and impurities are encountered.

Structural studies of the capsular polysaccharide from Haemophilus pleuropneumoniae serotype 2

1987 ◽  
Vol 65 (5) ◽  
pp. 414-422 ◽  
Author(s):  
Eleonora Altman ◽  
Jean-Robert Brisson ◽  
Malcolm B. Perry
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Molecular Weight ◽  
Capsular Polysaccharide ◽  
Structural Studies ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Structure Formula ◽  
Nuclear Magnetic

The capsular polysaccharide of Haemophilus pleuropneumoniae serotype 2 (ATCC 27089) is composed of D-glucose (two parts), D-galactose (one part), glycerol (one part), and phosphate (one part). Hydrolysis, dephosphorylation, methylation, enzymic studies, and 1H and 13C nuclear magnetic resonance experiments showed that the polysaccharide is a high molecular weight polymer of a tetrasaccharide repeating units, linked by monophosphate diester and having the following structure:[Formula: see text]

Regioselective synthesis of new 7,8-dichlorobenzofuro[3,2-c]quinoline-6,9,10(5H)-triones from reactions of 4-hydroxy-2-quinolones with 3,4,5,6-tetrachloro-1,2-benzoquinone

2020 ◽  
Vol 44 (7-8) ◽  
pp. 388-392
Author(s):  
Ashraf A Aly ◽  
Alaa A Hassan ◽  
Nasr K Mohamed ◽  
Lamiaa E Abd El-Haleem ◽  
Stefan Bräse
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Elemental Analysis ◽  
Mass Spectra ◽  
Regioselective Synthesis ◽  
Two Dimensional ◽  
New Compounds ◽  
Nuclear Magnetic

A novel series of 7,8-dichlorobenzofuro[3,2- c]quinoline-6,9,10(5 H)-triones was obtained regioselectively in good yields. The products were formed by the reactions of the 4-hydroxy-2(1 H)-quinolinones with 3,4,5,6-tetrachloro-1,2-benzoquinone in tetrahydrofuran as the solvent. Infrared, nuclear magnetic resonance (two-dimensional nuclear magnetic resonance), mass spectra and elemental analysis were used to elucidate the structures of new compounds.

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