A proton magnetic resonance investigation of the structure of urea

1955 ◽  
Vol 19 ◽  
pp. 195 ◽  
Author(s):  
E. R. Andrew ◽  
D. Hyndman
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Resonance Investigation ◽  
Magnetic Resonance Investigation

Protonenresonanz-spektroskopische Untersuchungen am Chlor-, Brom- und Methylcyclobutadieneisentricarbonyl / A Proton Magnetic Resonance Investigation on Chloro-, Bromo- and Methyl-cyclobutadiene-irontricarbonyl

1974 ◽  
Vol 29 (3-4) ◽  
pp. 219-227 ◽  
Author(s):  
Hans Albert Brune ◽  
Hans Hanebeck ◽  
Gernot Horlbeck ◽  
Hans Hüther
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Electron Distribution ◽  
Membered Ring ◽  
Bond Orders ◽  
Higher Symmetry ◽  
Resonance Investigation ◽  
Cyclic Diene ◽  
Magnetic Resonance Investigation ◽  
Single Bonds

Proton magnetic resonance spectra including all observable 13C-H-couplings have been measured for chloro-cyclobutadiene-irontricarbonyl.bromo-cyclobutadiene-irontricarbonyl and methyl-cyclobutadiene-irontricarbonyl. The results are discussed with respect to structure and bonding. The structure of a cyclic diene with alternating double and single bonds can be excluded for the four-membered ring of all three compounds. Instead the complex bonded cyclobutadiene contains an electron distribution of higher symmetry with — despite the influence of the substituent — nearly uniform bond orders.

A PROTON MAGNETIC RESONANCE INVESTIGATION OF ROTATIONAL ISOMERISM IN 1,1,2,2-TETRACHLORO-1-FLUOROETHANE

1961 ◽  
Vol 39 (1) ◽  
pp. 39-41 ◽  
Author(s):  
R. J. Abraham ◽  
H. J. Bernstein
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Resonance Spectrum ◽  
Rotational Isomerism ◽  
Coupling Constants ◽  
Proton Resonance ◽  
Resonance Investigation ◽  
Magnetic Resonance Investigation

The doublet separation in the proton resonance spectrum of the liquid was measured from −53 to 100 °C. From the variation of the separation with temperature approximate values of the trans and gauche HF coupling constants were obtained. The values of ΔH ≈ 400 cal/mole and ΔS ≈ 0 are also consistent with the data.

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