Nuclear magnetic resonance studies of hemoproteins IV. Hindered rotation of heme side methyl group as a probe for studying van der waals contacts in the heme side environments of myoglobin derivatives

1975 ◽  
Vol 386 (2) ◽  
pp. 542-555 ◽  
Author(s):  
Isao Morishima ◽  
Tetsutaro Iizuka
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Van Der Waals ◽  
Hindered Rotation ◽  
Methyl Group ◽  
Magnetic Resonance Studies ◽  
Van Der Waals Contacts ◽  
Nuclear Magnetic

Nuclear Magnetic Resonance Studies of some Trimethyl Tin Carbamates

1972 ◽  
Vol 50 (9) ◽  
pp. 1386-1389 ◽  
Author(s):  
A. E. Lemire ◽  
J. C. Thompson
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Low Temperature ◽  
Chloroform Solution ◽  
Activation Parameters ◽  
Hindered Rotation ◽  
Magnetic Resonance Studies ◽  
Hexane Solution ◽  
Nuclear Magnetic

The low temperature n.m.r. spectra of some trimethylstannyl esters of N,N-dimethylcarbamic acid, N,N-dimethyldithiocarbamic acid, and N,N-dimethylmonothiocarbamic acid have been examined. Activation parameters for hindered rotation about the C—N bond in the trimethylstannyl ester of N,N-dimethylmonothiocarbamic acid have been determined to be: in hexane solution, Ea = 17.0 + 0.5 kcal/mol, [Formula: see text][Formula: see text][Formula: see text] in chloroform solution, Ea = 19.9 ± 0.5 kcal/mol, [Formula: see text][Formula: see text][Formula: see text]not available

Nuclear magnetic resonance studies on the configurations and conformations of heterocyclic nitrosamines

1968 ◽  
Vol 46 (17) ◽  
pp. 2827-2833 ◽  
Author(s):  
Y. L. Chow ◽  
C. J. Colón
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Methyl Group ◽  
Magnetic Resonance Studies ◽  
Rigid System ◽  
Nuclear Magnetic Resonance Spectra ◽  
Equatorial Proton ◽  
Configuration And Conformation ◽  
Nuclear Magnetic

The nuclear magnetic resonance spectra of various heterocyclic nitrosamines were studied in solution. A qualitative view of the long-range diamagnetic effects of a nitrosamino group is advanced and correlated with the chemical shifts of α-equatorial protons and the methyl group in those nitrosamines possessing a preferred conformation or a rigid system. The use of this correlation to decide the configuration and conformation of heterocyclic nitrosamines is discussed. A large chemical shift difference (ca. 3 p.p.m.) between a cis α-axial and a cis α-equatorial proton was noted.

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