Ring current calculations and proton nuclear magnetic resonance chemical shifts in 2,3-dicarbahexaborane-8 and some derivatives

1968 ◽  
pp. 557
Author(s):  
Thomas Onak ◽  
Dennis Marynick ◽  
Peter Mattischei
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Ring Current ◽  
Chemical Shifts ◽  
Proton Nuclear Magnetic Resonance ◽  
Nuclear Magnetic

Carbon-13 Nuclear Magnetic Resonance Studies of Some Methyl Substituted Diphenylmethanes

1974 ◽  
Vol 52 (18) ◽  
pp. 3196-3200 ◽  
Author(s):  
Gerald W. Buchanan ◽  
Giorgio Montaudo ◽  
Paolo Finocchiaro
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Ring Current ◽  
Chemical Shifts ◽  
Magnetic Resonance Studies ◽  
Nuclear Magnetic

Carbon-13 n.m.r. chemical shifts are reported for diphenylmethane and nine methylated derivatives. Results are compared with those for related methylbenzenes. In the case of tri-ortho-substituted materials the predominance of a perpendicular conformation is suggested. Ring current calculations show that in contrast to the 1H chemical shift interpretations, the 13C shielding trends cannot originate primarily from anisotropic effects.

THE RELATIVE ACCEPTOR POWER OF BORON TRIHALIDES TOWARD ACETONITRILE BY PROTON NUCLEAR MAGNETIC RESONANCE MEASUREMENTS

1966 ◽  
Vol 44 (8) ◽  
pp. 899-902 ◽  
Author(s):  
J. M. Miller ◽  
M. Onyszchuk
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Dipole Moments ◽  
Proton Nuclear Magnetic Resonance ◽  
Methyl Proton ◽  
Linear Relationships ◽  
Acceptor Activity ◽  
Nuclear Magnetic Resonance Spectra ◽  
Nuclear Magnetic

Proton nuclear magnetic resonance spectra of BF3, BCl3, and BBr3 adducts of acetonitrile have been measured in nitrobenzene solution. Single peaks were observed in each case and chemical shifts relative to tetramethylsilane decreased in the order BBr3 > BCl3 > BF3, suggesting that this is the order of acceptor activity toward acetonitrile. Linear relationships exist between methyl proton chemical shifts of CH3CN•BX3 and the heats of formation, dipole moments, and infrared vibrational shifts of the same or related adducts.

Synthesis of Methyl-5,6,11,12-tetrahydrodibenzo[a,e]cyclooctenols and a conformational study by proton nuclear magnetic resonance

1983 ◽  
Vol 36 (3) ◽  
pp. 517 ◽  
Author(s):  
KE White ◽  
BJ Slater ◽  
SH Graham
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Membered Ring ◽  
Proton Nuclear Magnetic Resonance ◽  
Boat Conformation ◽  
Geminal Proton ◽  
Twist Boat ◽  
Axial Site ◽  
Nuclear Magnetic

A series of methyl-5,6,11,12-tetrahydrodibenzo[a,e]cycloocten-5-ols were synthesized, and their conformations assigned by means of proton nuclear magnetic resonance. Placing substituents in three of the four available sites on the eight-membered ring enabled the chemical shifts of the geminal proton to be observed. It was found that the three sites have intrinsic chemical shifts. The compounds studied were found to populate a twist-boat conformation, with bulky substituents preferentially populating the axial site.

A Study of the Proton Nuclear Magnetic Resonance Spectra of Aryl and Mono- and Disubstituted N-Methylazoles

1973 ◽  
Vol 51 (14) ◽  
pp. 2315-2322 ◽  
Author(s):  
Richard Noel Butler
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Structural Characteristics ◽  
Proton Nuclear Magnetic Resonance ◽  
Methyl Group ◽  
Nuclear Magnetic Resonance Spectra ◽  
Azole Ring ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

Proton n.m.r. spectra of 111 substituted azoles are compared. The influence of the azole ring on the chemical shifts of substituent phenyl protons is discussed. A correlation between N-methyl chemical shifts and the structural characteristics of the N-methyl group in mono- and disubstituted azoles is noted.

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