Premium
Spectroscopic investigations on butadiene derivatives. 1 H, 13 C and 15 N NMR studies on the π‐electron distribution and intramolecular mobility of aminobuta‐1,3‐dienes
Author(s) -
Michalik Manfred,
Freier Thomas,
Zahn Kerstin,
Peseke Klaus
Publication year - 1997
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/(sici)1097-458x(199712)35:12<859::aid-omr189>3.0.co;2-u
Subject(s) - chemistry , intramolecular force , carbon 13 nmr , aryl , carbon 13 nmr satellite , chemical shift , proton nmr , kinetic energy , computational chemistry , crystallography , stereochemistry , nuclear magnetic resonance spectroscopy , fluorine 19 nmr , organic chemistry , quantum mechanics , alkyl , physics
The 1 H, 13 C and 15 N NMR spectra of a series of 5‐alkylthio‐3‐aryl‐2‐cyano‐5‐dialkylaminopenta‐2,4‐dienenitriles ( 4 and 5 ) with different amino and aryl substituents were recorded. The NMR chemical shifts are correlated with electronic effects of the substituents on the donor side of the butadiene system and also the para ‐phenyl substituents X. Dynamic 1 H and 13 C NMR measurements showed rotational processes about the C‐2,C‐3, C‐3,C‐4, C‐4,C‐5 and C‐5,N bonds in 4 and 5 , the kinetic and thermodynamic parameters of which were determined by lineshape analysis. The assignment of the lineshape alterations was made on the basis of signal intensities and separations and from the influence of the donor substituents, the phenyl substituents X and the solvents on the energy barriers. © 1997 John Wiley & Sons, Ltd.