Int. J. Mol. Sci. 2005, 6(1), 52-62; doi:10.3390/i6010052
Article

13C-NMR Based Evaluation of the Electronic and Steric Interactions in Aromatic Amines

1, 1,* email, 2 and 1
Received: 16 April 2004; in revised form: 24 January 2005 / Accepted: 25 January 2005 / Published: 31 January 2005
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: Chemical shifts of the para carbon atoms, δ(13C-4), in a series of aromatic amines were used to calculate the σp, σR and σOR substituent constants for different amino groups. 1-Pyrrolidino, N,N-di-n-butylamino and N,N-diethylamino groups were found to be the most strong electron-donors. ortho-Substitution decreases the donor properties of the amino group. The amino groups in 2,6-di-i-propylaniline and N,N-2,6-tetramethylaniline have very weak electron-donor properties. The nitrogen atom in benzoquinuclidine and N,N-dimethyl-2,6-di-i-propylaniline have an electron-acceptor character. The calculated substituent constants of the amino groups studied are consistent with the spectral and reactivity data available in literature. Values of δ(15N) cannot be used as a direct measure of electronic effects of the N atom in anilines.
Keywords: Amino groups; substituent effects; steric inhibition to resonance; 13C- and 15N-NMR; aromatic amines
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MDPI and ACS Style

Zakrzewska, A.; Gawinecki, R.; Kolehmainen, E.; Ośmiałowski, B. 13C-NMR Based Evaluation of the Electronic and Steric Interactions in Aromatic Amines. Int. J. Mol. Sci. 2005, 6, 52-62.

AMA Style

Zakrzewska A, Gawinecki R, Kolehmainen E, Ośmiałowski B. 13C-NMR Based Evaluation of the Electronic and Steric Interactions in Aromatic Amines. International Journal of Molecular Sciences. 2005; 6(1):52-62.

Chicago/Turabian Style

Zakrzewska, Anna; Gawinecki, Ryszard; Kolehmainen, Erkki; Ośmiałowski, Borys. 2005. "13C-NMR Based Evaluation of the Electronic and Steric Interactions in Aromatic Amines." Int. J. Mol. Sci. 6, no. 1: 52-62.

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