Title of article :
Modulations in restricted amide rotation by steric induced conformational trapping
Author/Authors :
Krishnan، نويسنده , , V.V. and Thompson، نويسنده , , William B. and Goto، نويسنده , , Joy J. and Maitra، نويسنده , , Kalyani and Maitra، نويسنده , , Santanu، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2012
Pages :
4
From page :
124
To page :
127
Abstract :
The rotation around the amide bond in N,N-diethyl-m-toluamide (m-DEET) has been studied extensively and often used in laboratory instructions to demonstrate the phenomenon of chemical exchange. Herein, we show that a simple modification to N,N-diethyl-o-toluamide (o-DEET) significantly alters the dynamics of the restricted rotation around the amide bond due to steric interactions between the ring methyl group and the two N-ethyl groups. This alters the classic two-site exchange due to restricted rotation around the amide bond, to a three-site exchange, with the third conformation trapped at a higher-energy state compared to the other two. This often overlooked phenomenon is elucidated using variable-temperature NMR, two-dimensional exchange spectroscopy and molecular modeling studies.
Journal title :
Chemical Physics Letters
Serial Year :
2012
Journal title :
Chemical Physics Letters
Record number :
1932590
Link To Document :
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