In the amide, N,N–dimethylacetamide (DMA), we can see in the 1H NMR spectrum that the two methyl groups bonded to the nitrogen produce two different signals (Figure 1). To comprehend this, we need to look at resonance stabilization. Resonance stabilization is when electrons are delocalized amid multiple atoms (Scheme 2). In the case of amides, this creates a hybrid structure that results in the C–N bond having some double-bond character (therefore the rotation is restricted). At room temperature, DMA due to the contribution of the double character results in the methyl groups bonded to the nitrogen to be chemically different. At higher temperatures the energy barrier to rotation is overcome and there is rapid rotation of the C–N bond, which creates an environment that is equivalent for both N–methyl groups.