What is the lowest energy alternative resonance structure for this compound:
CH3-CH-N<triple bond>N
There is a negative charge on CH and a positive charge on the central N
To determine the lowest energy alternative resonance structure for the compound CH3-CH-N≡N with a negative charge on CH and a positive charge on the central N, we need to consider the stability of the different resonance structures.
1. Start by identifying the atoms and their formal charges. In this case, the CH group has a negative charge, and the central N has a positive charge.
2. Next, examine the connectivity of the atoms and the electron distribution. The CH3-CH-N≡N can be rearranged as CH3-N=CH-N+, where the double bond is rearranged to have a positive charge on the nitrogen and a negative charge on the nitrogen.
3. Based on the principle of electronegativity, we know that carbon tends to have a lower electronegativity than nitrogen. Therefore, placing a negative charge on carbon is generally less stable than placing a positive charge on nitrogen.
4. The most stable resonance structure will have the negative charge on the more electronegative atom (the nitrogen) and the positive charge on the less electronegative atom (the carbon). Therefore, the lowest energy alternative resonance structure for this compound is CH3-N=CH-N+, with the negative charge on the nitrogen and the positive charge on the central carbon.
In summary, the lowest energy alternative resonance structure for the compound CH3-CH-N≡N with a negative charge on CH and a positive charge on the central N is CH3-N=CH-N+, where the negative charge is on the nitrogen and the positive charge is on the central carbon.