Question

Which of the two `O_2NCH_2CH_2O` or `CH_3CH_2O^-` is expected to be more stable and why?

Answer 1

`O_2NCH_2CH_2O`. Also, I think it has a negative charge...so should be `O_2NCH_2CH_2O^-`

Explanation:

Both situations you are comparing this reactive species called an Ethoxide ion, which is the conjugate base of Ethanol. Ethanol is a terrible acid (as in, it is not an acid), so its conjugate base is really strong!

I'm talking about the `...CH_2O^-` part.

The oxygen in this is very reactive and is a strong nucleophile in part because it is loaded with electrons.

Carbon chains are generally electron donating groups, so they have a tendency in this situation to increase the reactivity of the `...CH_2O^-` part. I sort of envision this as the tide of electrons is being pushed toward the `...CH_2O^-` part, making it more reactive.

The NO2 group, however, is generally an electron withdrawing group, and the presence of this group will diminish the reactivity of the `...CH_2O^-` part. The tide of electrons are now not being pushed toward the `...CH_2O^-` part, but rather toward the NO2, and this diminishes the `...CH_2O^-` part's reactivity.