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

1 Answer
Mar 9, 2018

Answer:

#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.