Textbook Problem 6.21

[Sophia Zhao]

Why can't oxygen accept protons in this molecule?

[alexjung1A]

It is much less likely to due to the formal charge; it has a formal charge of 0 and has a full, stable octet so it does not want to accept or lose any protons or electrons.

[jennaj3k]

Oxygen is more electronegative than oxygen so it's unlikely to share its electrons. If it did, then thymine would have a positive charge which isn't stable. Nitrogen is less electronegative and more likely to share its electrons, so its going to accept those protons.