Why is the carbonyl IR stretch in an ester higher than in a ketone: crystal structure data mining.
Henry S. Rzepa · 2016
In this post, I pondered upon the C=O infra-red spectroscopic properties of esters, and showed three possible electronic influences: The red (and blue) arrows imply the C-O bond might shorten and the C=O bond would lengthen; the green the reverse. So time for a search of the crystal structure database as a reality check.