It Isn't, It Is: The C-H•••X (X = O, N, F, Cl) Interaction Really Is Significant in Crystal Packing

Arguments about the importance or otherwise of the interaction between a C-H group and an electronegative atom such as oxygen, nitrogen, or halogen have rumbled on for 50 years or more. The latest contribution to the debate, published recently in this journal, tended to downplay the significance of the interaction. However, a comparison of observed interaction frequencies with those expected from surface area considerations sheds a different light on the matter.