We know now what a molecular substituent effect on reactivity might feel like to the touch, thanks to this work by Shu, Haley, and colleagues! Read all about it in work just published in J. Am. Chem. Soc.
Mechanism Dictates Mechanics: A Molecular Substituent Effect in the Macroscopic Fracture of a Covalent Polymer Network
Shu Wang, Haley K. Beech, Brandon H. Bowser, Tatiana B. Kouznetsova, Bradley D. Olsen, Michael Rubinstein, and Stephen L. Craig