Jeremy’s paper, “Trapping a Diradical Transition State by Mechanochemical Polymer Extension“, appears in the August 27 issue of Science. The paper describes how mechanical tension can be used to trap a gem-difluorocyclopropane (gDFC) in a 1,3-diradical that is formally a transition state in its stress-free electrocyclic isomerization. The trapped diradical lives long enough that we can observe its noncanonical participation in bimolecular addition reactions. Furthermore, the application of a transient tensile force induces a net isomerization of the trans–gDFC into its less-stable cis isomer, leading to the counterintuitive result that the gDFC contracts in response to a transient force of extension.
To hear Jeremy narrate an animated simulation of the force-induced chemistry (and let’s be honest — who wouldn’t want to hear that?), check out this Youtube video, or read more at the Futurity website.