Our work on tension trapping and “contraction by extension” has been highlighted by Chemical and Engineering News.
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.
Congratulations to Jeremy Lenhardt, who has kept the Departmental Recognition Award (and reserved parking space next to the building) in the group for another month. The Chair’s announcement of the award reads as follows:
The Departmental recognition award committee has decided that August’s Departmental recognition award (and the reserved parking space for that month) goes to Jeremy Lenhardt, first author on the newest Science paper out of Duke Chemistry.
As most of you know, general journals such as Science and Nature are exceedingly selective, and publication in such journals reflects well on the Department. The research needs to be more than just novel and important-it also has to be compelling to a general audience (when I consider such a submission, my first question is “Why would a geologist want to read this paper?”). Their paper (which will be out shortly) is entitled “Trapping a Diradical Transition State by Mechanochemical Polymer Extension.” It recognizes success in the chemical equivalent of catching lightning in a bottle — trapping (both dynamically and chemically) the transition state of a chemical reaction. Jeremy’s accomplishment is noteworthy in many respects, and it came with a fun and counterintuitive side story: a molecule that gets shorter after you pull it. Jeremy has had successes before (he is only the second Ph.D. student in our department’s history to have won an ACS Division of Organic Chemistry Graduate Student Fellowship), and other strong work is on the way.
Jenn Hawk’s many contributions to the Department have recently resulted in the receipt of the July 2010 Chemistry Departmental Recognition Award. Congratulations to Jenn! The award notice from the Chair reads as follows:
The Departmental recognition award committee has decided that this month’s Departmental recognition award (and the reserved parking space) goes to Jennifer Hawk, who exemplifies the combination of research, service and teaching dedication we see in our best graduate students.
Jenn was nominated by another student, who notes that she “is a positive asset to the Chemistry Department who, rather than saying what should be done instead leads by example and gets things done…While involved in PLU and her own research pursuits, Jenn also showed exemplary care and dedication in teaching; she helped teach an undergraduate class designed by her and fellow graduate students as well as TAing this past semester.” In addition to the teaching mentioned above, her research was recognized by the NC Polymer Discussion Group at the Gilbert Awards Symposium in Raleigh, NC, on May 13, and she has just finished a term as PLU president. I can heartily endorse this nomination, and should add that the course she helped teach (Chemistry 32) was brand new and complex.
Congratulations to Ashley Black and Jeremy Lenhardt, who have been awarded Burroughs Wellcome and C. R. Hauser Memorial Fellowships, respectively, from the Department in recognition of their research accomplishments!