This is the second in what will hopefully become a series of blog posts (previously) focusing on the fascinating work of Dan Singleton (professor at Texas A&M). My goal is to provide concise and accessible summaries of his work and highlight conclusions relevant to the mechanistic or computational chemist. Today I want to discuss one of my favorite papers, a detailed study of the nitration of toluene by Singleton lab at Texas

The recently reported synthesis[cite]10.1126/science.abq0516[/cite] of octafluorocubane established a sublimation point as 168.1–177.1°C (a melting point was not observed). In contrast, the heavier perfluoro-octane has an m.p. of -25°C. Why the difference?

Over the past few weeks, I’ve been transfixed, and saddened, by Eric Gilliam’s three-part series about the history of MIT (my alma mater ). I’ll post a few quotations and responses below, but if you’re interested you should just go read the original essays (1, 2, 3). Why MIT Was Created This quote highlights how MIT was intended to be a counter-cultural university, founded on a distinctly different model than other institutions (like

Organic chemists often think in terms of potential energy surfaces, especially when plotting the results of a computational study. Unfortunately it is non-trivial to generate high-quality potential energy surfaces.

Now that our work on screening for generality has finally been published in Nature , I wanted to first share a few personal reflections and then highlight the big conclusions that I gleaned from this project. This project originated from conversations I had with Eugene Kwan back in February 2019, when I was still an undergraduate at MIT.

Derek Lowe reports the story[cite]10.1126/science.abq0516[/cite] that the recently synthesized octafluorocubane can absorb one electron to form a radical anion – an electron in a cube . So I thought it would be fun to compute exactly where that electron sits!

A previous post was triggered by Peter alerting me that interactive electronic supporting information ( IESI ) we had submitted to a journal in 2005[cite]10.1021/ic0519988[/cite] appeared to be strangely missing from the article landing page. This set me off recollecting our journey, which had started around 1998, and to explore what the current state of these ancient IESI s were in 2022.

Previously, I looked at autocatalytic mechanisms where the carboxyl group of an oxetane-carboxylic acid could catalyse its transformation to a lactone, finding that a chain of two such groups were required to achieve the result. Here I look at an alternative mode where the oxetane-carboxylate itself acts as the transfer chain, via a H-bonded dimer shown below.

One common misconception in mechanistic organic chemistry is that reactions are accelerated by speeding up the rate-determining step. This mistaken belief can lead to an almost monomaniacal focus on determining the nature of the rate-determining step. In fact, it's more correct to think of reactions in terms of the rate-determining span: the difference between the resting state and the highest-energy transition state.

Having established a viable model for the unexpected isomerism of oxetane carboxylic acids to lactones[cite]10.1021/acs.orglett.2c01402[/cite], and taken a look at a variation in the proton transfer catalyst needed to accomplish the transformation, I now investigate the substrate itself.