I recently started reading Blink, by Malcolm Gladwell. He opens the book with a story of some art experts assessing a purportedly recently discovered ancient statue. The boffins in the laboratory test the materials and find them to be old stone, aged as to be expected for a recovered artefact. The art historians take a brief look and get a gut-instinct that something is wrong. The scientists have their tests and well founded logical paths to their conclusion that the statue is legitimate. The historians, struggle though they may to articulate what exactly the issue is, know it is a forgery - and turn out to be correct.

I have been collaborating with some chemical engineers recently, and had a similar experience. To the engineers, all pathways that could be drawn out seem equally sensible and therefore likely. What they didn’t have is my synthetic chemistry training and experience on mechanisms and energetic transition states. I found myself struggling to explain all of the necessary background understanding that I was leaning on to reason my way to propose a series of plausible pathways. I was relying on my ‘chemical intuition’ if you will. That hard won mental model of chemical space, what is known and what trends are likely to apply. Mine is still developing, and I hope to never stop the learning process.

What I really enjoy during conversations with other chemists is the glimpse into their chemical intuition. A hardcore synthetic chemist may have a deeply ingrained sense of leaving groups and how to get some difficult step to work, as well as an encyclopaedic knowledge of named reactions. An organometallic chemist may have an innate feeling for which ligand should stabilise a reactive intermediate long enough to test a mechanistic question. And a computational chemist will be able to know the right level of theory and basis sets to get a useful answer without spending a year on the calculation.

In all of these cases, the knowledge/understanding/intuition/vibe is not a simple flow chart in their mind. Long gone are the days of high school chemistry where a solubility table can be committed to memory and, surprise surprise, the question happens to be perfectly solvable just by recalling the table. There are a swathe of inputs that slowly chip away and shape the understanding until a nicely formed (and hopefully accurate, or at least useful) mental model is formed.

I think of myself as a Jack-of-all-trades type chemist, reluctant to be pigeon-holed into any one camp. It is good for me to remember that my chemical intuition will (hopefully) be broader, but necessarily (though unfortunately) be less complete than a specialist. I also think this idea demonstrates a bit of the ‘art’ that goes into science.