Field of Science

Memo to chemists: Move away from the molecule

Megacities of the future - with their heterogeneous population and large-scale problems - will challenges the imagination of chemists (Image: Bldg Blog)
Harvard chemist George Whitesides probably does not consider himself a philosopher of chemistry, but he is rapidly turning into one with his thought-provoking pronouncements on the future of the field and its practitioners. His latest rumination is a piece in the Annual Reviews of Analytical Chemistry provocatively titled "Is the Focus on Molecules Obsolete?" where he uses analytical chemistry as an excuse to really pontificate on the state and progress of chemical science. Along the way he also has some valuable words of advice for aspiring chemists.

Whitesides's main message to young chemists is to stop focusing on molecules. Given the nature of chemistry this advice may seem strange, even blasphemous. After all it's the molecule that has always been the heart and soul of chemical science. And for chemists, the focus on molecules has manifested itself through two important activities - structure determination and synthesis. The history of chemistry is essentially the history of finding out the structure of molecules and of developing new and efficient methods of making them. Putting these molecules to new uses is what underpins our modern world, but it was really a secondary goal for most of chemistry's history. Whitesides tells us that the focus of the world's foremost scientific problems is moving away from composition to use, from molecules to properties. Thus the new breed of chemists should really focus on creating properties rather on creating molecules. The vehicle for Whitesides's message is the science and art of analytical chemistry which has traditionally dealt with developing new instrumentation and methods for analyzing the structure and properties of molecules.

Of course, since properties depend on structures, Whitesides is not telling us to abandon our search for better, cleaner and more efficient techniques of synthesis. Rather, I see what he is saying as a kind of "platform independence". Let's take a minute to talk about platform independence. As the physicist Leo Kadanoff has demonstrated, you can build a computer by moving around 1s and 0s or by moving around buckets of water, with full buckets essentially representing 1s and empty ones representing 0s. Both models can give rise to computing. Just like 1s and 0s simply turn out to be convenient abstract moving parts for building computers, similarly a certain kind of molecule should be seen as no more than a convenient vehicle for creating a particular property. That property can be anything from "better stability in whole blood" to "efficient capture of solar energy" to "tensile strength". The synthesis of whatever molecular material gives rise to particular properties is important, but it should be secondary; a convenient means to an end that can be easily replaced with another means. As an example from his own childhood, Whitesides describes a project carried out in his father's company in which his job was to determine the viscosities of different coal-tar blacks. The exact kind of coal-tar black was important, but what really counted was the property - viscosity - and not the molecular composition.


Firstly, health care. Right now most of the expenditure on health care, especially in the United States, is on end-of-life care. Preventative medicine and diagnostics are still relegated to the sidelines. One of the most important measures to drive down the cost of healthcare will be to focus on prevention, thus avoiding the expensive, all-out war that is often waged - and lost - on diseases like cancer during their end stages. Prevention and diagnostics are areas where chemistry can play key roles. We still lack methods that can quickly and comprehensively analyze disease markers in whole blood, and this is an area where analytical and other kinds of chemists can have a huge impact. And no method of diagnostics is going to be useful if it's not cheap, so it's obvious that chemistry will also have to struggle to minimize material cost, another goal which it has traditionally been good at addressing, especially in industry.






First published on the Scientific American Blog Network.


  1. In other words I am an analytical chemist and I have managed to convince all of you that the Holy Grail you should be going for is the thing that will make my research group even bigger. This is mission controlled research that adds very little to human knowledge. These are implementations-albeit clever and cost effective ones-of known things. Unlike Prof Whitesides I am not pontificating against it, I realize that it has its place and is indeed important and some new knowledge will come out of it, but unfortunately this type of thinking is not of service to any science. This is like reading the object orientated mission statement of EPSRC from some years ago. What is so wrong making molecules that are just interesting or for the sake of them. The creative fun and struggle to make something unknown (or complex). It's not as if it hasn't paid off before. Think why do we spend vast amounts of money on CERN or telescopes?

    1. Of course it's important, Whitesides is only asking chemists to expand their horizons and diversify a bit.


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