I was scrolling through my RSS feed the other day, and got to thinking, as I often do, what I would have made of that activity back in the pre-internet days. But then I starting thinking about the abstracts I was scrolling through, and what I would have made of them. And there’s a theme in many of them (especially in the higher-tier journals) that would have seemed very strange and (to be honest) outright futuristic.

That might be summarized as “all this nano stuff”. But I’m not making fun of it – to be sure, it’s been a fashionable field for some years now, and there is (as expected) a fair amount of it that appears neither very useful nor very interesting. But it’s worth stepping back and seeing how much it’s permeated chemistry. Everywhere you look, there are papers that work on what you might call the “molecular engineering” scale. Instead of a paper from (say) 25 years ago that might have reported several different heterogeneous catalysts, and how the different routes of preparing them led to different activities, you would now more likely see a discussion of their real particle shapes and sizes, their edge defects, etc., and how those correlated with their bulk activities.

Similarly, you see more supramolecular chemistry than ever before, larger assemblies of natural and unnatural molecules being dealt with as just more things to do chemistry on. Crystal structures are described as frameworks for engineering – this channel can be filled with X, the surface bonds accommodate dopant Y. Surface chemistry in general, long something of a mystery, gets a good deal of attention, as the tools become available to speak of it in more than general terms. Just exactly how many molecules (or atoms) are layered on this substrate, and how close are they to each other?

It’s not that chemistry has been ignoring all these topics for all these years. We’ve known for a long time that they were important, but we didn’t have as much ability to follow things on that scale. Importantly, many of these have moved well beyond the “stamp collecting” stage – you know, “here’s a new such-and-such, and here’s another, and over there they’ve found six more of them”. I’m seeing fewer and fewer of the “Hey, check it out, we made some nanohelices” sort of paper (at least in the better journals), and I don’t miss them. Now it’s more likely to be something like “Here’s how the photoactivity of those nanohelices depends on the pitch of the helix, and here’s how to incorporate nitrogen heterocycles in the right spacing to enhance it”. That may or may not be the sort of thing you’re interested in per se, but it shows a real increase in ability and understanding, and that has to be good news.

Chemistry started out classifying bulk materials, starting with the alchemists sorting out what was a metal and what wasn’t, and attempting to understand why. As analytical techniques improved, we began to deal with individual molecular structures, a great advance – but in the end, we don’t live in a world of individual molecular structures. Molecules are always surrounded by other molecules, be that in a pure single crystal, a mixed powder, a colloidal particle floating in a liquid, a fleck of something moving along in an air current, or a group of a dozen proteins and cofactors assembling on a specific region of a DNA molecule. And although these things are larger, more complex than our usual objects of study, and harder to deal with, they still have specific structures, motions, and landscapes of their own. That region between a single molecule and a handful of substance is going to keep us all busy for a long time to come.