This week we welcome graduate student Tim Dreier (@NotHF) from Colorado State University. Tim started out as an economist, worked through banking to end up in a far more fulfilling career in chemistry. Here’s Tim, and his story of how he ended up studying gold clusters and why it matters.
This is a bit of a long story, but I’ll try to keep it moving. Because I went to university straight away after high school when I most decidedly should not have, I ended up getting a degree in economics. I also pursued a minor in drinking heavily and making poor choices. I gave exactly zero thought to the sort of career I wanted, and fell into banking afterwards. It was…not the most fun I’ve ever had at a job. After a few years I started thinking about what else I might do instead, or if I should go back to school. In the end, I took a couple of chemistry courses because I remembered liking my chemistry classes in high school, once I got to organic chemistry, I was hooked. I was fortunate enough to have a very encouraging undergraduate advisor, and after a couple of years finished my chemistry degree then went off to graduate school.
Well, I came to graduate school thinking I wanted to develop new reactions in organic chemistry, so I initially joined a lab to do just that. Because I didn’t think about the right things when initially joining a group, I ended up in an untenable position after a couple of years. I got through my candidacy exam, but my project wasn’t going anywhere and my working relationship with the PI deteriorated pretty badly. I don’t think there’s a villain in that story, I think that because of the unique relationship between advisors and graduate students how well personalities fit is incredibly important.
So about halfway through my third year I changed groups. I’d come from an organometallic background as an undergraduate, and had spent the first couple of years in the lab pursuing more organometallic chemistry, so I wanted to do something sort of related. I was fortunate that somebody in the department 1) was kind of looking to replace a knuckle dragging organicker who was leaving and 2) was doing some stuff that I thought was kind of interesting upon really digging into it at the suggestion of a friend. So that’s how I ended up working on ultrasmall nanoparticles (nanoclusters, atomically defined nanoparticles) mostly in the regime of thiolate-protected gold clusters.
I think what keeps me in this field, and interested in the related ones, is there’s so much that hasn’t been done. There are really only about 20 years of gold nanocluster work behind us, and only about the last 10 have really solid results. Before there were crystal structures of the clusters, it was difficult to really understand their structure through other means. I think that’s pretty exciting, and I think that there are a lot of opportunities to do some pretty interesting things with these clusters both from a pure inorganic chemistry perspective & with biological applications.
I’m going to try very hard to put this in normal people language. That’s harder than I thought it would be, but I’ve been practicing. So when we think of materials (or any matter for that…matter) I think there are three pretty common size regimes people think about. From small to large: molecules, nanoscale stuff, and bulk. When it comes to metals specifically we usually think of molecules containing a single metal atom as the smallest stuff, and bulk metals like sheets of aluminum as the largest. Nanoparticles are kind of in between: too large to know their chemical formula and think about them as molecules, but too small to have all the same properties as the bulk metal. Nanoparticles often have properties that are different from the bulk metal and that depend on the size of the particle and its shape.
Well, it turns out that when you make a nanoparticle small enough, or a molecule whose primary structure is metal atoms large enough, you start to get another unique kind of behavior that is much more “molecule like” than that of nanoparticles. We call these things nanoclusters. I study the behavior, synthesis, and modification of nanoclusters made of gold protected with tiolates.* My doctorol work has mostly focused on the mechanism by which clusters are formed during their synthesis, trying to understand the fundamentals of how we can modify the synthetic approach in order to achieve new properties for gold-thiolate nanoclusters. *sulfur-containing compounds that are otherwise mostly hydrocarbons.
Motivation: why should the lay public care about your research/work? Because it’s awesome! More seriously, gold nanoclusters have actually been shown to have some pretty interesting biological and materials properties. I’m more interested in the bioinorganic aspects, personally, so I’ll talk about those for a second. In particular, some gold nanoclusters have demonstrated pretty decent antimicrobial properties all on their own, with okay looking toxicity in mouse models. We all know that antibiotic resistance is a big deal. In addition, some work has shown that if you take fragments of drug molecules (or whole drug molecules) and stick them to the surface of gold nanoclusters you can improve their effectiveness. I think in the long-term understanding how that works could be really important for developing new drugs of last resort for things like microbial infections.
Of course, that’s a long way from the sort of fundamental & synthetic work that I do. So why care about that? If we can more fully understand how nanoclusters are formed during their synthesis, and how we can push on different variables to achieve new structures in a predictable way, we’ve can add an entirely new dimension to how biological problems can be approached with these systems. But we’ll never get to that point without some groundwork first. I kind of think of it as like organic chemistry was in the early 20th century – trying to find new ways to make interesting compounds so we can figure out how to solve complex problems with chemistry.
Do you have any interesting external/extracurricular obligations? None that are science-related. Do a bit of dog fostering & related volunteer work, but mostly because of my wife.
Any interesting hobbies you’d like to share? Interesting to whom? I promise my hobbies are interesting to me, at least. I’ve been playing pencil-and-paper tabletop RPGs off-and-on since middle school when I was 12 or 13. I have been playing reasonably consistently since my first bout of college from 2000-2004. Like all young RPG aficionados of a certain age, I cut my teeth on AD&D, then moved on to 3rd/3.5th edition. Now, though I mostly play other systems that may or may not be d20-based. D20-wise I’ve most recently played Numenera & 13th Age. I’m presently playing in a Dungeon World game that we migrated over from Torchbearer after Torchbearer proved to be too much of a grind. I’d like to get back to playing some stuff that uses the Gumshoe system like Ashen Stars or Trail of Cthulhu at some point. I’d also like to revisit the Warhammer 40k RPG universe either by way of Dark Heresy or Black Crusade.
So, basically, I’m a huge nerd with huge nerd hobbies. Out of necessity I have also recently taken to learning a bit about home repair.
Ideal Day Off: I’m pretty lucky in that my friends from college still hold an annual reunion/party every year in October. This past year was I think the 13th Rocktoberfest. The 4th year to have live-band karaoke, which is always a lot of fun. I’ve more or less succeeded in being the not worst performer (except for that one year when I did a Future of the Left song and didn’t pace my beer consumption correctly), which I’ll take. So I love everything about Rocktoberfest, I love all the people I get to see there who I don’t otherwise see often, and on the occasions when we can get a short game together prior, perfection.
Please welcome Tim to Real Scientists!