Student Q&A: Connor MacNeil

By Wendy Plump
Monday, Mar. 30, 2020

Connor MacNeil spent last fall in the Department of Chemistry through the Visiting Student Research Collaborator (VSRC) program, temporarily leaving his Ph.D. work at the University of Lethbridge, Alberta, Canada for a four-month posting to the Chirik Lab.

While at Frick, MacNeil contributed significantly to the long-standing asymmetric catalysis project the lab is conducting in collaboration with Merck. He discovered a straightforward way to make intermediates relevant to cobalt-catalyzed hydroformylation that has eluded chemists for decades. The resulting research was published online in Angewandte Chemie earlier this month.

MacNeil anticipates returning to Princeton Chemistry as a postdoc next fall. So it is with special pride that we introduce the first in a series of graduate student Q&As by giving him the inaugural slot. Here, MacNeil discusses his research, his motivation, and his experience as a member of the Frick community.

Was your VSRC program assignment a success?

Connor MacNeil, visiting graduate student
Photo by Jon Darmon

I really do mean this, the VSRC program is a once-in-a-lifetime opportunity. Being able to conduct research, not only at Princeton but with Professor Paul Chirik and the incredible group of grad students and postdocs in his lab, was an invaluable experience. I was excited to be a part of it. I only had September through as much of December as I could fit into my schedule to get my project done. There’s a phrase that I’m trying to think of: I think it’s, “Underpromise, overdeliver.” You come in, you work hard, you learn things – the burden of expectation is not huge on a visiting student because of the compressed timeline. So, if you are fortunate and the project is working and you have the support of your colleagues, you can make a positive impact. That’s what I tried to do.

Did your PhD advisor support your decision to visit Princeton?
It’s a little confusing because my supervisor here in Canada is also named Paul, Paul Hayes. It’s the tale of two Pauls. I had just finished up a paper and I asked my supervisor about the program. He was very supportive and thought it would be great for my career to make those connections. I’m in my fourth year and writing up my thesis now. It was just the right time to do this.  

What made you seek out the Chirik lab?

Obviously, with Princeton catalysis, the reputation precedes them. You have these amazing researchers like Abigail Doyle, Dave MacMillan, Rob Knowles – this incredible group of people. But really, I wanted to work with Professor Chirik. If he was operating a research lab in Alaska, I would have made the trek up there. I’ve admired the work he’s done since I started in graduate school. In my research at Lethbridge I use rhodium, which is an expensive precious metal, very scarce, and not at all sustainable. So, part of what drew me to Professor Chirik’s lab is that he uses this concept of base metal catalysis to get metals that are not only cheaper but abundant to do the same types of chemistry, and sometimes the performance is superior!  

How did you enjoy it?

Professor Chirik’s managerial style is something that I really responded to positively. He meets with his team a lot. We have subgroups once a week, group meetings every week, and he always pops his head into the lab to see how you’re doing. And that was really nice. Having such a large group, you don’t expect to see the guy that often. But he really takes an active role in shaping the projects and talking through how to overcome certain challenges.

What skills did you sharpen while you were here?

The skills I learned in Professor Chirik’s lab – even just the way his lab runs – offered me a new perspective. What I brought back to the lab in Canada will hopefully make it a better place. That’s what I want my legacy to be: when I leave my own PhD lab, that I made it a better place. The things I learned in the Chirik Group were how to think more deeply about catalysis, which is something that I really didn’t have a lot of experience with; how to operate reactions under high pressure in these special Parr reactors, which allow you to push a catalyst to its limit; and supplementing my skills with some computational chemistry, which is something that I really wanted to pick up while I was at Princeton. There was a lot of help from grad students and postdocs to do that.

You also collaborated with the Merck Catalysis Group...

That was one of the biggest privileges, working with them up in Rahway. It gave me a real look at how a research scientist in industry operates, how they think about problems, and what they do. These campuses are closed to the public; it’s not like you can just walk in there. So, it really gave me an idea on how these amazing scientists conduct their research. To be a part of that was invaluable to my understanding of how chemistry scales from the lab to industry in making things that have an impact on people in everyday life.

Can you talk about your success with hydroformylation intermediates?

I’ll be completely frank here: I just wanted to make a positive impact and learn as much as I could during my time. With hydroformylation, which is so critical to industry, all we see is what goes in and what comes out. We don’t really know what’s inside the ‘’black box.’’ We’re blind to what’s actually occurring in catalysis. What I was able to do was isolate and characterize a few of these intermediates relevant to catalysis so we can answer questions like– how do they react? What do they look like in 3D space? And how do they interact with different substrates? I think that’s important when thinking about any catalytic reaction. You can take it apart piecemeal – we know the reaction works or doesn’t, and now we can get into that black box and see the players that are driving the results.

How did you proceed?

The first thing I wanted to do was prepare a pre-catalyst based loosely on what the active catalyst might look like before it’s engaged in the cycle. And we had an idea of what that might be. Going after that, I had this picture in my head. I thought, “I know this is what it has to look like, so how do I make this simply?” My first month was me just kind of taking a crack at it from a couple different ways. Some of it looked promising and some of it didn’t. There was failure along the way. It was during my third or fourth sub-group meeting with Professor Chirik where I was able to say that I had isolated this cobalt hydride precatalyst. I was fortunate that my friend and mentor Aaron Zhong helped me get an X-ray crystal structure to show what the molecule looks like in 3D space. So, after toiling away in the lab trying to figure this out, we had the materials we needed to really go after each of the intermediates in the reaction and to study them in detail. But the key to success was isolating that cobalt hydride.

Any advice on how to maximize one's time at Princeton?

I’ll answer the question in two ways. I would say, for Princeton in general, reach out to a grad student or a postdoc who’s in a group that you’re interested in and ask them questions. Everyone I met at Princeton was so accommodating and really took the time to make me feel comfortable and answer my questions, whether it was about my research or what train to catch to get to New York City. Be proactive in your own learning. And if you’re joining a group, read their papers.

For Professor Chirik’s lab, my only piece of advice is to make sure you are in good with Jonathan Darmon, coordinating editor and lab manager for Professors Chirik and Brad Carrow. He is so good at solving every problem that you might have. He was my first point of contact in figuring out visa stuff, how to get settled, where to look for a place to live. He is a Swiss Army knife of chemistry knowledge. So, my advice is simply: get to know Jon on your first day. Walk right into his office and introduce yourself.