Reactions: Yi Lu

Yi Lu is in the Department of Chemistry at the University of Illinois at Urbana-Champaign, and works in the areas of bioinorganic, bioanalytical, and biomaterials chemistry.

1. What made you want to be a chemist?

My choice to being a chemist was not as glorifying as many others who choose chemistry as a major or career. When I was in high school, I was pretty good at all subjects. When it came down to choosing a major when I applied for colleges, I had a hard time making a decision. I ended up choosing chemistry as a major by a slim margin, partly due to the fact that it is the subject that I did not have to study very hard and still can get a top grade. In retrospect, I realized I had an excellent chemistry teacher who was not tough to students and yet was good at inspiring them. I think I benefited from his influence.

2. If you weren’t a chemist and could do any other job, what would it be – and why?

When I was a child, I wanted to be a librarian, because I loved reading all kinds of books, fictions or non-fictions, and I thought, naively, that librarian was an ideal job because I would be paid to read books that I love (and will always to be the first to get the sought-after books so that I don’t have to be put on the waiting list). My favourite weekend activity was to go to either local bookstores or local libraries to read and borrow books for the coming week. I also tried to figure out better book catalogue systems in the library, and systems so that I can get the book I want faster. Now with my busy schedule, I have not had much time to read much other than papers in science journals. I am longing for the quiet days so that I can read those novels that I have missed. So I would realize my childhood dream of being a librarian if I weren’t a chemist.

3. What are you working on now, and where do you hope it will lead?

My group members are working on three exciting areas. In the bioinorganic chemical area, we are working on designing functional metalloenzymes involved in biomass conversions, biofuel cells, photosynthesis and water oxidation. We have already found many non-covalent interactions that are responsible for high enzymatic functions. We hope this research will lead to efficient and cost-effective alternatives to native enzymes for alternative energies.

In the bioanalytical area, we are developing novel biosensors for on-site and real-time environmental monitoring and point-of-care medical diagnostic tests. This research has already lead to two startup companies that are commercializing sensor products, one of which uses the widely available personal glucose meter to detect many non-glucose targets (a paper published in Nature Chemistry last year).

Finally, we are exploring genertic codes using different combination of DNA sequences for abiological nanomaterials. We believe this research may lead to fine-control of nanomaterials assembly at an unprecedented level, similar to what DNA can do to control biological materials such as protein structures and functions.

4. Which historical figure would you most like to have dinner with – and why?

Linus Pauling. Among the many brilliant scientists, Linus Pauling has amazing deep insights into chemical principles and theories from many complicated data, and he is also very good at summarizing and explaining the principles and theories in ways that are quite accessible to non-specialists.

5. When was the last time you did an experiment in the lab – and what was it?

Embarrassingly, I have not done an experiment in the lab for a while. The last time I did an experiment was a few years ago when I tried to prepare and give a demo to high school students using research results carried out in my group — we have developed dipstick tests for toxic metal ions such as lead and organic molecules using DNAzyme or aptamer-functionalized gold nanoparticles. It is very cool that we can use what we have accomplished in the lab to inspire a young generation of students.

6. If exiled on a desert island, what one book and one music album would you take with you?

With so many books that I want to read, it is really difficult for me to decide on one book. May I bring a book series, such as Encyclopedia Britannica? I hope to know every entry in the encyclopedia by the time I am rescued from the desert island. For music album, I like classic music and would like to bring a complete album from Beethoven—it is the kind of music I have never been tired of hearing many times.

7. Which chemist would you like to see interviewed on Reactions – and why?

I have two suggestions. The first is Harry Gray from Caltech, my postdoc advisor. He is in my mind the Linus Pauling of today. The second is Joan Valentine, my Ph.D. advisor. She is an ideal mentor and I always learn new things from her.

 

 

Reactions: Matt Rattley

Matt Rattley is in the Department of Chemistry at the University of Oxford, and works on cascade catalysis in heterocycle synthesis — and is also one of the winners of our In Your Element essay competition.

1. What made you want to be a chemist?

I think it had a lot to do with my teachers in school – my first A Level teacher in particular (a brilliant man called John Luton) was very passionate about science and definitely passed on the bug. It might also be a bit of rebellion, as my parents repeatedly refused my requests for a chemistry set for birthdays or Christmas.

2. If you weren’t a chemist and could do any other job, what would it be – and why?

If I were more talented, I’d enjoy doing music – I’ve played the bassoon in quite a few orchestras at school and university, but I don’t think I could make a career out of it. I’d also quite like to open a bakery – baking, after all, is just edible chemistry that always works (and it definitely smells better!)

3. What are you working on now, and where do you hope it will lead?

At the moment I’m not in the lab – I’ve just finished my Masters project, which involved making cinchona-derived phase-transfer catalysts with H-bonding groups incorporated into the scaffold. They were a bit tricky to prepare, but thankfully they worked on the first thing we tried (the nitro-Mannich reaction), and having screened that, some of the others in the lab are finding some new reactions that it can also catalyse. In a few months I’ll be working on some cascade reactions to stereoselectively prepare saturated heterocycles for my doctorate.

4. Which historical figure would you most like to have dinner with – and why?

I’d quite like to meet Gibbs – considering the massive contribution he made to physical chemistry, he’s barely known at all outside of chemistry, so I’d be interested to talk to him about his work and how/why he kept himself so hidden away.

5. When was the last time you did an experiment in the lab – and what was it?

The last experiment for my Masters a month or two ago was attempting to prepare a dialkoxyborane – it didn’t work too well, it just ended up making a polymer mess. To add insult to injury, my borane source (as the dimethylsufide complex) led to some unpleasant smelling waste, my labmates weren’t too impressed…

6. If exiled on a desert island, what one book and one music album would you take with you?

The book would probably have to be Roger Penrose’s “Road to Reality” – it’s as easy to read as good pop-sci, but it’s a very challenging look through the maths & science that underpins the universe – being exiled on a desert island might give me enough time to read and understand it all! As for the music – that’s pretty tough, but I’d probably go for the soundtrack to Bernstein’s “West Side Story” – the symphonic version is one of the best pieces I’ve ever played, I don’t think I could get tired of listening to it.

7. Which chemist would you like to see interviewed on Reactions – and why?

Prof Yujiro Hayashi gave a lecture at Oxford last year on some remarkable one-pot syntheses – he seemed like an interesting man with some very clever ideas, it’d be great to hear from him.

Reactions: Peter Crowley

Peter Crowley is in the School of Chemistry at NUI Galway, and works on non-covalent interactions and self assembly in biological systems.

1. What made you want to be a chemist?

Back in the early eighties my mother once used butter to wash tar off my hands and I remember being fascinated by the process. So, I was hooked on chemistry long before I knew the word. As a fifteen year old I was fortunate to have a great teacher – Joe Lynam. I still think about his classes on van der Waals interactions.

2. If you weren’t a chemist and could do any other job, what would it be – and why?

Sometimes I wish I had studied anthropology so I could contribute to the story of earth’s exploration by early man. And otherwise, I’d like to be an organic pea farmer. Peas are a great source of protein, with much of the nitrogen provided by symbiotic bacteria.

3. What are you working on now, and where do you hope it will lead?

The lab is focused on weak interactions of proteins. We hope to figure out how the crowded and heterogeneous intracellular environment affects protein interactions. The role of low-affinity small molecule ligands is central to our interests. There is much to be learned on how these interactions influence protein assembly and function in vivo.

4. Which historical figure would you most like to have dinner with – and why?

The American alchemist George Starkey would be an interesting character to dine with. Apparently, he produced pigments from flies, which had metamorphosed from worms that were fed on redweed… 17th century chemical biology?

5. When was the last time you did an experiment in the lab – and what was it?

The last serious experiments I did were NMR titrations of cytochrome c with sulfonatocalixarene. Last month I did a few quick experiments with a new ligand. More on this later… Every week I look at crystallization drops and admire the beautiful patterns, gels, precipitates and crystals that proteins form.

6. If exiled on a desert island, what one book and one music album would you take with you?

If only one book was allowed it would have to be a good English dictionary. There’s endless amusement in words. Music albums get on my nerves after a while so I’d rather listen to the wind and waves. Though, Te Deum by Arvo Pärt might suit.

7. Which chemist would you like to see interviewed on Reactions – and why?

Adam Urbach. His work on protein and peptide recognition by cucurbituril is impressive.

Life and death with nitrogen

During our essay competition last year, quite a few participants who chose to write about nitrogen mentioned that they were interested, intrigued or amused by the fact that nitrogen was deemed ‘lifeless’ when it was first discovered as an element.

It is true that elemental nitrogen — the N2 gas that constitutes a large part of the Earth’s atmosphere — does not on its own support combustion or life. Based on this observation, chemists referred to it as ‘noxious’, ‘fixed’ or ‘burnt’ air, or delightfully antique names like ‘mephitic’ or ‘phlogisticated’ air. This last term comes from the wonderful ‘phlogiston theory’ that appeared in the 17th century to explain combustion (in particular) through the presence of the fire-like element ‘phlogiston’. I’ll leave you to read about it and its decline, which saw phlogiston gradually demoted from a substance to a principle, to an outdated theory when the role of oxygen was better understood.

© ALEX WING

In this issue’s ‘in your element’ article (free to nature.com registrants), Michael Tarselli — the author of the winning entry on nitrogen for last year’s competition — mentions quite a few traits of nitrogen that illustrate just how obsolete its previous appellation is.

Although N2 is colorless, odorless, tasteless, and really not very reactive, we’re spoilt for choice when it comes to mentioning nitrogen’s involvement in crucial processes. Both chlorophyll and haem enzymes, for example, rely on porphyrins to take care of the tiny matters of photosynthesis and transporting oxygen in the blood. A possible way to ferry hydrogen as a fuel is through ammonia borane (H3N–BH3) complexes and — to stay in the realm of renewable energies — the ‘hangman’ architectures devised by the Nocera group as active water-splitting catalysts also feature a macrocycle coordinated to a cobalt centre through nitrogen atoms.

Of course we can find many examples of nitrogenated compounds that do have pretty harmful effects, either on the environment or our health — Tarselli explains how the high nitrogen:carbon ratio of melamine (nitrogen-packed 1,3,5-triazine-2,4,6-triamine) recently attracted attention for all the wrong reasons.

On an ambiguous note, the Haber–Bosch process developed in the early 20th century to ‘fix’ N2 and convert it into useful species (something some plants do very well but chemists not so easily) produces ammonia and other nitrogenated species by reacting N2 and H2 over an iron catalyst. It was quickly put to use, to make both nitrates for the gunpowder and explosives of World War I and cheaper fertilizers that would dramatically boost food production worldwide. I refer you to this C&EN article on the topic.

But it’s impossible to try and mention all of the fields greatly impacted by nitrogenated species. I’ll just mention another one of nitrogen’s traits, for those of you who like bangs and flashes: its tendency to form explosive compounds. Just think of the well-known TNT, nitroglycerin, nitrogen triiodide, but also the recently synthesized azobis(tetrazole) (C2H2N10!)

Anne

Anne Pichon (Associate Editor, Nature Chemistry)

Reactions: Richard Wilson

Richard Wilson is in the Heavy Elements and Separation Sciences Group at Argonne National Laboratory, and works on the fundamental inorganic chemistry of the actinide elements. His work focuses on correlating periodic chemical trends found in the actinide elements with their molecular structure and chemical properties to better understand the nature of bonding in these elements.

1. What made you want to be a chemist?

Chemistry was a field that I initially struggled with quite a bit. Like a lot of other college freshman I wanted to become a physician, so I put my nose to the grind stone in my freshman chemistry courses and found out that I actually kind of liked the subject. I had the good fortune of having some pretty good chemistry professors as well. It turned out that counting the number of bees visiting a flower in a biology class wasn’t my thing. It is the hands-on nature and the challenge of laboratory work that makes being a chemist fun for me.

2. If you weren’t a chemist and could do any other job, what would it be – and why?

Well if everything were to fall into place somehow, I would definitely love to make wine. Chemistry you can drink. It’s no doubt hard work, and certainly not easy, but I think there is a thrilling selflessness (or narcissism) in crafting something truly exceptional for others to enjoy – and of course for me to enjoy as well.

3. What are you working on now, and where do you hope it will lead?

I’m gearing up to start a new project with protactinium. A lot of people in the f-element community stopped working on protactinium many years ago. It’s tricky to work with and very very rare. But, what is puzzling to me is that many computational treatments of the actinides ignore Pa, as if the actinide series goes Th, U, Np, Pu etc. I’m optimistic that we’ll find some interesting chemistry here since it treads a fine chemical line between transition metal behaviour and actinide behaviour. It will no doubt be exciting to see where this research goes.

4. Which historical figure would you most like to have dinner with – and why?

Dmitri Mendeleev. I want to know if his three traits of a good chemist (none of them fit for print) as told to me by a colleague are true.

5. When was the last time you did an experiment in the lab – and what was it?

I was last in the lab a couple weeks ago. We were working on synthesizing and crystallizing some plutonium coordination complexes for study using Raman spectroscopy.

6. If exiled on a desert island, what one book and one music album would you take with you?

So, I’d definitely take Stravinsky’s “Rite of Spring”, as for reading material I think I should probably be forced to finish “The Brothers Karamazov”.

7. Which chemist would you like to see interviewed on Reactions – and why?

I’d like to see Richard Andersen from U.C. Berkeley interviewed. He’s pretty colorful and knows a little something about molecules. He always has a good story to tell whether you like it or not. No, I don’t think he’s Russian.

The Molecular Olympics

The creation of well-known macroscopic objects in molecular form is something that usually leads me to mutter under my breath and roll my eyes. Every now and then, a paper or a press release will herald the synthesis of a molecular ‘X’, where X = pretzel, wheelbarrow, car, tie fighter (yes, really), and so on — I’m not going to link to these, your favourite search engine will do you proud if you really want to know more about these things. In some cases, if you tilt your head to one side and perhaps squint a bit, you can maybe understand the analogy; and admittedly, sometimes the analogy is one of function rather than form. Because of a certain major sporting event that is happening in London at the moment, however, I’m going to make an exception — and be slightly less grumpy about such things.

Olympic, er..., rings!

The iconic image associated with the modern Olympic Games is one that many people know well — it consists of five rings linked together to form a chain. I presume it would be OK to reproduce the symbol here on the blog, but I’m not taking any chances, considering the somewhat overzealous manner in which the Olympic family protect their rights… So, I’ve put a bit of a chemistry twist on it: look, hexagons! (And it’s actually easier to draw in ChemDraw that way too…).

Our first competitor (over there on the left) is a molecule that has been named ‘olympicene’ (Wikipedia link here) — and it has received a fair amount of coverage over the past few months, so I’m not going to describe the project in any detail (follow those links for lots of great stories). Particularly striking, however, are some of the AFM images of the actual molecule, which can be found on Flickr. As pointed out by Prof. Martyn Poliakoff of the Periodic Table of Videos, however, it’s fairly obvious that the five six-membered rings in olympicene are not linked together as they are in the Olympic logo. They are fused together to form something that, at first glance, has a passing resemblance to the Olympic rings.

If you look closely at olympicene, you will see that the top-middle ring is fused with all of the other four rings. If you number the individual rings from left to right, the structure has a row of three fused rings along the top (1, 3 and 5) and two fused rings at the bottom (2 and 4). Go back and look at the Olympic rings themselves, and you’ll see that (using the same numbering scheme), ring 1 is only connected to ring 2, ring 2 connects with rings 1 and 3 and so on. Perhaps picene (shown above to the right – Wikipedia link here) would be a better match for the actual Olympic rings?

Alternatively, how about making a molecule that contains five interlocked rings — just like the Olympic symbol? This idea was actually first proposed way back in 1960 by van Gulick (more on this at the end of the post) and the experimental realization was reported in the international edition of Angewandte Chemie in 1994. It came out of the labs of Fraser Stoddart (disclaimer: I did my PhD with Fraser and worked is his lab for many years, so I have a soft spot for interlocked molecules), but the main protagonist stood at the lab bench was David Amabilino, who is currently at the Institut de Ciència de Materials de Barcelona. The title of the paper is simply ‘Olympiadane’ (don’t you love scientific papers with one-word titles?). The structure of this [5]catenane is shown below – Wikipedia link here.

This molecule obviously has the same topology as the Olympic rings, but looks very different on paper (and also in the X-ray crystal structure, which was reported in this JACS paper). Each of the five rings is made up of smaller rings joined together to form closed loops. And three different types of ring make up olympiadane. Rings 2 and 4 (the red ones) are the same, as are rings 1 and 5, but ring 3 (while similar to rings 1 and 5) is different yet again. So, if we’re giving out medals for molecules that best resemble the Olympic rings, which molecule (picene, olympicene or olympiadane) gets the gold, and where do silver and bronze go? As I pointed out above, I’m biased, so I’ll leave it to you lot to fight it out in the comments.

And now back to van Gulick… he wrote a manuscript back in 1960 about ‘theoretical aspects of the linked ring problem’ that was circulated as a preprint, but ultimately rejected from the journal Tetrahedron for ‘not being chemistry’. The paper was finally published in the New Journal of Chemistry in 1993 (I can’t find this online anywhere, but the reference is New J. Chem. 17, 619–625 (1993) if you are interested) and in the same issue, there is a preface written by David Walba explaining the story behind the van Gulick paper (again, I can’t find that either, but it’s page 618). Funny how times change, and what was dismissed as ‘not chemistry’ over 50 years ago, is now being used to promote chemistry in the mainstream media!

Stuart

Stuart Cantrill (Chief Editor, Nature Chemistry)

Transatlantic Tales: School days

Posted on behalf of Nessa

————————-

Moving to a new lab always carries those compulsory first few weeks of introductions, where you get a little glimpse into the lives of the new people around you, and get to share a bit of your own too. In many ways, it’s the most interesting bit of the non-chemistry part of the process. Starting from the start, talk sometimes gets round to your (pre-university) school days.

Of course, mine weren’t very long ago — although it feels like another lifetime. My main memories of school are how much I hated the place. However, since starting uni, I have regularly come across news articles about how a core of scientists are sure that the UK education system is failing the teenagers getting ready to become researchers of the future. On the other side of the pond, the issues are very different, with some teachers ready to teach creationism in science lessons.

British A-levels (taken by those who choose to study at 16-18) are the worst of it — because by then, teenagers with any interest in science outside of the classroom are reading up and realizing what’s wrong in the classroom. Teenagers who aren’t doing the extras are stuck with the ‘science’ prescribed to them — is memorizing unexplained series of facts how we go about research? Of course it’s not — but that’s what these students will think. Is following a list of prescriptive instructions how we do work in the lab? No — but that’s what A-level pupils are going to believe about a science career.

From what I’ve gleaned, the US high school system varies vastly between regions and social groups. There’s a high proportion of homeschooling and, as ever, the religious-right rules the roost. High levels of ‘sciphobia’ and misunderstanding of science by the general population are the fundamental issues here. Huge divides mean that many schools fail to give their pupils the inspiration to fulfil their potentials, and only a select few establishments regularly provide the boost to get the most able into university and ultimately, a fulfilling science career.

It seems as though some of our issues are shared… haven’t we been having the ‘good schools vs failing schools’ debate in the UK for as long as I can remember? It seems to me that no real change will be made until governments stop flipping back and forth between curricula and recycling old ideas (4-module to 6-module, back to 4-module A levels), and begin looking at the content to see what knowledge would benefit students most. And I’m betting it’s not memorizing the structure of a blast furnace.

Nessa (you can find me on G+ here)

Reactions: Xiaogang Liu

Xiaogang Liu is an associate professor in the Department of Chemistry at National University of Singapore. He also holds a joint appointment as senior research scientist with the Institute of Materials Research and Engineering, Agency for Science, Technology and Research. His research interests include nanomaterials synthesis, lanthanide luminescence and surface science for catalysis, sensing, and biomedical applications.

1. What made you want to be a chemist?

I was trained in the fields of chemical engineering when studying in college. But after I moved to the States to pursue my graduate study, I was largely influenced by my former Masters supervisor John Sibert. His enormous passion and dedication to organic chemistry played a pivotal role in influencing me to pursue chemistry as a career. My former PhD supervisor Chad Mirkin also influenced me tremendously with his enthusiasm for knowledge in nanochemistry. He really taught me how to get my work up to standard.

2. If you weren’t a chemist and could do any other job, what would it be – and why?

I would probably be a physician. My mother is a retired doctor (internal medicine) and I have always envisioned myself to follow in her footstep.

3. What are you working on now, and where do you hope it will lead?

I am currently working on developing approaches to the synthesis of luminescent rare-earth nanomaterials, particularly photon upconversion nanocrystals that are able to convert two (or more) low energy pump photons to a higher-energy output photon. These nanomaterials, which are approximately 20 nanometers in diameter, are biocompatible and mix rapidly with biomolecules in water. When illuminated with a near-infrared laser, they give rise to multicolored visible luminescence. I am also interested in mechanistic investigation of fascinating energy transfer between different lanthanide ions confined within a nanoscopic region. I hope these studies could lead to substantial impacts on fundamental science and biotechnology.

4. Which historical figure would you most like to have dinner with – and why?

There are quite many people I would like to have dinner with. If I have to choose one, I would ask Albert Einstein to join me for dinner. I would ask him to share his violin experience and pass on some of his music. Many scientists have fallen in love with music. But this love is not always rewarded with perfect mastery.  My personal hobbies are playing the harmonica and guitar, and I am desperately seeking a balance between research and time for my instruments.

5. When was the last time you did an experiment in the lab – and what was it?

It was about a year ago when I taught my student how to grow organic single crystals suitable for X-ray diffraction studies. If I have more time on hand, I would certainly enjoy spending time carrying out more experiments with my students.

6. If exiled on a desert island, what one book and one music album would you take with you?

This is a hard one. I might prefer to relax and indulge in the beauty that nature has endowed on the island. Not everyone has such opportunity to enjoy sounds and music of the nature peacefully.

7. Which chemist would you like to see interviewed on Reactions – and why?

My former MSc supervisor John Sibert. His own research work and personality have inspired me over the years. And I have not heard much from him more than a decade.