Chemistry World blog (RSC)
Looking around Form Form Form’s laboratory in Hackney, London, you can’t help but notice that the standard lab equipment has been modified, tweaked, personalised and adjusted using Sugru – the mouldable silicone rubber adhesive they manufacture. When I went to visit them with Phillip Broadwith, Chemistry World‘s business editor, to learn about the history and chemistry of Sugru, we asked a simple question: ‘what can Sugru do for scientists?’
Jude Pullen, head of R&D, took us through a handful of ‘lab hacks’ – quick and simple ways to make lab equipment safer, more efficient and easier to use:
Can you think of a way to use Sugru in the lab? Let us know by commenting below, or find us on Twitter: @ChemistryWorld
Guest post from Tom Branson
In a bold move by Organic and Biomolecular Chemistry, the journal has unveiled the latest superhero in the fight to save the common scientist from the ruthlessness of today’s laboratories.
With great power comes great selectivity
Standing firm with test tube in hand, Raney Cobalt-man is a new character from Catalyst Comics. The star wears a rather tight, bright cobalt blue coloured outfit, reflecting one of the element’s most notorious uses. How Raney Cobalt-man gained his powers, we will never know. But perhaps it was in a careless lab accident, and if so, he has certainly learnt his lesson. Now with goggles and elbow-length gloves (not to mention a full body suit and special groin area protection), Raney Cobalt-man is a true ambassador for PPE.
This first adventure takes our hero into the domain of the domino reaction where he’s be helped by his trusty sidekick, Dihydrogen Boy. The young assistant plays an essential role in their joint mission to catalyse peace and his support is needed even more as the hero ages. Here in the domino reaction, they join forces to selectively bring harmony cascading through the scientific community.
But where are the other great chemical heroes of today? Well, I suppose there is the elementally named Iron Man – a brilliant scientist, although he was actually more of an engineer. The Flash was first a forensic scientist who came by his powers after a lightning bolt hit his lab. This mishap is, of course, one of the many dangers of working alone late at night. The lovable Chemist Hulk may also be familiar to those folks on Twitter, this mean green scientist likes nothing better than to tweet about ‘SMASHING PUNY MOLECULES’.
Raney Cobalt-man is the hero that chemists deserve, but is it the one they need right now?
In this edition of the Raney Cobalt-man comics, the eponymous hero is helped by Martin Banwell and colleagues from the Australian National University. Together they review an underappreciated reagent and compare its powers to that of its nemesis, Raney Nickel-man. The story tells that high pressure from Dihydrogen Boy can often be off-putting for those wanting to call upon Raney Cobalt-man’s selective powers. But these drawbacks are simply overcome by using a larger amount of Raney Cobalt-man and therefore less of his annoying sidekick.
Comic book and science fans alike may be waiting a while before Raney Cobalt-man’s next adventure hits our book shelves, but be sure to pick up the first edition over at OBC.
Guest post by Jen Dougan
I attended five weddings this year, between February and October, making 2014 most definitely the Year of the Wedding. Each day was unique and reflected closely the couple, their relationship, vision and hopes for the future. And while there was a broad range of traditions at each, whether religious or humanist approaches, one tradition – the exchange of rings – provided a common element throughout.
The element is, of course, gold. But what is the chemistry of this symbol that is ritually shared as a sign of commitment and lasting love?
Gold is the most noble of metals, it doesn’t corrode or oxidise in the Earth’s moist, oxygen-rich atmosphere. Ductile and malleable, it can be fashioned at will and, since it doesn’t tarnish, is an ideal material for producing jewellery. The decorative attributes of gold have long been coveted – examples of gold jewellery have been found in the tombs of the Queens of Egypt and Sumeria, 3000 years BC.
Gold is one of only three coloured elemental metals (the others being copper and caesium). Most metals appear whitish-grey as they reflect all wavelengths of visible light. Gold, on the other hand, due to its electronic configuration exhibits a reduction in reflectivity efficiency in the blue region of the visible spectrum. It has, in the pure form, a striking yellow colour and brilliant lustre for which it became known by the latin Aurum, meaning ‘shining dawn’ (depicted by artist Murray Robertson in the image above).
Today the purity of gold jewellery is expressed in terms of ‘karat’. Pure gold is 24 karat, where, K = 24(Masspure/Masstotal), meaning 24/24 parts of the material are gold, by weight. In practice, even 24K gold is often stated as 99.99% pure due to residual impurities from the extraction process. Although 24K gold can be used for jewellery, the softness of pure gold means that alloying the metal to improve its physical properties or to design colour variants is a popular approach. The European standard, for instance, is 18 karat, meaning 18/24 parts are gold (75% pure by weight). The other 25 % of the weight is made up of another material (in the case of jewellery, a second metal) to make an alloy, which is typically stronger than the pure metal.
The improved strength of gold alloys occurs when, having melted two or more metals together, a new structural phase is formed on cooling. The precipitation of the added metal atoms reduces slippage of the original atoms across one another.
Common alloys of gold for jewellery fall into the yellow gold or white gold categories. Most jewellery alloys of yellow gold, including that of rose and green-shade gold, fall within the Au-Ag-Cu system (see image above). Zn is sometimes added to further increase the alloy strength and to change the red colour of high Cu alloys to a paler rose.
For white gold, Au-Pd-Ag is a common alloy system, where Pd is used as a bleaching agent. Nickel, another metal capable of producing the desired bleaching effect to produce white gold, is a known skin sensitiser and has become less popular in jewellery making.
The bleaching effect occurs due to the added material changing the reflectivity of the alloy in the low energy part of the visible spectrum. In all cases, the relative ratio of the alloy’s components dictate the resulting hue and mechanical characteristics. The alloy systems allow the characteristics to be achieved such that the design lasts the length of a marriage and beyond.
A word of warning/advice to the newlyweds: although your gold is stable, it is not chemically inert. Avoid exposure to mercury, with which the gold will form an amalgam; cyanide salts, which will react with your band; and aqua regia* in which it will dissolve. Of course, if you encounter any of these three materials by accident, you have greater worries than the integrity of your wedding ring!
The chemical susceptibility of gold for these reagents has proven useful. Mercury and cyanide salts have been used to extract gold from its ore. In fact, gold cyanidation, developed industrially in the 1880s by Glaswegian chemists John Stewart McArthur and Robert and William Forrest is still the main method of gold extraction – and the biggest use of sodium cyanide – globally. The ability of aqua regia to dissolve gold helped foil the Nazis during World War II. Two German Nobel laureates had placed their medals (23K gold) at the Niels Bohr Institute in Copenhagen for safe-keeping. But removing gold from Nazi Germany was a grievous offense and with the laureates names inscribed on the medal, this was an incriminating piece of evidence. ‘While the invading forces marched in the streets’, George de Hevesy – a (future) Nobel laureate himself – dissolved the medals in aqua regia. While the laboratories were laboriously searched by the Nazis, the medals remained dissolved, but undiscovered, on the bench. The metal was recovered after the war and the medals recast and returned to the laureates.
Whatever gold you choose for your wedding band, you add to a rich history of human civilisation fascinated by and adorned with gold. And to the newlywed class of 2014, congratulations!
* Note: Aqua regia is latin for ‘King’s water’, a 1:3 nitric:hydrochloric acid solution, it is known in Russia as Tsar’s vodka and its ability to dissolve gold is shown wonderfully in this Periodic Table of Videos.
- The Chemistry of Gold, M. Concepción Gimeno, Modern Supramolecular Gold Chemistry: Gold-Metal Interactions and Applications, 2009, Ed. Antonio Laguna http://onlinelibrary.wiley.com/doi/10.1002/9783527623778.ch1/summary
- Precipitation hardening and ordering of carat gold jewellery alloys, Gold Bulletin, 1978, 11, 4, p 116, W.S.R. (William S. Rapson)
- Phase Transformations in 18-Carat Gold Alloys Studied by Mechanical Spectroscopy, PhD Thesis, John Hennig, 2010, ÉCOLE POLYTECHNIQUE FÉDÉRALE DE LAUSANNE, http://infoscience.epfl.ch/record/144083/files/EPFL_TH4635.pdf
- Coloured Gold Alloys, Gold Bulletin, 1999, 32, 4, 115, Cristian Cretu & Elma van der Lingen http://link.springer.com/article/10.1007%2FBF03214796
- Alkali Metal Cyanides, Ullmann’s Encyclopedia of Industrial Chemistry, 2006, DOI: 10.1002/14356007.i01_i01, Andreas Rubo, Hanau-Wolfgang, Raf Kellens, Jay Reddy, Norbert Steier, Wolfgang Hasenpusch
- Nobel medals in aqua regia: http://www.nobelprize.org/nobel_prizes/about/medals/
Guest post by JessTheChemist
‘Where the telescope ends, the microscope begins. Which of the two has a grander view?’ – Victor Hugo
In 1873, German physicist Ernst Abbe reported that the resolution limit of the optical microscope was 0.2 micrometres. Although this still remains true, recent work in the field of microscopy – specifically Stimulated Emission Depletion (STED) microscopy and single-molecule microscopy – has allowed scientists to visualise molecules smaller than this limit. This is accomplished by tagging molecules with fluorescent labels, which allows a more detailed picture to be visualised. On Wednesday 8th October 2014 Eric Betzig, Stefan Hell and William Moerner were awarded the Nobel prize in chemistry for their ground-breaking work in ‘the development of super-resolved fluorescence microscopy’. You can learn more about the ins and outs of the Nobel prize winners’ work by reading the recent Chemistry World article.
I am interested in finding out how chemists are connected to each other, and in particular, investigating whether your likelihood of winning a Nobel prize is increased by having a high number of laureates in your family tree. It is also interesting to see how closely related, if at all, are the scientists that share a prize.
If we consider his academic pedigree, one might say that Eric Betzig was destined to become a Nobel prize winner. He is connected to a number of notable laureates, including the father of nuclear physics, Ernest Rutherford. Rutherford won the Nobel prize for chemistry in 1908 ‘for his investigations into the disintegration of the elements, and the chemistry of radioactive substances’. Through Rutherford, Betzig is also connected to Niels Bohr, who won the Nobel prize for physics in 1922 for ‘his services in the investigation of the structure of atoms and of the radiation emanating from them’.
Additionally, Betzig is academically related to John William Strutt (Lord Rayleigh) who won the prize for physics for the discovery of argon in 1904, along with his collaborator Sir William Ramsay, who won the 1904 chemistry prize for the same discovery. With ancestry like that, Betzig was always destined for greatness.
Alternatively, William Moerner is closely linked to Dudley Herschbach and Yuan T. Lee, who won the 1986 Nobel prize in chemistry ‘for their contributions to the dynamics of chemical elementary processes’. To find out more about Herschbach and Lee’s academic family connections, check out last month’s blog post about one of their connections, Sir Harry Kroto.
Although Eric Betzig and William Moerner worked independently from one another, they both developed single-molecule microscopy, so it is not a surprise that their lineage is intertwined. As you can see from the tree, they are connected via some of the science greats such as Linus Pauling.
Stefan Hell worked in a slightly different field to Betzig and Moerner and, amongst others, is connected to biochemists Robert Huber and Johann Deisenhofer, who won the 1988 Nobel prize for chemistry ‘for the determination of the three-dimensional structure of a photosynthetic reaction centre’. As predicted, however, all three of the prize winners can be connected through their academic relations – via Deisenhofer, Hell can be connected to Moerner and, therefore, Betzig.
As you can see, all three winners have a rich Nobel history but what I found particularly interesting about this academic family tree is that it contains scientists from all sorts of backgrounds – from nuclear physics to biochemistry to organic chemistry. This led me to think, what kind of scientists am I connected to? To find out what kind of scientists you are connected to, head to academictree.org, where you can add yourself to the website and start creating your very own tree. You never know who you may be connected to.
And don’t forget to tweet me (@Jessthechemist) with suggestions for the focus of next month’s blog post!
Guest post by Heather Cassell
Space in the lab is always at a premium; you need more things than you have space for, so it makes sense for multi-group labs to share equipment, consumables and buffer stocks that everyone uses. This inevitably causes trouble when someone doesn’t look after the equipment, or fails to restock things after using them.
It is a frequent problem. You are about to start an experiment, so you’ve checked that the equipment will be free, you’ve planned your samples and now you just need to dilute from a communal buffer stock. All too often there is only a dribble left, so you have to make a fresh stock of buffer before you start, delaying your experiment by precious minutes. Your next stop is the communal chemical stocks, where you find there is either nothing left or such a trifling amount that it is of no use to anyone. This often prompts sarcastic mutterings of ‘how considerate’, or something rather more profane.
In my experience, this is especially common with flammable solvents. As these need to be kept in a special vented cupboard, there is only a limited amount of room for the big brown bottles they are delivered in. The nature of the bottles themselves also conspires to make it all too easy to get caught out: you check in advance that there is a bottle of solvent available, see one in the cupboard and relax into the next task. Of course, when you need it, the brown bottle has concealed the fact that there is only a drop left, never quite enough for what you need to do.
So how does a frustrated chemist deal with this situation? There are several options: you can go to the on-site chemical stores and buy a new one (assuming they are open and have what you need in stock); you can go begging to other groups to see if you can borrow some; or you can simply abandon your half made buffer or experiment and do something else instead.
Even for the renownedly polite English scientist, repeatedly buying a replacement bottle of the same solvent – even though you use only a small amount each time – can test the patience. You end up subtly enquiring to find out who else is using it, so you can politely suggest they stop leaving it in such a maddeningly useless state. Inevitably, your fellow lab denizens will only own up to using a small amount (never a large volume, oh no), and they always leave plenty in the bottle after use.
So where is the rest of the solvent going? As a scientist, I have to rule out untestable hypotheses like ‘the solution magically disappears’. I’ve also never seen a colleague drinking a cup of buffer (though it has occurred to me that they might), so either that isn’t the explanation or they’re very subtle about it. The answers to these questions may never found, but every time it happens you resolve to check more thoroughly before each planned experiment. Until the next time, of course…
With just under week until the announcements start, Nobel prize fever is officially here.
The official shortlist is shrouded in secrecy, giving those making their predictions about who might win little to go on – but that hasn’t stopped them.
— Nobel medal
As usual, Thomson Reuters have released their Nobel forecast, which uses citation numbers and other statistical wizardry to predict the winners in each category. This approach has successfully predicted 35 Nobel prize winners over the past 12 years.
This time round they highlight three possible chemistry winners – the inventors of the organic light emitting diode (Ching Tang and Steven Van Slyke), RAFT polymerization (Graeme Moad, Ezio Rizzardo, San Thang) and mesoporous materials (Charles Kresge, Ryong Ryoo, Galen Stucky).
Elsewhere, less official speculations – perhaps based more on a hunch – have begun flying around. On the Everyday Scientist blog, chemist Sam Lord has put together some suggestions. Like the number crunchers at Reuters, Lord has some past successes (though he didn’t predict last year’s computational chemistry winners - Karplus, Levitt and Warshel). He thinks the 2014 prize could go to a key historical invention, such as the contraceptive pill, or the lithium-ion battery (also a top pick for The Curious Wavefunction blogger Ashutosh Jogalekar), but also mentions broader areas such as microfluidics, nanotechnology and next-generation sequencing. If last year is anything to go by, there’s much to be said for gut feeling as well as advanced number crunching. As always, we’ll just have to wait a little longer for that all-important announcement from Sweden.
If you want to get into the Nobel spirit and hear more about the possible winners this year, our features editor Neil Withers joined representatives from Nature Chemistry and C&EN to begin the countdown to the 2014 chemistry Nobel in a Google hangout – watch the whole discussion here.
Guest post by Rowena Fletcher-Wood
I first heard the story of the discovery of nylon during a chemistry class in school – it was told as a serendipitous discovery. A young lab assistant, clearing up at the end of a long day, clumsily poured two mixtures in together and noticed a precipitate. Dipping in a stirring rod, he pulled out a thin string, which he stretched out into a tough, translucent fibre. He realised the potential of his discovery, reported it to his superiors and left them to the tiresome job of working out what he had done to make it.
It’s funny how we use accident to shape our understanding of discovery and achievement, as though we want to excuse hard work and apologise for years of learning. It’s somehow disappointing, unromantic: the story of research whisks away that tantalising fantasy of stumbling upon treasure, reserving discovery for the experts.
The real story of nylon, interesting though it may be, is a bit of stretch from serendipity.
There was a young lab assistant, and his name was Julian Hill. He was working in the DuPont research laboratory, led by the rigorous organic chemist Wallace Hume Carothers, who had taken on the challenging ‘synthetic fibre race’. At the time, synthetic polymers were a mysterious conception; what they were made of and how they related to simpler compounds was unknown. The DuPont team had studied complex natural products such as cellulose and silk and from their understanding had developed polyamides through the condensation of dicarboxylic acids with diamines – fantastically interesting but, at the time, not particularly useful.
Julian Hill had been working with polyester when, dipping in a stirring rod, he pulled out a thin string, which he stretched out into a tough, translucent fibre – just like in the story I was told. But this was not considered extraordinary. Often, discovery is not about observing properties, but recognising them. One day, when Carothers was absent from the lab, the chemists decided to go rogue with the polyester and have a competition to see how long they could stretch it. They raced down the hall, delicately extending the fibre. They had extended it to four times the original length when it stopped. It would not stretch any more.
Suddenly, Hill understood: as they stretched the fibre, chains of molecules snapped into position, orienting themselves into a chain of a discrete thickness. This would be the basis for the first fully synthetic fibres.
But nylon was far from invented. The melting points of the polyesters they had were far too low for any practical applications, and so they returned to polyamides and began stretching those instead. It took 9 months, a patent for the ’cold-drawing’ process of making fibres by removing them from the water of condensation, and 80 new polyamides before the most promising, nylon-6,6, was discovered in May 1934.
Nylon, a dyeable, durable, shiny thermoplastic first entered the market in 1938 as the bristles of a toothbrush, before being appropriated for women’s hosiery in 1940. DuPont declined to trademark the name ‘nylon’, instead allowing it to enter the lexicon as an alternative name for ‘stockings’. The new ‘nylons’ were a huge success. Nowadays, this fantastic fabric, which leaves a lower carbon footprint than wool, is used for meat wrappings, instrument strings and carpets, amongst many other things. Its only downside is its toxicity upon heating: it melts rather than burns, and breaks down to produce hydrogen cyanide.
This is ironic, actually, because Carothers never got to see his creation take hold. In 1937, just as his achievements were being celebrated and developed, he committed suicide with cyanide. He had suffered with depression and was grieving for the loss of his sister, but his suicide came as a shock. The suicide has been described as an ‘embarrassment’ for DuPont, and records relating to Carothers were lost or destroyed. This may help to explain why the discovery of nylon has since been wrapped in myth and mystery.
Guest post from Tom Branson
Science fiction often predicts future advances and has even prompted the development of some technologies. So should we be taking advantage of this association? Can we use a science fiction setting to showcase science fact? That idea is exactly what the latest cover of Angewandte Chemie has attempted to do.
It’s a trap!
There may be some of you who don’t immediately recognise the image above. It’s an homage to a scene in the Star Wars movies, where the plucky rebel alliance (piloting the small x-wing fighters) mount an attack on the Death Star, a moon-sized weapon of mass destruction and flagship of the evil empire. Hijacking this iconic scene is a certain way to grab the attention (George Lucas himself used it twice), especially by tapping into the current hype for the forthcoming films. But there doesn’t immediately appear to be a solid link between the rebel’s cause and Angewandte’s publishing ideals. In this case I’m not sure if the cover image really works to enhance and explain the research or actually provides a distraction from the science within. It’s certainly a fun image and a good way to get instant recognition of an idea, especially with fans of the franchise. That idea being the destruction of the evil empire, or in this case, evil cells.
In this interpretation the x-wing fighters have their own force fields and are carrying pills towards the Death Star, which itself looks to be in a dire state probably due to the growths in its innards. It should be a straightforward mission as long as the ships watch out for rogue fluorescing cells and a giant-lipidated-space-peptide.
This cover is very similar to an example from 2012 that also showed up in Angewandte. In both cases the empire, represented by the Death Star, took a beating, suggesting that there’s no sympathy for the Sith in the scientific community. For balance, I’d like to see someone’s interpretation of a Death Star nanoparticle destroying the peaceful bacterial population of Alderaan (I will accept joint authorship).
Stay on target
I love all things Star Wars (excluding Jar Jar Binks, of course) but this latest tie in to the franchise does seem a little out of place with the expanded Star Wars universe. No mention of carbonite or even ion cannons. But it does hint at the true content of the article: a new targeted drug delivery method. The group led by Boris Turk and Olga Vasiljeva from the Jožef Stefan Institute in Slovenia, have developed lipid vesicles conjugated to peptides that target extracellular cathepsin B (CtsB). CtsB is a cysteine protease that only translocates to the cell surface during cancer progression and is therefore a cancer-specific target. The research showed fluorophores and anticancer drugs could be transported in their vesicles and target the tumour environment.
For more about targeting cancer and less about the rebel alliance’s struggle, have a look at Angewandte Chemie.
Guest post by Jen Dougan
Of all the components of a cooked breakfast, a perfectly fried egg is arguably the most important. It’s for that reason, despite the myriad of other factors to consider – size/weight/colour/celebrity chef endorsement – that a frying pan’s non-stick credentials are key.
Polytetrafluoroethylene (PTFE), the ‘big daddy’ of non-stick, was discovered by accident in 1938. While attempting to make a new CFC refrigerant, American industrial research chemist Roy J. Plunkett noticed that a cylinder of tetrafluoroethylene had stopped flowing but its weight suggested something still inside. In his own words, ‘more out of curiosity… than anything else,’ Plunkett and his assistant cut open the cylinder to discover it was packed at the bottom and sides with a white, waxy solid. Analysis showed that the material was chemically inert, thermally and electrically resistant, and had very low surface friction.
What they had discovered was PTFE, a linear fluoropolymer prepared by the free-radical polymerisation of tetrafluorethylene. The carbon–fluorine bond is the strongest single bond in organic chemistry and the fluorine substituents shield the carbon skeleton from attack, making it chemically inert. Because of its useful material properties (and far from thoughts of fried eggs) PTFE was branded as Teflon and found uses in the Manhattan project, aerospace industries and even gecko research (it is the only known material to which a gecko’s feet cannot stick). But how did Teflon make its way from nuclear research into our kitchens?
By the 1950s Teflon was being used in fishing lines and a French woman asked her husband, an engineer, to coat her aluminium cooking pans with the material. PTFE-coated non-stick cookware was created, and launched as TefAl (from Teflon Aluminium). By the 1960s PTFE–coated cookware was being used in kitchens on both sides of the Atlantic.
However, on searching recently for a new frying pan I found many instances of implied safety issues with PTFE, mostly from ‘eco pan’ manufacturers and advocates. Two main themes recurred in accusations against PTFE cookware: concerns over perfluorooctanoic acid (PFOA), a surfactant used in its production, and ‘polymer fume fever’ – symptoms caused by inhaling polymer decomposition products.
PFOA is an environmentally persistent chemical and, in the mid-2000s, was classified by the US Environmental Protection Agency (EPA) as ‘likely to be carcinogenic to humans’. DuPont, a major user and producer of PFOA, settled with the EPA in 2005 over its failure to report possible health risks associated with PFOA. While PFOA is not present in PTFE cookware itself (it is destroyed during the manufacturing process), it was an environmental concern and after EPA stewardship, PFOA is no longer manufactured nor used by the major global fluoropolymer manufacturers, including DuPont.
Aside from PFOA concerns, PTFE coatings do begin to degrade at 260 °C. The decomposition of the polymer coating produces fumes, which, if inhaled, can cause ‘polymer fume fever’ – temporary symptoms much like the flu virus (see Shusterman DJ, Occup Med. 1993 8(3) 519). But just how likely is this to occur? It is possible to rapidly heat a pan to >260 °C, but if you follow the manufacturer’s instructions and don’t heat an empty pan,you would likely avoid any instances. The most common fats used in cooking have a smoke point well below 260 °C, which should act as a sufficient indicator of pan temperature and kitchen safety. Obviously, heating the pan without fat as a temperature gauge is riskier and should be avoided.
Still not keen on PTFE? There are alternatives. Used for cookware since the Han Dynasty in China (206 BC – AD 260) and still popular with cooks today, cast iron pans have unquestionably stood the test of time. Cast iron frying pans come bare or with an enamelled coating. Bare cast iron pans are porous and to achieve a non-stick finish worthy of a fried egg, oil is polymerised to form a hydrophobic layer across the pan surface. This process, known as ‘seasoning,’ can be repeated as required (depending on treatment of the pan), though is usually recommended yearly.
I’m satisfied that with normal use, PTFE pans will produce perfectly fried eggs without adverse health effects (apart from a risk of increased cholesterol). The only remaining question is whether to have them over-easy or sunny side up?
My name is Jen Dougan and I am a Field Applications Scientist with an SME, developing diagnostic tools for clinical analysis. My job involves working with our R&D teams and customers in the field to drive and support product and applications development.
I recently moved into this position after a PhD and two post-docs (and a brief stint in science policy) in bio-nano-analytical chemistry. What I’ve loved about the transition into this role is the chance to ask questions and provide answers in a fast-paced, rigorous environment. It’s been fantastic to see some of the techniques used through my PhD and post-docs in action in a clinical setting.
Real world applications of chemical research are a central theme of this blog. I’ll be contributing regular posts here, to explore the chemistry in our every day lives. From the clothes we wear to the goods we use, it really is a chemical world.
Guest post by JessTheChemist
‘Scientists have a responsibility, or at least I feel I have a responsibility, to ensure that what I do is for the benefit of the human race’ – Harry Kroto
Thank you for your nominations for this month’s blog post. It was great to see so many of you getting involved in this series, highlighting interesting Nobel laureates for me to cover. However, I could only pick one winner, so I decided to write about Harry Kroto, inspired by this tweet from Bolton School:
— BoltonSchoolChem (@Chem_BoltonSch) August 20, 2014
Harry Kroto has a formidable CV. Not only is he a highly distinguished and talented chemist, but he does a great deal to improve the teaching of chemistry to future generations. This has included setting up the not-for-profit Vega Science Trust, which helps scientists communicate with the public at large, and even returning to his childhood school to build Buckyballs with students.
Kroto began his career at the University of Sheffield where he gained his PhD in high resolution electronic spectra of radicals. After time spent in Canada and the USA, he returned to the UK – to the University of Sussex – to begin his independent research career. His research concentrated on the identification of carbon chains in the interstellar medium, which included work at Rice University, where Kroto and colleagues, Richard Smalley and Robert Curl, discovered the existence of C60 or Buckminsterfullerene. The discovery itself has become a well known scientific story, recently retold by Rowena Fletcher-Wood here on the Chemistry World blog. After numerous publications on the subject, Curl, Kroto and Smalley were awarded the Nobel Prize in chemistry in 1996 ‘for their discovery of fullerenes’. As with many other Nobel laureates, there’s a detailed biography of Kroto published by the Nobel foundation here.
Kroto is related to a number of influential scientists. He is distantly related to Roger Kornberg, who won the Nobel prize in chemistry in 2006 for his work on the molecular basis of eukaryotic transcription. Kornberg was lucky enough to work for the Nobel prize winner, Francis Crick, who famously contributed to the proposal that DNA had a double helical structure, along with James Watson.
Kroto’s academic partners and fellow Nobel prize winners, Curl and Smalley also have impressive scientific pedigree. Curl’s academic father was E. Bright Wilson, a pioneer in spectroscopy, and grandfather was Linus Pauling, who won both the Nobel prize in chemistry and the Nobel peace prize. Curl is also academic brother to Dudley Herschbach, winner of the Nobel prize in chemistry in 1986 for contributions towards the molecular dynamics of elementary chemical processes. Hershbach shared the prize with the Hungarian-Canadian chemist John Polanyi and Yuan T. Lee, the first person from Taiwan to be awarded a Nobel prize. Smalley is academically descended from William Lipscomb, who took the 1976 Nobel prize in chemistry for his contributions to borane chemistry. Not shown in our family tree are Thomas Steitz and Ada Yonath, who both went on to win Nobel prizes after time spent in Lipscomb’s lab. Lipscomb also demonstrated his sense of humour by regularly presenting at the Ig Nobel awards. Curl is also connected to Peter Atkins, author of undergraduate students’ favourite physical chemistry textbook!
As you can see, Kroto has an eclectic lineage, and rich academic family history, from chemical biologists to physical chemists. Do you want to know what your academic genealogy is? If so, head to academictree.org, where you can add yourself to the website and start creating your very own tree.
‘As for monkshood and wolfsbane, they are the same plant, which also goes by the name of aconite.’ – Severus Snape, Harry Potter and the Philosophers Stone by J. K. Rowling
In Harry Potter’s very first potions lesson he learnt about the magical properties of aconite. Muggle chemists, it seems, are only one step behind the magical world.
Aconitine – spelt slightly differently by scientists – has a highly complex structure that has never before been synthesised in the lab. But now, Duncan Gill from the University of Huddersfield, UK, has been awarded a £133,481 grant to develop a synthetic route to obtain this illusive molecule.
Attempts to make aconitine began after Czech chemist Karel Wiesner revealed its chemical structure in 1959. Weisner went on to publish several papers on the synthesis of alkaloids and terpenoids, an important initial step towards making the molecule. However, it wasn’t until last year that a major milestone was reached, when a team of researchers from the Memorial Sloan Kettering Cancer Institute, New York, announced the total synthesis of the related compound, neofinaconitine. Building on the work of his predecessors, Gill will have to develop new chemical methods to reach his target molecule.
If successful, Gill, who has previously worked as a process chemist at AstraZeneca, will need to be particularly careful when handling this compound. Aconitine is a potent neurotoxin and has been dubbed the ‘Queen of poisons’. One of the most notable references to aconitine comes from William Shakespeare’s Romeo and Juliet: it is the main ingredient in the toxic potion drunk by Romeo with fatal consequences.
The grant has been provided by the Leverhulme Trust and will be enough to employ a full-time post-doctoral advisor. Only time will tell if they can bring this fictional favourite to life in a laboratory setting.
Guest post by Heather Cassell
Sometimes it happens when I’m reading a research paper, sometimes when I’m doing an experiment, analysing data or learning a new technique; or more often when I’m reading Twitter. It’s that moment when you discover something new and interesting, or re-discover a fact that you used to know, and it makes you pause and think ‘ooh, that’s interesting’. For me the discovery usually leads to a massive detour into reading things other than those I was meant to be reading or working on, but I always learn something from it and sometimes it’s actually relevant to my work. Whether it directly affects research or not, the ‘ooh, that’s interesting’ moment is at the heart of scientific investigation.
It can be great when it happens during an experiment, but it can also be deeply frustrating. An unexpected result forces you to seriously consider what is happening and to plan more experiments to further examine the anomaly. This encourages you to combine techniques, make use of all of the resources at your disposal or even seek out new collaborators. If the anomalous result is reliably proved correct and reproducible, then you will need to do more research to explain it. At its best, this is a very exciting time as you will get to learn new skills, create new knowledge and develop partnerships. At its worst, it can shatter your previous assumptions or even show that your idea or product is not as good as you think.
Personally, I really enjoy the flurry of activity associated with learning something new, especially a new experimental technique. I was recently involved with some experiments using atomic force microscopy (AFM) – I had a vague idea of what it was but I had never used this technique before. The analysis produced some amazing pictures but I had no idea what they meant, so I spent an enjoyable afternoon learning all about how AFM works and comparing the results we produced with results already published. The next time we used the machine I could analyse the images as they were formed, which was really helpful for determining if it was showing what we wanted or not. The ‘ooh, that’s interesting’ moment had provided the push I needed to learn a new skill.
Outside the lab, I really love spending time on Twitter. With so many scientists (and non-scientists) from different fields providing links to articles and blogs, there’s always more than enough to read. Just 10 minutes reading tweets can leave me with countless browser tabs open and new favourites to read. It’s now easier than ever to share your ‘ooh, that’s interesting’ moments with the world, meaning a tweet from a researcher half way across the globe can inspire new ways to think about my own research.
It is this process of discovery and continuous learning that is one of the main things I love about science. Now, back to Twitter…
Guest post by Rowena Fletcher-Wood
Scurvy plagued early sailors, and although many treatments were tried and promoted, a simple cure was masked for centuries behind a series of mistakes and misunderstandings.
This story begins at sea, long into a voyage after the fresh food stock had long run out and the sailors were left with only grains, hardtack and cured meats to eat. The sailors would become desperate as scurvy began to set in. Sailors were lost to scurvy in vast numbers, with estimates as high as two million lives lost between 1500–1800 AD.
Scurvy is an unpleasant disease in every way. Although symptoms take weeks or months to develop, they get very nasty. First you become lethargic, anaemic and pale, and all of your joints and muscles ache. You lose your appetite and begin to develop spots on your thighs and legs. Soon you become feverish, sick, and weak; gums soften and bleed, legs swell, old wounds reopen. Depression sets in. Eventually, scurvy takes hold completely: your teeth fall out and gums turn blue, you bleed beneath your skin and from the follicles of hairs. You suffer cardiac arrest and die.
Scurvy is caused by a deficiency in vitamin C (ascorbic acid), which is present in many foods – including tomatoes, sweet peppers, strawberries and spinach – but in particular citrus fruits. Several pathways in the body rely on vitamin C; it is vital for building collagen in tissues. We also use it for lipid metabolism, neurotransmission and strengthening bone and blood vessels. Although many species are capable of synthesising their own vitamin C, humans and a few other animals cannot – it is an essential nutrient that must come from our diet. But until 1927, we didn’t even know it existed.
The ancient Greek physician Hippocrates knew that fresh fruit, especially citrus, had an antiscorbutic effect – it could prevented and cure scurvy. In 1747, James Lind systematically proved that the addition of citrus fruit to the diet both treated and prevented the disease, in a candidate for the first ever clinical trial. But the medical establishment were not convinced, and continued to promote other approaches, including good hygiene, exercise, avoiding tinned meat and improving morale. Some of these approaches were successful, including prescribing the peppery herb scurvy-grass, which is related to horseradish. Unknown at the time, scurvy-grass leaves are rich in vitamin C.
A common belief was that the acidic principle treated scurvy: doctors believed any acid would do and that citric acid in fresh fruits was merely the best. Accidental destruction of ascorbic acid in treatments that would otherwise have been effective was common. Although vitamin C is present in milk, this was destroyed by the new process of pasteurisation, leaving bottle-fed babies susceptible to scurvy. James Lind himself was guilty too, bottling and selling lime juice that promptly oxidised and became useless.
When the 1867 Merchant Shipping Act insisted that all ships carry citrus fruits, fresh lemons were substituted for cheap, abundant West Indian limes which were more acidic but had only a quarter of lemons’ ascorbic acid content. These fruits were juiced, stored in air and piped through copper tubing, oxidising the vitamin C. Later tests in 1918 showed the juice to be almost useless, but at the time this was masked by simultaneous advances in diet and marine travel that reduced the prevalence of scurvy.
We owe the discovery of vitamin C to guinea pigs. Two Norwegian physicians, Axel Holst and Theodor Frølich, decided in 1907 to induce in guinea pigs a disease called beriberi, now known to be cause by a deficiency of vitamin B1. They used the same dietary restrictions they had used to induce the disease in pigeons, but the guinea pigs developed scurvy instead. Pigeons produce their own vitamin C, but like us, guinea pigs cannot. This was an exciting moment in medical history: the diseased guinea pigs were the first examples of non-human scurvy sufferers.
In 1932, the Hungarian biochemist Albert Szent-Györgyi posted a sample of hexuronic acid – which he had isolated in 1927 – to the University of Pittsburgh, asking them to test it on guinea pigs with scurvy. The results would gain him the Nobel prize for medicine five years later, and hexuronic acid was renamed ascorbic acid to celebrate its antiscorbutic effect.
Decades of nutritional experiments and almost–correct hypotheses had seen scurvy become increasingly rare, but it took almost 200 years – from Lind’s nutritional trials to Szent-Györgyi’s experiments – to identify the secret in citrus fruits.
Guest post from Tom Branson
A bright new reaction scheme has found its way to the cover of Inorganic Chemistry. Not content with old standard representations, this journal has been given the professional touch.
Framing metal complexes
The image puts a well needed shine on the conventional reaction scheme and perhaps suggests that we should now be teaching undergrads to paint as well as honing their ChemDraw skills. Two states of a porphyrin derivative complexed with zinc are shown here framed in audacious, golden swirls. And why not? If you’re proud of your work then go ahead and put a huge golden frame around it.
Let’s take a look at that zinc phthalocyanine complex, expertly drawn binding to HS–. Then give it a proton, follow the two giant arrows and you reach liberated hydrogen sulfide and the original zinc phthalocyanine. In case you hadn’t got it yet, the artwork explains for us that this process is all about protonation. The background is also a nice touch. A fantastic network of neurons is on show, blasting off new thoughts of possible bioinorganic applications. Hydrogen sulfide is known to play a role in neurotransmission and its reactivity with metal complexes may find practical applications in that field.
This journal cover art was created by artist Shanna Zentner. She was recommended to the authors of the article by colleagues at the University of Oregon, after she had previously produced artwork for other faculty members.
Zentner’s foray into the scientific literature started when her husband needed a cover for a chemistry journal. They thought a painting of the research would do nicely and so Zentner’s chemistry art career took off. Since then her painting skills have been commissioned for a number of other journal covers, with the artist and scientists often meeting to discuss the work and how to develop the imagery. Zentner champions science communication and believes that this type of work is ‘invaluable to the advancement of scientific literacy in the general public.’
Hydrogen sulfide reactivity
The actual research probes more deeply into the mechanism of H2S binding to both zinc and cobalt phthalocyanine complexes. The team, led by Michael Pluth, show that whilst the zinc variety reversibly binds HS–, the cobalt complex is instead reduced by HS– and can be oxidised back when exposed to air. This redox activity results in a colour change that could be used in colorimetric HS– detection.
Head over to Inorganic Chemistry for the full article and more bright results with metal phthalocyanine complexes.
Guest post by JessTheChemist
‘The noblest exercise of the mind within doors, and most befitting a person of quality, is study’ – Ramsay
A few years ago I had the pleasure of meeting Jack Dunitz at the Swiss Federal Institute of Technology (ETH) in Zurich. Little did I know that he was the academic great-great-grandson of the UK’s first chemistry Nobel Laureate, Sir William Ramsay. After discovering this connection, I decided to delve deeper to see which other chemistry legends Ramsay is connected to.
Ramsay began his career as an organic chemist, but his prominent discoveries were in the field of inorganic chemistry. At the meeting of the British Association in August 1894, Ramsay and Lord Rayleigh both announced the discovery of argon, after independent research. Ramsay then discovered helium in 1895 and systematically researched the missing links in this new group of elements to find neon, krypton, and xenon1. These findings led to Ramsay winning his Nobel prize in 1904 in ‘recognition of his services in the discovery of the inert gaseous elements in air, and his determination of their place in the periodic system’.
Ramsay worked with a wide range of chemists before winning his Nobel prize. At the start of his career Ramsay worked with Rudolf Fittig in Tübingen, Germany. Fittig, a successful organic chemist, is particularly known for discovering the pinacol coupling reaction. Ramsay’s noteworthy academic brothers via Fittig are Ira Remsen and Theodor Zincke. Remsen is recognised for contributing to the discovery of the first artificial sweetener: his co-worker, Constantin Fahlberg, accidentally discovered Saccharin by failing lab etiquette 101 – not washing his hands after a day working in the laboratory.2 On the other hand, Zincke is most famous for supervising the father of nuclear chemistry, Otto Hahn, who claimed the Nobel prize in chemistry (1944) ‘for his discovery of the fission of heavy nuclei’.3 This makes Ramsay the academic uncle of Hahn.
As well as academic brothers and nephews, Ramsay’s direct academic descendants have also achieved greatness. Frederick Soddy, Ramsay’s academic son, carried out research into radioactivity and proved the existence of isotopes, for which he won the 1921 Nobel Prize in chemistry.4 Unfortunately for the chemistry community, Soddy’s interests diverted to economics and politics, so he has no prominent academic offspring to speak of. Interestingly, he also has a lunar crater named after him! Other chemistry Nobel prize-winning descendants of Ramsay include the two-time winner, Frederick Sanger (1958, 1980), and Barry Sharpless (2001), who are both his academic great-great-grandsons. Ramsay also has more diverse Nobel prize winners in his family tree, with two winners for physiology or medicine: Har Gobind Khorana (1968) and Konrad Bloch (1964).
This summary of Ramsay’s academic family is by no means the complete list, but this does demonstrate that one great chemist can have an enormous effect on the generations of chemists to come. As you can see, Nobel prize winners seem to have excellent academic dynasties, but perhaps it isn’t the fact that their mentor won a Nobel prize that inspired them to greatness but their work ethic and abstract way of thinking.
In future posts we will look at other Nobel prize winners and the effect that they may have had on their academic offspring. If there is a particular winner that you would like to see featured, you can contact me on Twitter (@Jessthechemist).
1: Sir William Ramsay – Biographical. Nobelprize.org. Nobel Media AB 2013. Web. 6 Jan 2014.
2: Chemical Heritage Magazine ‘the persuit of sweet:a history of saccharin’
3: Otto Hahn – Biographical. Nobelprize.org. Nobel Media AB 2013. Web. 6 Jan 2014.
4: Frederick Soddy – Biographical. Nobelprize.org. Nobel Media AB 2013. Web. 7 Jan 2014.
I am a postdoctoral fellow at the Institute of Process Research and Development (iPRD) at the University of Leeds. My research is on the synthesis of chiral amines relevant to the pharmaceutical industry but I have a general interest in organic chemistry, catalysis and sustainable methodologies. When I am not in the lab, I blog at The Organic Solution on a range of topics including chemical research, postdoc life and outreach experiences. Recently, I have become interested in the connection between chemists across the globe which has led me to create an academic twitter tree.
To continue this academic tree theme, this blog will explore certain strands of the chemistry Nobel Laureate family tree using the Royal Society of Chemistry’s Chemical Connections. The blog will delve into the life and heritage of different chemistry Nobel Laureates and, amongst other things, we shall find out if having a Nobel winner in your lineage could have an effect on your career, for example, does having a Nobel winner in your ancestry mean you are more likely to achieve academic greatness? If there is a Nobel winner that you would like to see featured, please get in touch.
Guest post by Heather Cassell
I love working in the lab. I’m happiest when I’m pottering about among the bottles and the beakers getting on with my work. Most of my experience has been in multi-group labs of varying sizes; all have generally been good fun to work in, with lots of people to talk to who each have different skills and experiences. This can be very useful when you need any help, especially when you are learning new techniques.
One thing you can rely on happening in the lab at some point, especially a large lab used by many groups, is the appearance of Mysteriously Abandoned Glassware. Usually the bottle, beaker, or flask is unlabelled. If you’re lucky enough to have a label, it’s guaranteed to be so faded you can’t read it. Sometimes the glassware contains a colourless liquid; other times a crystalline material, evidence of the previous presence of now long lost liquid. A common variation of the Mysteriously Abandoned Glassware is the flask/beaker of something that has had Virkon (a pink disinfectant) added to it and left in the sink, again with no label in sight to point us to the perpetrator. Over time, the pink Virkon discolours, but the glassware remains Mysteriously Abandoned.
Over the years, I have realised I have a fairly low mess tolerance (compared to the other people I work with), at least in the lab; my office desk is another matter! I like a clean and tidy bench to work on and the same goes for communal areas, so while others are happy to ignore the things that have been left, I find myself doing something about it. I’m always the one tidying up as I am waiting for the centrifuge to run, or doing other lab jobs (filling up hand towels, checking stock levels, emptying disposal bins…). In the case of Mysteriously Abandoned Glassware, I end up trying to find the owner (often a mystery) then trying to work out what it is.
More often than not, the solution is something fairly innocuous like a buffer (Tris or PBS), which we dilute from concentrated stocks, or an alcohol (ethanol or methanol). After I’ve worked out what it is and how to dispose of it, I’ll send the glassware to be washed or do it myself. Within hours, you can guarantee that someone will come and say, ‘have you seen my [insert common solvent here]? I left it somewhere…’ The lab will stay reasonably tidy for a few days or maybe even a few blissful weeks, before another piece of Mysteriously Abandoned Glassware materialises and the cycle continues.
I’m Heather Cassell (née Stubley). I did a BSc in biochemistry and genetics at the University of Leeds, then I moved to the University of York where I did an MRes in biomolecular sciences followed by a PhD investigating enzyme activity in non-aqueous solvents. I am currently finishing my first postdoc position working as a research fellow in molecular and cell biology at the University of Surrey. The project involves cloning proteins of interest and attaching them to polymers or other nanoparticles then assessing their toxicity and cellular location in liver related cell lines.
I decided to write a ‘life in the lab’ blog strand because I love working as a scientist, especially the time spent in the lab itself – despite the many challenges. It gives me a chance to share my enthusiasm for working as a researcher and all things science-related. I plan to give an early career scientist’s view of life in the lab, balancing work and childcare, procrastination and productivity, research and recreation.
Guest post by Rowena Fletcher-Wood
Among the many accidental discoveries through the ages is an experiment designed to probe carbon molecules in space, which unearthed a new terrestrial molecule.
It all happened in an 11-day whirl, between 1 September 1985, when Harry Kroto first arrived at Rice University, US, and 12 September, when he, along with Richard Smalley and Robert Curl, submitted a paper to Nature: ‘C60 Buckminsterfullerene’. Eleven years later, in 1996, the three were awarded the Nobel prize for chemistry.
Indeed, a Nobel prize may have been some consolation to Smalley and Curl, who were initially reluctant to delay their research on silicon and germanium semiconductors to let Kroto play with carbon. Kroto was exploring a completely different area of research: cyanopolyynes, alternating C–N chains detected in interstellar space using radiotelescopes. Although the evidence for their existence was good, the origin of these compounds was still unknown. Kroto postulated that they may form in the vicinity of red giants, and wanted to use Smalley’s laser-generated supersonic cluster beam to recreate this high-heat atmosphere and uncover mechanisms for their formation.
After agreeing to let Kroto use the apparatus, the three scientists, helped by graduate students James Heath, Sean O’Brien and Yuan Liu, loaded a graphite disk onto the beamline in a helium chamber and vaporised it into a plasma at temperatures exceeding the surface temperatures of most stars. Under high pressure helium, the vapour cooled and condensed, forming new interatomic bonds and aligning into different-sized clusters, which were immediately pulse ionised and swept into a mass spectrometer for analysis.
First, the students found Kroto’s expected carbon snakes, but then they noticed a distinct peak at C = 60 and a smaller one at C = 70. The abundance of C60, and increasing yield under higher pressure conditions suggested a very stable, closed-shell macromolecule. Unlike Kekulé’s benzene ring, buckminsterfullerene was not identified through dreaming, but through the resourceful application of sticky tape and cardboard cut outs. The model was proposed: a truncated icosahedron, consisting of twenty hexagons and twelve pentagons, like a carbon football. The name, buckminsterfullerene, was inspired by the architect famous for his similar-looking geodesic domes.
Since then, enthusiastic exploration into other fullerene allotropes has revealed that we could have accidentally discovered buckyballs long ago using much lower-tech equipment: a burning candle produces buckyballs in its soot by vaporising wax molecules. Not only that, but buckyballs occur in geological formations on Earth and, since 2010, have been detected in cosmic dust clouds. The ball-like carbon molecule wasn’t even a new idea: between 1970 and 1973, three independent research groups led by Eiji Osawa of Toyohashi University of Technology, R W Henson of the Atomic Energy Research Establishment, and D A Bochvar of the USSR, predicted the existence of the C60 molecule and calculated its stability. However, their work was purely theoretical, and didn’t get the attention it deserved. Buckyballs were discovered, rather than made, so perhaps it’s not surprising that they were found by accident: more surprising is that that weren’t found before.