1. What made you want to be a chemist?

When I was twelve years old, I reasoned that if I only knew what matter was made of, I would understand “Life, the Universe, and Everything”. Chemistry not only seemed to provide an answer to this big question but, luckily, the recipes to make fun explosives.

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

I guess being an artist would be an attractive alternative although I think I lack talent. Both the art that artists can create and the molecules that chemists can make, are truly novel.

3. How can chemists best contribute to the world at large?

Chemistry is different from biology and physics in that it creates new things. Chemistry has changed the world with the invention of new molecules and reactions. Just consider antibiotics, the discovery of nuclear fission, the polymerase chain reaction, cracking or the industrial synthesis of ammonia. All these achievements and many others had a profound impact on the world. The next big challenge for chemists is just around the corner: Solving the energy problem of our planet!

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

Emil Fischer, a master of chemical intuition and an organic synthesis genius. I wonder why and how he was so much ahead of his time.

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

In 2004 I had a relatively small group, but was convinced a certain molecule would be a good catalyst. It was Easter Sunday; nobody was in the lab and so I made it myself. It involved a Grignard reaction and an acetalization. Unfortunately, the catalyst was pretty much inactive…

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

B.K.S. Iyengars’s “Light on Yoga” and Bach’s St. Matthew Passion.

Ben List is in the Department of Homogenous Catalysis at the Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, Germany, and develops new concepts for catalysis.

Raman spectroscopy can detect cancer and probe the surface of Mars. This most widely applicable of analytical techniques is even helping the art world spot fakes, as Robin Clark, a pioneer of the technology, reveals at the Royal Society next week.

Anna Winterbottom

On 7 February UCL Professor Robin Clark will deliver the annual Bakerian lecture at the Royal Society, entitled ‘Raman Microscopy, Pigments and the Arts/Science Interface’.

The talk draws on his varied career, which has encompassed transition metal chemistry, electronic, infrared, Raman and resonance Raman spectroscopy, and Raman microscopy.

Clark will describe his work on spotting art forgeries using scientific techniques, and interdisciplinary collaborations. “I have been trying very hard to bridge the gap between the arts and the sciences over the past decade or so by endeavouring to obtain access to important artwork and artefacts for which questions of provenance, date, authenticity, etc., might be answerable by way of pigment identification,” he says. “We have been very successful at this. Indeed the field is now expanding rapidly all over the world.”

An experimental philosophy

The annual Bakerian lecture, established by the Royal Society in 1775 on any topic of ‘natural history or experimental philosophy’, has a tradition of choosing distinguished polymaths. Previous speakers include James Clerk Maxwell, John Tyndall, Michael Faraday and Clark’s former supervisor Lord Lewis of Newnham.

Born in New Zealand, Clark first undertook research at the University of Canterbury to study fluorescence quenching under Walter Metcalf. After a stint at the University of Otago researching high pressure chemistry, he completed a PhD in transition metal chemistry at UCL in 1961, where he has remained since.

Clark’s research group has made key advances both in the theory and practice of Raman and in resonance Raman spectroscopy, leading to applications across chemistry, biochemistry, solid state chemistry, and physics.

Applications of Raman spectroscopy continue to diversify. For example, it was recently claimed that a combination of confocal laser scanning microscopy and Raman spectroscopy might be applicable to analysing rocks on Mars for signs of life, and the technique has been championed for detecting fake medicines.

Clark predicts that further expansions will include applications in medicine including spectroscopic mapping of tissues and in forensic science for tracing drugs and for detecting explosives from a crime scene.

Scientific sleuthing

The forthcoming lecture will focus on the applications of Raman microscopy in artistic and archaeological studies. This draws on pioneering collaborations with libraries and museums to use Raman microscopy to identify pigments and dyes of micrometre dimensions on medieval manuscripts, paintings, papyri, icons, ceramics and archaeological artefacts.

By studying the probable sources and dates of pigments, Clark’s group provided evidence consistent with the attribution to Vermeer of the Young Woman Seated at a Virginal (1). In the controversial case of the ‘Vinland map’ — discovered in 1957 and claimed to depict the Americas pre-Columbus — Raman analysis confirmed the presence of a compound (anatase) which is in the form of a twentieth century industrial product. This indicates the map to be a forgery (2).

The group also investigated reports that the Lindisfarne Gospels, composed around 715 AD, made use of a blue pigment called lazurite, extracted from the mineral lapis lazuli found in remote valleys of northern Afghanistan (3). “This claim implied that lapis lazuli had been traded to Northumbria at this improbably early date,” says Clark. “Our Raman studies clearly showed that the pigment was not lazurite but indigo, available in England since at least Roman times.”

Two cultures still?

Clark is disappointed that initiatives to do with the scientific investigation of art appear largely to be science-driven. He believes that this is primarily because scientists are prepared to immerse themselves in books on art and archaeology, whereas few of their counterparts in the arts engage with scientific literature.

“Greater parity here would lead to many further and much more effective alliances and advances,” he says. “This will surely happen in the future.”

References

1) Burgio, L. et al. Pigment Identification by Spectroscopic Means: Evidence Consistent with the Attribution of the Painting Young Woman Seated at a Virginal to Vermeer. Anal. Chem., 77, 1261–1267 (2005). DOI: 10.1021/ac048481i

2) Clark, R. J. H. The Vinland Map – Still a 20th Century Forgery. Anal. Chem., 76, 2423–2423 (2004).

3)settingerror.html Brown, K. L. & Clark, R. J. H. The Lindisfarne Gospels and two other 8th century Anglo-Saxon/Insular manuscripts: pigment identification by Raman microscopy. J.Raman Spectrosc., 35, 4–12 (2004).