Thursday, 1 December 2011

Interview - Dr Deborah Kays -Chemistry Lecturer

The NSB was chuffed to have the opportunity to interview Chemistry Lecturer Dr Deborah Kays recently.

The interview kicked off with a few questions about how Debbie had become interested in Chemistry. Debbie recalled how, as a youngster, one of the books that she possessed had a section on chemistry which included an article on how two very reactive and dangerous chemicals, Sodium and Chlorine, react together to form safe, edible, inert table salt (sodium chloride). This left a deep impression on Deborah and was one of the reasons she later took up Chemistry as a career.

It was also worth noting that Debbie “only” took the standard double-science GCSE exam (although one suspects that her grade was far from standard !) which shows that you do not need to take the three separate sciences at GCDE to make a career in the sciences.

Debbie obtained both her graduate degree, PhD and initial postdoctoral research post at Cardiff University, with her research work focussing on the chemistry of Boron and on investigation the nature of chemical bonds. After a spell at Oxford University she was appointed Lecturer in Inorganic Chemistry at the University of Nottingham in 2007.

NSBV asked Dr Kays for her top tip for students as whatever strategy she was using had celearly worked. Debbie's response was that students should practice, practice, practice as there is a significant component of the study of Chemistry that is simply rote learning of facts, tables and reaction schemes.

Regarding her time at Oxford, Dr Kays mentioned that one unusual aspect of Oxford University was the college system. Usually, after spending the working day with other chemists, the evening meal would be at the college and one could end up sitting next to a historian, engineer or physicist !

This was quite different from more conventional universities, where one easily spend all ones time surrounded by people from a similar technical background.

A large part of the interview involved a discussion covering the basics (in layman's terms) of what atoms are and how they bond to each other. So let's get down and dirty with the basic components of all the materials we see around us. . .

All the matter you see around you, the chair you are sitting on, the metal case of the computer you are using, the muscles and blood in your body, even the air around you - is composed of basic building blocks called atoms.

Atoms are very, very, very small. 10million of them lined up end to end would form a line just 1mm long.

They are composed of a small nucleus (containing protons and neutrons) which is surrounded by a cloud of electrons. It’s probably easiest to see an example in pictorial form:

As you can see, the number of +ve and -ve charges balances out.

It’s worth mentioning that the nucleus is typically just 1/10,000th of the size of the atom, so the overwhelming majority of an atom is just empty space !!

By the way, the simplest element is Hydrogen, which has just one electron and one proton:
There are about 90 different types of naturally occurring atoms. These are the elements we recognise from everyday life (oxygen, iron, carbon, gold etc). Each element is known by its “chemical symbol” (Oxygen= O, Iron=Fe, Carbon=C, Gold=Au etc)

Different elements have different numbers of protons in the nucleus (the number of neutrons also changes but it is the number of protons that is key)

For example, Oxygen has 8 protons (and thus also 8 electrons) while Iron has 56 protons (and, wait for it, 56 electrons)

Importantly, the electrons form distinct layers (known as shells) and elements that have full shells are inert and will not react with other elements.

The innermost shell can hold 2 electrons. As you have seen, Helium atoms have this shell filled nicely. This is why Helium does not react with anything (and why Helium airships are much safer than Hydrogen ones).

The next two shells can hold 8 and 18 electrons respectively. Let’s take a look at the example of oxygen:
As mentioned previously, atoms want to fill their electron shells. One way they can do this is to bond with other atoms and “share” electrons.

When two or more atoms bond together, they form a “molecule”

To take an example of how bonding can do this, let us look at water, a simple but oh-so-important molecule. In the diagram below, you can see how the Oxygen forms a bond with each of two Hydrogen atoms. The bonds allow the Oxygen and the Hydrogen to share electrons, thus filling the spaces in their respective outer shells.
The two Hydrogen atoms share their single electrons with the Oxygen, thus giving the Oxygen a full outer orbital of 8 electrons, whilst the Oxygen shares two of its electrons with the Hydrogens (one each), thus giving them a full outer orbital of 2 electrons (remember, the first shell only holds two electrons)

The picture painted here is, in reality, quite a simplistic one. There are many types of bonding (e.g ionic bonding, double bonds, metallic bonding, delocalised bonding) and the behaviour of electrons is actually more like a wave than a hard particle moving around a nucleus. However, this simple approach does have the tremendous advantage of being intuitive and of explaining a fair amount of basic chemistry.

As you may have worked out, Oxygen will often make try to make two bonds with other atoms. And in just the same way as this is characteristic of the Oxygen atom, so other elements have their own characteristic number of bonds that they will try to form. For example:

Hydrogen 1 bond
Chlorine 1 bond
Magnesium 2 bonds
Nitrogen 3 bonds
Carbon 4 bonds

Often, the bonds between atoms are represented by lines, so water could be represented as :
It’s worth mentioning that Carbon has the interesting property of being able to form long chains. For example, Polythene (as used in carrier bags etc) is formed of molecules thousands of atoms long and has the structure below (remember, Carbon wants to make four bonds, Hydrogen wants to make just one):
Another, somewhat less laborious, way of writing the structure of Polythene is like this :
Lastly, when chemists draw structures, they often don’t bother putting all the Hydrogen atoms down, and sometimes just use kinks in the line to denote where the carbons are (chains of carbon are genuinely kinked like this, so it’s not an arbitrary convention). For example, the Polythene molecule shown above might be notated as :
By the way, you can read the fascinating story of how Polythene was discovered here. Dear reader, if you have gotten this far, I salute you. The hard work is now over, and it’s payback time.

You should now have the tools to understand, more or less, the structure of many of the chemical compounds that are around us.

To kick off, why not check out these bad boys at Wikipedia (one tiny note, if you see bonds that are wedges or dashes, it just means that they are bonds angled towards you or away from you respectively)

Lactic Acid.This is the chemical that causes the burning sensation in your legs or arms after very vigouous excersise.
Vitamin C

Whilst the compounds above are pretty straightforward, the proteins that are produced by plants, animals and bacteria are staggeringly complicated.

Have a look at Haemoglobin, the protein that transports oxygen in your blood.

Or Testosterone, the hormone that makes males. . .er. .. male.

Or Fibrilin, a building product of elastic fibres in connective tissue

Lastly, check out these protein image galleries. Literally awe-inspring.

Now, to be fair, we have drifted some considerable distance away from the discussion in the interview so let us get back there by mentioning Dr Kays' comments on the research that she undertakes.

Given that Dr Kays' work in very much in the “blue sky” area, with no immediate compounds or industrial applications on the horizon, BFTF asked how the research was funded. Debbie explained that the work was investigating the nature of chemical bonds and this improved understanding would be of value to chemistry generally. Having said that, these “complexes” as they are known, may lead to improved catalysts in the future.

Dr Kays then went on to explain how the process of making (or synthesizing) new chemicals works. Firstly, the researcher looks at the literature to see what kinds of reactions, or combinations of reactions, are likely to get them from their starting compounds to the molecule that that wish to make and study. At each step of the process, they will assess what chemicals have been made before filtering, distilling or otherwise processing the material to remove unwanted compounds (or unused reactants) before moving to the next step. Debbie commented that some reactions may work well, with 100% of the reactants being converted to the chemical required for the next step in the process whereas in other cases only a small fraction of the reactants may be converted. In the worst case, the reaction may not give the researcher what they want at all !

On the other hand, Debbie said that it is a wonderful feeling to produce a new chemical, perhaps a chemical that no one has ever seen before and that this had been one of the highlights of her PhD work.

Wondering whether this was something that you or I could share in, NSB mentioned a recent article by Ben Goldacre which described how an ordinary member of the public had been able to show that the “'Threefold variation' in UK bowel cancer rates" reported by the BBC was very largely the effect of small health authorities having more variable cancer rates that larger health authorities (in the same way that a people tossing a coin twice will have a much more variable rate of “heads” than people tossing a coin 100 time). Debbie was certainly supportive of the public getting involved in this kind of “Citizens Research” activity

NSB was interested in the kind of jobs that chemistry graduates might end up in. Debbie responded by saying that a degree in chemistry was highly values across many careers because it was perceived as being difficult and in requiring a numerate, organised mind. Thus graduates could move on from their initial degree to a further qualification, or to industry or to a completely different sector such as banking.

Moving towards the end of the interview, NSB asked Debbie to name a chemist that she particularly admired. Expecting a response along the lines of Curie, Rutherford, Mendeleev or Ibn Hayyan, BFTF was surprised to hear Debbie choose Professor Phil Power.

With his name not being one that could be described as “household” (and the subject of scientists not being as well know as footballers is something that we could perhaps discuss another day) Debbie explained that for many years the maximum number of bonds that had been produced between tow atoms had been four and that many chemists had believed achieving a “quintuple” bond was impossible.

But Prof Power only went and did it, didn’t he !! His development of a Chromium complex that contained 5 bonds was a real breakthrough. You can read about it here.

Penultimately, this is perhaps a good time to mention a few pointers towards more information about Dr Kays and her work. You can find out more about her research here and she appears in one of Nottingham University’s groovy “Periodic Videos” here

UPDATE: 14 June 12

Researchers have managed to create the first room temperature Boron triple bond - could open up whole new vistas of chemical possibilities.

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