Letters: June 2007

From Peter Plesch

When in 1989 I was writing the paper entitled The relation between reduction potential and solvation energy for some aryl-methylium ions, (J. Chem. Soc. Perkin Trans. 2, 1989, 1139), I needed the ionisation potentials of the tri-4-X-phenylmethyl radicals, where X = Cl, H, and MeO, as these numbers could not be found. 

In the literature for the first and third of these compounds, that publication is still effectively incomplete. Recently, wanting to clear up unfinished business, I found that the required information still cannot be found, even by the librarians of the RSC. 

I would be most grateful to anyone who can supply my with the two numbers I need. Advice on where and how I might find them is of no use to me at all, as I am rather immobile now and also computer-incompetent. 

P H Plesch CChem FRSC
Keele University, UK

 

From Michael Baldwin 

Your article New limits set on chirality  (Chemistry World, May 2007) implies that neopentane is inherently chiral, but that it was necessary to prepare the deuterated version in order to make it detectable. Neopentane is, of course, a symmetrical molecule, with identical methyl groups being directed from a central carbon to the apexes of a tetrahedron. It is the incorporation of different numbers of deuterium atoms into these methyl groups which imparts chirality. Nevertheless, it is an impressive demonstration of the power of Raman optical imaging. 

M K Baldwin CChem FRSC
By email

 

From Jim Horler

Dylan Styles’ Bench Monkey article (Chemistry World, May 2007) brought back some pleasant memories of the carefree atmosphere in industrial and college labs in the 1950s and 60s. 

My first task at the age of 16 in an industrial lab was to make my own distilled water bottle to the familiar design shown in the photograph and it was a matter of some pride to ensure the bends in the glass didn’t collapse during blowing, the two pieces of glass tubing finished up in a straight line and you didn’t put the rubber bung cutter through your hand. 

I can remember testing organic spots which included beta-naphthylamine, the first test for which was odour and having taken several sniffs I dutifully wrote ’ammoniacal’. At the end of the day, providing you had no cuts, you washed your hands in conc. HCl which got them remarkably clean. 

Of course nostalgia is not new and I remember reading a poem at that time one couplet of which ran more or less,  

Gone are the lips that sucked those pipettes, 
Gone are the eyes that read those burettes,
But still, after all those years I see,
Antimony coming down in Group 2b.

Despite Google I cannot find the rest of this poem or its origin. Can any reader help? 

J Horler CChem MRSC
By email

 

From Chris Ennis

The scientific case for anthropogenic climate change is an exceedingly strong one. A synthesis of the science is provided by the Intergovernmental Panel on Climate Change (IPCC) and is freely available. 

In response to Julian Overnell’s letter (Chemistry World, May 2007), solar activity is accounted for in models of past climate; greenhouse gases neither do, nor are expected to, ’explain it all’. In answer to his point that we need to know the magnitude of the effect of solar activity on climate: we do. According to the IPCC’s Fourth Assessment Report we are 90 per cent certain that changes in solar irradiance have given rise to a natural radiative forcing between 2.5 per cent and 50 per cent of the anthropogenic radiative forcing, with the most likely value being 7.5 per cent. That is, global warming is mostly human made. 

In response to Ed Walker’s letter (Chemistry World, April 2007), ice cores do indeed show temperature increases preceding CO₂ mixing ratio increases, due to dissolved CO₂ being released as oceans warm. The time lag between temperature rise and CO₂ mixing ratio rise is due to the large thermal mass of the oceans. By contrast, in the contemporary situation CO₂ mixing ratio rise has preceded the global average temperature rise. According to the IPCC’s Fourth Assessment Report, at its 2005 value of 379 ppm, the CO₂ mixing ratio ’exceeds by far the natural range over the last 650 000 years (180 to 300 ppm)’. Furthermore, this extra CO₂ has been shown, through isotopic analysis and by simple accountancy, to be anthropogenic, largely the result of fossil fuel burning. That is, the recent dramatic rise of the CO₂ mixing ratio is mostly human made. 

C J Ennis, CChem MRSC
By email

 

From Mario Pagliaro

The recent debate on scientific method opened by Ian Whitfield (Chemistry World, March 2007) vividly renders how the methodological question is still a hot topic among scientists themselves. 

Correlation is not causation, rightly says Whifield, and to make hypothesis is not sufficient for scientific progress; but gone are the days, objects Delmonte (Chemistry World, April 2007), when we could prove things, as many situations in the natural sciences could never be proved, only disproved. These themes are subtle and must be included in the education of young scientists as they are crucial to the very evolution of science and its role in contemporary and future society. This is not only because otherwise science will simply become another ’religion’, but in order to enable scientists to plan better research and interact more effectively with society. 

Take a look, for instance, at the Masters course on critical thinking in science at the Institute for Scientific Methodology, Palermo, Italy (www.i-sem.net). 

M Pagliaro AMRSC
By email

 

From Ian Miller

I agree with Clive Delmonte’s criticism of peer review (Chemistry World, March, 2007), but I feel there is an additional problem relating to publication: rejection without peer review. Editors now do this frequently. For purposes of example only (and not to complain) I have had one review that showed 64 examples that contradicted a textbook statement rejected because ’it had too many mathematics’. I have been told by the editor of another journal not to send any further papers employing discrete mathematics to reach a conclusion. Another multidisciplinary paper that contradicted an ’established’ position was rejected by journals over a four year period because nobody would review it. Catch 22! 

A further paper showed that if atomic orbitals in heavy atoms are not hydrogen-like (see Aust. J. Phys., 1987, 40, 329) then a further quantum effect applies in forming the chemical bond. This was rejected by the editor on the grounds that 99 per cent of the readers would not be interested. If that is true, then it is a sad day for our science. Yes, there are very few papers that contradict standard theory, and most of those are wrong, but what about those that are not? Why is the editor the gate-keeper, and why, when the peer review process cannot find anything genuinely wrong with the paper, is publish not the default position? Do we need a dedicated ’outside the box’ journal? 

Either we wish to understand or we do not. If we do, we must base rejection on that which disagrees with observation, and not on prejudice. If we do not, then why did we take up science? 

I Miller MRSC
By email