May's reactive profilee is chemical informatics expert Wendy Warr who has been at the forefront of information retrieval and analysis in chemistry for many years. Science writer David Bradley interviewed Wendy for Reactive Reports magazine. He asked her how has the world of chemical info changed since those days: "It's changed beyond recognition," she said, "We no longer have to code structures into WLN: graphical structure input is the norm and every end user has a PC. You can even access the CAS Registry system on your BlackBerry nowadays."

Read the full interview in Issue 55 of Reactive Reports, along with news of the byproducts of cell death, testing times for tequila, and how the fizz went out of the benzene in soft drinks story.

Welcome to the WebElements forums. Enjoy them and do please join in! Things look different here so please note:

1. All the old posts are still here
2. If you posted here before your account is still here but you will need to reset your password - do this by using the request new password link on the menu to the top right.
3. If you had an account but had not posted before - apologies but you will need to recreate your account
4. If you like to use bbcode, then sub- and superscripts now work, so: [Mn(OH₂)₆]²⁺
5. You can post and view molecules using the new bbcode tag [jmol] - more details elsewhere
6. Use the news aggregator links to the right to view recent titles and summaries for papers in some of the best chemistry journals
7. File downloads are back (see menu to lower left)
8. The feed address for news is now http://nexus.webelements.info/rss.xml while each forum has its own feed (see each forum for details)

If the site's security measures cause problems with your legitimate access to the site please do let me know via the Contact menu item and I will try to help.

This site now has the ability to display molecules interactively via the Jmol Java applet. This should mean that some stories or articles may come to mean a little more. Here is a simple example.

The motivation for this came from CHMEMCONF Spring 2006 and in particular Bob Hanson's paper. What I've done here is made a small extension to the software I'm using here (Drupal) so that molecules can be embedded simply with a bbcode type string, in this case:

[jmol=300]H3N-BF3.mol[/jmol]

I'll issue a note with more details on how to do this after further work

This month's Reactive Chemist is Martin Walker of the State University of New York College at Potsdam. Walker, like myself is a native of the north-east of England. Read my interview to find out why he left, what made him stay in the US and why he thinks chemists will never do without conferences.

He also revealed why he is so keen to make the chemistry portal within Wikipedia work for the global chemical community: "At present, there is an unbelievable amount of chemical information out there, but most of this is inaccessible from a general web search without paying money. I found my students using web searches as a principle method for finding information, but there is limited free information on the web. There are some very useful sites like organic-chemistry.org and webelements.com, but material on these sites still carries copyright restrictions," he said.

We also touched on the "negative" publicity that Wikipedia as a whole has received recently.

Check out the latest issue of the chemistry magazine, Reactive Reports to read my full interview with Prof Walker.

Workers at The University of Wisconsin-Madison in the USA have managed to release thin membranes of semiconductors from a substrate and transfer them to new surfaces. The freed membranes which are just tens of nanometers thick retain all the properties of silicon in wafer form but the nanomembranes are flexible. By varying the thicknesses of the silicon and silicon-germanium layers composing them, membrane shapes are possible ranging from flat to curved to tubular.

Potential applications include flexible electronic devices, faster transistors, nano-size photonic crystals that steer light, and lightweight sensors for detecting toxins in the environment or biological events in cells.

The scientists made a three-layer nanomembrane composed of a thin silicon-germanium layer sandwiched between two silicon layers of similar thinness. The membrane sat upon a silicon dioxide layer in a silicon-on-insulator substrate. The nanomembranes may be etched away from the oxide layer with hydrofluoric acid.

Although the Wisconsin team grew their nanomembranes on silicon-on-insulator substrates, the method should apply to many substances beyond semiconductors, such as ferroelectric and piezoelectric materials. The key requirement is a layer, like an oxide, that can be removed to free the nanomembranes.

Science Writer David Bradley recently interviewed PubChem's Steve Bryant about the inspiration behind this open access chemical searching resource, the growing number of molecules in the database, and some of the problems the fledgling site has faced, including errors and legal tussles. You can read the interview in full in the March issue of the online chemistry news magazine Reactive Reports. If PubChem doesn't tickle your fancy then perhaps swell gels or repulsive particles will.

A compact and portable mid-IR reflectance spectrometer has been used to study surface materials on marble non-invasively, first in the lab and then on Italian works of art: the "Deposizione dalla Croce" by Benedetto Antelami in Parma Cathedral and "David" by Michelangelo in the Galleria dell'Accademia in Florence. You can read the full story in science writer David Bradley's spectroscopynow news round-up here.

The US FDA and national food agencies around the globe are reinvestigating the safety of the food and drinks preservative sodium benzoate after a fifteen year hiatus. Soluble benzoates are converted into an antimicrobial form, benzoic acid, in acid conditions and as such are used as preservatives in soft drinks and various foodstuffs. Read the full story and add your own comments at the Sciencebase Science Blog.

In the latest issue of the Reactive Reports chemistry webzine, science writer David Bradley interviews NMR expert Gary Martin about his experiences with this powerful analytical technique and his views on the future of the technology and novel applications.

Martin spent the first 14 years of his career at the University of Houston before moving to Burroughs Wellcome, Co., in 1989, and then to Upjohn in 1996, which, through a series of mergers and acquisitions, left him working for Pfizer a few years ago. He has spent much of his career focused on the identification of natural product structures and subsequently synthetic compounds originating in drug discovery, and more recently the identification of impurity and degradant structures of drug molecules. In the Spring, he takes up a new position at Schering-Plough's facility in Summit, New Jersey, where he will no doubt use his pioneering NMR techniques to the full once more.

One of the sacred cows of synthetic chemistry seems to have gone mad. According to US chemists, they have found that they don't need to dissolve their reagents in a solvent to make a reaction proceed, writes David Bradley in the latest issue of the Resonants NMR webzine.