Chemistry

Previously, only amorphous polymer materials approached such levels of performance. On the other hand, these “gigantic respiration” and their respiration, which takes place at constant overall shape, is reversible. This discovery, of interest for numerous industrial applications, is published in the journal Science on March 30, 2007.


Structure of chromium (III) diphenyl dicarboxylate, one of the gigantic respiration crystalline solids, in its crude form following synthesis (middle), with all traces of solvent removed (on the left), and after absorption of solvent and increase in volume (on the right).

Credit: G. Ferey - CNRS 2007

There is a new kid on the cheminformatics block. ChemSpider Beta went live on Saturday March 24, 2007 with over 10 million compounds. Anyone using other free online molecular databases (like eMolecules or Chemistry Search Lookup Service) should definitely give this one a spin. At this time, it is possible to use the system not only to find molecules in databases but also to predict molecular properties (like density and boiling point), which can come very handy. But the best reason for keeping an eye on this one is that it is led by Tony Williams.

Chemists from the National Institute of Standards and Technology (NIST) and Arizona State University have proposed an elegantly simple technique for cleaving proteins into convenient pieces for analysis.

The Virginia Tech chemistry research group that has been creating molecular complexes that use solar energy to produce hydrogen from water has added an additional capacity to their supramolecule.

Karen Brewer, professor of chemistry, explains that the new, more robust molecules still harness light and covert it to chemical energy by splitting water to produce hydrogen. “What is different is the way the systems function. It is a three part molecule. The first part is a light absorber, harnessing visible and UV light. The second part is an electron reservoir. The third part is the catalysis to make hydrogen from water.” All of these sub-units are coupled into one large supramolecular assembly.

Ladybugs may look pretty but they also have a dark side. In some places, the polka-dotted insects have become a nuisance by invading homes and crops, including some vineyards. To make matters worse, the bugs produce a foul-smelling liquid that, besides irritating homeowners, can be inadvertently processed along with grapes and taint the aroma and flavor of wine.

Now, chemists at Iowa State University in Ames, Iowa, say they have identified several compounds that are responsible for the ladybug’s noxious odor, a finding that could lead to new strategies to detect and eliminate the offensive compounds.

Craftsmen tile walls or floors by hand; but how can you get an ordered monolayer onto a substrate when the "tiles" are microscopically small instead of big and easy to handle? Previously, self-assembly processes have been the method of choice for this scale. Korean researchers have now come to the realization that even such tiny components can be arranged in a "do-it-yourself" method. As they describe in the journal Angewandte Chemie, their manually produced monolayers of microcrystals are qualitatively superior to the self-assembled variety.

Ultrasonic irradiation can break down ionic liquids into more environmentally benign compounds, say scientists.

Ionic liquids are widely regarded as a greener alternative to many commonly used solvents. But, concerns about their toxicity have raised questions about their use in large scale industrial applications, especially those that involve the creation of large amounts of waste.


High frequency sound waves break ionic liquids into non-toxic components. Image: Chemical Science

I realize that the audience for this blog tends to be more broad based than on UsefulChem but once in a while I'll throw in an organic chemistry puzzle to see if there are any organic chemists out there lurking.

Ever since we isolated our Ugi products, we've been trying to cyclize them to the diketopiperazines. As described by Hulme, we are trying to effect an intramolecular transamidation catalyzed by trifluoroacetic acid (TFA).

Last week I had the pleasure of getting interviewed by Janet Babin at the WHYY studio in Philly. Janet is putting together a piece on Open Notebook/Open Source Science for her Marketplace series on NPR.

It was encouraging to see how much interest is being generated on this topic lately, especially in the popular media.

The way people search for and find chemistry information is always in flux.

Right now, Open Access is a hot topic (e.g. Open Source Archivangelism post) and it is interesting to see how those seeking OA sources are connecting with those who choose to share information in that way.