Use of hydrogen as fuel for vehicles is currently stunted because it is difficult to store in a cost-effective and convenient way. Using metal is too expensive and leads to environmental issues.
Chemists at UC Riverside now offer a possible solution. A class of carbenes – molecules that have unusual, highly reactive carbon atoms – can mimic, to some extent, the behavior of metals, the chemists have found. Called cyclic alkyl amino carbenes or CAACs, these organic molecules, the researchers report, could be used to develop carbon-based systems for storing hydrogen.
Using what is thought to be the world’s smallest pipette, two researchers at the U.S. Department of Energy’s Brookhaven National Laboratory have shown that tiny droplets of liquid metal freeze much differently than their larger counterparts. This study, focused on droplets just a billionth of a trillionth of a liter in size, is published in the April 15, 2007, online edition of Nature Materials.
“Our findings could advance the understanding of the freezing process, or ‘crystallization,’ in many areas of nature and technology,” said Eli Sutter, a scientist at Brookhaven’s Center for Functional Nanomaterials (CFN) and the lead author of the study.
This week in Science, Yale researchers present “roadmaps” showing that shared protons, a common loose link between two biological molecules, simply vibrate between the molecules as a local oscillator, rather than intimately entangling with the molecular vibrations of the attached molecules.
Led by Professor Mark A. Johnson in the Department of Chemistry, the new data reveal distinct, isolated vibrational patterns, solely associated with the bridging proton, that change dramatically according to the chemical properties of the tethered molecules.
Two oxygen atoms on different molecules are connected by their mutual attraction to an extra proton, shown as a fuzzy ball between them.
Small, clever process technology is essential for the future, but is it possible? Dutch-sponsored researcher Fernando Benito López investigated the possibilities of the so-called lab-on-a-chip: microreactor chips in which chemical reactions can take place under (high) pressure. The results were very promising. The reaction rate increased compared to conventional equipment, the measurements were accurate and safety was not a problem. Moreover it was possible to follow and regulate the reaction during the process.
Thanks to Joanna Scott
, we've been taking advantage of our invitation to contribute to the Nature island on Second Life. Beth
made a copy of the Open Notebook Science building and created a cemetery filled with blue obelisks so that multiple students can take organic chemistry quizzes
at the same time.
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.
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.