ChemWeb Newsletter

Not a subscriber? Join now.January 25, 2005


This week in The Alchemist: Opportunity "unearths" some meteorite chemistry on Mars and chemists find the root of terpenoids in the plant cell. French scientists have revealed their predictive powers in understanding radiation damage in materials and a Russian and Dutch team have produce white light in a europium-iridium system. Finally, a water filter made from dung and clay could revolutionize the lives of millions.

A very low-tech approach to materials makes a water filter effective in removing common microbes, such as Escherichia coli. The new technology was developed by Australian National University materials scientist Tony Flynn. It uses everyday raw materials, including coffee grounds, clay, and cow dung, which are molded into a filter that can then be hardened without the need for an expensive, energy hungry kiln. The cheap system could bring clean water to millions.

Opportunity spectrometers revealed the first meteorite to be found on a planet other than Earth, this week, according to NASA scientists. The Opportunity Rover currently scouring the Martian surface spotted an unusual rock-shaped object bedded in the planet's ruddy dust, headed straight for it, and carried out a spectroscopic analysis. The results revealed the meteorite to be rich in iron and nickel, which makes it chemically similar to only a small fraction of meteorites that fall on earth and a new puzzle for Mars watchers.

Researchers at Purdue University and the Max Planck Institute for Chemical Ecology in Germany have discovered that plants use just one cellular pathway to create thousands of different terpenoids. Their findings could overturn the received wisdom regarding plant biochemistry that at least two pathways are involved in building the precursors for terpenoids. The team has now demonstrated that a unique source located in the same part of the plant cell in which photosynthesis takes place is the root of all plant terpenoid precursors. The research will have important implications for engineering plant metabolism to make useful products in medicine and other areas.

A predictive model could help materials scientists understand the effects of radiation on the microstructure of iron and other materials, according to results published in the January issue of Nature Materials. Radiation-induced defects affect directly the microstructure of a material and so change its mechanical properties. The nuclear industry is keen to understand the kinetics of such changes, now that might be possible, thanks to the model developed by a team at the Nuclear Energy Division of the French Commissariat a l'Energie Atomique.

Researchers from The Netherlands and Russia have examined how transition metal complexes can act as light-gathering antennas for the photoluminescence of europium and found they could make their system emit white light. The study reveals that a photoluminescent iridium complex can transfer a proportion of absorbed light energy to a photoluminescent europium complex and make it glow even if the radiation is below the threshold at which europium normally photoluminesces. The result is white emission as the iridium complex emits the blue-green component while the europium complex emits red light.