ChemWeb Newsletter

Not a subscriber? Join now.November 23, 2011

contents
special message from ChemWeb

To Our Site Visitors,
We continue to receive your feedback, and this is appreciated. Please keep it coming. We at ChemWeb appreciate your interest in our site and the Alchemist Newsletter, and hope you find it useful and of value to your professional activities. We welcome additional feedback from as many members of our audience, as possible.

To help us stay relevant to your changing needs, we'd be grateful if you'd share with us the chemical/chemistry specialties and/or techniques which are of particular interest to you, as well as any features you'd like to see added to our site. Please e-mail your thoughts to us at chemsuggestions@chemweb.com.

If this copy of the Alchemist Newsletter was not addressed to you, we invite you to sign up for your own free subscription here.

Thank you!



overview

How low can you go, asks The Alchemist this week. Well, if you're liquid water no colder than about 48 Celsius, the point below which it seems impossible to maintain water in the liquid state. The Alchemist also learns about two alternatives to polluting that involve retrieving carbon from waste streams as alternatives to petrochemical feedstocks. In medical news, a bactericidal protein could side-step antibiotic resistance in E coli, we hear, and we discover a new material that glows in the near-infrared for hundreds of hours after just one minute exposed to sunlight. Finally, a double chemistry award winner.




Burning the organic gases released from biomass in landfills is common enough, but perhaps a "greener" option would be to utilize the biogas as a feedstock for the chemicals industry. Jouko Arvola of the University of Oulu and colleagues there and at Oulu University of Applied Sciences point out that biomass can be readily converted to methane through anaerobic fermentation, which could then be used as an industrial carbon source. "The use of biogas can be promoted by identifying existing industrial sites currently using fossil-based gas as raw material and by analysing whether they can utilise biogas," the team says.





Could carbon dioxide become a useful source of carbon for chemical feedstocks rather than a pariah of climate change? Thibault Cantat and colleagues at the Institut Rayonnement Mati?re de Saclay in Gif-sur-Yvette, France, point out that despite its position as a greenhouse gas, carbon dioxide is a non-toxic and readily available C1 source. "Only a handful of processes using this starting material have been developed, because carbon dioxide is a very stable molecule that cannot easily be made to react," says Cantat. A diagonal, as opposed to vertical or horizontal, approach to converting carbon dioxide using inexpensive organosilanes offers a hybrid solution. "Variation of the reaction partners should allow us to make a whole series of chemical compounds that are normally obtained from petrochemical feedstocks," explains Cantat.





Ever since the first antibiotics were used to treat bacterial infection, bacteria have evolved resistance to these drugs. Successive or multiple antibiotics have previously been the best approach to addressing this issue. However, in recent years many bacteria have emerged that display multiple resistance and so fail to respond to antibiotics. Among these superbugs are highly resistant strains of E coli O157:H7, MRSA, C. difficile and others. Now, a protein-based alternative to antibiotics developed by AvidBiotics in the US has shown promise against E. coli O157:H7-induced diarrhea and intestinal inflammation. Tests in animals show not only efficacy in treating the bacteria but also lead to a significant reduction in the number of bacteria shed in their feces.





A novel material that emits a long-lasting near-infrared glow after just one minute's exposure to sunlight has been developed by US scientists. Zhengwei Pan of the University of Georgia and colleagues claim the new material could be used in new medical diagnostics technology, give the military and law enforcement agencies a "secret" source of illumination and perhaps lead to highly efficient solar cells. A matrix of zinc and gallogermanate into which chromium(III) ions can be intercalated acts as a labyrinthine trap for capturing solar energy releasing it over a 360-hour period as NIR, which can only be seen with "night-vision" cameras.





Craig Anderson of Bard College is the recipient of the Henry Dreyfus Teacher-Scholar Award for 2011 in recognition of his accomplishments in scholarly research with undergraduates as well as a compelling approach to teaching. The unrestricted research grant of $60,000 follows a $198,000 award that Anderson received in August from the Chemical Structure, Dynamics and Mechanisms Program of the Chemistry Division of the National Science Foundation.





Chemists at the University of Utah have discovered that the absolute minimum temperature at which water can stay liquid is - 48 degrees Celsius (-55 F). At this temperature, the molecular structure of supercooled water changes physically to form tetrahedral, with each water molecule loosely bonded to four others, according to a study by Valeria Molinero and Emily Moore. "This intermediate ice has a structure between the full structure of ice and the structure of the liquid,” she adds. “We’re solving a very old puzzle of what is going on in deeply supercooled water."