A load of Bowls

by David Bradley

A load of bowls

Goverdhan Mehta and Srirama Sarma at the Indian Institute of Science, in Bangalore are trying to build a buckyball from scratch. Rather than using the standard carbon discharge techniques they hope to be able to synthesise the soccer-ball shaped molecules from simpler carbon units so they can control the inclusion of functional groups in a far more specific way than the simple substitution or addition of groups to the fullerene surface.

Mehta and Sarma have now developed a simple route to the bowl-shaped fragments benzocorannulenes, which provide a recognised starting point for fullerene synthesis. They begin with the polyaromatic organic compound 13-methylbenzochrysene, which is readily available from 9-methyl-phenanthrene. The use of FVP (flash vacuum pyrolysis) leads to the sequential formation of five- and six-membered rings to build up the buckybowls. 'Our strategy is not only quite general but conceptually so simple that it should be possible to adapt it for the synthesis of the buckyball itself,' says Mehta. The team is continuing efforts in that direction. (Chemical Communications, 2000, 19)

BN, BN

Tough, tiny cages of boron nitride can trap silver particles according to Japanese researchers who say the capsules could be used as ball bearings in nanotechnology devices of the future, components in high-density optical-magnetic memory devices, catalysis, biotechnology and single electronic transistors. Takeo Oku and colleagues at Osaka University have devised a method that works at 700 Celsius to encapsulate metal ions in spherical capsules of boron nitride. They can easily mass produce (up to a gram) cheaply. The team simply mixes urea and boric acid in water with silver nitrate dissolved in deionised water. Evaporating off the solvent leaves a dry material, which can be annealed by heating in hydrogen for 7 hours. This reduces the BN to a stiff cage-like framework in which the silver particles are trapped. The team could see their tiny BN balls using high-resolution electron microscopy and see their structure with energy dispersive spectroscopy. (Journal of Materials Chemistry, 2000, 255)

Resistance isn't futile

Medicinal chemists may be partly to blame for the rise of antibacterial resistance to antibiotics because no new classes have been developed since the 1960s, at least that is the implications of a recent paper in the British Medical Journal. According to medical microbiologist Sebastion Amyes of the University of Edinburgh, it has taken a long time to determine the extent of the problem and we still have a lot to learn about the way bacteria develop resistance to antibiotics. Almost all the drugs launched since the 1960s have been modifications of antibiotics developed up to 1961, explains Amyes, which means bacteria that evolved resistance to one generic antibiotic type did not have much to learn to overcome its chemical descendants. Increased knowledge through genomics and molecular biology, however, will ultimately provide chemists with new strategies with which to design chemical weapons for the bug war. (British Medical Journal, 2000, 320, 199) sciencebase homepage
Read more scientific discoveries news, medical news headlines, and chemistry articles

Back to the sciencebase homepage