Fullerene-style gold cages
Scientists in the USA have succeeded in producing stable molecular cages made of pure gold. The structures, which are at least 0.6 nanometers in size, consist of a network of 16, 17 or 18 gold atoms.
Previous theoretical studies had suggested Au20 as the most likely candidate for a gold buckyball. However, their simulations showed the researchers working with Lai-Sheng Wang that molecules with up to 15 gold atoms are flat and take on a pyramid shape with more than 19 gold atoms. The now also experimentally built Au16 is reminiscent of the Au20 pyramid, from which the four corner atoms were removed and which then relaxed somewhat, describes Wang.
Carbon fullerenes or buckyballs are the models for the molecule cages that could still accommodate a foreign atom inside. Named after the architect Buckminster Fuller and his self-supporting dome constructions, the molecule consisting of 60 carbon atoms is reminiscent of a soccer ball, with ten more carbon atoms the shape warps in the direction of a rugby ball. The gold variant, which according to the scientists is the first pure metal replica of a fullerene, appears much more angular.