Jul 22, 2011 09:30 GMT  ·  By
A scanning electron microscope image shows a new material that self-assembles into a polyhedron using the attractive interactions associated with hydrogen bonds
   A scanning electron microscope image shows a new material that self-assembles into a polyhedron using the attractive interactions associated with hydrogen bonds

A group of investigators at the New York University (NYU) announce the development of a new type of structure, that is hollow on the inside, and therefore capable of carrying other chemicals. The molecular containers are very small, which means that they are well suited for biological applications.

Studies such as this one are extremely important because their results could be used to develop methods of controlling chemical reactions more closely. Burning, rusting and burning are just a few example of the reactions taking place all around us, all the time.

Controlling these processes can be done via chemicals called catalysts, which can contribute to either speeding up or slowing down the speed of a reaction, changing its outcome, or jump-start interactions between materials that would otherwise not readily interact.

Promote desirable reactions and limiting undesirable ones are the two major goals of industrial chemistry, and the creation of the hollow molecules can go a long way towards seeing that they are achieved in more areas than currently possible.

NYU experts say that their structures could for example be made to carry catalysts, which would only be released under a very specific set of circumstances, that would not occur naturally in the reactions.

Mike Ward, a professor in the Department of Chemistry at the university, says that chemists could even use the flask-like structures as stand-alone laboratories, conducting reactions within the structures.

“We wanted to create frameworks to serve as the 'hotel' for 'guest' molecules, which can deliver the function independent of framework design,” Ward explains. He is the author of a new paper detailing the findings, which appears in the July 22 issue of the top journal Science.

“This makes it possible to separate chemicals based on size or perform reactions inside well-defined cages, which could potentially give you more control over chemical reactivity and reaction products,” the expert adds.

“Moreover, these frameworks may prove ideal for encapsulating a wide range of guest molecules, producing materials with new optical or magnetic properties,” he goes on to say.

He adds that the shape of the new structures was inspired from the work of famous Greek mathematician Archimedes, who revealed the existence of 13 shapes known as Archimedean solids.

Each of these objects has a specific number of sides that meet at corners which are all identical. The new structures are shaped like truncated octahedrons, a press release from the US National Science Foundation (NSF) explains.

“By using geometric design principles and very simple chemical precursors, the Ward group has been able to construct relatively sturdy materials which contain many identically sized and shaped cavities,” explains NSF Division of Materials Science program director Michael Scott.

“The hollow space inside these materials offers many exciting opportunities for chemists to do things such as isolate unstable molecules, catalyze unknown reactions and separate important chemical compounds,” the official concludes.