A new class of tiny particles fashioned from metal and organic building blocks may lead to novel catalysts and sensors, say the chemists who synthesized the structures. They've created nanoscale and microscale spheres that can contain a diverse array of chemical ingredients.
Complexes called metal-organic coordination polymers form when dissolved metal ions and organic molecules combine into a chain with an alternating pattern. In some solvents, the bonds are strong enough to hold and the polymers can precipitate, but in other solutions, the polymers' bonds fall apart. Previously, chemists had made stable polymers only as macroscale solids.
Chad A. Mirkin and Moonhyun Oh of Northwestern University in Evanston, Ill., found that by slowly adding ether to metal ions and organic molecules in a solvent, they could interrupt the polymerization process. They were left with porous, spherical, polymer particles between 1 and 2 micrometers in diameter. The spheres, each a long ch