It鈥檚 a tight squeeze. Researchers have controlled a chemical reaction by squeezing specially designed molecules between a pair of diamonds. This could be a more precise way to make custom molecules on demand for use in pharmaceuticals.
There are several ways to initiate a chemical reaction that breaks molecular bonds or moves electrons around. You can add heat, electricity or light, or simply pull the molecule apart. Now, at Stanford University and his colleagues have initiated these sorts of reactions by simply squeezing the whole molecule. This is the first time anyone has started an asymmetrical chemical reaction by just squeezing.
High pressure is a simple way to create some types of molecular changes, like turning graphite into diamonds. But most reactions are symmetrical across an entire molecule 鈥� because the pressure is coming from all sides, every part of the graphite鈥檚 structure shifts in the same way to become diamond.
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For more sophisticated, asymmetrical reactions, the molecule needs some sort of internal structure that put pressure on a particular location. Melosh and his colleagues accomplished this by placing the part of the molecule in which they wanted the reaction to take place between two rigid molecules called carboranes.
Anvil inside an anvil
Then, they placed this 鈥渕olecular anvil鈥� inside a larger diamond anvil to squeeze the whole thing to pressures of 12 gigapascals, over 100 times the pressure at the bottom of the Mariana Trench.
At these pressures, atomic bonds in the molecule, a copper sulfide cluster, broke. Electrons moved from the sulfur atoms in the molecule to the copper atoms, creating pure crystals of copper.
This method does not require chemical solvents or catalysts, making it more efficient. 鈥淭here is potential for this to change industrial processes, the way that we make materials or pharmaceuticals,鈥� says at Queen鈥檚 University Belfast in the UK.
Melosh says this type of precise control could be useful for building custom molecules on demand, especially for pharmaceutical applications.
鈥淔or a lot of biological molecules, you have to have the substituents on the exact right areas of that molecule. A bond at one spot could be ineffective 鈥� or worse, toxic 鈥� and the other could be efficacious,鈥� says Melosh. 鈥淵ou have a lot more control with this method than others.鈥�
Nature
Read more: Carbon seen bonding with six other atoms for the first time
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