Carborane acid

Carborane acids are a special group of superacids. A superacid is a substance that is much stronger than a regular acid. These acids are famous because they are incredibly powerful. Some are estimated to be one million times stronger than pure sulfuric acid.

They are known as Brønsted acids because they work by releasing a tiny particle called a proton. This proton is what makes the acid act so strongly on other things. Scientists study them to understand how the strongest substances in the world work.

The way these acids work comes down to their unique shape. They have a tiny cage made of eleven boron atoms and one carbon atom. This cage is called a carboranate anion.

To make the acid even stronger, scientists add atoms like chlorine or fluorine to the cage. These atoms act like shields and help pull energy away from the center. This makes it much easier for the acid to let go of its proton. Because the cage is so stable, the acid can perform its job without falling apart.

Scientists have been working with these shapes for a long time. A scientist named Walter Knoth first made the carboranate cage at DuPont in 1967. Later, a group of scientists in the Czech Republic improved how to add halogens to the cage. In 2004, Professor Christopher Reed and his team at the University of California, Riverside, discovered and made the carborane acid.

Making these acids is a very hard job. It can take 13 different steps to finish the process. Scientists must use special equipment called a glovebox to keep out even tiny bits of water.

There are many important facts about these powerful chemicals. The most studied version uses eleven chlorine atoms to surround the cage.

There is also a version made with fluorine that is even stronger. The fluorinated version can even change carbon dioxide, which is a very difficult task. This makes it possibly the strongest acid known to science. In the gas phase, some versions have a measured acidity of 241 kcal/mol. These numbers show just how much energy is involved in their reactions.

You can think of these acids as being both strong and gentle at the same time. Most superacids are very harsh and destroy the molecules they touch. However, carborane acids are unique because they can change a molecule without breaking it.

For example, they can work on a carbon shape called a fullerene without decomposing it. This is like a tool that can turn a screw perfectly without scratching the wood around it. Because they are so stable, they can even be stored in glass bottles. This makes them very useful for special jobs in chemistry labs.