Nitrogen-carbon bonds are found in nylon, fertilizer, insecticide, and in every protein. Bringing together carbon and nitrogen typically requires large amounts of energy. Chirik has developed a new reaction that uses carbon monoxide and molecular nitrogen to make these bonds.

In its naturally occurring form, molecular nitrogen, which is made up of two nitrogen atoms held together by a triple bond, is one of the most stable molecules that exists. "It has no negative or positive ends, so it's very hard to make it react," says Chirik. Other chemists are working on mimicking biological enzymes that "fix" molecular nitrogen to make ammonia that could be used as the feedstock for organic chemicals. Chirik's lab, in contrast, is developing a reaction for breaking the nitrogen bond not to make ammonia but to make organic-nitrogen compounds directly.

The key to the Cornell reaction, which takes two steps to break the nitrogen bonds, is a complex containing the metal hafnium. In the first step, two metal complexes surround each nitrogen molecule, caging it in. The hafnium complexes react with the nitrogen, breaking two of the bonds and creating an intermediate molecule. Then carbon monoxide is added to the mixture. Carbon monoxide is also a very stable compound and would not react with molecular nitrogen. But carbon monoxide will react with the nitrogen-hafnium intermediate, breaking the final nitrogen bond to form an organic molecule called oxamide that is released from the hafnium complex by the addition of acid.

"People producing organo-nitrogen compounds today have to make ammonia first," says Christopher Cummins, professor of chemistry at MIT. The nice thing about the new Cornell technique, he says, is that "they are developing reactions to make nitrogen into organo-nitrogens directly." Cummins points out that the only company to do this industrially, American Cyanamid, used hydropower produced by Niagara Falls to make an electrical arc powerful enough to drive the reaction.

The Cornell chemistry isn't ready for industrial use yet. So far, the reaction they've developed isn't catalytic, and therefore isn't practical. The hafnium complex makes it possible for the reaction to proceed in ambient conditions, but it gets used up during the reaction. Chirik is working on "how to get the pieces off the metal" so that it can be reused. The Cornell researchers are also trying to determine how general the reaction is.