Nitrogen is essential to life. A crucial step in the nitrogen cycle is the conversion of the nitrite ion NO2− to the nitric oxide molecule NO by the enzyme copper nitrite reductase, which is found in a variety of bacteria.

Trevor Hayton and his colleagues at the University of California, Santa Barbara, have synthesized a copper-nitrosyl radical that has been proposed to play a key part in this reaction. They found that it contains a surprisingly long bond between the copper and nitrogen atoms, and suggest that this arrangement provides a model of how the nitric oxide interacts with the copper during its formation.

J. Am. Chem. Soc. doi:10.1021/ja105930b (2010)