Sidesplitting Nickel Breaks Up Laughing Gas

Many people are familiar with laughing gas—nitrous oxide, N₂O—for the euphoric effects it produces when inhaled as an anesthetic for dental procedures. The compound’s extreme inertness is what helps make it effective. Chemists have been interested in finding ways to make N₂O more reactive to remediate its effects as a greenhouse gas or to use it as a reagent in industrial syntheses in the same way H₂, CO, and other small-molecule gases are used. Kay Severin and coworkers at the Swiss Federal Institute of Technology, Lausanne, have devised a process in which a nickel complex inserts itself sidelong into N₂O’s N–N bond and cuts it in two (Inorg. Chem. 2013, DOI: 10.1021/ic401524w). The team’s trick to cracking up N₂O rests with the reactive power of an N-heterocyclic carbene. When added together, the carbene grabs N₂O’s terminal nitrogen, holding the molecule and weakening the N–N bond for a nickel cyclooctadiene complex to attack. The separated N and NO fragments could be released from the resulting dimeric nickel nitrosyl complex or transferred to an organic molecule in a separate step.