A nitrene with staying power

Nitrenes—octet-defying molecules with a neutral nitrogen atom bonded to only one other substituent—are typically so reactive that their lifetimes are measured in nanoseconds. But now chemists have created a nitrene that lasts for 3 days. The molecule is likely to find use as a ligand for transition-metal complexes, much like carbenes did in the 1990s, say University of Bremen chemists Jens Beckmann and Emanuel Hupf , who led the work. The new nitrene owes its long lifetime to its surrounding substituent: a scaffold known as M S Fluind, which was first reported in 2011 by Kohei Tamao of Kyoto University and colleagues. In recent years, chemists have used variations of M S Fluind to stabilize other fleeting intermediates, including a bismuthinidene and a stibinidene. This bulky scaffold prevents the nitrene from reacting and provides electronic stabilization. "With this magic substituent, we're basically building up a wall behind the nitrogen atom,"