Stable version of interstellar carbene made

Cyclopropenylidene is a triangular carbene that has long been observed in outer space. Like other carbenes, it has a dicoordinate carbon center with only six valence electrons. Although cyclopropenylidene can easily survive in the near-vacuum of space, it has been considered to be too reactive to exist under ordinary conditions. Now, Guy Bertrand of the University of California, Riverside, and colleagues have synthesized a cyclopropenylidene derivative (shown) with a diisopropylamino group attached to each of the carbene center's adjacent carbons (Science, published online April 13, dx.doi.org/10.1126/science.1126675). The air-sensitive compound can be heated, and even melted (109 °C), with little decomposition. Previously, the best way to stabilize carbene centers was to replace adjacent carbon atoms with electron donors like nitrogen. Bertrand says the new strategy could be useful for synthesizing stable versions of other unstable interstellar molecules and could help scientists understand how such molecules form in space.