Hydroxymethylene: The brief life of a carbeneOrganic molecules with a carbon atom that forms only two bonds and contains two non-bonding valence electrons are known as carbenes. Many are highly reactive and have long been considered too short-lived for direct observations. Of these, hydroxymethylene (H–C–OH) is of particular interest as it is implicated in the photochemistry of formaldehyde and has been suggested to form carbohydrates in extraterrestrial environments. It had never been observed, but now hydroxymethylene has been synthesized, then trapped in an argon matrix at 11 K. Even in these conditions it rearranges with a half-life of just 2 hours to form formaldehyde, using a mechanism involving rapid hydrogen tunnelling. This means that hydroxymethylene is unlikely to be identified spectroscopically or to be around long enough to be involved in the formation of sugars in space.News and Views: Physical chemistry: Cool it, babyA long-sought but short-lived molecule has been made and characterized for the first time. This compound decays at low temperatures using an unusual trick — a mechanism known as quantum tunnelling.Markku Räsänendoi:10.1038/453862aFull Text | PDF (825K)Letter: Capture of hydroxymethylene and its fast disappearance through tunnellingPeter R. Schreiner, Hans Peter Reisenauer, Frank C. Pickard IV, Andrew C. Simmonett, Wesley D. Allen, Edit Mátyus & Attila G. Császárdoi:10.1038/nature07010First paragraph | Full Text | PDF (307K) | Supplementary informationTop of page