Deuterium and Hydrogen Tunneling in the Hydrogenation of 4‐Oxocyclohexa‐2, 5‐dienylidene. Issue 25 (2nd May 2014)

• Record Type: Journal Article
• Authors: Henkel, Stefan; Ertelt, Melanie; Sander, Wolfram
• Is Part Of: Chemistry. Volume 20:Issue 25(2014)
• Page Start: 7585
• Page End: 7588
• Publication Date: 2014-05-02
• Subjects: carbenes -- EPR spectroscopy -- hydrogen activation -- IR spectroscopy -- matrix isolation; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201402064
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: 4‐Oxocyclohexa‐2, 5‐dienylidene is a highly reactive triplet ground state carbene that is hydrogenated in solid H2, HD, and D2 at temperatures as low as 3 K. The mechanism of the insertion of the carbene into dihydrogen was investigated by IR and EPR spectroscopy and by kinetic studies. H or D atoms were observed as products of the reaction with H2 and D2, respectively, whereas HD produces exclusively D atoms. The hydrogenation shows a very large kinetic isotope effect and remarkable isotope selectivity, as was expected for a tunneling reaction. The experiments, therefore, provide clear evidence for both hydrogen tunneling and the rare deuterium tunneling in an intermolecular reaction. Abstract : Tunnel beats mountain pass : Triplet oxocyclohexadienylidene readily reacts with H2, HD, and even D2 at 3 K by a tunneling reaction. The experiments provided clear evidence for both hydrogen tunneling and the rare deuterium tunneling in an intermolecular reaction (see figure).