title: Abiotic methanogenesis from organosulphur compounds under ambient conditions.
abstract: Methane in the environment is produced by both biotic and abiotic processes. Biomethanation involves the formation of methane by microbes that live in oxygen-free environments. Abiotic methane formation proceeds under conditions at elevated temperature and/or pressure. Here we present a chemical reaction that readily forms methane from organosulphur compounds under highly oxidative conditions at ambient atmospheric pressure and temperature. When using iron(II/III), hydrogen peroxide and ascorbic acid as reagents, S-methyl groups of organosulphur compounds are efficiently converted into methane. In a first step, methyl sulphides are oxidized to the corresponding sulphoxides. In the next step, demethylation of the sulphoxide via homolytic bond cleavage leads to methyl radical formation and finally to methane in high yields. Because sulphoxidation of methyl sulphides is ubiquitous in the environment, this novel chemical route might mimic methane formation in living aerobic organisms.
authors: 1] Institute of Earth Sciences, University of Heidelberg, Im Neuenheimer Feld 234-236, 69120 Heidelberg, Germany [2] Max Planck Institute for Chemistry, Hahn-Meitner-Weg 1, 55128 Mainz, Germany.
authors: Frederik
authors: F
authors: Althoff
authors: Anorganisch-Chemisches Institut, University of Heidelberg, INF 270, 69120 Heidelberg, Germany.
authors: Kathrin
authors: K
authors: Benzing
authors: Anorganisch-Chemisches Institut, University of Heidelberg, INF 270, 69120 Heidelberg, Germany.
authors: Peter
authors: P
authors: Comba
authors: Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, UK.
authors: Colin
authors: C
authors: McRoberts
authors: School of Chemistry and Chemical Engineering, Queenńs University Belfast, Stranmillis Road, Belfast BT9 5AG, UK.
authors: Derek R
authors: DR
authors: Boyd
authors: Centre for Organismal Studies, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany.
authors: Steffen
authors: S
authors: Greiner
authors: 1] Institute of Earth Sciences, University of Heidelberg, Im Neuenheimer Feld 234-236, 69120 Heidelberg, Germany [2] Max Planck Institute for Chemistry, Hahn-Meitner-Weg 1, 55128 Mainz, Germany.
authors: Frank
authors: F
authors: Keppler
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D008697:Methane / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013457:Sulfur Compounds / Q000737:chemistry*
chemical_list: D013457:Sulfur Compounds; D006861:Hydrogen Peroxide; D008697:Methane; D001205:Ascorbic Acid