Previously unknown class of metalorganic compounds revealed in meteoritesOPEN ACCESS 

Alexander Ruf, Basem Kanawati, Norbert Hertkorn, Qing-Zhu Yin, Franco Moritz, Mourad Harir, Marianna Lucio, Bernhard Michalke, Joshua Wimpenny, Svetlana Shilobreeva, Basil Bronsky, Vladimir Saraykin, Zelimir Gabelica, Régis D. Gougeon, Eric Quirico, Stefan Ralew, Tomasz Jakubowski, Henning Haack, Michael Gonsior, Peter Jenniskens, Nancy W. Hinman, and Philippe Schmitt-Kopplin

PNAS 2017
published ahead of print February 27, 2017
doi:10.1073/pnas.1616019114

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“Significance

In this study we report the discovery of a previously unrecognized chemical class, dihydroxymagnesium carboxylates, [(HO)2MgO2CR]−, gained from nonterrestrial meteoritic analyses. The existence of such low-coordination organomagnesium anionic compounds expands our knowledge and understanding of extreme environments from which the early solar system emerged and has evolved. The appearance this CHOMg chemical class extends the previously investigated vast diversity of CHNOS groups in meteoritic soluble organics. Experimental evidence is given for the connection between the evolution of organic compounds and minerals. These thermostable compounds might have contributed to the stabilization of organic molecules on a geological time scale, which emphasizes their potential astrobiological relevance.

Abstract

The rich diversity and complexity of organic matter found in meteorites is rapidly expanding our knowledge and understanding of extreme environments from which the early solar system emerged and evolved. Here, we report the discovery of a hitherto unknown chemical class, dihydroxymagnesium carboxylates [(OH)2MgO2CR]−, in meteoritic soluble organic matter. High collision energies, which are required for fragmentation, suggest substantial thermal stability of these Mg-metalorganics (CHOMg compounds). This was corroborated by their higher abundance in thermally processed meteorites. CHOMg compounds were found to be present in a set of 61 meteorites of diverse petrological classes. The appearance of this CHOMg chemical class extends the previously investigated, diverse set of CHNOS molecules. A connection between the evolution of organic compounds and minerals is made, as Mg released from minerals gets trapped into organic compounds. These CHOMg metalorganic compounds and their relation to thermal processing in meteorites might shed new light on our understanding of carbon speciation at a molecular level in meteorite parent bodies.”