Gradual and stepwise pyrolyses of insoluble organic matter from the Murchison meteorite revealing chemical structure and isotopic distribution.
Gradual and stepwise pyrolyses of insoluble organic matter from the Murchison meteorite revealing chemical structure and isotopic distribution.
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默奇森陨石中不溶性有机物的逐步热解揭示了化学结构和同位素分布。
DOI：
10.1016/j.gca.2011.09.015
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Okumura F. and Mimura K.
中科院分区：
文献类型：
--
作者：
Nagahara;H.;Ozawa;K.;Ogawa;R.;Tachibana;S.;and Chiba;H.;Okumura F. and Mimura K.
为了研究Murchison陨石中不溶性有机质（IOM）的详细结构和同位素不均一性，我们进行了两种类型的热解实验：逐步热解和逐步热解。IOM的热解产物含有5种特定的有机基团：脂肪族烃、芳香族烃、含硫化合物、含氮化合物和含氧化合物。热解产物的释放温度和组成表明，IOM由热不稳定部分和热稳定部分组成。热不稳定部分主要用作键合和取代基部分，其结合分散在整个IOM中的热稳定部分。连接基和取代基部分由C4至C8的脂肪族烃、具有多达6个环的芳香族烃、磺基和硫醇基（IOM中硫的主要储库）以及羧基和羟基（氧的主要储库）组成。然而，热稳定的部分是由多环芳烃（PAHs）的含氮杂环的IOM。同位素数据表明，脂肪烃和芳烃的连接部分和取代部分富含D和13 C，而热稳定部分缺乏D和13 C。结构和同位素特征表明，IOM是由富含D和13 C的含硫和含氧化合物混合形成的（例如，星际介质中的极性化合物（ISM））和缺乏D和13 C的含氮多环芳烃（例如，ISM中的聚合化合物）。
To study the detailed structural and isotopic heterogeneity of the insoluble organic matter (IOM) of the Murchison meteorite, we performed two types of pyrolytic experiments: gradual pyrolysis and stepwise pyrolysis. The pyrolysates from the IOM contained 5 specific organic groups: aliphatic hydrocarbons, aromatic hydrocarbons, sulfur-bearing compounds, nitrogen-bearing compounds, and oxygen-bearing compounds. The release temperatures and the compositions of these pyrolysates demonstrated that the IOM is composed of a thermally unstable part and a thermally stable part. The thermally unstable part mainly served as the linkage and substituent portion that bound the thermally stable part, which was dispersed throughout the IOM. The linkage and substituent portion consisted of aliphatic hydrocarbons from C4to C8, aromatic hydrocarbons with up to 6 rings, sulfo and thiol groups (the main reservoirs of sulfur in the IOM), and carboxyl and hydroxyl groups (the main reservoirs of oxygen). However, the thermally stable part was composed of polycyclic aromatic hydrocarbons (PAHs) containing nitrogen heterocycles in the IOM. Isotopic data showed that the aliphatic and aromatic hydrocarbons in the linkage and substituent portion were rich in D and13C, while the thermally stable part was deficient in D and13C. The structural and isotopic features suggested that the IOM was formed by mixing sulfur- and oxygen-bearing compounds rich in D and13C (e.g., polar compounds in the interstellar medium (ISM)) and nitrogen-bearing PAHs deficient in D and13C (e.g., polymerized compounds in the ISM).