Sturtz Miranda, House Christopher
Department of Geosciences, Pennsylvania State University, 116 Deike Building, University Park, PA 16802, USA.
Life (Basel). 2023 Jul 7;13(7):1524. doi: 10.3390/life13071524.
Hydrothermal systems are areas in which heated fluids and organic molecules rush through basaltic material rich in metals and minerals. By studying malononitrile and acetonitrile, we examine the effects of metal and mineral nanoparticles on nitrile compounds in anoxic, hydrothermal conditions representing a prebiotic environment of early Earth. Polymerization, reduction, cyclization, and a phenomenon colloquially known as 'chemical gardening' (structure building via reprecipitation of metal compounds or complexing with organics) are all potential outcomes with the addition of metals and minerals. Reduction occurs with the addition of rhodium (Rh) or iron (II) sulfide (FeS), with positive identification of ethanol and ethylamine forming from acetonitrile reduction. We find that polymerization and insoluble product formation were associated with oxide minerals, metallic nickel (Ni), and metallic cobalt (Co) acting as catalysts. Oxide minerals strongly promoted polymerization into insoluble, tar-like products of nitriles. FeS, iron-nickel alloy (FeNi), and rhodium are unique cases that appear to act as reagents by actively participating in chemical gardening without returning to their initial state. Further, FeS tentatively had a phase change into the mineral parabutlerite. This research aims to identify metals and metal minerals that could best serve nitrile catalysis and reactions on early Earth.
热液系统是受热流体和有机分子流经富含金属和矿物质的玄武岩物质的区域。通过研究丙二腈和乙腈，我们考察了金属和矿物纳米颗粒在代表早期地球益生元环境的缺氧热液条件下对腈化合物的影响。聚合、还原、环化以及俗称“化学花园”的现象（通过金属化合物的再沉淀或与有机物络合来构建结构）都是添加金属和矿物质后可能产生的结果。添加铑（Rh）或硫化亚铁（FeS）会发生还原反应，可确定乙腈还原生成了乙醇和乙胺。我们发现聚合反应和不溶性产物的形成与作为催化剂的氧化物矿物、金属镍（Ni）和金属钴（Co）有关。氧化物矿物强烈促进腈聚合成不溶性的焦油状产物。FeS、铁镍合金（FeNi）和铑是独特的例子，它们似乎通过积极参与化学花园过程而不恢复到初始状态来充当试剂。此外，FeS初步发生了相变，变成了副铁滑石矿物。这项研究旨在确定在早期地球上最适合腈催化和反应的金属及金属矿物。
