Micrometer-Sized Water Droplets Induce Spontaneous Reduction
Micrometer-Sized Water Droplets Induce Spontaneous Reduction
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DOI：
10.1021/jacs.9b03227
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发表时间：
2019-07-10
影响因子：
15
通讯作者：
Zare, Richard N.
中科院分区：
文献类型：
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作者：
Lee, Jae Kyoo;Samanta, Devleena;Zare, Richard N.
大量的水作为惰性溶剂用于许多化学和生物反应。在这里，我们报告一个惊人的例外。我们观察到，在微米大小的水滴（微滴），自发还原的几个有机分子发生，丙酮酸乳酸，硫辛酸二氢硫辛酸，富马酸琥珀酸，草酰乙酸苹果酸。这种还原在微滴中进行，没有任何添加的电子供体或受体，也没有任何施加的电压。在四种情况中的三种情况下，当溶解的有机物质的浓度小于0.1 μ M时，还原效率为90%或更高。这些反应在大体积水中都不会自发发生。一个证明将水微滴还原成有机分子的可能广泛应用的例子是将苯乙酮还原成1-苯基乙醇。总之，这些结果表明，微滴通过使水分子具有高度电化学活性而无需任何添加的还原剂或施加的电势，为绿色化学提供了新的基础。以这种方式，含水微滴可能在前生物时代为非生物还原反应提供了途径，从而在生物还原机器出现之前为有机分子提供了还原能力。
Bulk water serves as an inert solvent for many chemical and biological reactions. Here, we report a striking exception. We observe that in micrometer-sized water droplets (microdroplets), spontaneous reduction of several organic molecules occurs, pyruvate to lactate, lipoic acid to dihydrolipoic acid, fumarate to succinate, and oxaloacetate to malate. This reduction proceeds in microdroplets without any added electron donors or acceptors and without any applied voltage. In three of the four cases, the reduction efficiency is 90% or greater when the concentration of the dissolved organic species is less than 0.1 mu M. None of these reactions occurs spontaneously in bulk water. One example demonstrating the possible broad application of reduction in water micro droplets to organic molecules is the reduction of acetophenone to form 1-phenylethanol. Taken together, these results show that microdroplets 'provide a new foundation for green chemistry by rendering water molecules to be highly electrochemically active without any added reducing agent or applied potential. In this manner, aqueous microdroplets might have provided a route for abiotic reduction reactions in the prebiotic era, thereby providing organic molecules with a reducing power before the advent of biotic reducing machineries.