Charge Transport through Self‐Assembled Monolayers of Monoterpenoids
Charge Transport through Self‐Assembled Monolayers of Monoterpenoids
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通过单萜自组装单层的电荷传输
DOI：
10.1002/anie.201902997
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Whitesides, George M.
中科院分区：
文献类型：
--
作者：
Cafferty, Brian J.;Yuan, Li;Baghbanzadeh, Mostafa;Rappoport, Dmitrij;Beyzavi, M. Hassan;Whitesides, George M.
在生命起源的过程中，选择特定类别的分子广泛结合到细胞中的过程的性质是有争议的。在这些选定的类别中，有多异戊二烯及其衍生物。本文验证了多异戊二烯类化合物是膜的早期贡献者的假设，部分原因是它们(或其衍生物)可以通过量子隧道促进电荷传输。它测量了不同不饱和度的端羧基单萜(O2C(C9HX))和烷酸酯(O2C(C7HX))自组装单分子膜(SAM)之间的电荷传输，以银(AGTS)为底电极，以Ga2O/Egain为上电极。对线性长度匹配碳氢化合物(饱和和不饱和)的自组装膜电流密度的测量表明，完全不饱和的分子比完全饱和的分子传输电荷的速度快大约10倍。电荷传输的相对速率的增加与碳-碳双键的数目有关，但与共轭程度无关。这些结果表明，多异戊二烯类化合物--即使是完全不饱和的--也不是足够好的隧道导体，其导电性不足以使它们成为益生菌世界的基石。
The nature of the processes at the origin of life that selected specific classes of molecules for broad incorporation into cells is controversial. Among those classes selected were polyisoprenoids and their derivatives. This paper tests the hypothesis that polyisoprenoids were early contributors to membranes in part because they (or their derivatives) could facilitate charge transport by quantum tunneling. It measures charge transport across self‐assembled monolayers (SAMs) of carboxyl‐terminated monoterpenoids (O2C(C9HX)) and alkanoates (O2C(C7HX)) with different degrees of unsaturation, supported on silver (AgTS) bottom electrodes, with Ga2O3/EGaIn top electrodes. Measurements of current density of SAMs of linear length‐matched hydrocarbons—both saturated and unsaturated—show that completely unsaturated molecules transport charge faster than those that are completely saturated by approximately a factor of ten. This increase in relative rates of charge transport correlates with the number of carbon–carbon double bonds, but not with the extent of conjugation. These results suggest that polyisoprenoids—even fully unsaturated—are not sufficiently good tunneling conductors for their conductivity to have favored them as building blocks in the prebiotic world.