Molecular "surgery" on a 23-gold-atom nanoparticle.
Molecular "surgery" on a 23-gold-atom nanoparticle.
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DOI：
10.1126/sciadv.1603193
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发表时间：
2017-05
期刊：
影响因子：
13.6
通讯作者：
Jin R
中科院分区：
文献类型：
--
作者：
Li Q;Luo TY;Taylor MG;Wang S;Zhu X;Song Y;Mpourmpakis G;Rosi NL;Jin R
表面图案的变化提供了纳米颗粒特性的精确定制。与分子化学相比，纳米化学还远远无法在原子水平上定制颗粒结构和功能。人们已经开发出许多可以在不改变主要碳骨的情况下精确定制有机分子中特定基团的有效方法，但对于纳米粒子而言，在不改变其他部分结构（例如替换特定表面基序和删除一两个金属原子）的情况下实现粒子中特定位点的原子级定制仍然极其困难。这个问题严重限制了纳米化学家了解纳米颗粒中的不同基序如何影响其整体特性。我们通过两步金属交换方法演示了对原子精确的 23 金原子 [Au23(SR)16]− 纳米颗粒表面基序进行的位点特异性“手术”，这导致两个表面金原子的“切除”并形成新的 21 金原子纳米颗粒 [Au21(SR)12(Ph2PCH2PPh2)2]+， 而不改变起始纳米颗粒结构的其他部分。这种纳米团簇的精确手术揭示了表面图案和内核的不同反应性：表面图案对光吸收的影响最小，但对光致发光的影响明显（即剪裁后发光增强了10倍）。第一性原理计算进一步揭示了形成[Au21(SR)12(Ph2PCH2PPh2)2]+的热力学优选反应途径。这项工作是朝着原子级精确、多功能纳米化学发展迈出的重要一步，用于精确定制纳米团簇结构以控制其性能。
Changes to surface motifs provide precise tailoring of nanoparticle properties. Compared to molecular chemistry, nanochemistry is still far from being capable of tailoring particle structure and functionality at an atomic level. Numerous effective methodologies that can precisely tailor specific groups in organic molecules without altering the major carbon bones have been developed, but for nanoparticles, it is still extremely difficult to realize the atomic-level tailoring of specific sites in a particle without changing the structure of other parts (for example, replacing specific surface motifs and deleting one or two metal atoms). This issue severely limits nanochemists from knowing how different motifs in a nanoparticle contribute to its overall properties. We demonstrate a site-specific “surgery” on the surface motif of an atomically precise 23-gold-atom [Au23(SR)16]− nanoparticle by a two-step metal-exchange method, which leads to the “resection” of two surface gold atoms and the formation of a new 21-gold-atom nanoparticle, [Au21(SR)12(Ph2PCH2PPh2)2]+, without changing the other parts of the starting nanoparticle structure. This precise surgery of the nanocluster reveals the different reactivity of the surface motifs and the inner core: the least effect of surface motifs on optical absorption but a distinct effect on photoluminescence (that is, a 10-fold enhancement of luminescence after the tailoring). First-principles calculations further reveal the thermodynamically preferred reaction pathway for the formation of [Au21(SR)12(Ph2PCH2PPh2)2]+. This work constitutes a major step toward the development of atomically precise, versatile nanochemistry for the precise tailoring of the nanocluster structure to control its properties.