Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada.
J Am Chem Soc. 2021 Nov 24;143(46):19474-19485. doi: 10.1021/jacs.1c08877. Epub 2021 Nov 13.
Thus far, no correlation between nanocluster structures and their electrochemiluminescence (ECL) has been identified. Herein, we report how face-centered-cubic and hexagonal close-packed structures of two Au(SR) nanocluster isomers determine their chemical reactivity. The relationships were explored by means of ECL and photoluminescence spectroscopy. Both isomers reveal unprecedented ECL efficiencies in the near-infrared region, which are >10- and 270-fold higher than that of standard Ru(bpy), respectively. Photoelectrochemical reactivity as well as ECL mechanisms were elucidated based on electrochemistry, spooling photoluminescence, and ECL spectroscopy, unfolding the three emission enhancement origins: (i) effectively exposed reactive facets available to undergo electron transfer reactions; (ii) individual excited-state regeneration loops; (iii) cascade generations of various exited states. Indeed, these discoveries will have immediate impacts on various applications including but not limited to single molecular detection as well as photochemistry and electrocatalysis toward clean photon-electron conversion processes such as light-harvesting and light-emitting technologies.
迄今为止，尚未发现纳米团簇结构与其电化学发光（ECL）之间存在相关性。在此，我们报告了两种 Au(SR)纳米团簇异构体的面心立方和六方密堆积结构如何决定其化学反应性。通过 ECL 和光致发光光谱研究了这些关系。两种异构体在近红外区域均表现出前所未有的 ECL 效率，分别比标准 Ru(bpy)高 10 和 270 倍。基于电化学、卷绕光致发光和 ECL 光谱学阐明了光电化学反应性和 ECL 机制，揭示了三种发光增强起源：（i）有效暴露的可进行电子转移反应的反应性面；（ii）单个激发态再生循环；（iii）各种激发态的级联生成。事实上，这些发现将立即对各种应用产生影响，包括但不限于单分子检测以及光化学和电催化，以实现清洁的光子-电子转换过程，如光捕获和发光技术。
