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 Au₂₁(SR)₁₅ 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)₃²⁺, 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.

中文翻译：

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识别两种 Au21 纳米簇异构体对明亮近红外电化学发光的高光电化学活性位点

到目前为止，尚未确定纳米团簇结构与其电化学发光（ECL）之间的相关性。_{在此，我们报告了两种 Au 21} (SR) ₁₅纳米簇异构体的面心立方和六方密排结构如何决定它们的化学反应性。通过 ECL 和光致发光光谱法探索了这些关系。两种异构体在近红外区域显示出前所未有的 ECL 效率，比标准 Ru(bpy) ₃ ^{2+高 > 10 倍和 270 倍}， 分别。基于电化学、缠绕光致发光和 ECL 光谱阐明了光电化学反应性以及 ECL 机制，揭示了三个发射增强来源：（i）有效暴露可用于进行电子转移反应的反应性面；(ii) 单独的激发态再生循环；(iii) 各种退出状态的级联世代。事实上，这些发现将对各种应用产生直接影响，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，例如光捕获和发光技术。