Compared to emissive silver-thiolate clusters, their alkynyl cousins are, however, usually luminescence silent. Herein we report a novel silver-alkynyl cluster based NbO-type framework (SD/Ag18) showing unprecedented triple emission spanning from the visible to near-infrared (NIR) region. It is a 3D framework constructed from a [Cl@Ag₁₆] cluster based unit, which is further quadruply bridged by the surrounding four Ag atoms through Ag⋯Ag interactions, giving a 4-connected NbO topology. Although SD/Ag18 exhibits weak orange-red emission at room temperature, its emission becomes strong upon cooling, with three emission maxima at 524, 647 and 1036 nm, respectively, covering both the visible and NIR regions. The visible emissions involve triplet alkynyl-to-metal charge transfer mixed with a cluster-centered state, whereas the participation of cPrCC⁻ in the frontier orbitals of the cluster may be responsible for the NIR emission. The unusual emissions, especially in the NIR-II region, are observed, for the first time, in silver complexes.

中文翻译：

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基于六癸核银炔基团簇的NbO框架，具有从可见光到近红外II区的三重发射†

与发光的硫醇银簇相比，它们的炔基表亲通常不发光。在本文中，我们报告了一种新型的基于银-炔基团簇的NbO型框架（SD / Ag18），其空前的三重发射跨越了从可见光到近红外（NIR）区域。它是一个基于[Cl @ Ag ₁₆ ]簇的单元构建的3D框架，该单元通过AgDAg相互作用被周围的四个Ag原子进一步四联桥接，从而形成了4个连接的NbO拓扑结构。虽然SD / Ag18在室温下呈现弱的橙红色发射，在冷却时其发射变强，在可见光和近红外区域分别具有524、647和1036 nm的三个发射最大值。可见的排放涉及三重态炔-金属电荷转移与群集为中心的状态下混合，而CPRC参与Ç ^-在群集的前线轨道可以负责的NIR发射。首次在银配合物中观察到异常排放，特别是在NIR-II地区。