Structure evolution has become an effective way to assemble novel monolayer‐protected metal nanomolecules. However, evolution with alkynyl‐stabilized metal clusters still remains rarely explored. Herein, we present a carboranealkynyl‐protected gold nanocluster [Au₂₈(C₄B₁₀H₁₁)₁₂(tht)₈]³⁺ (Au₂₈, tht=tetrahydrothiophene) possessing an open‐shell electronic structure with 13 free electrons, which was isolated by a facile self‐reduction method with 9‐HC≡C‐closo‐1,2‐C₂B₁₀H₁₁ as the two‐in‐one reducing and protecting agent. Notably, Au₂₈ undergoes a complete transformation in methanol into a stable and smaller‐sized nanocluster [Au₂₃(C₄B₁₀H₁₁)₉(tht)₆]²⁺ (Au₂₃) bearing 12 valence electrons and crystal‐field‐like split superatomic 1D orbitals. The transformation process was systematically monitored with ESI‐MS and UV/Vis absorption spectra. Au₂₈ and Au₂₃ both display optical absorption covering the UV/Vis–NIR range and NIR emission, which facilitates their potential application in the biomedical and photocatalytic fields.

中文翻译：

---

碳硼烷炔保护的金纳米团簇：尺寸转换和UV / Vis–NIR光学特性

结构演变已成为组装新型单层保护的金属纳米分子的有效方法。但是，仍然很少探索炔基稳定的金属簇的演化。本文中，我们提出了具有硼烷炔基保护的金纳米簇[Au ₂₈（C ₄ B ₁₀ H ₁₁）₁₂（tht）₈ ] ³⁺（Au ₂₈，tht =四氢噻吩），具有带有13个自由电子的开壳电子结构，其中用容易自还原法分离9-HC≡C-闭合碳-1,2--C ₂乙₁₀ ħ ₁₁作为二合一的还原和保护剂。值得注意的是，Au ₂₈在甲醇中经历了完全转变，形成了一个稳定且尺寸较小的纳米簇[Au ₂₃（C ₄ B ₁₀ H ₁₁）₉（tht）₆ ] ²⁺（Au ₂₃），带有12个价电子和晶体场。像分裂的超原子1D轨道。通过ESI-MS和UV / Vis吸收光谱系统地监测了转化过程。金₂₈和金₂₃ 两者均显示出涵盖UV / Vis-NIR范围和NIR发射的光吸收，这有利于它们在生物医学和光催化领域中的潜在应用。