While superacids are solvents for individualizing carbon nanotubes, the behavior of insulating C₆₀ is different. The final ionization state depends on the superacid used. With chlorosulfonic acid, chlorination is observed while with fuming sulfuric acid, sulfonation has been reported. Both reactions are fast and it is important to characterize the first step to understand the involved reaction mechanisms. Employing Raman spectroscopy and first-principles calculations, we show that C₆₀⁺ is present with chlorosulfonic acid and surprisingly C₆₀²⁺ ions are predominantly formed during the first seconds after immersion in fuming sulfuric acid.

中文翻译：

---

过酸中C ₆₀阳离子形成的初始阶段

虽然超强酸是用于使碳纳米管个体化的溶剂，但绝缘C ₆₀的行为却有所不同。最终的电离状态取决于所用的超酸。用氯磺酸观察到氯化，而用发烟硫酸观察到磺化。两种反应都很快，表征第一步的特征以了解所涉及的反应机理很重要。利用拉曼光谱法和第一性原理计算，我们显示出C ₆₀ ⁺与氯磺酸一起存在，并且令人惊讶的是，C ₆₀ ²⁺离子主要是在浸入发烟硫酸后的最初几秒钟内形成的。