Abstract High-resolution mass spectra of helium droplets doped with C60 and formic acid (FA) are ionized by electrons. Positive ion mass spectra reveal cluster ions [(C60)pFAn]+ together with their hydrogenated and dehydrogenated counterparts. Also observed are ions containing one or more water (W) molecules. The abundance distributions of these ions reveal several interesting features: i) [(C60)pFAn]+ ions are more abundant than hydrogenated [(C60)pFAnH]+ ions even though the opposite is true in the absence of C60 (i.e. if p = 0); ii) although [C60FA]+ is the most abundant ion containing a single C60, multiple C60 suppress the [(C60)pFA]+ signal; iii) an enhanced stability of [(C60)pW1FA5H]+ and [(C60)pW2FA6H]+ mirrors that of [W1FA5H]+ and [W2FA6H]+, respectively. On the other hand, the enhanced stability of [C60FA6H]+ finds no parallel in the stability pattern of [FAnH]+ or FAn+. Negative ion mass spectra indicate a propensity for non-dissociated [(C60)pFAn]- anions if p ≥ 1 which contrasts with the dominance of dehydrogenated [FAn-H]- anions.

中文翻译：

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含有 C60 和甲酸簇的氦液滴的电子附着和电子电离

摘要 掺杂 C60 和甲酸 (FA) 的氦液滴的高分辨率质谱被电子电离。正离子质谱显示簇离子 [(C60)pFAn]+ 及其氢化和脱氢对应物。还观察到含有一个或多个水 (W) 分子的离子。这些离子的丰度分布揭示了几个有趣的特征：i) [(C60)pFAn]+ 离子比氢化 [(C60)pFAnH]+ 离子更丰富，即使在没有 C60 的情况下情况相反（即如果 p = 0); ii) 尽管 [C60FA]+ 是含有单个 C60 的最丰富的离子，但多个 C60 会抑制 [(C60)pFA]+ 信号；iii) [(C60)pW1FA5H]+ 和 [(C60)pW2FA6H]+ 的增强稳定性分别反映了 [W1FA5H]+ 和 [W2FA6H]+ 的稳定性。另一方面，[C60FA6H]+ 增强的稳定性与 [FAnH]+ 或 FAn+ 的稳定性模式没有相似之处。如果 p ≥ 1，则负离子质谱表明倾向于非离解 [(C60)pFAn]- 阴离子，这与脱氢 [FAn-H]- 阴离子的优势形成对比。