论文标题
质子温度下的质子转移
Proton transfer at subkelvin temperatures
论文作者
论文摘要
我们展示了一种新的方法，可以通过质子转移在1 K以下的温度下通过质子转移电离分子或分子簇。该方法产生了新生的离子并在很大程度上消除了次级反应，即使是臭名昭著的“精致”分子。质子化是在液体氦纳米条（HND）内实现的，并从（h $ _ {2} $）的形成开始，$ _ {m} $ _ {m} $ h $^{+} $ ions作为质子供体。在一个单独且随后的步骤中，HND用质子受体分子掺杂，X。质子转移发生在X和冷质子供体离子之间，这种方法避免了如果首先掺杂HND，则避免释放出大量的过量能量，然后将其离子化。质谱是在碰撞电池中剥离过量的氦气和氢后记录的，该方法表明，通过质子转移括号来确定分子和簇的质子亲和力，以调查在sub-kelvin温度下的天体相关的离子 - 分子反应，并准备XH $^$^$^{+sisserriest，以调查sub-kelvin温度下的质子。
We demonstrate a novel method to ionize molecules or molecular clusters by proton transfer at temperatures below 1 K. The method yields nascent ions and largely eliminates secondary reactions, even for notoriously "delicate" molecules. Protonation is achieved inside liquid helium nanodroplets (HNDs) and begins with the formation of (H$_{2}$)$_{m}$H$^{+}$ ions as the proton donors. In a separate and subsequent step the HNDs are doped with a proton acceptor molecule, X. Proton transfer occurs between X and the cold proton donor ions inside a helium droplet, an approach that avoids the large excess energy that is released if HNDs are first doped and then ionized. Mass spectra, recorded after stripping excess helium and hydrogen in a collision cell, show that this method offers a new way to determine proton affinities of molecules and clusters by proton-transfer bracketing, to investigate astrochemically relevant ion-molecule reactions at sub-kelvin temperatures, and to prepare XH$^{+}$ ions that are suitable for messenger-tagging action spectroscopy.
