Laimer Felix, Zappa Fabio, Scheier Paul, Gatchell Michael
Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, 6020, Innsbruck, Austria.
Departamento de Física-ICE, Universidade Federal de Juiz de Fora, Campus Universitário, 36036-900, Juiz de Fora, MG, Brazil.
Chemistry. 2021 May 3;27(25):7283-7287. doi: 10.1002/chem.202005004. Epub 2021 Mar 12.
The detection of multiply charged helium droplet anions is reported for the first time. By ionizing droplets of superfluid helium with low energy electrons (up to 25 eV), it was possible to produce droplets containing up to five negative charges, which remain intact on the timescale of the experiment. The appearance sizes for different charge states are determined and are found to be orders of magnitude larger than for the equivalent cationic droplets, starting at 4 million He atoms for dianions. Droplets with He* as charge carriers show signs of being metastable, but this effect is quenched by the pickup of water molecules.
首次报道了对多电荷氦液滴阴离子的检测。通过用低能电子（最高25电子伏特）使超流氦液滴电离，有可能产生含有多达五个负电荷的液滴，这些液滴在实验时间尺度上保持完整。确定了不同电荷态的出现尺寸，发现其比等效阳离子液滴的尺寸大几个数量级，二价阴离子从400万个氦原子开始。以He*作为电荷载体的液滴显示出亚稳迹象，但这种效应会因水分子的俘获而淬灭。
