Detection and frequency measurement of rotational transitions of molecular anions

富山大学的可调谐远红外光谱仪成功地探测到了分子阴离子（带负电的分子离子）在远红外区的纯旋转跃迁。观察了OH^-阴离子J=1←0、2←1、3←2和4←3的低J旋转谱线，并精确测量了它们的频率。通过对现有数据的分析，得到了精度提高一到两个数量级的分子参数。本课题为分子阴离子的精密旋转光谱研究开辟了新的领域。

Pure rotational transitions of molecular anion(negatively charged molecular ion) in the far-infrared region have been successfully detected by the tunable far-infrared spectrometer in Toyama University. The low-J rotational lines, J=1←0,2←1,3←2,and 4←3 of the OH^-anion were observed and their frequencies were precisely measured. Molecular parameters which are more precise by one or two orders of magnitude were obtained by the analysis of the present data.The present research project made it possible to open a new field of precise rotational spectroscopy of molecular anions.