We investigate molecular dynamics of two supercooled room temperature ionic liquids (RTILs) above of their glass transition temperature by means of dynamic light scattering and broadband dielectric spectroscopy from nanoseconds up to ≈10⁵$\approx {10}^5$ seconds. We show that a direct comparison of the raw data of these two techniques allows us to identify the reorientation of ions in the dielectric data, giving experimental evidence to a very recently proposed model of Gainaru et. al, [1] stating that the conductivity process in ionic liquids takes place through a reorientational step of ions escaping their cage formed by surrounding counterions. Within this approach we can also understand the apparent decoupling of time constants from dielectric spectroscopy and light scattering, often found in ionic liquids, in a very natural way. Furthermore, as a consequence of knowing the reorientational part of the dielectric spectrum, we are able to show that two more processes contribute to these spectra, which are due to electrode polarization effects. The relative position of all three contributions vary among the systems and may overshadow each other, thus complicating the data analysis and favor misinterpretations.

我们通过动态光散射和宽带介电谱（从纳秒到≈10 ⁵）研究了两种高于玻璃化转变温度的过冷室温离子液体（RTIL）的分子动力学。$\approx {10}^5$秒。我们表明，直接比较这两种技术的原始数据可以使我们确定介电数据中离子的重新取向，从而为最近提出的Gainaru等人的 模型提供实验证据。人， [1]指出离子液体中的电导率过程是通过重新定向的步骤进行的，该步骤是使离子逃逸出被周围抗衡离子形成的笼子。在这种方法中，我们还可以很自然地理解时间常数与介电谱和光散射之间的明显去耦关系（通常在离子液体中发现）。此外，作为已知介电谱的重新定向部分的结果，我们能够表明，由于电极极化效应，还有两个过程对这些谱有贡献。所有这三个贡献的相对位置在系统之间有所不同，并且可能彼此掩盖，因此使数据分析变得复杂，并且容易造成误解。