Acetylene and benzene are two common molecules formed in Titan’s atmosphere, and are likely components of the lake evaporites. It is known that these two molecules can form a cocrystal, a molecule with a structure that is unique from that of the component molecules. Thus, we sought to study this cocrystal using an experimental setup that simulates Titan surface conditions (90 K, 1.5 bar). Using Fourier transform infrared (FTIR) spectroscopy, we characterize new spectral absorptions, band shifts, and morphological sample changes associated with this cocrystal from 1 to 2.6 μm, which overlaps with Cassini VIMS wavelength range (0.35–5.1 μm). This is the first study of the resulting acetylene–benzene cocrystal under Titan-relevant temperature and pressure. The cocrystal forms at 135 K and is stable down to 90 K. Our findings can be applied to the cocondensation process in Titan’s atmosphere, as well as the ongoing effort to better characterize the composition and spectral properties of Titan’s lake evaporites. These results can also provide a stepping stone to future surface missions such as Dragonfly, which will closely examine relevant surface materials on Titan.

乙炔和苯是土卫六大气中形成的两种常见分子，很可能是湖泊蒸发岩的组成部分。众所周知，这两种分子可以形成共晶体，这种分子的结构与组成分子的结构不同。因此，我们试图使用模拟泰坦表面条件（90 K，1.5 bar）的实验装置来研究这种共晶。使用傅里叶变换红外 (FTIR) 光谱，我们表征了与该共晶相关的新光谱吸收、带移和形态样品变化，从 1 到 2.6 μ m，与 Cassini VIMS 波长范围 (0.35-5.1 μ m) 重叠米）。这是在与泰坦相关的温度和压力下对所得乙炔-苯共晶的首次研究。共晶体在 135 K 时形成，并稳定到 90 K。我们的研究结果可应用于土卫六大气中的共冷凝过程，以及正在进行的努力以更好地表征土卫六湖蒸发岩的成分和光谱特性。这些结果还可以为未来的地面任务提供垫脚石，例如蜻蜓号，它将仔细检查土卫六上的相关表面材料。