五氟苯酚(PFP)、 五氟苯甲酸(PFBA)与联吡啶(BP)利用溶剂缓慢挥发的方法制得BP/PFP和BP/PFBA两种共晶, 并获得其晶体结构。 结合密度泛函理论模拟对这两种共晶的红外和拉曼光谱进行解析。 红外光谱证明两种共晶内部存在氢键作用。 拉曼光谱表明BP/PFBA共晶内部的氢键强于BP/PFP。 此外, 结合红外、 拉曼及晶体结构数据可知, 在BP/PFP共晶中同时存在氢键和π—π相互作用。 弱相互作用的差异导致其共晶的结构上的差异。 该研究对进一步理解共晶结构和性质以及指导共晶设计具有一定的研究意义。

Pentafluoro phenol (PFP) and pentafluorobenzoic acid (PFBA) as ligands were combined with 4,4’-bipyridine (BP) to obtain two kinds of co-crystals, BP/PFP and BP/PFBA, respectively. Raman and infrared spectra of two co-crystals and their precursors were obtained. The relevant peaks were analyzed, with the help of the calculated spectra throughdensity functional theory (DFT). Infrared spectra show rich hydrogen bonds existed in these two co-crystals. Raman characterization indicates that hydrogen bonding in the BP/PFBA co-crystal is stronger than that in the BP/PFP. In addition, combined with infrared, Raman and crystal structure data, it is found that hydrogen bond and π-π interaction coexist in the BP/PFP co-crystal. The difference of weak interaction results in the difference of crystal structure. This study displays significance for further under standing of the structure and properties of co-crystals, which is helpful for the design of novel co-crystals.