Nemec Vinko, Cinčić Dominik
Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia.
Cryst Growth Des. 2022 Oct 5;22(10):5796-5801. doi: 10.1021/acs.cgd.2c00793. Epub 2022 Sep 13.
In this work, we present a systematic study of the capability of the sp hybridized sulfur atom for halogen bonding both in a small building block, tetrahydro-4-thiopyran-4-one, and two larger ones derived from it, Schiff bases with a morpholine fragment on the other end of the molecule. These three building blocks were cocrystallized with six perhalogenated aromates: 1,4-diiodotetrafluorobenzene, 1,3,5-triiodotrifluorobenzene, 1,3-diiodotetrafluorobenzene, 1,2-diiodotetrafluorobenzene, iodopentafluorobenzene, and 1,4-dibromotetrafluorobenzene. Out of the 18 combinations, only 7 (39%) yielded cocrystals, although with a high occurrence of the targeted I···S halogen bonding motif in all cocrystals (71%), and in imine cocrystals the I···O motif (100%) as well as, surprisingly, the I···N motif (100%). The I···S halogen bonds presented in this work feature lower relative shortening values than those for other types of sulfur atoms; however, the sp sulfur atom could potentially be more specific an acceptor for halogen bonding.
在这项工作中，我们系统地研究了sp杂化硫原子在一个小分子结构单元四氢-4-硫代吡喃-4-酮以及由其衍生的另外两个较大分子结构单元（分子另一端带有吗啉片段的席夫碱）中形成卤键的能力。这三个结构单元与六种全卤代芳烃共结晶：1,4-二碘四氟苯、1,3,5-三碘三氟苯、1,3-二碘四氟苯、1,2-二碘四氟苯、碘五氟苯和1,4-二溴四氟苯。在这18种组合中，只有7种（39%）得到了共晶体，尽管在所有共晶体中目标I···S卤键模式的出现频率很高（71%），并且在亚胺共晶体中I···O模式（100%）以及令人惊讶的I···N模式（100%）也出现了。这项工作中呈现的I···S卤键的相对缩短值低于其他类型硫原子的卤键；然而，sp硫原子可能是更具特异性的卤键受体。
