Utilizing Sulfoxide···Iodine Halogen Bonding for Cocrystallization
摘要:
The propensity of a range of different sulfoxides and sulfones to cocrystallize with either 1,2- or 1,4-diiodotetrafluorobenzene, via I center dot center dot center dot O=S halogen bonding, was investigated. Cocrystallization occurred exclusively with 1,4-diiodotetrafluorobenzene in either a 1:1 or 1:2 stoichiometry of the organohalide and the sulfoxide, respectively, depending on the sulfoxide used. It was found that the stoichiometry observed was not necessarily related to whether the oxygen acts as a single halogen bond acceptor or if it is bifurcated; with I center dot center dot center dot pi interactions observed in two of the cocrystals synthesized. Only those cocrystals with a 1:2 stoichiometry exhibit C-H center dot center dot center dot O hydrogen bonding in addition to I center dot center dot center dot O=S halogen bonding. Examination of the Cambridge Structural Database shows that (i) the I center dot center dot center dot O=S interaction is similar to other I center dot center dot center dot O=S interactions, and (ii) the I center dot center dot center dot pi interaction is significant, with the distances in the two cocrystals among the shortest known.