Cocrystals of bis(hexamethylbenzene)iron hexafluorophosphate and tetrafluoroborate with arenes: A structural study

Structural studies of hexafluorophosphate and tetrafluroborate salts of the bis(hexamethyl-benzene)iron dication [(HMB)2Fe]2+ show a surprisingly wide variety of different stoichiometries and packing arrangements not anticipated in previous studies. In the cocrystal of ferrocene:[Fe(HMB)2][BF4]2 we observed an unexpected near-perpendicular orientation instead of the heterosoric parallel stacking more commonly observed.