The structural landscape of ferrocenyl polychalcogenides

Halogen bond (HaB) assisted co-crystallization strategy was used to explore the structural landscape of ferrocenic polychalcogenides varying from a rather compact ferrocenophane triselenide (1,1’-FcSe₃) to bulky diferrocenyl ditelluride (Fc₂Te₂) and its mixed-valent derivative (FcTeTeI₂Fc). Comparison of the supramolecular organization in their native crystals and respective cocrystals with the iconic halogen bond donor, 1,4-diiodotetrafluorobenzene (p-DITFB), demonstrate three different patterns: 1) conservation of the chain structures for FcTeTeI₂Fc, 2) transformation of single Se···Se intermolecular interaction to double for FcSe₃, and 3) for Fc₂Te₂, in the absence of specific and directed intermolecular interactions, the cocrystal packing of Fc₂Te₂ is governed only by p-DITFB HaBs directionality. This allows a rough glimpse of ferrocenic polychalcogenides structural landscape and shows the directions and methods for its further detailization.