Text this: Impressive 1D (Ferrocenyl⋯C₆F₅<i>R</i>⋯)_n Stacking Due to Cooperative Interactions in <i>N</i>-(Ferrocenylmethyl)Pentafluorobenzenecarboxamide: Four Crystal Structures and Contacts Analyses in <i>N</i>-(Ferrocenylalkyl)Benzenecarboxamides