Email Post: Syntheses, crystal structures and Hirshfeld surface analyses of (3aR,4S,7R,7aS)-2-(perfluoro­pyridin-4-yl)-3a,4,7,7a-tetra­hydro-4,7-methano­iso­indole-1,3-dione and (3aR,4S,7R,7aS)-2-[(perfluoro­pyridin-4-yl)­oxy]-3a,4,7,7a-tetra­hydro-4,7-methano­iso­indole-1,3-dione