Fig. 4: Single-crystal X-ray structure analysis of BCE[5].

Crystal structures and C − H⋅⋅⋅O distances (Å) of (a) sym-BCE[5] and c its packing mode. b asym-BCE[5] and d its packing mode. (Oxygen atoms, red; TPE, blue; Carbon atoms, gray; Hydrogen atoms, white; disordered solvent molecules are omitted for clarity).