Fig. 3: A general strategy for constructing vapochromic system toward VOCs.

a Structures of hybrid[4]arene (H), 1,2,4,5-tetracyanobenzene (TCNB), benzene (Bz), cyclohexane (Cy), toluene (Tol) and pyridine (Py), and schematic representation of vapochromic behaviors of H-TCNBα after exposure to Cy, Bz, Tol and Py vapors. b PXRD patterns of H-TCNBα before (I) and after capture of (II) Cy, (III) Bz, (IV) Py, (V) Tol, (VI) chlorobenzene, (VII) 2-chlorotoluene, (VIII) n-hexane, (IX) 2-methylpentane, (X) BrCH2CH3 and (XI) BrCH2CH2Br.