Surface co-crystallization with an organic single crystal enables vapochromic and luminescent detection of phenols

We present a novel approach for the vapochromic and luminescent detection of phenols through surface co-crystallization with single crystals of 9,10-bis((E)-2-(pyridin-4-yl)vinyl)anthracene BP4VA. Upon exposure to 2,4,6-trifluorophenol (2,4,6-TFP), 3,4,5-trifluorophenol (3,4,5-TFP), and phenol (PhOH) vapor, BP4VA crystals exhibit significant changes in color and fluorescence intensity, offering a sensitive detection method. Detailed structural insights into intermolecular interactions are obtained from single-crystal and powder X-ray diffraction, as well as FT-IR and ¹H NMR spectroscopies. Scanning electron microscopy and energy dispersive X-ray spectroscopy demonstrate the reversibility of these changes, with crystal morphology and surface composition nearly returning to near-pristine single crystals of BP4VA after annealing. The recoverability of single crystals enables a promising platform for the detection of volatile organic compounds.