Guest molecules have been absorbed into crystals of a metallocyclic host by sublimation of volatile solids at room temperature. The guest exchanges are accompanied by color changes. Since the crystals remain intact, evidence of guest inclusion could be obtained using single-crystal X-ray diffraction. The results are also supported by thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), and ultraviolet-visible spectroscopy (UV-vis).