A pyrene-based metal-organic framework (MOF) SION-8 captured iodine (I-2) vapor with a capacity of 460 and 250 mg g(MOF)(-1) at room temperature and 75 degrees C, respectively. Single-crystal X-ray diffraction analysis and van-der-Waals-corrected density functional theory calculations confirmed the presence of I-2 molecules within the pores of SION-8 and their interaction with the pyrene-based ligands. The I-2-pyrene interactions in the I-2-loaded SION-8 led to a 10(4)-fold increase of its electrical conductivity compared to the bare SION-8. Upon adsorption, >= 95 % of I-2 molecules were incarcerated and could not be washed out, signifying the potential of SION-8 towards the permanent capture of radioactive I-2 at room temperature.