Reversible structural change of host framework triggered by desorption and adsorption of guest benzene molecules in Fe(NCS)2(bpp)2·2(benzene) (bpp = 1,3-bis(4-pyridyl)propane)

► Assembled iron complex enclathrating benzene molecules. ► Reversible desorption and adsorption of the benzene molecules. ► Accompanying reversible structural change of host framework. ► Reversible change of Mössbauer spectra. ► Explanation of the reversible change.