Co(cycloheptylamine)(2)Ni(CN)(4) host complex has been prepared in powder form and its vibrational spectra are investigated. The vibrational assignment of the cycloheptylamine in various phases (gas, solution, liquid and complex) are facilitated by means of DFT calculations performed on the free ligand molecule. The spectral data suggest that the prepared complex is similar in structure to the Hofmann-dma-type hosts. The sorption processes of some aromatic guests (benzene, toluene, o-, m-, p-xylene, 1,2-, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,4-dibromobenzene and naphthalene) in this host complex have also been examined at room temperature by gravimetric and spectroscopic measurements. The desorption of the benzene guest against time has been measured. The structure of the Co(cycloheptylamine)(2)Ni(CN)(4) host changes on inclusion of the guest molecule and recovers after liberation.