Guest encapsulations in non-porous crystals of fully fluorinated dinuclear metal complexes with the M2O2 core (M = Fe3+, Co2+, Ni2+).

Two different coordination types of fully fluorinated dinuclear metal complexes, [Fe2L4(OMe)2] and [M2L4(OH2)2] (M = Co2+, Ni2+ and HL = bis(pentafluorobenzoyl)methane), were obtained. All of the complexes form non-porous crystals, which act as hosts for the adsorption of various benzene derivatives, e.g., benzene, toluene, p-xylene, anisole, and small gas molecules, e.g., CO2, O2, and NO. The complex of iron selectively adsorbs NO in high amounts and the complex of cobalt is found to store adsorbed O2.