A 2D noninterpenetrated flexible metal-organic porous solid, {[Cu-2(cis-chdc)(2)(bpee)]center dot H2O}(n) (1) based on a paddle-wheel building unit has been constructed using a mixed-ligand system. Guest-induced irreversible internetwork displacements of the 2D grids result in permanent porosity in the framework, as realized by the selective CO2 sorption over N-2. The different affinity and selectivity of the solvent molecules was correlated with the internal polarity of the pore surfaces.