A 2D flexible metal-organic porous solid, {[Ni(1,3-adc)(bpp)(H2O)(2))(H2O)(EtOH)}, (1), has been synthesized using flexible organic linkers. The desolated framework, {[Ni(1,3-adc)(bpp)]}, (1'), undergoes structural contraction and exhibits double-step hysteretic adsorption for CO2, H2O, and MeOH and single-step gate-opening behavior with EtOH. These observations are correlated with the elect of the polarity and window dimension of the pore to the corresponding adsorbate molecules.