Multistep phase transition induced by CO2 adsorption observed in a novel microporous medium based upon 1-D coordination polymer: [Cu(II)2(O2CPh)4(2,5-dmpyz)]n

A novel crystalline solid, [Cu(II)2(O2CPh)4(2,5-dmpyz)]n (2,5-dmpyz = 2,5-dimethyl-pyrazine), was synthesized and characterized by single-crystal X-ray diffraction analysis. The compound demonstrates multistep phase transition induced by CO2 adsorption, which readily obeys the Clausius–Clapeyron equation in terms of the set of partial pressures of CO2 and transition temperatures.