and PF-MOF2, respectively. This is in line with the larger steric hindrance of the fluorine atom if compared with hydrogen. Degradation coming from PSE cannot be considered the main cause of the observed microporosity reduction, since the small amount of zirconium found in solution after the exchange indicates a very small degree of degradation (Table ); thus, PSE does not seem to affect the framework stability. The total pore volume derived from the N2 isotherm at 196 °C, measured at p/p0 = 0.98, equals 0.57, 0.45, 0.36 and 0.17 Empty symbols denote desorption branches.