Zn-based metal–organic frameworks (MOFs) of pyridinemethanol–carboxylate conjugated ligands: Deprotonation-dependent structures and CO2 adsorption

Abstract

Two Zn-based metal–organic frameworks (MOFs) of pyridinemethanol–carboxylate conjugated ligands, namely, [Zn(L1)]n xSol (1, 3D) and [Zn(L2)2]n (2, 1D) (H2L1 = 4-(6-(hydroxymethyl)pyridin-3-yl)benzoic acid; H2L2 = 3-(6-(hydroxymethyl)pyridin-3-yl)benzoic acid) have been synthesized and structurally characterized. The dimensionalities of 1 and 2 are defined by the deprotonation states of the ligands. Specifically, the 3D MOF 1 features a rod-shaped Zn–O/COO chain as the secondary building unit (SBU) which effectively hinder network interpenetration, whereas the 1D chain of 2 mimics an edge-sharing octahedron with each Zn center serving as the vertex. MOF 1 reversibly uptakes CO2 and exhibits a Brunauer–Emmett–Teller (BET) surface of 345 m2 g−1, and remains crystalline upon activation, an indication of permanent porosity.