Cd(II)-Schiff-Base Metal–Organic Frameworks: Synthesis, Structure, and Reversible Adsorption and Separation of Volatile Chlorocarbons

A new Cd(II)-MOF (1) was successfully synthesized on the basis of a new long double Schiff-base ligand and Cd(SCN)2. Its crystal structure was determined by X-ray diffraction. In 1, each pair of Cd(II) nodes is bridged by two inversely related μ-SCN– to form infinite inorganic chains with the remaining two trans-positions being occupied by two Schiff-base ligands to generate a 3D framework with rhombus-like channel (∼9 × 9 Å). 1 can reversibly absorb CH2Cl2 and CHCl3 at different temperature without collapsing of the host framework. Furthermore, it displays a strict size selectivity and can completely separate these volatile chlorocarbons of CH2Cl2 and CHCl3 in liquid and vapor phases.