1D and 2D Thiazole‐Based Copper(II) Coordination Polymers: Synthesis and Applications in Carbon Dioxide Capture

The reaction of different copper(II) salts with a class of thiazole‐based ligands under solvothermal conditions produces three crystalline 1D/2D coordination polymers: [Cu(κ‐ N ‐thiazole) 4 (SiF 6 )] ∞ ( 1 (1D)), {Cu[μ‐(κ‐ N :κ ‐COO )‐ L 1 ] 2 ⋅(H 2 O)} ∞ ( 2 (2D); H L 1 =2‐aminothiazole‐5‐carboxylic acid), and {Cu[μ‐(κ‐ N :κ ‐COO )‐ L 2 ] 2 ⋅1.5 (H 2 O)} ∞ ( 3 (2D); H L 2 =thiazole‐5‐carboxylic acid). All the materials have been characterized through common solid‐state techniques: single‐crystal (XRD) and (variable‐temperature) powder X‐ray diffraction (PXRD), infrared spectroscopy (IR), thermogravimetric analysis combined with mass spectrometry (TGA‐MS), and BET surface area and pore‐size distribution measurements. Polymer 3 shows a porous structure made of squared channels formed by the ordered stacking of the planar sheets along the a crystallographic axis (inner surface area equal to 15 m 2  g −1 , as inferred from N 2 adsorption at T =77 K on the pre‐activated form), and it has been exploited for CO 2 physisorption at ambient temperature ( T =303 K) and pressure ( p   CO   2max.=920 torr). A remarkable CO 2 uptake equal to 9.0 wt % was recorded under these mild conditions, thereby making the material promising for carbon dioxide capture in post‐combustion flue gas, in which the key factor for a successful performance is the high chemical selectivity for CO 2 over N 2 .